Lakes in temperate ecoregions

– Case studies –

Hundreds, if not thousands, of recently published papers are dealing with the impact of Climate Change on freshwater ecosystems.

Here you find summaries of a few hundred papers, which we consider as most relevant.

Shallow

Abiotic indicators

Acidification: deposition / Dillon, P.J., B.L. Skjelkvale, K.M. Somers &a ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Acidification: deposition

Reference

Dillon, P.J., B.L. Skjelkvale, K.M. Somers & K. Torseth (2003): Coherent responses of sulphate concentration in Norwegian lakes: relationships with sulphur deposition and climate indices. Hydrology and Earth System Sciences 7(4): 596-608.

Description

When evaluating the recovery of acidified lakes confounding effects of climatic conditions / climate change have to be considered: Average SO₄^2- concentration trends explained by wet S deposition and NAOI, AOI.

Acidification: import (wetlands), nutrients: depletion / Carvalho, L. & B. Moss (1999): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Acidification: import (wetlands), nutrients: depletion

Reference

Carvalho, L. & B. Moss (1999): Climate sensitivity of Oak Mere: a low altitude acid lake. Freshwater Biology 42: 585-591.

Description

Response of Lake Oak Mere to drought with rapid and substanial changes in acidity and nutrients. A decline in water level caused by less precipitation in 1990- 92 decreased on the one hand pH (by 2 units!), Si, alkalinity, SRP, TP, NO₃-N and caused on the other hand an increase in NH₄-N.

Nutrients: minerlisation, release (sediment) / Jensen, J.P., Pedersen, A.R., Jeppesen, E., S ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Nutrients: minerlisation, release (sediment)

Reference

Jensen, J.P., Pedersen, A.R., Jeppesen, E., SØndergaard, M. (2006): An empirical model describing the seasonal dynamics of phosphorus in 16 shallow eutrophic lakes after external loading reduction. Limnology and Oceanography 51: 791-800. (Euro-limpacs paper)

Description

Based on a detailed mass balance in a shallow hypertrophic Danish lake under recovery, we developed a simple empirical model relating the seasonal variation in lake total phosphorus (TP) concentrations to external loading, accumulated phosphorus in the sediment, hydraulic retention time, and water temperature. The aim was to describe the early recovery phase following an external loading reduction, i.e., when internal phosphorus loading is high, and to include seasonal dynamics. We tested the model on 8 years of data from 16 shallow (mean depth: 1-10 m), eutrophic, unstratified, or only temporarily stratified Danish lakes. For each of these lakes we first calibrated the exchangeable phosphorus pool in the sediment (Ps), leaving all other parameters as for Lake Søbygård. Estimated annual mean TP deviated on average 12% from observed values in the 16 lakes, compared to 37% when using the Vollenweider steady state model. Moreover, the estimated seasonal dynamics and trend following the external loading reduction closely mimicked the observed pattern. Model results suggest that TP in the sediment does not provide an adequate description of the exchangeable P pool. In Lake Arreskov, which has shifted from a turbid to a clear-water state following fish kill and biomanipulation, the model significantly overestimated TP. In a global warming scenario with a 2.5-4.4°C mean annual temperature increase, the model predicts higher TP and faster decreasing PH. Although simple, the empirical model predicts reasonably well the seasonal dynamics of TP following a P loading reduction in a variety of shallow turbid lakes. The model, however, is inadequate for describing seasonal dynamics following a shift from a turbid to a clear-water state.

Nutrients: minerlisation, release (sediment) / Jensen, J.P., Pedersen, A.R., Jeppesen, E., S ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Nutrients: minerlisation, release (sediment)

Reference

Jensen, J.P., Pedersen, A.R., Jeppesen, E., Søndergaard, M. (2006): An empirical model describing the seasonal dynamics of phosphorus in 16 shallow eutrophic lakes after external loading reduction. Limnology and Oceanography 51: 791-800.

Description

Based on a detailed mass balance in a shallow hypertrophic Danish lake under recovery, we developed a simple empirical model relating the seasonal variation in lake total phosphorus (TP) concentrations to external loading, accumulated phosphorus in the sediment, hydraulic retention time, and water temperature. The aim was to describe the early recovery phase following an external loading reduction, i.e., when internal phosphorus loading is high, and to include seasonal dynamics. We tested the model on 8 years of data from 16 shallow (mean depth: 1-10 m), eutrophic, unstratified, or only temporarily stratified Danish lakes. For each of these lakes we first calibrated the exchangeable phosphorus pool in the sediment (Ps), leaving all other parameters as for Lake Sabygard. Estimated annual mean TP deviated on average 12% from observed values in the 16 lakes, compared to 37% when using the Vollenweider steady state model. Moreover, the estimated seasonal dynamics and trend following the external loading reduction closely mimicked the observed pattern. Model results suggest that TP in the sediment does not provide an adequate description of the exchangeable P pool. In Lake Arreskov, which has shifted from a turbid to a clear-water state following fish kill and biomanipulation, the model significantly overestimated TP. In a global warming scenario with a 2.5-4.4°C mean annual temperature increase, the model predicts higher TP and faster decreasing pH. Although simple, the empirical model predicts reasonably well the seasonal dynamics of TP following a P loading reduction in a variety of shallow turbid lakes. The model, however, is inadequate for describing seasonal dynamics following a shift from a turbid to a clear-water state.

Nutrients: N-/P-flux; eutrophication general / Jeppesen, E., Meerhoff, M., Jakobsen, B.A., H ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Nutrients: N-/P-flux; eutrophication general

Reference

Jeppesen, E., Meerhoff, M., Jakobsen, B.A., Hansen, R.S., Søndergaard, M., Jensen, J.P., Lauridsen, T.L., Mazzeo, N., Branco, C. (2007): Restoration of shallow lakes by nutrient control and biomanipulation-the successful strategy varies with lake size and climate. Hydrobiologia 581(1): 269-285.

Description

Major efforts have been made world-wide to improve the ecological quality of shallow lakes by reducing external nutrient loading. These have often resulted in lower in-lake total phosphorus (TP) and decreased chlorophyll a levels in surface water, reduced phytoplankton biomass and higher Secchi depth. Internal loading delays recovery, but in north temperate lakes a new equilibrium with respect to TP often is reached after p<10-15 years. In comparison, the response time to reduced nitrogen (N) loading is typically p<5 years. Also increased top-down control may be important. Fish biomass often declines, and the percentage of piscivores, the zooplankton:phytoplankton biomass ratio, the contribution of Daphnia to zooplankton biomass and the cladoceran size all tend to increase. This holds for both small and relatively large lakes, for example, the largest lake in Denmark (40 km²), shallow Lake Arresø, has responded relatively rapidly to a ca. 76% loading reduction arising from nutrient reduction and top-down control. Some lakes, however, have proven resistant to loading reductions. To accelerate recovery several physico-chemical and biological restoration methods have been developed for north temperate lakes and used with varying degrees of success. Biological measures, such as selective removal of planktivorous fish, stocking of piscivorous fish and implantation or protection of submerged plants, often are cheap versus traditional physico-chemical methods and are therefore attractive. However, their long-term effectiveness is uncertain. It is argued that additional measures beyond loading reduction are less cost-efficient and often not needed in very large lakes. Although fewer data are available on tropical lakes these seem to respond to external loading reductions, an example being Lake Paranoá, Brazil (38 km²;). However, differences in biological interactions between cold temperate versus warm temperate-subtropical-tropical lakes make transfer of existing biological restoration methods to warm lakes difficult. Warm lakes often have prolonged growth seasons with a higher risk of long-lasting algal blooms and dense floating plant communities, smaller fish, higher aggregation of fish in vegetation (leading to loss of zooplankton refuge), more annual fish cohorts, more omnivorous feeding by fish and less specialist piscivory. The trophic structures of warm lakes vary markedly, depending on precipitation, continental or coastal regions locations, lake age and temperature. Unfortunately, little is known about trophic dynamics and the role of fish in warm lakes. Since many warm lakes suffer from eutrophication, new insights are needed into trophic interactions and potential lake restoration methods, especially since eutrophication is expected to increase in the future owing to economic development and global warming.

Oxygen depletion / George, D.G., V.A. Bell, J. Parker & R.J. ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Oxygen depletion

Reference

George, D.G., V.A. Bell, J. Parker & R.J. Moore (2006): Using a 1-D mixing model to assess the potential impact of year-to-year changes in weather on the habitat of vendace (Coregonus albula) in Bassenthwaite Lake, Cumbria. Freshwater Biology 51(8): 1407-1416.

Description

Bassenthwaite Lake in Cumbria is one of only two English lakes containing a population of vendace (Coregonus albula). The spatial distribution and survival of this fish is strongly influenced by the temperature and oxygen content of the water. In summer, this fish moves into deeper, colder water but avoids areas where the oxygen content is low. In recent years, there has been a dramatic decline in the number of vendace found in the lake, a trend that may have been exacerbated by a succession of warm summers. Bassenthwaite only becomes stably stratified during calm, warm periods when a significant proportion of the deep water becomes anoxic. Here, a one dimensional (1-D) process-based temperature-oxygen model is used to simulate the year-to-year variations in the severity of these 'extreme events'. The results are discussed in relation to the conservation status of the species and the potential effect of climate change on its survival in the English Lake District.

Water temperature; Nutrients / Christoffersen, K., Andersen, N., Sønd ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Water temperature; Nutrients

Reference

Christoffersen, K., Andersen, N., Søndergaard, M., Liboriussen, L., Jeppesen, E. (2006): Implications of climatic inforced temperature increases on freshwater pico- and nanoplankton populations in artificial ponds during 16 months. Hydrobiologia 560: 259-266.

Description

Global warming scenarios foresee increases in air temperatures of 3-5 %deg;C in Northern European regions within the next 70 years. To evaluate the potential effects of global warming on shallow eutrophic lakes, a flow-through experiment combining three temperature scenarios and two nutrient levels was conducted in 24 outdoor mesocosms. Eight mesocosms were unheated and acted as controls, while sixteen were heated ? eight according to the Intergovernmental Panel on Climate Change?s (IPCC) climate scenario A2 down-scaled to regional level (2.5-4.4 °C, depending on season) and eight according to scenario A2+ with an additional 50% temperature increase. Half of the mesocosms were enriched with nitrogen and phosphorus to simulate increased runoff from terrestrial sources due to the increased precipitation predicted by the A2 scenario. The other half were un-enriched and received only natural nutrient input from the groundwater that fed all the mesocosms. The abundance and development pattern of the microbial communities within the mesocosms were tracked during a 16-month period. Generally, the results showed that the abundances of picoalgae, bacteria and heterotrophic nanoflagellates changed in a similar manner over time; abundances being lower in winter than in summer. Warming in itself had no effect on abundance, albeit it significantly modified the positive effect of the nutrients. Only at ambient temperatures did the whole microbial assemblage respond positively to nutrients. In the A2 scenario, only picoalgae responded to nutrients, while in the A2+ scenario all but the heterotrophic nanoflagellates showed a response. Elevated winter temperatures seemed not to be more important for the microbial assemblage than elevated summer temperatures. Our results demonstrate that the direct effects of warming were far less important than the nutrient effect. The results furthermore reveal that warming and nutrients in combination set off complex interactions. In consequence, global warming may possibly have pronounced effects on aquatic ecosystems if accompanied by increased nutrient loading.

Early warning indicators

Clear water timing / Scheffer, M., D. Straile, E.H. van Nes &, ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Clear water timing

Reference

Scheffer, M., D. Straile, E.H. van Nes &, H. Hosper (2001): Climatic warming causes regime shifts in lake food webs. Limnology and Oceanography 46(7): 1780-1783.

Description

Long time series from 71 shallow lakes to demonstrate that with the temperature of lake water the probability of clear water phase increases. Also showing a distinct climate-related shift in the timing of clear water phases in the shallow lakes which causes earlier clear water phase.

Clear water timing / Straile, D. (2002): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Clear water timing

Reference

Straile, D. (2002): North Atlantic Oscillation synchronizes food-web interactions in central European lakes. Proceedings of the Royal Society of London 269: 391-395.

Description

Higher water temperature (esp. winter/spring). Timing of early summer algal suppression (clear water timing) advanced by approx. 2 weeks within the last 30 years. Faster population growth of herbivores (i.e. Daphnia) due to warmer water.

Ice cover timing / Weyhenmeyer, G.A., M. Meili & D.M. Living ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Weyhenmeyer, G.A., M. Meili & D.M. Livingstone (2004): Non-linear response of ice-breakup. Geophysical Research Letters 31(7): 1-4.

Description

Long-term records (4 decades). Lake ice phenology: Potentially important for employment of lake ice phenologies as climate indicators. Relationship between air temperature and timing of lake ice breakup shows arc cosine function. Nonlinearity results in marked differences in the response of timing in ice breakup to changes in air temperature between colder and warmer regions and cold.

Ice cover timing / Fang, X. & H.G. Stefan (2000): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Fang, X. & H.G. Stefan (2000): Projected climate change effects on winterkill in shallow lakes in the northern United States. Environmental Management 25(3): 291-304.

Description

Under current climate conditions winterkill occurs typically in shallow eutrophic lakes of the northern contiguous United States. Climate warming is projected to eliminate winterkill in these lakes. This would be a positive effect of climate warming. Fish species under ice may still experience periods of stress and zero growth due to low DO (<3 mg/liter) conditions under projected climate warming.

Ice cover timing / Johnson, S.L. & H.G. Stefan (2006): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Johnson, S.L. & H.G. Stefan (2006): Indicators of climate warming in Minnesota: Lake ice covers and snowmelt runoff. Climatic Change 75(4): 421-453.

Description

Although hidden among strong variability from year to year, ice-out dates on 73 lakes have been shifting to an earlier date at a rate of -0.13 days/year from 1965 to 2002, while ice-in dates on 34 lakes have been delayed by 0.75 days/year from 1979 to 2002. From 1990 to 2002 the rates of change increased to -0.25 days/year for ice-out and 1.44 days/year for ice-in. In conclusion, records of five hydrologic parameters that are closely linked to air temperature show a trend that suggests recent climate warming in Minnesota, and especially from 1990 to 2002. The recent rates of change calculated from the records are very noteworthy, but must not be used to project future parameter values, since trends cannot continue indefinitely, and trend reversals can be seen in some of the long-term records.

Ice cover timing / Marszelewski, W. & R. Skowron (2006): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Marszelewski, W. & R. Skowron (2006): Ice cover as an indicator of winter air temperature changes: case study of the Polish Lowland lakes. Hydrological Sciences Journal-Journal Des Sciences Hydrologiques 51(2): 336-349.

Description

ice break-up dates were recorded to occur much earlier than in the past on all the lakes, with time advance being on average from 0.6 to 0.8 day year^-1. The period with ice cover has been getting shorter at the rate of 0.8 to 0.9 day year^-1, with the exception of Lake Hancza, the deepest lake in the European Lowland, where the rate of 0.4 day year^-1 was recorded. Similarly, there was a decreasing tendency in the maximum thickness of the ice cover, at the rate of 0.26 to 0.60 cm year^-1. Despite similar tendencies, all those changes showed diverse dynamics in particular lakes. The proposed indicator of the ice cover stability confirms the above statements, and thus, the undergoing climatic changes.

Mixis timing/type change, clear water timing / Chen, C.Y. & C.L. Folt (1996): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Mixis timing/type change, clear water timing

Reference

Chen, C.Y. & C.L. Folt (1996): Consequences of fall warming for zooplankton overwintering success. Limnology and Oceanography 41: 1077-1086.

Description

Early Warning Indicators, Food webs prim/sec prod, Primary Production, Secondary Production - Zooplankton
Spring temperature increase (Jan to May). Change from dimictic to warm monomictic. Less intense ice cover. Spring temperature increase (lake mean temperature). Earlier phytoplankton spring maximum. Intensity of phytoplankton spring maximum lower. Earlier zooplankton maximum (clear water phase), possibly earlier onset of grazing pressure causes lower phytoplankton maxima.

Secondary Production - Zooplankton
D. catawba: change from sexual to asexual reproduction at warmer fall temperatures. Survival unchanged between 15-25 °C, significant reduction in survival when >30 °C. E. lacustris: September survival and reproductive rates decline with increasing temperatures, resting eggs stimulated to hatch by temperatures above 15 °C in autumn, may lead to a loss of cohort: hatched individuals possibly unable to reach maturity before winter. Comment: Disruption in overwintering strategies by autumn warming could alter biogeographic range of species.

Secondary Production - Zooplankton
E. lacustris: September survival and reproductive rates decline with increasing temperatures, resting eggs stimulated to hatch by temperatures above 15 °C in autumn, may lead to a loss of cohort: hatched individuals possibly unable to reach maturity before winter. Comment: Disruption in overwintering strategies by autumn warming could alter biogeographic range of species.

Stratification characteristics / George, D.G., V.A. Bell, J. Parker & R.J. ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Stratification characteristics

Reference

Description

Thermal structure / Jones, I., George, G. & C. Reynolds (2005 ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Thermal structure

Reference

Jones, I., George, G. & C. Reynolds (2005): Quantifying effects of phytoplankton on the heat budgets of two large limnetic enclosures. Freshwater Biology 50(7): 1239-1247.

Description

Enclosures with different nutrient supplies and consequently different phytoplankton populations. Changes in the heat budget were assumed to be induced by the biological differences between the enclosures. The proposed mechanism is an increased surface absorption of solar radiation leading to extra surface warming and a consequent excess loss of heat to the atmosphere through long-wave emittance and sensible and latent heat fluxes, conservatively estimated to be of the order of 10-30 Wm^-2 (more important in warmer lakes than in colder ones). Thermocline depth and strength were also altered by the response to differences in phytoplankton. Any changes in climate or in nutrient loading from the catchment which substantially affect abundance or timing of phytoplankton populations in a lake will consequently also change the thermal structure of the lake.

Water temperature, stratification characteristics / Wilhelm, S., Hintze, T., Livingstone D. M., A ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Water temperature, stratification characteristics

Reference

Wilhelm, S., Hintze, T., Livingstone D. M., Adrian, R. (2006): Long-term response of daily epilimnetic temperature extrema to climate forcing. Canadian Journal of Fisheries and Aquatic Sciences 63(11): 2467-2477.

Description

Twenty years (1983-2002) of hourly summer temperature data from the epilimnion of Müggelsee, a shallow lake in northern Germany, showed a long-term increase, with the rate of increase of the daily minima (nighttime temperatures) exceeding that of the daily maxima (daytime temperatures). This does not simply reflect the long-term behaviour of air temperature, which did not exhibit a significant degree of day?night asymmetry. A sensitivity analysis based on a heat-balance model revealed that the daily extrema of the lake surface equilibrium temperature responded differently not only to shifts in air temperature, but also to shifts in wind speed, relative humidity, and cloud cover, suggesting that long-term changes in all four variables contribute to day-night asymmetry in the epilimnetic temperature. A comparison of nighttime and daytime estimates of the heat flux components into the lake indicates that the emission of long-wave radiation from the atmosphere is likely to be the main process responsible for day?night asymmetry in the epilimnetic temperature. Although this process is partially dependent on air temperature, it is also dependent on relative humidity and cloud cover. The influence of long-term changes in these additional driving variables on epilimnetic temperatures cannot therefore be neglected.

Food webs

Clear water timing / Strecker, A.L., T.P. Cobb & R.D. Vinebroo ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Clear water timing

Reference

Strecker, A.L., T.P. Cobb & R.D. Vinebrooke (2004): Effects of experimental greenhouse warming on phytoplankton and zooplankton communities in fishless alpine ponds. Limnology and Oceanography 49(4): 1182-1190.

Description

Warming significantly suppressed total zooplankton biomass because large cladocerans (Daphnia pulex) declined while rotifer (Keratella cochlearis, Conochilus unicornis) abundance increased during the second half of the experiment. In contrast, warming did not affect total phytoplankton biomass but significantly altered community composition by favoring phytoflagellates (Mallomonas, Synura, Trachelomonas) over larger filamentous green algae (Mougeotia, Phymatodocis). Warming did not significantly increase dissolved nitrogen and phosphorus concentrations. Therefore, warmer growing conditions and reduced grazer biomass best explained the increased abundance of more edible, fast-growing phytoflagellates in the warmed mesocosms. Our findings support the hypothesis that moderate warming can destabilize plankton dynamics, thereby potentially reducing the reliability of water quality and food resources for higher trophic levels (e.g., planktivorous fish) in shallow cold-water ecosystems.

Clear water timing changed / Scheffer, M., D. Straile, E.H. van Nes &, ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Clear water timing changed

Reference

Scheffer, M., D. Straile, E.H. van Nes &, H. Hosper (2001): Climatic warming causes regime shifts in lake food webs. Limnology and Oceanography 46(7): 1780-1783.

Description

Mixis timing/type change, clear water timing / Chen, C.Y. & C.L. Folt (1996): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Mixis timing/type change, clear water timing

Reference

Chen, C.Y. & C.L. Folt (1996): Consequences of fall warming for zooplankton overwintering success. Limnology and Oceanography 41: 1077-1086.

Description

Phytoplankton maximum, blooms timing, population timing, growth, maximum / De Senerpont Domis, L.N., W.M. Mooij, S, H&uu ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Phytoplankton maximum, blooms timing, population timing, growth, maximum

Reference

De Senerpont Domis, L.N., W.M. Mooij, S, Hü:lsmann, E.H. van Nes & M. Scheffer (2007): Can overwintering versus diapausing strategy in Daphnia determine match-mismatch events in zooplankton-algae interactions? Oecologia 150(4): 682-698.

Description

Daphnids overwintering population: parallel shifts in phytoplankton phenology due to climate warming. Emerging population of daphnids: Changes in the photoperiod-temperature interaction may cause the hatch to be too late and mismatch their phytoplankton prey. A decoupling of the trophic relationship between the keystone herbivore Daphnia and its algal prey can result in the absence of a spring clear water phase. Analysis of 36 temperate lakes showed that shallow lakes have a higher potential for climate induced match-mismatches, as the probability of active overwintering daphnids decreases with lake depth.

Pico-, nanoplankton, epilithon / Baulch, H.M., D.W. Schindler, M.A. Turner, D. ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Pico-, nanoplankton, epilithon

Reference

Baulch, H.M., D.W. Schindler, M.A. Turner, D.L. Findlay, M.J. Paterson & R.D. Vinebrooke (2005): Effects of warming on benthic communities in a boreal lake: Implications of climate change. Limnology and Oceanography 50(5): 1377-1392.

Description

rates of light-saturated photosynthesis and dark respiration were positively correlated with water temperature. Warming effects on epilithic community composition heterogeneous and difficult to predict. Warming consistently led to increased bacterial cell densities, but increases in total algal biovolume and diatom biovolume were seen only in an early successional tile community. Effects on the composition of the invertebrate community (studied only on well-developed tile biofilms) were small.

Pico-, nanoplankton, epilithon / Christoffersen, K., N. Andersen, M. Sø ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Pico-, nanoplankton, epilithon

Reference

Christoffersen, K., N. Andersen, M. Søndergaard, L. Liboriussen &, E. Jeppesen (2006): Implications of climate-enforced temperature increases on freshwater pico- and nanoplankton populations studied in artificial ponds during 16 months. Hydrobiologia 560: 259-266.

Description

Generally, the results showed that the abundances of picoalgae, bacteria and heterotrophic nanoflagellates changed in a similar manner over time; abundances being lower in winter than in summer. Warming in itself had no effect on abundance, albeit it significantly modified the positive effect of the nutrients. Only at ambient temperatures did the whole microbial assemblage respond positively to nutrients. In the A2 scenario, only picoalgae responded to nutrients, while in the A2+ scenario all but the heterotrophic nanoflagellates showed a response. Elevated winter temperatures seemed not to be more important for the microbial assemblage than elevated summer temperatures. Our results demonstrate that the direct effects of warming were far less important than the nutrient effect. The results furthermore reveal that warming and nutrients in combination set off complex interactions. In consequence, global warming may possibly have pronounced effects on aquatic ecosystems if accompanied by increased nutrient loading.

Uncoupling food chains, timing mismatch, loss of top predators, lake morphometry (especially depth) / De Senerpont Domis, L.N., W.M. Mooij, S, H&uu ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Uncoupling food chains, timing mismatch, loss of top predators, lake morphometry (especially depth)

Reference

Description

Zooplankton: food-web changes, trophic interactions; phytoplankton: food-web changes, trophic interactions, biomass decreased / Carvalho, L. & A. Kirika (2003): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Food webs
Indicator	Zooplankton: food-web changes, trophic interactions; phytoplankton: food-web changes, trophic interactions, biomass decreased

Reference

Carvalho, L. & A. Kirika (2003): Changes in a shallow lake functioning: response to climate change and nutrient reduction. Hydrobiologia 506-509: 789-796.

Description

Reappearance of Daphnia. Phytoplankton: biomass decreased, food-web changes, trophic interactions with zooplankton.Spring Daphnia densities showed an even stronger, and significant, positive relationship with spring water temperatures. It is clear from this that the scale of climate change predicted in the future will significantly alter the functioning of shallow lakes and seasonal patterns in water quality.

Primary production

Abundance nano-, picoplankton / Christoffersen, K., N. Andersen, M. Sø ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Abundance nano-, picoplankton

Reference

Description

Bacterioplankton / Carvalho, L. & A. Kirika (2003): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Bacterioplankton

Reference

Carvalho, L. & A. Kirika (2003): Changes in a shallow lake functioning: response to climate change and nutrient reduction. Hydrobiologia 506-509: 789-796.

Description

Epilithon / Baulch, H.M., D.W. Schindler, M.A. Turner, D. ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Epilithon

Reference

Description

Makrophytes exotic species / Wei, A.H. & P. Chow-Fraser (2006): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Makrophytes exotic species

Reference

Wei, A.H. & P. Chow-Fraser (2006): Synergistic impact of water level fluctuation and invasion of Glyceria on Typha in a freshwater marsh of Lake Ontario. Aquatic Botany 84(1): 63-69.

Description

Native Typha latifolia vs. Exotic Glyceria maxima, invasive Phragmites australis: Water level fluctuation was the major natural disturbance and it alone accounted for 88% of the variation in Typha. After partitioning out the effect of water level, both human population growth and the presence of exotic species were still significantly related to the decline of native Typha. We suggest that multiple stressors interact with each other to influence changes in native Typha community and cause greater detrimental impact. An important implication of our results is that projected water level decline due to climate change may not necessarily favor the restoration of a desirable native marsh because of the presence of other disturbances such as exotic and invasive species and altered nutrient regime.

Makrophytes, community, distribution, production / McKee, D., K. Hatton, J.W. Eaton, D. Atkinson ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Makrophytes, community, distribution, production

Reference

McKee, D., K. Hatton, J.W. Eaton, D. Atkinson, A. Atherton, I. Harvey & B. Moss (2002): Effetcs of simulated climate warming on macrophytes in freshwater microcosm communities. Aquatic Botany 74: 71-83.

Description

2 years of simulation of two climate warming regimes for macrophyte communities showed an increasing relative abundance and increasing growth rate of Lagarosiphon major and had no significant influence on the relative abundance and growth rate of Elodea nuttallii and Potamogeton natans. By nutrient addition only the growth rate of E. nuttallii was significantly increased.

Makrophytes, community, distribution, production / Rooney, N. & J. Kalff (2000): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Makrophytes, community, distribution, production

Reference

Rooney, N. & J. Kalff (2000): Inter-annual variation in submerged macrophyte community biomass and distribution: the influence of temperature and lake morphometry. Aquatic Botany 68: 321-335.

Description

Primary Production:Interannual variation in underwater light climate: No effect on macrophyte colonization. Early season warm temperatures: deeper macrophyte colonization, greater wet weight biomass, increase in whole lake biomass. This effect is most pronounced in eutrophic shallow lake systems, not applicable to deeper systems.

Early Warning Indicators - Water temperature: Increased air temperature: Warmer surface temperatures in all lakes. Clear lakes: volume of cold water reduced (<10 °C). Colored lakes (DOC > 4 mg/l): cold water volume stable resp. Increased

Early Warning Indicators - Stratification characteristics: Shallower mixing depths, stronger thermal gradient in metalimnion in all lakes.

Makrophytes: community, distribution, production; phytoplankton: biomass, diversity, community composition / Turner, M.A., Huebert, D.B., Findlay, D.L., H ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Makrophytes: community, distribution, production; phytoplankton: biomass, diversity, community composition

Reference

Turner, M.A., Huebert, D.B., Findlay, D.L., Hendzel, L.L., Jansen, W.A., Bodaly, R.A., Armstrong, L.M. & S.E.M. Kasian (2005): Divergent impacts of experimental lake-level drawdown on planktonic and benthic plant communities in a boreal forest lake. Canadian Journal of Fisheries and Aquatic Sciences 62(5): 991-1003.

Description

water level lowerd by 2-3 m experimentally: Water-chemistry: neither nitrogen nor phosphorus concentration changed. Phytoplankton biomass, species assemblages, productivity, and nutrient status were largely unaffected except for small changes in species diversity and relative abundance of cyanobacteria and cryptophytes. The principal disruption for benthic algae was loss of colonizable surfaces. Floating-leaved and submersed macrophytes (hydrophytes) responded initially with large decreases in biomass and cover. The subsequent response of hydrophytes to drawdown varied: relative frequency of isoetids such as Eriocaulon septangulare decreased, while that of pondweeds such as Potamogeton spirillus increased. The trophic impacts of declining lake levels, whether due to hydroelectric reservoir manipulations or climate change, are likely to be much greater in the littoral zone than in the pelagic zone if major nutrients are unaltered.

Phytoplankton / Elliott, J.A., May, L., (2008): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton

Reference

Elliott, J.A., May, L., (2008): The sensitivity of phytoplankton in Loch Leven (U.K.) to changes in nutrient load and water temperature. Freshwater Biology 53(1): 32-41.

Description

1. Loch Leven is a shallow, eutrophic lake in Scotland, U.K. It has experienced much change over the 30 years that it has been studied; this has primarily been due to reduced nutrient loads to the lake through active catchment management. Its recovery has been slow and, therefore, we used a phytoplankton community model (PROTECH) to test its sensitivity to changing nutrient loads and water temperature.
2. PROTECH was initialized to simulate the observed phytoplankton community in 1995 and was then repeatedly run through a combination of step-wise changes in water temperature and nutrient load (two treatments were simulated for nutrient load: one changing both nitrate and phosphorus, and one changing just phosphorus). The effect on total chlorophyll-a concentration, cyanobacteria abundance and phytoplankton diversity was examined.
3. Whilst changes in temperature had little effect, variations in the nutrient load produced a range of responses. Increasing only the phosphorus load caused a large increase in Anabaena abundance and total chlorophyll-a concentration. However, the opposite response was recorded when nitrate load was changed as well, with Anabaena increasing its biomass under reduced nutrient load scenarios.
4. The key factor determining the type of response appeared to be nitrogen availability. Anabaena, a nitrogen fixer, could exploit the phosphorus resource of Loch Leven under limiting nitrogen conditions, allowing it to dominate under most of the scenarios tested apart from those supplying extra nitrogen to the lake. The model predictions agree with the observed data, which show that Anabaena continues to dominate the summer phytoplankton bloom in Loch Leven despite the considerable reduction in phosphorus supply from the catchment. This research provides a possible explanation for this.

Phytoplankton biomass, diversity, community composition, minor changes in shallow, unstratified lakes, lake morphometry (especially depth) / Moss, B., D. McKee, D. Atkinson, S.E. Colling ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton biomass, diversity, community composition, minor changes in shallow, unstratified lakes, lake morphometry (especially depth)

Reference

Moss, B., D. McKee, D. Atkinson, S.E. Collings, J.W. Eaton, A.B. Gill, I. Harvey, K. Hatton, T. Heyes & D. Wilson (2003): How important is climate? Effects of warming, nutrient addition and fish on phytoplankton in shallow lake microcosms. Journal of Applied Ecology 40: 782–792.

Description

Total phytoplankton biovolume, chlorophyll a : very minor effect. Cryptophyceae, dinophyceae: decreased biovolumes. Oocystis pusilla, Cryptomonas erosa: decreased abundances.Tetraedron minimum, Micractinium pusillum: increased abundances. No change in cyanophytes, and 17 other predominant species. The factor warming has a considerably smaller effect on phytoplankton than the factors nutrients and fish. In shallow and unstratified lakes (macrophyte-dominated) global warming may not increase abundance of cyanophytes, whereas eutrophication and fish manipulations are important for the abundance of phytoplankton.

Phytoplankton community composition / Anneville, O., S. Gammeter & D. Straile ( ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton community composition

Reference

Anneville, O., S. Gammeter & D. Straile (2005): Phosphorus decrease and climate variability: mediators of synchrony in phytoplankton changes among European peri-alpine lakes. Freshwater Biology 50(10): 1731-1746.

Description

Multivariate analyses identified long-term changes in phytoplankton composition, which occurred coherently in all lakes despite the differing absolute phosphorus concentrations. In all lakes, the phytoplankton species benefiting from oligotrophication included mixotrophic species and/or species indicative of oligo-mesotrophic conditions. A major change in community composition occurred in all lakes at the end of the 1980s. During this period there was also a major shift in climatic conditions during winter and early spring, suggesting an impact of climatic factors. Our results provide evidence that synchronous long-term changes in geographically separated phytoplankton communities may occur even when overall biomass changes are not synchronous.

Phytoplankton community composition / Elliott, J.A., S.J. Thackeray, C. Huntingford ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton community composition

Reference

Elliott, J.A., S.J. Thackeray, C. Huntingford & R.G. Jones (2005): Combining a regional climate model with a phytoplankton community model to predict future changes in phytoplankton in lakes. Freshwater Biology 50(8): 1404-1411.

Description

PP community model PROTECH. the simulated spring bloom showed an increase in cyanobacteria dominance caused by greater success of Planktothrix. Also, the summer cyanobacteria bloom declined earlier because of nutrient limitation caused by the increased spring growth. Overall productivity in the lake did not change. Analysis showed that these predicted changes were driven by changes in water temperature, which were in turn triggered by the higher air temperatures predicted by the RCM.

Phytoplankton community composition / Strecker, A.L., T.P. Cobb & R.D. Vinebroo ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton community composition

Reference

Description

Phytoplankton community composition, maximum, blooms timing / Elliott, J.A., I.D. Jones & S.J. Thackera ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton community composition, maximum, blooms timing

Reference

Elliott, J.A., I.D. Jones & S.J. Thackeray (2006): Testing the sensitivity of phytoplankton communities to changes in water temperature and nutrient load, in a temperate lake. Hydrobiologia 559: 401-411.

Description

PP community model PROTECH. Annual mean phytoplankton biomass increased with increases in temperature and nutrient loading, although the latter had the larger effect. The phenology of the dominant phytoplankton taxa changed with increasing water temperature; the three spring blooming species all peaked earlier in the year. The simulated summer bloom of Anabaena became earlier in the year and the Chlorella bloom later. The increased phytoplankton biomass was largely dominated by the cyanobacterium Anabaena, which was especially prevalent during the summer bloom. This resulted in a progressive loss of phytoplankton biodiversity with increasing water temperature and nutrient supply. Model experimentation showed that whilst both factors greatly affected the community, the changes to nutrient loading generally had the greater effect and that at low nutrient levels the effect of water temperature change was reduced considerably. Finally, the model predicted that cyanobacteria have the potential to dominate the phytoplankton community, with clear consequences for water quality, and that this dominance was at its greatest when high water temperatures were combined with high nutrient loads.

Phytoplankton growth rates / Doyle, S.A., J.E. Saros & C.E. Williamson ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton growth rates

Reference

Doyle, S.A., J.E. Saros & C.E. Williamson (2005): Interactive effects of temperature and nutrient limitation on the response of alpine phytoplankton growth to ultraviolet radiation. Limnology and Oceanography 50(5): 1362-1367.

Description

Temp, nutrient, UV interaction: effect on growth rates of two diatoms, one chrysophyte, and one dinoflagellate species. Greater growth rates were observed at the higher temperature for all taxa, except the chrysophyte. UVR depressed the growth rates of all phytoplankton at 6 °C regardless of nutrient conditions. In contrast, at 14 °C, a negative effect of UVR was not observed for any species in the absence of nutrient additions; only with the addition of nutrients did UVR exposure depress the growth of one diatom species and the dinoflagellate. In alpine lakes, the effects of UVR exposure on phytoplankton depend on temperature and nutrient availability, indicating that climate change and enhanced atmospheric nitrogen deposition are likely to alter UV-temperature-nutrient relationships of plankton in high-UV systems.

Phytoplankton maximum, blooms timing / Chen, C.Y. & C.L. Folt (1996): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Chen, C.Y. & C.L. Folt (1996): Consequences of fall warming for zooplankton overwintering success. Limnology and Oceanography 41: 1077-1086.

Description

Phytoplankton maximum, blooms timing / Köhler, J., S. Hilt, R. Adrian, A. Nickl ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Köhler, J., S. Hilt, R. Adrian, A. Nicklisch, H.P. Kozerski & N. Walz (2005): Long-term response of a shallow, moderately flushed lake to reduced external phosphorus and nitrogen loading. Freshwater Biology 50(10): 1639-1650.

Description

Long-term responses of nutrient concentrations, plankton, macrophytes and macrozoobenthos to a reduction in external nutrient loading and to contemporary climatic change were studied. Results concerning climatic change: Water temperatures in Muggelsee have increased in winter, early spring and summer since 1979. The earlier development of the phytoplankton spring bloom was associated with shorter periods with ice cover, while direct temperature effects were responsible for the earlier development of the daphnid maximum in spring.

Phytoplankton maximum, blooms timing / Adrian, R., S. Wilhelm & D. Gerten (2006) ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Adrian, R., S. Wilhelm & D. Gerten (2006): Life-history traits of lake plankton species may govern their phenological response to climate warming. Global Change Biology 12(4): 652-661.

Description

Fast-growing plankton in spring (diatoms, Daphnia) showed significant and synchronous forward movements by about 1 month, induced by concurrent earlier ice break-up dates (diatoms) and higher spring water temperature (Daphnia). No such synchrony was observed for slow-growing summer zooplankton species with longer and more complex life cycles (copepods, larvae of the mussel Dreissena polymorpha). Although coexisting, the summer plankton responded species specifically to seasonal warming trends, depending on whether the timing of warming matched their individual thermal requirements at decisive developmental stages such as emergence from diapause (copepods), or spawning (Dreissena). Others did not change their phenology significantly, but nevertheless, increased in abundances. We show that the detailed seasonal pattern of warming influences the response of phyto- and zooplankton species to climate change, and point to the diverse nature of responses for species exhibiting complex life-history traits.

Primary production: plants / Secondary production - fish

Community change, diversity change / Fish distribution, richness, abundance change / Meerhoff, M., Clemente, J.M., Teixeira de Mel ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Primary production: plants / Secondary production - fish
Indicator	Community change, diversity change / Fish distribution, richness, abundance change

Reference

Meerhoff, M., Clemente, J.M., Teixeira de Mello, F., Iglesias, C., Pedersen, A.R., Jeppesen, E. (2007): Can warm climate-related structure of littoral predator assemblies weaken clear water state in shallow lakes? Global Change Biology 13: 1888-1897.

Description

Shallow lakes, the most abundant lake type in the world, are very sensitive to climatic changes. The structure and functioning of shallow lakes are greatly impacted by submerged plants, and these may be affected by climate warming in various, contrasting, ways.Following a space-for-time substitution approach, we aimed to analyse the role of aquatic (submerged and free-floating) plants in shallow lakes under warm climates. We introduced artificial submerged and free-floating plant beds in five comparable lakes located in the temperate zone (Denmark, 55-57 °N) and in the subtropical zone (Uruguay, 30-35°S), with the aim to study the structure and dynamics of the main associated communities.Regardless of differences in environmental variables, such as area, water transparency and nutrient status, we found consistent patterns in littoral community dynamics and structure (i.e. densities and composition of fish, zooplankton, macroinvertebrates, and periphyton) within, but substantial differences between, the two regions. Subtropical fish communities within the macrophyte beds exhibited higher diversity, higher density, smaller size, lower relative abundance of potentially piscivores, and a preference for submerged plants, compared with otherwise similar temperate lakes. By contrast, macroinvertebrates and cladocerans had higher taxon richness and densities, and periphyton higher biomass, in the temperate lakes. Several indicators suggest that the fish predation pressure was much stronger among the plants in the subtropical lakes. The antipredator behaviour of cladocerans also differed significantly between climate zones. Submerged and free-floating plants exerted different effects on the spatial distribution of the main communities, the effects differing between the climate zones. In the temperate lakes, submerged plants promoted trophic interactions with potentially positive cascading effects on water transparency, in contrast to the free-floating plants, and in strong contrast to the findings in the subtropical lakes.The higher impact of fish may result in higher sensitivity of warm lakes to external changes (e.g. increase in nutrient loading or water level changes). The current process of warming, particularly in temperate lakes, may entail an increased sensitivity to eutrophication, and a threat to the high diversity, clear water state.

Secondary production - fish

Growth, production, survival change / Fang, X. & H.G. Stefan (2000): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - fish
Indicator	Growth, production, survival change

Reference

Fang, X. & H.G. Stefan (2000): Projected climate change effects on winterkill in shallow lakes in the northern United States. Environmental Management 25(3): 291-304.

Description

Growth, production, survival change / George, D.G., V.A. Bell, J. Parker & R.J. ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - fish
Indicator	Growth, production, survival change

Reference

Description

Phyto- and Zooplankton production change / Moss, B., Stephen, D., Balayla, D.M., Becares ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - fish
Indicator	Phyto- and Zooplankton production change

Reference

Moss, B., Stephen, D., Balayla, D.M., Becares, E., Collings,S.E., Fernández Aláez, C., Fernández Aláez, M., Ferriol, C., García, P., Gomá, J., Gyllström, M., Hansson, L-A., Hietala, J., Kairesalo, T., Miracle, M.R., Romo, S., Rueda, J., Russell, V., Stahl-Delbanco, A., Svensson, M., Vakkilainen, K., Valentín, M., Van De Bund, W.J., Van Donk, E., Vicente, E., Villena, M.J. (2004): Continental-scale patterns of nutrient and fish effects on shallow lakes: synthesis of a pan-European mesocosm experiment. Freshwater Biology 49: 1633-1649. (Euro-limpacs paper)

Description

1. Results are analysed from 11 experiments in which effects of fish addition and nutrient loading on shallow lakes were studied in mesocosms. The experiments, five in 1998, six in 1999, were carried out in six lakes, distributed from Finland to southern Spain, according to a standard protocol. 2. Effects of the treatments on 29 standard chemical, phytoplankton and zooplankton variables are examined to assess the relative importance of bottom-up (nutrient enrichment) and top-down (fish predation) effects. For each year, the experiments in different locations are treated as replicates in a meta-analysis. Results of individual experiments are then compared in terms of the patterns of significant influences of nutrient addition and fish predation with these overall results (the baseline), and between years in the same location. 3. The overall meta-analysis gave consistent results across the 2 years, with nutrient loading influencing all of the chemical variables, and on average 31% of primary producer and 39% of zooplankton variables. In contrast, fish influenced none of the chemical variables, 11% of the primary producer and 44% of the zooplankton variables. Nutrient effects on the system were thus about three times greater than fish effects, although fish effects were not inconsiderable. 4. The relative importance of nutrients and fish in individual experiments often differed between years at the same location and effects deviated to varying degrees from the baseline. These deviations were treated as measures of consistency (predictability) of conclusions in repeat experiments. Consistency increased southwards and this is interpreted as a consequence of more variable annual weather northwards. 5. The influence of nutrient loading was greater southwards and this was probably manifested through naturally greater annual macrophyte abundance in warmer locations in consequence of the longer plant growing-season. There was no trend in the relative importance of fish effects with latitude but this may partly be an artefact of the simple fish community used. These findings suggest that nutrient control should be a greater priority than biomanipulation in the restoration of eutrophicated shallow lakes in warm temperate regions. 6. Starting conditions affected the outcome of experiments. High initial concentrations of total phosphorus and planktonic chlorophyll a concentration (created by local conditions prior to the experiment) led to de-emphasis of the importance of nutrient loading in the experiment.

Secondary production - fish

Phyto- and Zooplankton production change / Moss, B., Stephen, D., Balayla, D.M., Becares ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - fish
Indicator	Phyto- and Zooplankton production change

Reference

Description

1. Results are analysed from 11 experiments in which effects of fish addition and nutrient loading on shallow lakes were studied in mesocosms. The experiments, five in 1998, six in 1999, were carried out in six lakes, distributed from Finland to southern Spain, according to a standard protocol.
2. Effects of the treatments on 29 standard chemical, phytoplankton and zooplankton variables are examined to assess the relative importance of bottom-up (nutrient enrichment) and top-down (fish predation) effects. For each year, the experiments in different locations are treated as replicates in a meta-analysis. Results of individual experiments are then compared in terms of the patterns of significant influences of nutrient addition and fish predation with these overall results (the baseline), and between years in the same location.
3. The overall meta-analysis gave consistent results across the 2 years, with nutrient loading influencing all of the chemical variables, and on average 31% of primary producer and 39% of zooplankton variables. In contrast, fish influenced none of the chemical variables, 11% of the primary producer and 44% of the zooplankton variables. Nutrient effects on the system were thus about three times greater than fish effects, although fish effects were not inconsiderable.
4. The relative importance of nutrients and fish in individual experiments often differed between years at the same location and effects deviated to varying degrees from the baseline. These deviations were treated as measures of consistency (predictability) of conclusions in repeat experiments. Consistency increased southwards and this is interpreted as a consequence of more variable annual weather northwards.
5. The influence of nutrient loading was greater southwards and this was probably manifested through naturally greater annual macrophyte abundance in warmer locations in consequence of the longer plant growing-season. There was no trend in the relative importance of fish effects with latitude but this may partly be an artefact of the simple fish community used. These findings suggest that nutrient control should be a greater priority than biomanipulation in the restoration of eutrophicated shallow lakes in warm temperate regions.
6. Starting conditions affected the outcome of experiments. High initial concentrations of total phosphorus and planktonic chlorophyll a concentration (created by local conditions prior to the experiment) led to de-emphasis of the importance of nutrient loading in the experiment.

Secondary production - fish

Thermal habitat change, cold stenotherms + rare species reduced / Stefan, H.G., M. Hondzo, X. Fang, J.G. Eaton ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - fish
Indicator	Thermal habitat change, cold stenotherms + rare species reduced

Reference

Stefan, H.G., M. Hondzo, X. Fang, J.G. Eaton & J.H. McCormick (1996): Simulated long-term temperature and dissolved oxygen characteristics of lakes in the north-central United States and associated fish habitat limits. Limnology and Oceanography 41(5): 1124-1135.

Description

Model with parameters: Lake suface area, max depth (combined to lake morphology ratio): susceptibility to stratification, and trophic state; data of temperature and minimum oxygen requirements of cold, cool and warm water fish: modelled effect of latitude and climate change effects on fish habitat.

Zooplankton production and timing change / Köhler, J., S. Hilt, R. Adrian, A. Nickl ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - fish
Indicator	Zooplankton production and timing change

Reference

Description

Secondary production - zooplankton

Abundance nano-, picoplankton / Christoffersen, K., N. Andersen, M. Sø ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Abundance nano-, picoplankton

Reference

Description

Biomass / Shuter, B.J. & K.K. Ing (1997): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Biomass

Reference

Shuter, B.J. & K.K. Ing (1997): Factors affecting the production of zooplankton in lakes. Canadian Journal of Fisheries and Aquatic Sciences 54(2): 359-377.

Description

76 % of the observed variation in growing season weight-specific production rates could be accounted for by differences in temperature, length of growing season, and taxonomic group (Rotifera, Chydoroidea, Cyclopoida, Calanoida, ordered from highest rate to lowest). Within taxonomic groups, effects of population biomass density, individual body size, and food availability were not detected. 58% of the observed variation in growing season population biomass density could be accounted for by differences in individual body size, mean chlorophyll concentration, and lake mean depth. 24% of the observed variation in growing season length could be accounted for by differences in mean chlorophyll concentration and taxonomic group. Our findings suggest a simple model of the seasonal production cycle for limnetic zooplankton in which weight-specific rates of biomass production are largely set by temperature, and levels of biomass accumulation are largely set by food resource availability and individual body size. We briefly discuss the implications of this model for predicting the effects of climate change on lake productivity.

Invertebrates biomass, diversity, composition change / Burgmer, T., H. Hillebrand & M. Pfenninge ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Invertebrates biomass, diversity, composition change

Reference

Burgmer, T., H. Hillebrand & M. Pfenninger (2007): Effects of climate-driven temperature changes on the diversity of freshwater macroinvertebrates. Oecologia 151(1): 93-103.

Description

There were no direct linear effects of temperature and climate indices (North Atlantic Oscillation index) on species composition and diversity, but using multivariate statistics we were able to show that trends in average temperature have already had profound impacts on species composition in lakes. These significant temperature signals on species composition were evident even though we analysed comparatively short time periods of 10-15 years. Future climate shifts may thus induce strong variance in community composition.

Invertebrates biomass, diversity, composition change / Wilhelm, S. & R. Adrian (2007): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Invertebrates biomass, diversity, composition change

Reference

Wilhelm, S. & R. Adrian (2007): Long-term response of Dreissena polymorpha larvae to physical and biological forcing in a shallow lake. Oecologia 151(1): 104-114.

Description

Dreissena polymorpha: the first appearance of larvae per year and the decline in abundance of larvae in 2003 were driven by climatic influences, while the overall increase in abundance and length of D. polymorpha larvae in Muggelsee was more likely caused by changes in the trophic state of the lake rather than by climate warming.

Life-history characteristics changed: survival and reproduction rates decreasing, overwintering strategies, cold water species lack of dapausing/dispersal stages, population timing, growth, maximum / Chen, C.Y. & C.L. Folt (1996): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Life-history characteristics changed: survival and reproduction rates decreasing, overwintering strategies, cold water species lack of dapausing/dispersal stages, population timing, growth, maximum

Reference

Chen, C.Y. & C.L. Folt (1996): Consequences of fall warming for zooplankton overwintering success. Limnology and Oceanography 41: 1077-1086.

Description

Population timing, growth, maximum / Straile, D. (2002): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum

Reference

Straile, D. (2002): North Atlantic Oscillation synchronizes food-web interactions in central European lakes. Proceedings of the Royal Society of London 269: 391-395.

Description

Population timing, growth, maximum / Köhler, J., S. Hilt, R. Adrian, A. Nickl ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum

Reference

Description

Population timing, growth, maximum / Adrian, R., S. Wilhelm & D. Gerten (2006) ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum

Reference

Adrian, R., S. Wilhelm & D. Gerten (2006): Life-history traits of lake plankton species may govern their phenological response to climate warming. Global Change Biology 12(4): 652-661.

Description

Zooplankton biomass, diversity, composition change / Carvalho, L. & A. Kirika (2003): ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change

Reference

Carvalho, L. & A. Kirika (2003): Changes in a shallow lake functioning: response to climate change and nutrient reduction. Hydrobiologia 506-509: 789-796.

Description

Zooplankton biomass, diversity, composition change / Strecker, A.L., T.P. Cobb & R.D. Vinebroo ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change

Reference

Description

Secondary production - zooplankton

Zooplankton biomass, diversity, composition change / Gyllström, M., Hansson, L.A., Jeppesen, ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change

Reference

Gyllström, M., Hansson, L.A., Jeppesen, E., Garcia-Criado, F., Gross, E., Irvine, K., Kairesalo, T., Kornijow, R., Miracle, M.R., Nykänen, M., Noges, T., Romo, S., Stephen, D., Van Donk, E., Moss, B. (2005): The role of climate in shaping zooplankton communities of shallow lakes. Limnology & Oceanography 50(6): 2008-2021.

Description

We analyzed data from 81 shallow European lakes, which were sampled with standardized methods, for combined effects of climatic, physical, and chemical features of food-web interactions, with a specific focus on zooplankton biomass and community structure. Multiple-regression analysis showed that total phosphorus (TP) generally was the most important predictor of zooplankton biomass and community structure. Climate was the next most important predictor and acted mainly through its effect on pelagic zooplankton taxa. Benthic and plant-associated taxa (typically almost half the total zooplankton biomass) were, however, affected mainly by macrophyte coverage. Neither climate nor TP affected the relation between small and large taxa, and we found only a weak trend with increasing TP of increasing mean crustacean body mass. Dividing the data set into three climate zones revealed a pronounced difference in response to lake productivity between cold lakes, with long periods of ice cover, and the two warmer lake types. These "ice" lakes differed from the others with respect to the effect of TP on chlorophyll a, the zooplankton : chlorophyll a ratio, the chlorophyll a :TP ratio, and the proportion of cyclopoids in the copepod community. Our data suggest that bottom-up forces, such as nutrient concentration, are the most important predictors of zooplankton biomass. In addition, climate contributes significantly-possibly by affecting top-down regulation by fish-and may interact with productivity in determining the zooplankton standing biomass and community composition. Hence, the present study suggests that food-web dynamics are closely linked to climatic features.

Zooplankton biomass, diversity, composition change / Meerhoff, M., Iglesias, C., Teixeira de Mello ...

Climate Region	temperate
Ecosystem type	shallow
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change

Reference

Meerhoff, M., Iglesias, C., Teixeira de Mello, F., Clemente, J.M., Jensen E., Lauridsen, T.L., Jeppesen, E. (2007): Effects of habitat complexity on community structure and predator avoidance behaviour of littoral zooplankton in temperate versus subtropical shallow lakes. Freshwater Biology 52: 1009-1021.

Description

1. Structural complexity may stabilise predator-prey interactions and affect the outcome of trophic cascades by providing prey refuges. In deep lakes, vulnerable zooplankton move vertically to avoid fish predation. In contrast, submerged plants often provide a diel refuge against fish predation for large-bodied zooplankton in shallow temperate lakes, with consequences for the whole ecosystem.
2. To test the extent to which macrophytes serve as refuges for zooplankton in temperate and subtropical lakes, we introduced artificial plant beds into the littoral area of five pairs of shallow lakes in Uruguay (30°-35°S) and Denmark (55°-57°N). We used plants of different architecture (submerged and free-floating) along a gradient of turbidity over which the lakes were paired.
3. We found remarkable differences in the structure (taxon-richness at the genus level, composition and density) of the zooplankton communities in the littoral area between climate zones. Richer communities of larger-bodied taxa (frequently including Daphnia spp.) occurred in the temperate lakes, whereas small-bodied taxa characterised the subtropical lakes. More genera and a higher density of benthic/plant-associated cladocerans also occurred in the temperate lakes. The density of all crustaceans, except calanoid copepods, was significantly higher in the temperate lakes (c. 5.5-fold higher).
4. Fish and shrimps (genus Palaemonetes) seemed to exert a stronger predation pressure on zooplankton in the plant beds in the subtropical lakes, while the pelagic invertebrateChaoborus sp. was slightly more abundant than in the temperate lakes. In contrast, plant associated predatory macroinvertebrates were eight times more abundant in the temperate than in the subtropical lakes.
5. The artificial submerged plants hosted significantly more cladocerans than the freefloating plants, which were particularly avoided in the subtropical lakes. Patterns indicating diel horizontal migration were frequently observed for both overall zooplankton density and individual taxa in the temperate, but not the subtropical, lakes. In contrast, patterns of diel vertical migration prevailed for both the overall zooplankton and for most individual taxa in the subtropics, irrespective of water turbidity.
6. Higher fish predation probably shapes the general structure and dynamics of cladoceran communities in the subtropical lakes. Our results support the hypothesis that horizontal migration is less prevalent in the subtropics than in temperate lakes, and that no predator avoidance behaviour effectively counteracts predation pressure in the subtropics. Positive effects of aquatic plants on water transparency, via their acting as a refuge for zooplankton, may be generally weak or rare in warm lakes.

Lakes in general

Abiotic incidators

Carbon cycling change (DOC release/retention) / Futter, M.N., de Wit, H.A. (2007): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic incidators
Indicator	Carbon cycling change (DOC release/retention)

Reference

Futter, M.N., de Wit, H.A. (2007): What controls dissolved organic carbon concentrations in streams: a comparison of modelling approaches. Hydrology and Earth System Sciences Discussions 4: 3175?3207.

Description

Dissolved organic carbon concentrations ([DOC]) in surface waters are increasing in many regions of Europe and North America. These increases are likely driven by a combination of changing climate, recovery from acidification and change in severity of winter storms in coastal areas. INCA-C, a process-based model of climate effects on surface water [DOC], was used to explore the mechanisms by which changing climate controls seasonal to inter-annual patterns of [DOC] in the lake and outflow stream of a small Finnish catchment between 1990 and 2003. Both production in the catchment and mineralization in the lake controlled [DOC] in the lake. Concentrations in the catchment outflow were controlled by rates of DOC production in the surrounding organic soils. The INCA-C simulation results were compared to those obtained using artificial neural networks (ANN). In general, ?black box? ANN models provide better fits to observed data but process-based models can identify the mechanism responsible for the observed pattern. A statistically significant increase was observed in both INCA-C modelled and measured annual average [DOC] in the lake. This suggests that some of the observed increase in surface water [DOC] is caused by climate-related processes operating in the lake and catchment. However, a full understanding of surface water [DOC] dynamics can only come from catchment-scale process-based models linking the effects of changing climate and deposition on aquatic and terrestrial environments.

Model: DOC (release/retention) / Futter, M.N., Starr, M., Forsius, M., Holmber ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic incidators
Indicator	Model: DOC (release/retention)

Reference

Futter, M.N., Starr, M., Forsius, M., Holmberg, M. (2008): Modelling the effects of climate on long-term patterns of dissolved organic carbon concentrations in the surface waters of a boreal catchment. Hydrology and Earth System Sciences Special Issue (Eurolimpacs) 12: 437-447.

Description

N-flux, wet deposition / Hole, L. R., de Wit, H. A., Aas, W. (2008): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic incidators
Indicator	N-flux, wet deposition

Reference

Hole, L. R., de Wit, H. A., Aas, W. (2008): Influence of summer and winter climate variability on nitrogen wet deposition in Norway. Hydrology and Earth System Sciences Special Issue (Eurolimpacs).

Description

Dominating wind patterns around Norway may change due to climate warming. This could affect transport of polluted air masses and precipitation. Here, we study relations between reactive nitrogen wet deposition and air mass transport during summer and winter expressed in the form of climate indices, at seven sites in Southern Norway for the period 1980-2005. Atmospheric nitrate concentrations decreased with 0 to 50% in the period, particularly at sites with little precipitation, and mostly during 1990-2005. For comparison, reported reductions in emissions of oxidised nitrogen in Europe in 1989-2003 were 23%. Climate indices explained up to 36% of the variation in winter nitrate deposition at the western and northern sites - and also explained 60% of the variation in winter precipitation (R=0.77). This suggests that the variation in nitrate wet deposition is closely related to variation in precipitation, and that the climate indices seem to also partly control the variation in atmospheric nitrate concentrations (R=−0.45 at coastal sites). At the coastal sites, local air temperature was highly correlated (R=0.84) with winter nitrate deposition, suggesting that warm, humid winter weather results in increased wet nitrate deposition. For ammonia the pattern was similar, but this compound is more influenced by local sources. Expected severe increase in precipitation in western and northern regions as a consequence of climate change suggest that nitrogen deposition in these areas will increase under global warming if emissions are held constant.

Abiotic incidators/ Secondary production - zooplankton

N-/P-flux/ Zooplankton biomass, diversity, composition change / Ferguson, C. A., Carvalho, L., Scott, E. M., ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic incidators/ Secondary production - zooplankton
Indicator	N-/P-flux/ Zooplankton biomass, diversity, composition change

Reference

Ferguson, C. A., Carvalho, L., Scott, E. M., Bowman, A. W., Kirika, A. (2008): Assessing ecological responses to environmental change using statistical models. Journal of Applied Ecology 45: 193-203.

Description

1. There is a clear need to improve our ability to assess the ecological consequences of environmental change. Because of the complexity of ecosystems and a need to disentangle the effects of multiple pressures, predictions are often reliant on models and expert opinion. These require validation with observed data; in this respect, long-term data sets are particularly valuable.
2.Innovative statistical methods (nonparametric regression and additive models) are presented for identifying nonparametric ecological trends and changes in seasonality in response to environmental change. These are illustrated through the example of Loch Leven, a shallow freshwater lake. Monitoring data for 35 years are examined, spanning periods of enrichment, ecological recovery and changing climate.
3. Models are developed for phosphorus and nitrogen, temperature and rainfall, Daphnia, grazers, and chlorophyll a, with the ecological objectives of examining trends in water quality and the corresponding trends in nutrient availability, grazer abundance and climate.
4. The analysis highlighted a generally decreasing availability of P over the study period, and generally increasing nonparametric trends in nitrate concentration and rainfall. Increasing spring temperatures were also evident, as were significant nonparametric changes in density of summer grazers.
5. Significant reductions are highlighted in spring and summer chlorophyll a, related to the return of Daphnia to the loch. However, no response in chorophyll a to the later declining trends in P is apparent, but seasonality has changed.
6. Synthesis and applications. The analysis highlights the value of nonparametric statistical models for assessing complex ecological responses to environmental change. The models outlined can examine key ecological impacts of climate change, particularly effects on the timing of seasonal events and processes. The models are illustrated using long-term water-quality data from Loch Leven to explore patterns in key environmental drivers and ecological responses affecting freshwater ecosystems. Analysis of chlorophyll a, in particular, highlighted the value of examining the seasonal trends separately, with different trends evident for winter and spring and a changing seasonal pattern.

Abiotic indicators

Acidification / Wright, R.F., Aherne, J., Bishop, K., Camarer ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification

Reference

Wright, R.F., Aherne, J., Bishop, K., Camarero, L., Cosby, B.J., Erlandsson, M., Evans, C.D., Forsius, M., Hardekopf, D.W., Helliwell, R., Hruska, J., Jenkins, A., Kopáček, J., Moldan, F., Posch, M., Rogora, M. (2006): Modelling the effect of climate change on recovery of acidified freshwaters: Relative sensitivity of individual processes in the MAGIC model. Science of the Total Environment, Euro-limpacs Special Issue 365: 154-166.

Description

The MAGIC model was used to evaluate the relative sensitivity of several possible climate-induced effects on the recovery of soil and surface water from acidification. A common protocol was used at 14 intensively studied sites in Europe and eastern North America. The results show that several of the factors are of only minor importance (increase in pCO₂ in soil air and runoff, for example), several are important at only a few sites (seasalts at near-coastal sites, for example) and several are important at nearly all sites (increased concentrations of organic acids in soil solution and runoff, for example). In addition changes in forest growth and decomposition of soil organic matter are important at forested sites and sites at risk of nitrogen saturation. The trials suggest that in future modelling of recovery from acidification should take into account possible concurrent climate changes and focus specially on the climate-induced changes in organic acids and nitrogen retention.

Acidification / Kopač,ek, J., Vrba, J. (2006): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification

Reference

Kopač,ek, J., Vrba, J. (2006): Integrated ecological research of catchment-lake ecosystems in the Bohemian Forest (Central Europe): A preface. Biologia Bratislava 61, Supplement 20 61: 363-370.

Description

The Bohemian Forest (Šumava, Böhmerwald) is situated in Central Europe and is among the most acidified lake districts in the world. Deposition of S and N compounds in the area rapidly increased between 1950 and 1980, and reached a maximum in the 1980s. During the 1990s, acid deposition decreased substantially, and current levels are comparable to the early 20th century for SO&sub4 2− and NH₄+ , and to the mid 1960s for NO₃ − . These changes in acid deposition have led to a partial recovery of the Bohemian Forest lakes. This paper provides an overview of previous research, and details on the organization and aims of current research on the Bohemian Forest lakes. Available historical data and regular monitoring (since 1984) provide a valuable background for long-term ecological research of the catchment-lake ecosystems that currently focuses on (i) chemical reversal and biological recovery of the lakes, (ii) acidification impacts on in-lake nutrient cycling, (iii) climatic effects on water chemistry, and (iv) catchment processes, including soil biogeochemistry and acidification impacts on vegetation.

Acidification / Posch, M., Aherne, J., Forsius, M., Fronzek, ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification

Reference

Posch, M., Aherne, J., Forsius, M., Fronzek, S., Veijalainen, N. (2008): Modelling the impacts of European emission and climate change scenarios on acid-sensitive catchments in Finland. Hydrology and Earth System Sciences Special Issue (Eurolimpacs) 12: 449-463.

Description

The dynamic hydro-chemical Model of Acidification of Groundwater in Catchments (MAGIC) was used to predict the response of 163 Finnish lake catchments to future acidic deposition and climatic change scenarios. Future deposition was assumed to follow current European emission reduction policies and a scenario based on maximum (technologically) feasible reductions (MFR). Future climate (temperature and precipitation) was derived from the HadAM3 and ECHAM4/OPYC3 general circulation models under two global scenarios of the Intergovernmental Panel on Climate Change (IPCC: A2 and B2). The combinations resulting in the widest range of future changes were used for simulations, i.e., the A2 scenario results from ECHAM4/OPYC3 (highest predicted change) and B2 results from HadAM3 (lowest predicted change). Future scenarios for catchment runoff were obtained from the Finnish watershed simulation and forecasting system. The potential influence of future changes in surface water organic carbon concentrations was also explored using simple empirical relationships based on temperature and sulphate deposition. Surprisingly, current emission reduction policies hardly show any future recovery; however, significant chemical recovery of soil and surface water from acidification was predicted under the MFR emission scenario. The direct influence of climate change (temperate and precipitation) on recovery was negligible, as runoff hardly changed; greater precipitation is offset by increased evapotranspiration due to higher temperatures. However, two exploratory empirical DOC models indicated that changes in sulphur deposition or temperature could have a confoundinginfluence on the recovery of surface waters from acidification, and that the corresponding increases in DOC concentrations may offset the recovery in pH due to reductions in acidifying depositions.

Acidification: deposition / Dillon, P.J., B.L. Skjelkvale, K.M. Somers &a ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification: deposition

Reference

Description

Acidification: import (wetlands) / Evans, C.D., D.T. Monteith & R. Harriman ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification: import (wetlands)

Reference

Evans, C.D., D.T. Monteith & R. Harriman (2001): Long-term variability in the deposition of marine ions at west coast sites in the UK Acid Waters Monitoring Network: impacts on surface water chemistry and significance for trend determination. Science of the Total Environment 265: 115-129.

Description

Marine Na, Mg, SO₄ adsorption on soil exchange sites; associated displacement of non-marine cations: Ca, labile Al, H⁺ . The interannnual variation in marine wet Cl deposition is in phase with the NAO index. Na, Mg, SO₄ retention during Cl deposition (strong negative correlation with Cl input in lakes). Ca, labile Al, H⁺ have a positive correlation with Cl through soil displacement.

Acidification: import (wetlands) / Monteith, D.T., C.D. Evans & B. Reynolds ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification: import (wetlands)

Reference

Monteith, D.T., C.D. Evans & B. Reynolds (2000): Are temporal variations in the nitrate content of UK upland freshwaters linked to the North Atlantic Oscillation? Hydrological Processes 14: 1745-1749.

Description

Low NAO winter index, colder winters, results in high NO₃ concentrations in lakes and streams. May be linked to length of time of soil freezing.

Acidification: import (wetlands) / Aherne, J., Larssen, T., Dillon, P.J. & B ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification: import (wetlands)

Reference

Aherne, J., Larssen, T., Dillon, P.J. & B.J. Cosby (2004): Effects of climate events on environmental fluxes from forested catchments in Ontario, Canada: Modelling drought-induced redox processes. Water, Air and Soil Pollution: Focus 4: 37-48.

Description

Application of MAGIC model (biogeochemical model of acidification) in comparison to observed trends: Model reproduced successfully observed trends in sulphate retention. Including wetlands. Variation in precipitation. Drought periods: Oxidation of stored sulphur in wetlands, subsequent efflux into streams/lakes. Generation of wetland compartment with incorporated redox processes included in MAGIC model.

Acidification: release sediment / Vesely, J., V. Majer, J. Kopácek, J. & ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification: release sediment

Reference

Vesely, J., V. Majer, J. Kopácek, J. & S.A. Norton (2003): Increasing temperature decreases aluminum concentrations in Central European lakes recovering from acidification. Limnology and Oceanography 48(6): 2346-2354.

Description

Increasing temperature over 17 yr-period (1984-2001) (+1.27 ±0.49 °C). Decrease of total Al and Al³⁺ concentrations in lakes (Inverse relationship between temperature and solubility: lower mobilization and/or enhanced precipitation).

Carbon cycling change (DOC release/retention) / Evans, C.D., Monteith, D.T., Cooper, D.M. (20 ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Carbon cycling change (DOC release/retention)

Reference

Evans, C.D., Monteith, D.T., Cooper, D.M. (2005): Long-term increases in surface water dissolved organic carbon: Observations, possible causes and environmental impacts. Environmental Pollution 137(1): 55-71. (Euro-limpacs paper)

Description

Dissolved organic carbon (DOC) concentrations in 22 UK upland waters have increased by an average of 91% during the last 15 years. Rising trends have also been observed elsewhere in the UK, Northern Europe and North America. A range of potential drivers of these trends are considered, including changes in temperature, rainfall, acid deposition, land-use, nitrogen and CO₂ enrichment. Based on an examination of recent environmental changes, spatial patterns in observed trends, and analysis of time series, it is suggested that DOC may be increasing in response to a combination of rising temperatures and declining acid deposition; however it is difficult to clearly isolate mechanisms on the basis of monitoring data alone. Long-term DOC increases are likely to have wide-ranging impacts on freshwater biota, drinking water quality, coastal marine ecosystems and upland carbon balances. A full understanding of the significance of these increases requires further knowledge of the extent of natural long-term variability, and of the natural "reference" state of these systems.

Carbon cycling change (DOC release/retention) / Dillon, P.J. & Molot, L.A. (2005): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Carbon cycling change (DOC release/retention)

Reference

Dillon, P.J. & Molot, L.A. (2005): Long-term trends in catchment export and lake retention of dissolved organic carbon, dissolved organic nitrogen, total iron and total phosphorus: the Dorset, Ontario study, 1978-1998. Journal of Geophysical Research 110.

Description

[1] Annual catchment export of total phosphorus (TP), dissolved organic carbon (DOC), total iron (Fe), and dissolved organic nitrogen (DON) to seven lakes in central Ontario was measured between 1978 and 1998. Fluctuations in annual water discharge and total DOC load (including precipitation) to the lakes over the 20-year period were similar in the seven study lakes. DOC export to the lakes responded proportionally to changes in discharge, decreasing during drier and warmer years. There were similar but less accentuated variations in annual DOC lake concentrations. There were no clear regional trends evident during the 20-year period toward drier or wetter conditions, less DOC load, clearer lakes, etc., that could be interpreted as signaling a shift toward a different equilibrium state. The fraction of the DOC load retained by lakes (transferred to sediments and the atmosphere) increased during an extended dry period. Fe, TP, and DON export decreased more than DOC export during the extended dry period. Runoff appears to affect Fe, TP, and DON export first by controlling export of organic matter and second by affecting water table position and thus redox levels in the surface layer of peatlands. Permanently drier conditions with less runoff would likely lead to clearer lakes that are less productive. Conversely, increased runoff would lead to more colored and productive lakes. Both scenarios have implications for subsistence and sport fishing economies.

Carbon cycling change (DOC release/retention) / Evans, C.D., Monteith, D.T., Cooper, D.M. (20 ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Carbon cycling change (DOC release/retention)

Reference

Description

Dissolved organic carbon (DOC) concentrations in 22 UK upland waters have increased by an average of 91% during the last 15 years. Rising trends have also been observed elsewhere in the UK, Northern Europe and North America. A range of potential drivers of these trends are considered, including changes in temperature, rainfall, acid deposition, land-use, nitrogen and CO₂; enrichment. Based on an examination of recent environmental changes, spatial patterns in observed trends, and analysis of time series, it is suggested that DOC may be increasing in response to a combination of rising temperatures and declining acid deposition, however it is difficult to clearly isolate mechanisms on the basis of monitoring data alone. Long-term DOC increases are likely to have wide-ranging impacts on freshwater biota, drinking water quality, coastal marine ecosystems and upland carbon balances. A full understanding of the significance of these increases requires further knowledge of the extent of natural long-term variability, and of the natural "reference" state of these systems.

Carbon cycling change (DOC release/retention); Pollution (heavy metals) / Rose, N. L. (2007): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Carbon cycling change (DOC release/retention); Pollution (heavy metals)

Reference

Rose, N. L. (2007): The rise and fall of atmospheric pollution:The paleolimnological perspective. PAGES News 15(1): 15-16.

Description

Paleolimnological studies at remote lakes considering climate-driven releases of catchment-stored pollutants.

Carbon cycling change (TOC release/retention); Acidification / Vuorenmaa, J., Forsius, M., Mannio, J. (2006) ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Carbon cycling change (TOC release/retention); Acidification

Reference

Vuorenmaa, J., Forsius, M., Mannio, J. (2006): Increasing trends of total organic carbon concentrations in small forest lakes in Finland from 1987 to 2003. Science of the Total Environment, Euro-limpacs Special Issue 365: 47-65. (Euro-limpacs paper)

Description

rends in total organic carbon (TOC) concentrations over the period 1987?2003 were studied in 13 small forest lakes. Recovery from acidification (reduced SO&sub4; deposition) and long-term changes in runoff as potential drivers for the trends were examined. The results showed that TOC concentrations have increased throughout Finland. Ten of the 13 lakes showed a significant increasing TOC trend (p < 0.05), and included both clear water and humic lakes. The largest annual increase in TOC occurred in lakes with the largest average concentrations. The magnitude of the TOC trends were not significantly related to the proportion of peat soils in the catchment but the catchment size was an important predictor. Decreasing SO⊂4 deposition and improved acid?base status in soil due to the recovery from acidification implied an increased mobilisation of organic acids and TOC. There was little evidence that the long-term increasing trend in TOC concentrations was related to long-term changes in runoff. However, large seasonal and inter-annual fluctuations in runoff did appear to affect TOC concentrations for a number of years.

Carbon cycling change (TOC release/retention); Acidification / Vuorenmaa, J., Forsius, M., Mannio, J. (2006) ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Carbon cycling change (TOC release/retention); Acidification

Reference

Description

Trends in total organic carbon (TOC) concentrations over the period 1987-2003 were studied in 13 small forest lakes. Recovery from acidification (reduced SO₄ deposition) and long-term changes in runoff as potential drivers for the trends were examined. The results showed that TOC concentrations have increased throughout Finland. Ten of the 13 lakes showed a significant increasing TOC trend (p < 0.05), and included both clear water and humic lakes. The largest annual increase in TOC occurred in lakes with the largest average concentrations. The magnitude of the TOC trends were not significantly related to the proportion of peat soils in the catchment but the catchment size was an important predictor. Decreasing SO₄ deposition and improved acid?base status in soil due to the recovery from acidification implied an increased mobilisation of organic acids and TOC. There was little evidence that the long-term increasing trend in TOC concentrations was related to long-term changes in runoff. However, large seasonal and inter-annual fluctuations in runoff did appear to affect TOC concentrations for a number of years.

N-flux; Hydrology: runoff variations / Andersen, H.E., Kronvang, B., Larsen, S.E., H ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	N-flux; Hydrology: runoff variations

Reference

Andersen, H.E., Kronvang, B., Larsen, S.E., Hoffmann, C.C., Jensen, T.S., Rasmussen, E.K. (2006): Climate-change impacts on hydrology and nutrients in a Danish lowland river basin. Science of the Total Environment 365: 223-237.

Description

The Mike 11-TRANS modelling system was applied to the lowland Gjern river basin in Denmark to assess climate-change impacts on hydrology and nitrogen retention processes in watercourses, lakes and riparian wetlands. Nutrient losses from land to surface waters were assessed using statistical models incorporating the effect of changed hydrology. Climate-change was predicted by the ECHAM4/OPYC General Circulation Model (IPCC A2 scenario) dynamically downscaled by the Danish HIRHAM regional climate model (25 km grid) for two time slices: 1961-1990 (control) and 2071-2100 (scenario). HIRHAM predicts an increase in mean annual precipitation of 47 mm (5%) and an increase in mean annual air temperature of 3.2 °C (43%). The HIRHAM predictions were used as external forcings to the rainfall-runoff model NAM, which was set up and run for 6 subcatchments within and for the entire, Gjern river basin. Mean annual runoff from the river basin increases 27 mm (7.5%, p < 0.05) when comparing the scenario to the control. Larger changes, however, were found regarding the extremes, runoff during the wettest year in the 30-year period increased by 58 mm (12.3%). The seasonal pattern is expected to change with significantly higher runoff during winter. Summer runoff is expected to increase in predominantly groundwater fed streams and decrease in streams with a low base-flow index. The modelled change in the seasonal hydrological pattern is most pronounced in first- or second-order streams draining loamy catchments, which currently have a low base-flow during the summer period. Reductions of 40-70% in summer runoff are predicted for this stream type. A statistical nutrient loss model was developed for simulating the impact of changed hydrology on diffuse nutrient losses (i.e. losses from land to surface waters) and applied to the river basin. The simulated mean annual changes in TN loads in a loamy and a sandy subcatchment were, respectively, + 2.3 kg N ha−¹ (8.5%) and + 1.6 kg N ha−_-1;(6.9%).The rainfall-runoff model and the nutrient loss model were chained with Mike 11-TRANS to simulate the combined effects of climate-change on hydrology, nutrient losses and nitrogen retention processes at the scale of the river basin. The mean annual TN export from the river basin increased from the control to the scenario period by 7.7%. Even though an increase in nitrogen retention in the river system of 4.2% was simulated in the scenario period, an increased in-stream TN export resulted because of the simulated increase in the diffuse TN transfer from the land to the surface-waters.

Nutrients and oxygen: depletion / Straile, D., K. Jöhnk & H. Rossknech ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Nutrients and oxygen: depletion

Reference

Straile, D., K. Jöhnk & H. Rossknecht (2003): Complex effects of winter warming on the physicochemical characteristics of a deep lake. Limnology and Oceanography 48(4): 1432-1438.

Description

Higher winter temperature (gradient!). No complete mixis because of persistence of temperature gradients. No oxygen replenishment in the hypolimnion. Less upward mixing of P/Si, accumulation in hypolimnion.

Nutrients: eutrophication general / Evans, C.D., D.T. Monteith & D.M. Cooper ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Nutrients: eutrophication general

Reference

Evans, C.D., D.T. Monteith & D.M. Cooper (2005): Long-term increases in surface water dissolved organic carbon: Observations, possible causes and environmental impacts. Environmental Pollution 137(1): 55-71.

Description

Rising temperatures in combination with declining acid deposition may be the cause for increasing DOC concentrations. May have impacts on freshwater biota, drinking water quality, coastal marine ecosystems, upland carbon balances.

Oxygen depletion / DeStasio, B.T., D.K. Hill, J.M. Kleinhans, N. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Oxygen depletion

Reference

DeStasio, B.T., D.K. Hill, J.M. Kleinhans, N.P. Nibbelink & J.J. Magnuson (1996): Potential effects of global climate change on small north-temperate lakes: Physics, fish and plankton. Limnology and Oceanography 41(5): 1136-1149.

Description

Abiotic indicators/Early Warning Indicators:
Variable results, but tendency to deeper thermoclines, longer stratification (dependent on spring weather conditions). Shorter ice cover period or no freezing. Epilimnion: temperature increase. Hypolimnion: temperature variable (increase/decrease) depending on spring weather conditions for stratification timing. Depletion more pronounced, anoxia frequency increased mid- to late summer. Overlap in habitat use fish - plankton may vary. Migration amplitude zooplankton decreases (predation pressure). Increases in thermal habitats (fish), favorable esp. for warm water species. Results for cool and cold water species variable, may be exceeding upper threshold for lake trout. Warm and cool water fish may have increased stress mortality due to thermal stress.

Secondary Production - Fish:
Overlap in habitat use fish - plankton may vary. Migration amplitude zooplankton decreases (predation pressure). Increases in thermal habitats (fish), favorable esp. for warm water species. Results for cool and cold water species variable, may be exceeding upper threshold for lake trout. Warm and cool water fish may have increased stress mortality due to thermal stress.

Oxygen depletion / Jankowski, T., Livingstone, D.M., Forster, R. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Oxygen depletion

Reference

Jankowski, T., Livingstone, D.M., Forster, R., Bührer, H., Niederhauser, P.(2006): Consequences of the 2003 European heatwave for lakes: implications for a warmer world. Limnology & Oceanography 51(2): 815-819.

Description

In summer 2003 central Europe suffered an unusually severe heat wave, with air temperatures similar to those predicted for an average summer during the late 21st century. We use a unique set of over half a century of lake data from two lakes in Switzerland to determine the effect of the 2003 heat wave on water temperature and oxygen conditions in order to assess how temperate lakes will react when exposed to the increased ambient summer air temperatures that will be encountered in a generally warmer world and to test the predictions of relevant simulation models. In both lakes, surface temperature and thermal stability in summer 2003 were the highest ever recorded, exceeding the long-term mean by more than 2.5 standard deviations. The extremely high degree of thermal stability resulted in extraordinarily strong hypolimnetic oxygen depletion. These results are consistent with the predictions of the simulation models. Additionally, the results indicate that climatic warming will increase the risk of occurrence of deep-water anoxia, thus counteracting long-term efforts that have been undertaken to ameliorate the effects of anthropogenic eutrophication.

Pollution (PBDEs) / Gallego, E., Grimalt, J.O., Bartrons, M., Lop ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Pollution (PBDEs)

Reference

Gallego, E., Grimalt, J.O., Bartrons, M., Lopez, J.F., Camarero, L., Catalan, J., Stuchlik, E., Battarbee,R. (2007): Altitudinal gradients of PBDEs and PCBs in fish from European high mountain lakes. Environmental Science & Technology 41(7): 2196-2202.

Description

A first case of temperature-dependent distribution of polybromodiphenyl ethers (PBDEs) in remote areas is shown. Analysis of these compounds in fish from Pyrenean lakes distributed along an altitudinal transect shows higher concentrations at lower temperatures, as predicted in the global distillation model. Conversely, no temperature-dependent distribution is observed in a similar transect in the Tatra mountains (Central Europe) nor in fish from high mountain lakes distributed throughout Europe. The fish concentrations of polychlorobiphenyls (PCBs) examined for comparison showed significant temperature correlations in all these studied lakes. Cold trapping of both PCBs and PBDEs concerned the less volatile congeners. In the Pyrenean lake transect the concentrations of PCBs and PBDEs in fish were correlated despite the distinct use of these compounds and their 40 year time lag of emissions to the environment. Thus, temperature effects have overcome these anthropogenic differences constituting at present the main process determining their distributions. These cases of distinct PBDEs and PCBs behavior in high mountains likely reflect early stages in the environmental distribution of the former since they have been under secondary redistribution processes over much shorter time than the latter.

Rising conductivity / Thies, H., Nickus, U., Mair, V., Tessadri, R. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Rising conductivity

Reference

Thies, H., Nickus, U., Mair, V., Tessadri, R., Tait, D., Thaler, B., Psenner, R. (2007): Unexpected response of high alpine lake waters to climate warming. Environmental Science and Technology 41(21): 7424-7429.

Description

Over the past two decades, we have observed a substantial rise in solute concentration at two remote high mountain lakes in catchments of metamorphic rocks in the European Alps. At Rasass See, the electrical conductivity increased 18-fold. Unexpectedly high nickel concentrations at Rasass See, which exceeded the limit in drinking water by more than 1 order of magnitude, cannot be related to catchment geology.Weattribute these changes in lake water quality to solute release from the ice of an active rock glacier in the catchment as a response to climate warming. Similar processes occurred at the higher elevation lake Schwarzsee ob Sölden, where electrical conductivity has risen 3-fold during the past two decades.

Sediments: Al, Fe, hydroxide precipitation / Kopáček, J., Klementová, S., Norton, S. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Sediments: Al, Fe, hydroxide precipitation

Reference

Kopáček, J., Klementová, S., Norton, S. A. (2005): Photochemical production of ionic and particulate aluminium and iron in lakes. Environmental Science & Technology 39(10): 3656-3662. (Euro-limpacs paper)

Description

Photochemical liberation of allochthonous organically bound aluminum (Al) and iron (Fe) and in-lake hydroxide precipitation are important sources of these metals to lake sediments. Mass budgets of ionic Al and Fe (Ali, Fei), organically bound Al and Fe (Alo, Feo), and particulate Al and Fe (Alp, Fep) were measured for two western Czech Republic forest lakes (Ple šné and Čertovo) in the 2000-2003 hydrological years. The lakes were net sinks of Ali, Alo, and Feo and net sources of Alp and Fep. The average Alo and Feo inputs from terrestrial sources (66-110 and 12-17 mmol m^-2yr^-1, respectively, on a lake area basis) were reduced 45% and 25% in the lakes. Mass budgets of dissolved organic carbon, particulate organic C, and Al species indicated that only a minor part of the observed in-lake retention of Alo could be explained by coagulation and sedimentation of organic matter, or from Ali hydrolysis and formation of Alp. Laboratory experiments with a short-time irradiation (∼300 nm, ∼800 W m^-2) of water from inlets to Ple šné Lake showed the importance of photochemical processes in the liberation of Al and Fe from Alo and Feo. After 12 h of irradiation, Alo and Feo concentrations decreased 54 ± 6% and 70 ± 16%, respectively, compared to those of the dark controls. The photoliberated Alo and Feo increased the Ali and Fei concentrations reciprocally, on a 1:1 mass basis. The subsequent hydrolysis of Ali and Fei in lakes forms insoluble hydroxides, increasing the sediment concentrations of Al and Fe.

Sediments: Al, Fe, hydroxide precipitation / Kopáček, J., Klementova, S., Norton, S. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Sediments: Al, Fe, hydroxide precipitation

Reference

Kopáček, J., Klementova, S., Norton, S. A. (2005): Photochemical production of ionic and particulate aluminium and iron in lakes. Environmental Science & Technology 39(10): 3656-3662.

Description

Photochemical liberation of allochthonous organically bound aluminum (Al) and iron (Fe) and in-lake hydroxide precipitation are important sources of these metals to lake sediments. Mass budgets of ionic Al and Fe (Ali, Fei), organically bound Al and Fe (Alo, Feo), and particulate Al and Fe (Alp, Fep) were measured for two western Czech Republic forest lakes (Ple šné and Čertovo) in the 2000-2003 hydrological years. The lakes were net sinks of Ali, Alo, and Feo and net sources of Alp and Fep. The average Alo and Feo inputs from terrestrial sources (66-110 and 12-17 mmol m^-2 yr^-1, respectively, on a lake area basis) were reduced 45% and 25% in the lakes. Mass budgets of dissolved organic carbon, particulate organic C, and Al species indicated that only a minor part of the observed in-lake retention of Alo could be explained by coagulation and sedimentation of organic matter, or from Ali hydrolysis and formation of Alp. Laboratory experiments with a short-time irradiation (∼300 nm, ∼800 W m^-2) of water from inlets to Ple šné Lake showed the importance of photochemical processes in the liberation of Al and Fe from Alo and Feo. After 12h of irradiation, Alo and Feo concentrations decreased 54 ± 6% and 70 ± 16%, respectively, compared to those of the dark controls. The photoliberated Alo and Feo increased the Ali and Fei concentrations reciprocally, on a 1:1 mass basis. The subsequent hydrolysis of Ali and Fei in lakes forms insoluble hydroxides, increasing the sediment concentrations of Al and Fe.

Thermocline depth / McCormick, M.J. (1990): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Thermocline depth

Reference

McCormick, M.J. (1990): Potential changes in thermal structure and cycle of Lake Michigan due to global warming. Transactions of the American Fisheries Society 119: 183-194.

Description

Earlier onset of stratification, season increases by up to two months. Stronger stratification, less energy for large-scale vertical mixing. No full turnover in most winters leads to permanent thermocline in deeper regions (below shallow seasonal thermocline). Elevated summer and winter heat contents, summer increase less than winter increase.

Thermocline depth, nutrients: depletion and general eutrophication / Schindler, D.W., S.E. Bayley, B.R. Parker, K. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Thermocline depth, nutrients: depletion and general eutrophication

Reference

Schindler, D.W., S.E. Bayley, B.R. Parker, K.G. Beaty, D.R. Cruikshank, E.J. Fee, E.U. Schindler & M.P. Stainton (1996): The effects of climatic warming on the properties of boreal lakes and streams at the Experimental Lakes Area, northwestern Ontario. Limnology and Oceanography 41(5): 1004-1017.

Description

Higher water temperatures, deeper thermoclines, higher alkalinities, higher concentrations of base cations and nitrogen, lower DOC, silica and P. Increased phytoplankton biomass. Habitats for cold stenotherms reduced slightly. Increased water retention.

Water temperature / Livingstone, D.M., Lotter, A.F., Kettle, H. ( ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Water temperature

Reference

Livingstone, D.M., Lotter, A.F., Kettle, H. (2005): Altitude-dependent differences in the primary physical response of mountain lakes to climatic forcing. Limnology & Oceanography 50(4): 1313-1325.

Description

Simultaneous hourly measurements of lake surface water temperature (LSWT) during summer and early autumn 2000 in 29 lakes in the Swiss Alps revealed the presence of two altitudinally distinct thermal regimes. The threshold separating the low-altitude from the high-altitude regime was located at ˜2,000 m above sea level during early summer 2000 but rose as summer progressed. Within the low-altitude regime, LSWTs are strongly related to altitude and surface air temperature. On crossing the threshold to the high-altitude regime, the LSWT lapse rate increases sharply, but the relationship of LSWT to both altitude and air temperature weakens considerably. A difference in the response of low-altitude and high-altitude mountain lakes to climatic forcing in early summer may have implications for climate change studies in which mountain lakes are employed either for paleoclimate reconstructions or as sensitive indicators of current climate change. Any long-term temporal change in the threshold altitude would imply that lakes close to the threshold may not always have been located in the same thermal regime, with consequences for paleolimnological climate reconstructions. Predictions of the effects of future climate warming on high-altitude mountain lakes may have to take into account the possibility of a concomitant rise in the threshold altitude.

Early warning indicators

Clear water timing / Straile, D. (2000): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Clear water timing

Reference

Straile, D. (2000): Meteorological forcing of plankton dynamics in a large and deep continental European lake. Oecologia 122: 44-50.

Description

Higher spring water temperature. Higher, earlier population growth rates of Daphnia (May), earlier summer decline (July). Earlier phytoplankton suppression. Earlier, longer-lasting clear water phase.

Clear water timing / Straile, D. (2002): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Clear water timing

Reference

Straile, D. (2002): North Atlantic Oscillation synchronizes food-web interactions in central European lakes. Proceedings of the Royal Society of London 269: 391-395.

Description

Ice cover timing / Weyhenmeyer, G.A., M. Meili & D.M. Living ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Weyhenmeyer, G.A., M. Meili & D.M. Livingstone (2004): Non-linear response of ice-breakup. Geophysical Research Letters 31(7): 1-4.

Description

Ice cover timing / Johnson, S.L. & H.G. Stefan (2006): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Johnson, S.L. & H.G. Stefan (2006): Indicators of climate warming in Minnesota: Lake ice covers and snowmelt runoff. Climatic Change 75(4): 421-453.

Description

Ice cover timing / Marszelewski, W. & R. Skowron (2006): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Description

Stratification characteristics / Straile, D., K. Jöhnk & H. Rossknech ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Stratification characteristics

Reference

Straile, D., K. Jöhnk & H. Rossknecht (2003): Complex effects of winter warming on the physicochemical characteristics of a deep lake. Limnology and Oceanography 48(4): 1432-1438.

Description

Stratification characteristics / DeStasio, B.T., D.K. Hill, J.M. Kleinhans, N. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Stratification characteristics

Reference

Description

Thermal structure / Jones, I., George, G. & C. Reynolds (2005 ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Thermal structure

Reference

Jones, I., George, G. & C. Reynolds (2005): Quantifying effects of phytoplankton on the heat budgets of two large limnetic enclosures. Freshwater Biology 50(7): 1239-1247.

Description

Water temperature / Livingstone, D.M., Padisak, J. (2007): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Water temperature

Reference

Livingstone, D.M., Padisak, J. (2007): Large-scale coherence in the response of lake surface water temperatures to synoptic-scale climate forcing during summer. Limnology & Oceanography 52(2): 896-902.

Description

Daily mean lake surface-water temperatures (LSWTs) measured in Swiss Alpine lakes in summer and early autumn 2000 were compared with LSWTs measured simultaneously in Lake Balaton, Hungary, 750 km to the east. The Swiss lakes are small (0.0043-0.46 km²), predominantly oligotrophic, and are located in a mountainous environment, some at altitudes >2,000 m above sea level, whereas Lake Balaton is a large (593 km²), shallow, mesotrophic lake situated in the much lower-lying Carpathian Basin. Despite the large distance separating the two regions and the extreme differences in character between the lakes, the LSWTs in Switzerland and Hungary exhibited a coherent response to synoptic-scale meteorological forcing, expressed in terms of exponentially smoothed air temperature, which can be viewed as a causal forcing variable in its own right and as a proxy for other forcing variables with which it is correlated. The coherent response of LSWT in very dissimilar lakes in two different geographical regions of Europe demonstrates that large-scale climatic forcing on synoptic timescales is much more important for lakes than previously thought. This appears to be particularly true for low-altitude lakes, whereas lakes at higher altitudes exhibit more heterogeneity in their response.

Water temperature, Ice cover timing / š porka, F., Livingstone, D.M., Stuchlik ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Water temperature, Ice cover timing

Reference

š porka, F., Livingstone, D.M., Stuchlik, E., Turek, J., Galas, J. (2006): Water temperatures and ice cover in lakes of the Tatra Mountains. Biologia Bratislava, 61 Supplement 18 61: 77-90.

Description

In 2000 and 2001, miniature thermistors with integrated data loggers were employed to measure lake surface water temperatures (LSWTs) and temperature profiles in high-altitude mountain lakes lying between 1580 and 2145 m a.s.l. on both the Slovak and Polish sides of the Tatra Mountains. This allowed the annual cycle of water temperatures and ice cover in these lakes to be described quantitatively, and their dependence on lake altitude above sea level to be investigated. LSWTs in the Tatra Mountains are found to decrease approximately linearly with increasing altitude from late spring to autumn. LSWT in summer can be modelled well in terms of exponentially smoothed ambient air temperature. Although the timing of ice-off is dependent on altitude, the timing of ice-on is not; the dependence of the duration of ice cover on altitude is therefore wholly due to the altitudinal dependence of the timing of ice-off. The temperature profile measurements allow quantitative characterization of summer and winter stagnation, and spring and autumn turnover.

Water temperature, mixis timing/type change / Strub, P.T., T. Powell & C.R. Goldman (19 ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Water temperature, mixis timing/type change

Reference

Strub, P.T., T. Powell & C.R. Goldman (1985): Climatic forcing: Effects of El Niño on a small, temperate lake. Science 227: 55-57.

Description

Earlier/later mixing, anomalously large/small heat storage (max heat content August) below mixed layer.

Water temperature, stratification characteristics / McCormick, M.J. (1990): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Water temperature, stratification characteristics

Reference

McCormick, M.J. (1990): Potential changes in thermal structure and cycle of Lake Michigan due to global warming. Transactions of the American Fisheries Society 119: 183-194.

Description

Water temperature, stratification characteristics / Ferguson, C., Scott, M., Bowman, A., Carvalho ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Water temperature, stratification characteristics

Reference

Ferguson, C., Scott, M., Bowman, A., Carvalho, L. (2007): Model comparison for a complex ecological system. Journal of the Royal Statistical Society Series A 170(3): 691-711.

Description

The ecological consequences of climate change and its interaction with other environmental pressures, such as nutrient pollution, are little understood. For freshwater ecosystems, knowledge of these combined effects is required for water resource management and in particular for successful implementation of the European Community Water Framework Directive 2000, which requires that all surface waters should be at, or above, "good status" by 2016. Statistical analysis of detailed long-term environmental data sets can be used to unravel these combined effects and Loch Leven (Scotland) has one of the largest and most extensive of such data sets. The system has been routinely monitored since 1967 and over this period there has been evidence of climate change and a period of eutrophication and recovery at the loch. Transfer functions, additive models and varying-coefficient models are used to explore the effects of these influences on the complex ecological system at Loch Leven.

Food webs

Most affected fish: autumn spawners / Nyberg, P., Bergstrand, E., Degerman, E. & ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Food webs
Indicator	Most affected fish: autumn spawners

Reference

Nyberg, P., Bergstrand, E., Degerman, E. & O. Enderlein (2001): Recruitment of pelagic fish in an unstable climate: studies in Swedens four largest lakes. Ambio 30(8): 559-564.

Description

Early ice break-up. Higher spring-/summer water temperatures. Coregonus albula (autumn-spawner): hatching shortly after ice break-up and warm spring temperatures beneficial in oligotrophic lakes with few predatory species. Early ice break-up: mismatch of hatching and spring development of zooplankton; warm spring temperatures: (in eutrophic lakes) higher predation by warm-water predatory species. Effects result in weak year-classes. Osmerus eperlanus, Stizostedion lucioperca positively correlated to summer (Aug/Sep) temperatures. Independent of spring temperatures, because adapts as spring-spawners to prevailing prey conditions. Comment: Autumn spawners may have difficulties in adapting to global warming; life history can explain large variations observed in year-class strength between years.

Phytoplankton maximum, blooms timing, population timing, growth, maximum / De Senerpont Domis, L.N., W.M. Mooij, S, H&uu ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Food webs
Indicator	Phytoplankton maximum, blooms timing, population timing, growth, maximum

Reference

Description

Uncoupling food chains, timing mismatch, loss of top predators / Straile, D. & W. Geller (1998): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Food webs
Indicator	Uncoupling food chains, timing mismatch, loss of top predators

Reference

Straile, D. & W. Geller (1998): The response of Daphnia to changes in trophic status and weather patterns: a case study from Lake Constance. ICES Journal of Marine Science 55: 775-782.

Description

Earlier stratification. Higher spring water temperature. No light limitation. Phytoplankton: Higher productivity. Higher and earlier Daphnia biomass (in spite of lower trophy). Hypothesis: mismatch in timing of fish larvae feeding on earlier Daphnia maximum? Hypothesis: Amphibians: food-web changes, changes in trophic interactions.

Uncoupling food chains, timing mismatch, loss of top predators / Petchey, O.L., P.T. McPhearson, T.M. Casey &a ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Food webs
Indicator	Uncoupling food chains, timing mismatch, loss of top predators

Reference

Petchey, O.L., P.T. McPhearson, T.M. Casey & P.J. Morin (1999): Environmental warming alters food-web structure and ecosystem function. Nature 402: 69-72.

Description

Disproportionate loss of top predators and herbivores, dominance of autotrophs and bacterivores. Zoogeographical boundaries could move 500-600 km north. Growth and production increases for fish in colder than optimum habitats. Decrease of growth and production for fish at or above thermal optimum.

Uncoupling food chains, timing mismatch, loss of top predators, lake morphometry (especially depth) / De Senerpont Domis, L.N., W.M. Mooij, S, H&uu ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Food webs
Indicator	Uncoupling food chains, timing mismatch, loss of top predators, lake morphometry (especially depth)

Reference

Description

Water temperature; algae: food-web changes/trophic interactions; zooplankton: food-web changes/trophic interactions, productivity, biomass / Straile, D. (2000): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Food webs
Indicator	Water temperature; algae: food-web changes/trophic interactions; zooplankton: food-web changes/trophic interactions, productivity, biomass

Changed heat budget. Change of state between dimictic and warm monomictic. Shifts in phytoplanktonand zooplankton populations dependent on change of alpine lakes being below or above timberline.

Cold water species: changed distribution/extinction, bacterioplankton / Adrian, R. & R. Deneke (1996): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Cold water species: changed distribution/extinction, bacterioplankton

Reference

Adrian, R. & R. Deneke (1996): Possible impact of mild winters on zooplankton succession in eutrophic lakes of the Atlantic European area. Freshwater Biology 36: 757-770.

Description

April water temperature increase by 2.58 °C within 21 years. Shift from a dominance of diatoms and cryptophytes to cyanobacteria. Shift from dominance of large-bodied Daphnia galeata to smaller D. cucullata. Decrease in abundance of Cyclops kolensis. Increase in C. vivinus, which is also present in winter (without diapause). The temperature effect is species specific, not functional group specific.

Cold water species: changed distribution/extinction, bacterioplankton / Schindler, D.W., S.E. Bayley, B.R. Parker, K. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Cold water species: changed distribution/extinction, bacterioplankton

Reference

Description

Diversity / Schindler, D.W., K.G. Beaty, E.J. Fee, D.R. C ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Diversity

Reference

Schindler, D.W., K.G. Beaty, E.J. Fee, D.R. Cruikshank, E.R. DeBruyn, D.L. Findlay, G.A. Linsey, J.A. Shearer, M.P. Stainton & M.A. Turner (1990): Effects of Climatic warming on lakes of the Central Boreal Forest. Science 250: 967-970.

Description

Thermocline deepens. Higher residence time. Ice cover decreased by 3 weeks (autumn onset without change, earlier thawing). Increased water temperature. TDN, SO₄, Ca increase; (also caused by burned forests). N to P value from 25:1 to 50:1 (also caused by burned forests).Phytoplankton diversity increased, no changes in dominant species, increased biomass.

Makrophytes: community, distribution, production; phytoplankton: biomass, diversity, community composition / Turner, M.A., Huebert, D.B., Findlay, D.L., H ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Makrophytes: community, distribution, production; phytoplankton: biomass, diversity, community composition

Reference

Description

Phytoplankton community composition / Anneville, O., S. Gammeter & D. Straile ( ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Phytoplankton community composition

Reference

Description

Phytoplankton growth rates / Doyle, S.A., J.E. Saros & C.E. Williamson ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Phytoplankton growth rates

Reference

Description

Phytoplankton maximum, blooms timing / Straile, D. (2000): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Straile, D. (2000): Meteorological forcing of plankton dynamics in a large and deep continental European lake. Oecologia 122: 44-50.

Description

Higher spring water temperature. Higher, earlier population growth rates of Daphnia (May), earlier summer decline (July). Earlier phytoplankton suppression. Earlier, longer-lasting clear water phase.

Phytoplankton maximum, blooms timing / Weyhenemeyer, G.A., T. Bleckner & K. Pett ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Weyhenemeyer, G.A., T. Bleckner & K. Pettersson (1999): Changes of the plankton spring outburst related to the North Atlantic Oscillation. Limnology and Oceanography 44(7): 1788-1792.

Description

North Atlantic Oscillation: long-term variability strongly related to changes in timing and composition of phytoplankton spring peaks. Regional parameters as ice-breakup and nutrient concentrations no stronger relation than NAO.

Secondary production - fish

Distribution range change (thermal habitat) / Carpenter, S.R., Fisher, S.G., Grimm, N.B. &a ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Distribution range change (thermal habitat)

Reference

Carpenter, S.R., Fisher, S.G., Grimm, N.B. & J.F. Kitchell (1992): Global change and freshwater ecosystems. Annual Review of Ecology and Systematics 23: 119-139.

Description

Review on effects of climate warming on freshwater ecosystems, concerning productiviy of phytoplankton, increase in zooplankton and invertebrates. Also changed fish distribution due to changed thermal limits.

Distribution range change (thermal habitat) / Jansen, W. & R.H. Hesslein (2004): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Distribution range change (thermal habitat)

Reference

Jansen, W. & R.H. Hesslein (2004): Potential effects of climate warming on fish habitats in temperate zone lakes with special reference to Lake 239 of the experimental lakes area (ELA), north-western Ontario. Environmental Biology of Fishes 70: 1-22.

Description

Salvelinus namaycush thermal habitat progressively reduced, disappeared in littoral areas in spring and summer. Perca flavescens thermal habitat increase for temperature rise up to 4 °C, disappeared for 9 °C increase.

Distribution range change (thermal habitat) / Mackenzie-Grieve, J.L. & J.R. Post (2006) ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Distribution range change (thermal habitat)

Reference

Mackenzie-Grieve, J.L. & J.R. Post (2006): Projected impacts of climate warming on production of lake trout (Salvelinus namaycush) in southern Yukon lakes. Canadian Journal of Fisheries and Aquatic Sciences 63(4): 788-797.

Description

Warming: overall decrease in availability of optimal thermal habitat and in lake trout potential harvest, although considerable lake-specific variation in direction and magnitude of change exists. For southern Yukon lakes overall, 2 °, 4& deg;, and 6 ° C increases in mean annual air temperature lead to 12%, 35%, and 40% decreases in thermal habitat volume, respectively, and 8%, 19%, and 23% reductions in potential harvest, respectively.

Distribution range change (thermal habitat), growth, production, survival change / Petchey, O.L., P.T. McPhearson, T.M. Casey &a ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Distribution range change (thermal habitat), growth, production, survival change

Reference

Petchey, O.L., P.T. McPhearson, T.M. Casey & P.J. Morin (1999): Environmental warming alters food-web structure and ecosystem function. Nature 402: 69-72.

Description

Fish distribution, richness, abundance change / Jeppesen, E., Pekcan-Hekim, Z., Lauridsen, T. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Fish distribution, richness, abundance change

Reference

Jeppesen, E., Pekcan-Hekim, Z., Lauridsen, T. L., SØndergaard, M., Jensen, J. P. (2006): Habitat distribution of fish in late summer: changes along a nutrient gradient in Danish lakes. Ecology of Freshwater Fish 15(2): 180-190. (Euro-limpacs paper)

Description

The horizontal distribution of fish in lakes varies with species, age, predation risk, vegetation coverage and water clarity. Although sporadic data are available for specific lakes, little is known about how habitat distribution generally changes along a gradient in nutrients and clarity. Here we analyse littoral and pelagic fish catch data for 34 Danish lakes (covering 94 lake years) with contrasting total phosphorus (TP) concentrations and mean depth levels (but mainly eutrophic and shallow). Electrofishing was conducted during day along the shore or along the edge of the reed belt if such existed. Gill nets were set overnight for 18 h in open water. We calculated a littoral proportion as: LITPRO = (100 × number caught by electrofishing in the near-shore area)/(number caught by electrofishing in the near-shore area and nets in the open water). At all summer TP concentrations LITPRO was high for several `littoral' species such as gudgeon (Gobio gobio), rudd (Scardinius erythrophtalmus) and pike (Esox lucius) and low for more typical pelagic species like pikeperch (Sander lucioperca), ruffe (Gymnocephalus cernuus) and smelt (Osmerus eperlanus). However, for many of these species including the dominant roach (Rutilus rutilus) and perch (Perca fluviatilis) LITPRO increased with TP or lake water chlorophyll a (CHLA) for fish >10 cm, suggesting a more littoral distribution with increasing turbidity. Exceptions are pikeperch and bream (Abramis brama). For bream, LITPRO increased significantly with mean lake depth only. For fish ≤10 cm LITPRO showed only a weak relationship to TP, CHLA or depth. In accordance with the TP-dependent distribution, major changes occurred in the fish community structure during the monitoring period following nutrient loading reduction. A comparison of LITPRO from the first part of the monitoring period (1989?1993) with a subsequent period (1997?2003) for four abundant species showed a significant decline in LITPRO over time for large- and small-sized roach and perch and large rudd. This suggests a fast response in fish distribution to improved water quality. It further demonstrates that fish monitoring in lakes should cover both littoral and pelagic habitats to describe the recovery process.

Secondary production - fish

Fish distribution, richness, abundance change / Jeppesen, E., Pekcan-Hekim, Z., Lauridsen, T. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Fish distribution, richness, abundance change

Emphasis on existing stress on different ecosystems in interaction with potential climate change. Hydologic changes together with temperature changes will probably tend to favour invasive species over rare and threatened species.

Species richness change / Minns, C.K. & J.E. Moore (1995): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Species richness change

Reference

Minns, C.K. & J.E. Moore (1995): Factors limiting the distributions of Ontarios freshwater fishes: the role of climate and other variables, and the potential impacts of climate change. Canadian Special Publication of Fisheries and Aquatic Sciences 121: 137-160.

Description

Total species richness strongly related to air temperature. For 33 out of 61 fish species presence-absence pattern related to temperature, besides geographic factors.

Thermal habitat change, cold stenotherms + rare species reduced / Stefan, H.G., M. Hondzo, X. Fang, J.G. Eaton ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Thermal habitat change, cold stenotherms + rare species reduced

Reference

Description

Thermal habitat change, cold stenotherms and rare species reduced, thermal stress -> increased diseases and mortality / DeStasio, B.T., D.K. Hill, J.M. Kleinhans, N. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Thermal habitat change, cold stenotherms and rare species reduced, thermal stress -> increased diseases and mortality

Reference

Description

Secondary production - zooplankton

Biomass / Shuter, B.J. & K.K. Ing (1997): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Biomass

Reference

Shuter, B.J. & K.K. Ing (1997): Factors affecting the production of zooplankton in lakes. Canadian Journal of Fisheries and Aquatic Sciences 54(2): 359-377.

Description

DNA damage by radiation - temp induced / MacFadyen, E.J., C.E. Williamson, G. Grad, M. ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	DNA damage by radiation - temp induced

Reference

MacFadyen, E.J., C.E. Williamson, G. Grad, M. Lowery, W.H. Jeffrey & D.L. Mitchell (2004): Molecular response to climate change: temperature dependence of UV-induced DNA damage and repair in freshwater crustacean Daphnia pulicaria. Global Change Biology 10: 408-416.

Description

Molecular response to climate change: temperature dependence of UV-induced DNA damage and repair in freshwater crustacean Daphnia pulicaria: DNA damage, DNA repair, photoreactivation.

Invertebrate development, survival / Persaud, A.D. & N.D. Yan (2005): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Invertebrate development, survival

Reference

Persaud, A.D. & N.D. Yan (2005): Developmental differences and a test for reciprocity in the tolerance of Chaoborus punctipennis larvae to ultraviolet radiation. Canadian Journal of Fisheries and Aquatic Sciences 62(3): 483-491.

Description

UVR tolerance increased with larval age. Third and late fourth instar LD50 (median lethal dose) ranged from 52.3 to 62.2 J center dot cm^-2 and from 82.4 to 119.6 J center dot cm^-2, respectively, among the four depths. Reciprocity held for UVR exposure down to 5.0 m, i.e., toxicity was independent of dose rate. At any given depth, the LT50 (median lethal time) increased with larval stage, but even at 5.0 m, third and late fourth instars died in less than 10 and 20 h, respectively, under sunny skies. These results suggest that Chaoborus abundance and distribution might be affected by UVR, especially in clear lakes. If UVR levels continue to increase in some lakes because of stratospheric ozone loss and climate change, we predict that UVR damage to Chaoborus will increase in the future, thereby affecting trophic interactions in temperate freshwater food webs.

Invertebrates biomass, diversity, composition change / Burgmer, T., H. Hillebrand & M. Pfenninge ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Invertebrates biomass, diversity, composition change

Reference

Burgmer, T., H. Hillebrand & M. Pfenninger (2007): Effects of climate-driven temperature changes on the diversity of freshwater macroinvertebrates. Oecologia 151(1): 93-103.

Description

Secondary production - zooplankton

Population timing, growth / Van Doorslaer, W., Stoks, R., Jeppesen, E., D ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth

Reference

Van Doorslaer, W., Stoks, R., Jeppesen, E., De Meester, L. (2007): Adaptive responses to simulated global warming in Simocephalus vetulus: a mesocosm study. Global Change Biology 13: 878-886.

Description

Although several studies suggest the occurrence of microevolutionary responses that may allow local persistence of populations under global warming, rigorous experimental proof is lacking. Here, we combined the realism and rigid, replicated experimental design of a large-scale mesocosm study where populations of the zooplankter Simocephalus vetulus were exposed for 1 year to different global warming scenarios with a life table experiment under laboratory conditions at three temperatures that eliminated onfounding, nongenetic factors. Our results provide solid proof for a rapid icroevolutionary response to global warming in both survival and the subcomponents of individual performance (age at reproduction and number of offspring), which may allow populations of S. vetulus to persist locally under predicted scenarios of global warming. Such microevolutionary responses may buffer changes in community structure under global warming and help explain the outcome of previous mesocosm studies finding only marginal effects of global warming at the community level.

Secondary production - zooplankton

Population timing, growth, maximum / Straile, D. (2000): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum

Reference

Straile, D. (2000): Meteorological forcing of plankton dynamics in a large and deep continental European lake. Oecologia 122: 44-50.

Description

Higher spring water temperature. Higher, earlier population growth rates of Daphnia (May), earlier summer decline (July). Earlier phytoplankton suppression. Earlier, longer-lasting clear water phase.

Population timing, growth, maximum / Straile, D. (2002): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum

Reference

Straile, D. (2002): North Atlantic Oscillation synchronizes food-web interactions in central European lakes. Proceedings of the Royal Society of London 269: 391-395.

Description

Population timing, growth, maximum, zooplankton biomass, diversity, composition change / Straile, D. & W. Geller (1998): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum, zooplankton biomass, diversity, composition change

Reference

Straile, D. & W. Geller (1998): The response of Daphnia to changes in trophic status and weather patterns: a case study from Lake Constance. ICES Journal of Marine Science 55: 775-782.

Description

Zooplankton biomass, diversity, composition change, smaller-bodied zooplankton / Adrian, R. & R. Deneke (1996): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change, smaller-bodied zooplankton

Reference

Adrian, R. & R. Deneke (1996): Possible impact of mild winters on zooplankton succession in eutrophic lakes of the Atlantic European area. Freshwater Biology 36: 757-770.

Description

Susceptibility ecosystem

Review (anthropogenic stressors) / Søndergaard, M., Jeppesen, E. (2007): ...

Climate Region	temperate
Ecosystem type	lakes in general
Parameter group	Susceptibility ecosystem
Indicator	Review (anthropogenic stressors)

Reference

Søndergaard, M., Jeppesen, E. (2007): Editorial overview: anthroprogenic impacts on freshwater ecosystems and approaches to restoration.Journal of Applied Ecology 44: 1089-1094.

Description

Freshwater ecosystems have long been affected by numerous types of human interventions that have a negative impact on their water quality and ecological state. Fortunately, in most western countries the input of sewage to freshwater systems has been reduced, but hydromorphological alterations, eutrophication-related turbidity and loss of biodiversity remain major problems in many parts of the world. Such impacts prevent the achievement of a high or good ecological state, as defined by the European Water Framework Directive (WFD) or other standards. This paper synthesizes and links the findings presented in the seven papers of this special profile, focusing on the effects of anthropogenic stressors on freshwater ecosystems and on how to maintain and restore ecological quality. The papers cover a broad range of research areas and methods, but are all centred on the relationship between dispersal barriers, the connectivity of waterways and the restoration of rivers and lakes. The construction of dams and reservoirs disturbs the natural functioning of many streams and rivers and shore-line development around lakes may reduce habitat complexity. New methods demonstrate how reservoirs may have a severe impact on the distribution and connectivity of fish populations, and new techniques illustrate the potential of using graph theory and connectivity models to illustrate the ecological implications. Hydromorphologically degraded rivers and streams can be restored by addition of wood debris, but "passive" restoration via natural wood recruitment may be preferable. The most cost-effective way to restore streams may also include information campaigns to farmers on best management practices. Removal of zooplanktivorous fish often has marked positive effects on trophic structure in lakes, but there is a tendency to return to turbid conditions after 8-10 years or less unless fish removal is repeated. Development of new methods, as well as derivation of more general conclusions from reviewing the effects of previous restoration efforts, are crucial to achieve progress in applied freshwater research. The papers contained in this Special Profile contribute on both counts, as well as illustrating the importance of well-designed research projects and monitoring programmes to record the effects of the interventions. Such efforts are vital if we are to improve our knowledge of freshwater systems and to elaborate the best and most cost-effective recommendations. They may also help in achieving a good ecological state or potential in water bodies by 2015, as demanded by the European WFD.

Deep

Abiotic indicators

Acidification: deposition / Dillon, P.J., B.L. Skjelkvale, K.M. Somers &a ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Acidification: deposition

Reference

Description

Nutrients: depletion / Adrian, R., Deneke, R., Mischke, U., Stellmac ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Nutrients: depletion

Reference

Adrian, R., Deneke, R., Mischke, U., Stellmacher, R. & P. Lederer (1995): A long-term study of the Heiligensee (1975-1992). Evidence for effects of climatic change on the dynamics of eutrophied lake ecosystems. Archiv für Hydrobiologie 133(3): 315-337.

Description

Abiotic indicators/Early Warning Indicators: 1-3 weeks earlier onset of stratification. Absence of longer ice cover, which leads to changed light conditions. Oxygen: Rising trend. Rising P content in the hypolimnion. Early SRSi limitation. Shift in species dominance phyotplankton.

BacterioplanktonRising winter temperature. 1-3 weeks earlier onset of stratification. Absence of longer ice cover, changed light conditions. Oxygen: Rising trend. Rising P content in the hypolimnion. Early SRSi limitation. Shift in species dominance from cryptophytes (Rhodomonas minuta var. planctonica, Cryptomonas erosa) and green algae (Monoraphidium griffithii, Pandorina morum, Coelastrum microporum to cyanophytes: Lyngbya limnetica, Limnothrix redekei, Anabaena flos-aquae, Planktothrix agardhii. à effect on oxygen. No clear-water phase. Shift in seasonal abundances: Cyanophytes increased in winter. April: Diatoms disappeared (SRSi depletion), replaced by cyanophytes (spring bloom). Summer species occurred early in year (May/Jun), cryptophytes decreased overall. A dominance of Stephanodiscus parvus, Cyclotella compta, Synedra acus was inhibited by SRSi limitation in April. Algal blooms in autumn. Colder winters: cryptophytes (Rhodomonas minuta var. planctonica, Cryptomonas erosa); After clear water phase in June: green algae. Warmer winters: Shift to dominance of cyanophytes (Jan-Jun)(Lyngbya limnetica, Limnothrix redekel, Anabaena flos-aquae, Planktothrix agardhii). Increase in algal biomass (winter/spring). Hydro-chemistry: oxygen.

Bacterioplankton: Rising winter temperature. 1-3 weeks earlier onset of stratification. Absence of longer ice cover, changed light conditions. Oxygen: Rising trend. Rising P content in the hypolimnion. Early SRSi limitation. Shift in species dominance from cryptophytes (Rhodomonas minuta var. planctonica, Cryptomonas erosa) and green algae (Monoraphidium griffithii, Pandorina morum, Coelastrum microporum to cyanophytes: Lyngbya limnetica, Limnothrix redekei, Anabaena flos-aquae, Planktothrix agardhii. effect on oxygen. No clear-water phase. Shift in seasonal abundances: Cyanophytes increased in winter. April: Diatoms disappeared (SRSi depletion), replaced by cyanophytes (spring bloom). Summer species occurred early in year (May/Jun), cryptophytes decreased overall. A dominance of Stephanodiscus parvus, Cyclotella compta, Synedra acus was inhibited by SRSi limitation in April. Algal blooms in autumn. Colder winters: cryptophytes (Rhodomonas minuta var. planctonica, Cryptomonas erosa); After clear water phase in June: green algae. Warmer winters: Shift to dominance of cyanophytes (Jan-Jun)(Lyngbya limnetica, Limnothrix redekel, Anabaena flos-aquae, Planktothrix agardhii). Increase in algal biomass (winter/spring). Hydro-chemistry: oxygen.

Nutrients: eutrophication total P / Nicholls, K.H. (1999): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Nutrients: eutrophication total P

Reference

Nicholls, K.H. (1999): Effects of temperature and other factors on summer phosphorus in the inner Bay of Quinte, Lake Ontario: implications for climate warming. Journal of Great Lakes Research 25(2): 250-262.

Description

The strong influence of temperature on summer TP concentrations in the inner Bay of Quinte (where water and air temperatures are nearly I:I) has important implications for climate change. Summer average water temperature increases of 3 to 4 °C are within the range of those predicted by several general circulation models (GCMs with 2x CO₂ end points). The multiple regression model suggests that summer TP concentrations could about double with a water temperature rise of 3 to 4 °C above the 1990 to 1994 mean. This would effectively "undo" many benefits achieved to date in point-source TP loading control.

Nutrients: import (wetlands) reduced / Hillbricht-Ilkowska, A. (2002): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Nutrients: import (wetlands) reduced

Reference

Hillbricht-Ilkowska, A. (2002): Nutrient loading and retention in lakes of the Jorka river system (Masurian lakeland, Poland): Seasonal and long-term variation. Polish Journal of Ecology 50(4): 459-474.

Description

Less precipitation in total in the 1990s; melting of ice and snow cover and thawing of soil in spring determines annual N/P loading ("pulsed system"). Decrease in groundwater level. Lower discharge, lower water volume. Higher residence time. P, N loading to lakes from external sources reduced; N loading more reduced than P, approaching N:P ratio of 20:1. Decline of N / P retention, outflow export may be higher than inflow loading in lower situated lakes with a river as main source of nutrient loading. Consequently, no tendency of advancing eutrophication between 1970s and 1990s.

Nutrients: minerlisation, release (sediment) / Goedkoop, W. & E. Törnblom (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Nutrients: minerlisation, release (sediment)

Reference

Goedkoop, W. & E. Törnblom (1996): Seasonal fluctuations in benthic bacterial production and abundance in Lake Erken: The significance of major abiotic factors and sedimentation events. Ergebnisse der Limnologie 48: 197-205.

Description

Shorter ice-cover period. Higher spring temperatures. Enhanced remineralisation. More nutrients (enhanced bacterial activity). Higher summer phytoplankton and zooplankton biomass.

Nutrients: minerlisation, release (sediment), eutrophication general / Pettersson, K. & K. Grust (2002): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Nutrients: minerlisation, release (sediment), eutrophication general

Reference

Pettersson, K. & K. Grust (2002): Seasonality of nutrients in Lake Erken – effects of weather conditions. Verhandlungen der Internationalen Vereinigung für Theoretische und Angewandte Limnologie 28: 731-734.

Description

Shorter ice-cover period, earlier ice-breakup. Changed light conditions, longer mixing processes. Higher hypolimnetic temperature. Hydro-chemistry: eutrophying substances (e.g. DOC S N P). P/N release from sediment higher, entrainment earlier.

Oxygen depletion / Jankowski, T., D.M. Livingstone, H. Bühr ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Oxygen depletion

Reference

Jankowski, T., D.M. Livingstone, H. Bührer, R. Forster & P. Niederhauser (2006): Consequences of the 2003 European heat wave for lake temperature profiles, thermal stability, and hypolimnetic oxygen depletion: Implications for a warmer world. Limnology and Oceanography 51(2): 815-819.

Description

Water temp and oxygen content: half a century of lake data from two lakes in Switzerland. In both lakes, surface temperature and thermal stability in summer 2003 were the highest ever recorded, exceeding the long-term mean by more than 2.5 standard deviations. The extremely high degree of thermal stability resulted in extraordinarily strong hypolimnetic oxygen depletion. These results are consistent with the predictions of the simulation models. Additionally, the results indicate that climatic warming will increase the risk of occurrence of deep-water anoxia, thus counteracting long-term efforts that have been undertaken to ameliorate the effects of anthropogenic eutrophication.

Seasonality, eutrophication general / Pettersson, K., K. Grust, G. Weyhenmeyer & ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Seasonality, eutrophication general

Reference

Pettersson, K., K. Grust, G. Weyhenmeyer & T. Blenckner (2003): Seasonality of chlorophyll and nutrients in Lake Erken – effects of weather conditions. Hydrobiologia 506-509: 75-81.

Description

Shorter ice-cover period (by 7 weeks), earlier ice-breakup (4 weeks), thinner ice and snow cover. Better light conditions during winter. Yearly average rise of hypolimnetic water temperature by 0.7 °C (significant for winter and spring). Warm period: nitrate concentrations lower in late winter, elevated phosphate and ammonium in the hypolimnion in summer. Phytoplankton growth in winter below ice cover, doubling of chlorophyll a levels.

Water temperature / Livingstone, D.M. (1993): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Water temperature

The start of the clear-water stage (CWS) was correlated with winter temperatures. It started 5.8 days earlier per degree warming after warm winters (mean January-March temperature >= 2.5 °C) compared to cold winters (mean temperature < 2.5 °C). However, the end of the CWS remained relatively constant. Predation by L. kindtii and YOY percids on D. galeata started distinctly earlier, i.e. by 13.0 and 6.5 days per degree warming, respectively, in years when the average May temperature was high (>= 14 °C) compared to years when it was low (< 14 °C). Significant reductions of Daphnia abundance in midsummer occurred only in years in which the mean May temperature exceeded 14 °C. This temperature regime resulted in a match of over-exploitation of food resources by Daphnia during the CWS and strong predation by YOY percids and L. kindtii. Consumptive mortality increased at higher rates with a rise in temperature than net recruitment, resulting in lower Daphnia densities at the end of the CWS. Our data suggest that even low warming by 1.7 °C during a short, but critical seasonal period, resulting in the coincidence of two or more factors adversely affecting a keystone species, such as Daphnia, may induce changes in whole lake food webs and thus alter entire ecosystems.

Ice cover timing / Goedkoop, W. & E. Törnblom (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Description

Shorter ice-cover period. Higher spring temperatures. Enhanced remineralisation. More nutrients (enhanced bacterial activity). Higher summer phytoplankton and zooplankton biomass.

Ice cover timing / Pettersson, K., K. Grust, G. Weyhenmeyer & ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Pettersson, K., K. Grust, G. Weyhenmeyer & T. Blenckner (2003): Seasonality of chlorophyll and nutrients in Lake Erken – effects of weather conditions. Hydrobiologia 506-509: 75-81.

Description

Ice cover timing / Weyhenmeyer, G.A., M. Meili & D.M. Living ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Weyhenmeyer, G.A., M. Meili & D.M. Livingstone (2004): Non-linear response of ice-breakup. Geophysical Research Letters 31(7): 1-4.

Description

Ice cover timing / Johnson, S.L. & H.G. Stefan (2006): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Johnson, S.L. & H.G. Stefan (2006): Indicators of climate warming in Minnesota: Lake ice covers and snowmelt runoff. Climatic Change 75(4): 421-453.

Description

Ice cover timing / Marszelewski, W. & R. Skowron (2006): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Ice cover timing

Reference

Description

Ice cover timing, climatic memory hypolimnion, mixis timing/type change / Pettersson, K. & K. Grust (2002): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Ice cover timing, climatic memory hypolimnion, mixis timing/type change

Reference

Description

Mixis timing/type change, clear water timing / Chen, C.Y. & C.L. Folt (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Mixis timing/type change, clear water timing

Reference

Chen, C.Y. & C.L. Folt (1996): Consequences of fall warming for zooplankton overwintering success. Limnology and Oceanography 41: 1077-1086.

Description

Mixis timing/type change, clear water timing / Müller-Navarra, D.C., S. Güss & ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Mixis timing/type change, clear water timing

Reference

Müller-Navarra, D.C., S. Güss & H. von Storch (1997): Interannual variability of seasonal succession events in a temperate lake and its relation to temperature variability. Global Change Biology 3: 429-438.

Description

Spring temperature increase (Jan to May). Change from dimictic to warm monomictic. Less intense ice cover. Spring temperature increase (lake mean temperature). Earlier phytoplankton spring maximum, intensity of pp spring max lower. Earlier zooplankton max (clear water phase), possibly earlier onset of grazing pressure causes lower phytoplankton maxima.

Stratification characteristics / Winder, M. & D.E. Schindler (2004): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Stratification characteristics

Reference

Winder, M. & D.E. Schindler (2004): Climatic effects on the phenology of lake processes. Global Change Biology 10(11): 1844-1856.

Description

Long-term climate warming extended the duration of the stratification period by 25 days over the last 40 years. Earlier spring stratification (16 days) and (less) later stratification termination in fall (9 days). The phytoplankton spring bloom advanced parallel to stratification onset (about 19 days earlier): tight connection of spring phytoplankton growth to turbulent conditions. In contrast, the timing of the clear-water phase showed high variability and was mainly driven by biotic factors. Zooplankton: the timing of spring peaks in the rotifer Keratella advanced strongly, Leptodiaptomus and Daphnia showed slight or no changes. These changes have generated a growing time lag between the spring phytoplankton peak and zooplankton peak, which can be especially critical for the cladoceran Daphnia. Water temperature, PDO, and food availability affected the timing of the spring peak in zooplankton. Overall, the impact of PDO on the phenological processes were stronger compared with ENSO. Our results highlight that climate affects physical and biological processes differently, which can interrupt energy flow among trophic levels, making ecosystem responses to climate change difficult to forecast.

Thermal structure / Jones, I., George, G. & C. Reynolds (2005 ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Thermal structure

Reference

Jones, I., George, G. & C. Reynolds (2005): Quantifying effects of phytoplankton on the heat budgets of two large limnetic enclosures. Freshwater Biology 50(7): 1239-1247.

Description

Thermal structure / Crawford, G.B. & R.W. Collier (2007): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Thermal structure

Reference

Crawford, G.B. & R.W. Collier (2007): Long-term observations of deepwater renewal in Crater Lake, Oregon. Hydrobiologia 574: 47-68.

Description

Variability in the hypolimnion: temperature, salinity, and dissolved oxygen. Over the entire 14 year period, no statistically significant trend was observed in the annual hypolimnetic heat and salt content. Conditions during a strong ventilation year (1994-1995) and a weak ventilation year (1996-1997) were compared. The results suggest the major difference between these 2 years was the evolution of the stratification in the epilimnion during the first few weeks of reverse stratification such that thermobaric instabilities were easier to form during 1995-1997. Thus, the details of surface cooling and wind-driven mixing during the early stages of reverse stratification may determine the net amount of ventilation possible during a particular year.

Thermal structure, water temperature / Jankowski, T., D.M. Livingstone, H. Bühr ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Thermal structure, water temperature

Reference

Description

Water temperature, stratification characteristics / Livingstone, D.M. (2003): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Early warning indicators
Indicator	Water temperature, stratification characteristics

Dynamics of the colonial rotifers Conochilus hippocrepis and Conochilus unicornis were both best predicted by temperature and the density of single-celled bacterio- and phytoplankton smaller than 10 µm, but their seasonal peaks have become dramatically offset toward fall and spring, respectively, in recent years. Both species have been extirpated from the summer, seemingly because of midsummer declines in their food resources, which have been depressed by Daphnia since its establishment. However, climate warming has increased the length of the plankton growing season in Lake Washington, such that spring and fall offer greater abundance of food resources for Conochilus, offsetting modern exclusion of Conochilus from midsummer months. Additionally, greater distinction in temporal niches presumably has reduced possibilities for intrageneric competition, and both Conochilus species have achieved higher mean annual abundances in recent years.

Clear water timing changed / Winder, M. & D.E. Schindler (2004): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Food webs
Indicator	Clear water timing changed

Reference

Winder, M. & D.E. Schindler (2004): Climatic effects on the phenology of lake processes. Global Change Biology 10(11): 1844-1856.

Description

Mixis timing/type change, clear water timing / Chen, C.Y. & C.L. Folt (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Food webs
Indicator	Mixis timing/type change, clear water timing

Reference

Chen, C.Y. & C.L. Folt (1996): Consequences of fall warming for zooplankton overwintering success. Limnology and Oceanography 41: 1077-1086.

Description

Mixis timing/type change, clear water timing / Wagner, A. & J. Benndorf (2007): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Food webs
Indicator	Mixis timing/type change, clear water timing

Reference

Wagner, A. & J. Benndorf (2007): Climate-driven warming during spring destabilises a Daphnia population: a mechanistic food web approach. Oecologia 151(2): 351-364.

Description

Phytoplankton maximum, blooms timing, population timing, growth, maximum / De Senerpont Domis, L.N., W.M. Mooij, S, H&uu ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Food webs
Indicator	Phytoplankton maximum, blooms timing, population timing, growth, maximum

Reference

Description

Population timing, growth, maximum, clear water timing / Hampton, S.E., P. Romare &, D.E. Seiler (2 ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Food webs
Indicator	Population timing, growth, maximum, clear water timing

Reference

Hampton, S.E., P. Romare &, D.E. Seiler (2006): Environmentally controlled Daphnia spring increase with implications for sockeye salmon fry in Lake Washington, USA. Journal of Plankton Research 28(4): 399-406.

Description

The winter abundance of D. pulicaria and basic parameters of spring conditions are important predictors of the date of D. pulicaria spring increase, indicating greater reliance on pelagic population dynamics (versus diapause hatch) than D. thorata exhibited. D. pulicaria was a more consistent prey than D. thorata (larger population fluctuations). Thus, recently increasing D. thorata prominence could decrease diet consistency for sockeye fry. Timing of sockeye arrival to Lake Washington and Daphnia's increase to the switching threshold has become less concordant, so that fry in recent years have had to rely upon less profitable prey for longer periods. Long-term trends and species-specific differences in Daphnia phenology may affect fry through altering diet composition, with additional implications for other zooplankton withstanding greater predation pressure in Daphnia's absence.

Uncoupling food chains, timing mismatch, loss of top predators, lake morphometry (especially depth) / De Senerpont Domis, L.N., W.M. Mooij, S, H&uu ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Food webs
Indicator	Uncoupling food chains, timing mismatch, loss of top predators, lake morphometry (especially depth)

Reference

Description

Primary production

Bacterioplankton / Adrian, R., Deneke, R., Mischke, U., Stellmac ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Bacterioplankton

Reference

Description

Bacterioplankton / Goedkoop, W. & E. Törnblom (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Bacterioplankton

Reference

Description

Shorter ice-cover period. Higher spring temperatures. Enhanced remineralisation. More nutrients (enhanced bacterial activity). Higher summer phytoplankton and zooplankton biomass.

Bacterioplankton / Pettersson, K., K. Grust, G. Weyhenmeyer & ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Bacterioplankton

Reference

Pettersson, K., K. Grust, G. Weyhenmeyer & T. Blenckner (2003): Seasonality of chlorophyll and nutrients in Lake Erken – effects of weather conditions. Hydrobiologia 506-509: 75-81.

Description

Bacterioplankton / Tirok, K. & U. Gaedke (2007): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Bacterioplankton

Reference

Tirok, K. & U. Gaedke (2007): The effect of irradiance, vertical mixing and temperature on spring phytoplankton dynamics under climate change: long-term observations and model analysis. Oecologia 150(4): 625-642.

Description

Irradiance often dominated algal net growth rather than vertical mixing for the following reason: algal dynamics depended on algal net losses from the euphotic layer to larger depth due to vertical mixing. These losses strongly depended on the vertical algal gradient which, in turn, was determined by the mixing intensity during the previous days, thereby introducing a memory effect. This observation implied that during intense mixing that had already reduced the vertical algal gradient, net losses due to mixing were small. Consequently, even in deep Lake Constance, the reduction in primary production due to low light was often more influential than the net losses due to mixing. In the regression model, the dynamics of small, fast-growing algae was best explained by vertical mixing intensity and global irradiance, whereas those of larger algae were best explained by their biomass 1 week earlier. The simulation model additionally revealed that even in late winter grazing may represent an important loss factor during calm periods when losses due to mixing are small. The importance of losses by mixing and grazing changed rapidly as it depended on the variable mixing intensity. Higher temperature, lower global irradiance and enhanced mixing generated lower algal biomass and primary production in the dynamic simulation model. This suggests that potential consequences of climate change may partly counteract each other.

Cold water species: changed distribution/extinction, bacterioplankton / Adrian, R. & R. Deneke (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Cold water species: changed distribution/extinction, bacterioplankton

Reference

Adrian, R. & R. Deneke (1996): Possible impact of mild winters on zooplankton succession in eutrophic lakes of the Atlantic European area. Freshwater Biology 36: 757-770.

Description

Makrophytes: community, distribution, production; phytoplankton: biomass, diversity, community composition / Turner, M.A., Huebert, D.B., Findlay, D.L., H ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Makrophytes: community, distribution, production; phytoplankton: biomass, diversity, community composition

Reference

Description

Phytoplankton community composition / Anneville, O., S. Gammeter & D. Straile ( ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Phytoplankton community composition

Reference

Description

Phytoplankton community composition / Anneville, O., V. Ginot, J.C. Druart & N. ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Phytoplankton community composition

Reference

Anneville, O., V. Ginot, J.C. Druart & N. Angeli (2002): Long-term study (1974-1998) of seasonal changes in the phytoplankton in Lake Geneva: a multi-table approach. Journal of Plankton Research 24(10): 993-1007.

Description

Seasonal pp succession: interannual variation: 1974-1985, 1986-1991 (except 1988) and 1992-1996 (including 1988). During the first period, phytoplankton succession followed the reference annual pattern (Plankton Ecology Group (PEG) model), the typical autumnal community was missing during the second period, and this autumn community developed earlier during the third period. Good ability of the phytoplankton community of Lake Geneva to resist both inter-annual fluctuations and brutal shifts in the annual functioning of the system. We believe these shifts resulted from a gradual change in environmental parameters, including the deepening of the P-depleted layer and a change in its timing as a result of the long-term meteorological changes.

Phytoplankton community composition / Anneville, O., S. Souissi, S. Gammeter & ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Phytoplankton community composition

Reference

Anneville, O., S. Souissi, S. Gammeter & D. Straile (2004): Seasonal and interannual scales of variability in phytoplankton assemblages: comparison of phytoplankton dynamics in three peri-alpine lakes over a period of 28 years. Freshwater Biology 49(1): 98-115.

Description

Oligotrophication, T water incr: Trophic state responsible for differences in pp assemblages. Warmer water temperatures observed since 1988 have had a major impact on the winter composition of the lower basin of Lake Zurich by promoting Planktothrix rubescens. Some pp assemblages are found in all the lakes. Their patterns of occurrence display strong synchrony at the annual and/or inter-annual scales. However, temporal coherence between the lakes sometimes also involves different assemblages. Reduction in phosphorus had a great influence on long-term changes in pp composition. Seasonal meteorological forcing has also induced synchronous changes, but the same assemblages are not necessarily involved, because the pool of the well-placed candidate taxa that may develop is determined by the local environmental conditions, and mainly by phosphorus concentrations. In the most eutrophic lake, the seasonal pattern is characterised by a succession of more stages. However, the seasonal assembly dynamics involve the succession of species sharing common selective advantages that make them relatively stronger under these nutrient and light conditions.

Phytoplankton growth rates / Doyle, S.A., J.E. Saros & C.E. Williamson ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Phytoplankton growth rates

Reference

Description

Phytoplankton maximum, blooms timing / Chen, C.Y. & C.L. Folt (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Chen, C.Y. & C.L. Folt (1996): Consequences of fall warming for zooplankton overwintering success. Limnology and Oceanography 41: 1077-1086.

Description

Phytoplankton maximum, blooms timing / Müller-Navarra, D.C., S. Güss & ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Description

Phytoplankton maximum, blooms timing / Winder, M. & D.E. Schindler (2004): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Phytoplankton maximum, blooms timing

Reference

Winder, M. & D.E. Schindler (2004): Climatic effects on the phenology of lake processes. Global Change Biology 10(11): 1844-1856.

Description

Primary production in g C/m² / Brooks, A.S. & J.C. Zastrow (2002): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Primary production
Indicator	Primary production in g C/m²

Reference

Brooks, A.S. & J.C. Zastrow (2002): The potential influence of climate change on offshore primary production in Lake Michigan. Journal of Great Lakes Research 28(4): 597-607.

Description

The projected climate for the year 2090 showed an earlier stratification. A decrease of 3% of mean annual primary production attributed to shortened winter-spring mixis period, thus less nutrient entrainment (nutrients from the sediment are transported to the productive euphotic zone). Also a lesser extent in fall. Plus less light input for photosynthesis which increased cloud cover is responsible for.

Secondary production - fish

Growth, production, survival change / George, D.G. & D.P. Harris (1985): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - fish
Indicator	Growth, production, survival change

Reference

George, D.G. & D.P. Harris (1985): The effect of climate on long-term changes in the crustacean zooplankton biomass of Lake Windermere, UK Nature 316: 536-539.

Description

First conclusive evidence of climatologically induced variability in a freshwater planktonic ecosystem. Monitored (1940-1980). Variation in timing of stratification. Year-to-year variability of ZP species abundance, but no major shift in species dominance. Crustacean biomass is inversely related to mean June temperature (multiple regression: 35% variability explained). Very little relationship to year-class strength or survival of Perca fluviatilis (multiple regression: 6.5% variability explained).

Life-history: migration timing, spawning, emergence timing / Gillet, C. & P. Quetin (2006): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - fish
Indicator	Life-history: migration timing, spawning, emergence timing

Reference

Gillet, C. & P. Quetin (2006): Effect of temperature changes on the reproductive cycle of roach in Lake Geneva from 1983 to 2001. Journal of Fish Biology 69(2): 518-534.

Description

roach Rutilus rutilus: From October to April, climate warming accelerated the development of gonads, then in May, a thermal threshold that triggered the onset of roach spawning occurred earlier.

Non-native invasives / Rogers, C.E. & J.P. McCarty (2000): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - fish
Indicator	Non-native invasives

Reference

Rogers, C.E. & J.P. McCarty (2000): Climate change and ecosystems of the Mid-Atlantic Region. Climate Research 14: 235-244.

Description

Thermal habitat change, cold stenotherms + rare species reduced / Stefan, H.G., M. Hondzo, X. Fang, J.G. Eaton ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - fish
Indicator	Thermal habitat change, cold stenotherms + rare species reduced

Reference

Description

Zooplankton production and timing change / Hampton, S.E. (2005): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - fish
Indicator	Zooplankton production and timing change

Reference

Hampton, S.E. (2005): Increased niche differentiation between two Conochilus species over 33 years of climate change and food web alteration. Limnology and Oceanography 50(2): 421-426.

Description

Secondary production - invertebrates

Community change: species richness, diversity, assemblage structure. / Manca M., Portogallo M., Brown, M.E. (2007): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - invertebrates
Indicator	Community change: species richness, diversity, assemblage structure.

Population timing, growth, maximum / Müller-Navarra, D.C., S. Güss & ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum

Reference

Description

Population timing, growth, maximum / Straile, D. (2002): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum

Reference

Straile, D. (2002): North Atlantic Oscillation synchronizes food-web interactions in central European lakes. Proceedings of the Royal Society of London 269: 391-395.

Description

Population timing, growth, maximum, zooplankton biomass, diversity, composition change / Hampton, S.E. (2005): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - zooplankton
Indicator	Population timing, growth, maximum, zooplankton biomass, diversity, composition change

Reference

Hampton, S.E. (2005): Increased niche differentiation between two Conochilus species over 33 years of climate change and food web alteration. Limnology and Oceanography 50(2): 421-426.

Description

Zooplankton biomass, diversity, composition change / George, D.G. & D.P. Harris (1985): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change

Reference

George, D.G. & D.P. Harris (1985): The effect of climate on long-term changes in the crustacean zooplankton biomass of Lake Windermere, UK Nature 316: 536-539.

Description

Zooplankton biomass, diversity, composition change / Goedkoop, W. & E. Törnblom (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change

Reference

Description

Shorter ice-cover period. Higher spring temperatures. Enhanced remineralisation. More nutrients (enhanced bacterial activity). Higher summer phytoplankton and zooplankton biomass.

Zooplankton biomass, diversity, composition change, smaller-bodied zooplankton / Adrian, R. & R. Deneke (1996): ...

Climate Region	temperate
Ecosystem type	deep
Parameter group	Secondary production - zooplankton
Indicator	Zooplankton biomass, diversity, composition change, smaller-bodied zooplankton

Reference

Adrian, R. & R. Deneke (1996): Possible impact of mild winters on zooplankton succession in eutrophic lakes of the Atlantic European area. Freshwater Biology 36: 757-770.

Freshwater type.

Lakes in temperate ecoregions

– Case studies –

Shallow

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