Lakes in cold 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	cold
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.

Hydrology: water level / Noges, T., P. Noges & R. Laugaste (2003): ...

Climate Region	cold
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Hydrology: water level

Reference

Noges, T., P. Noges & R. Laugaste (2003): Water level as the mediator between climate change and phytoplankton composition in a large shallow temperate lake. Hydrobiologia 506(1-3): 257-263.

Description

Strong influence of the North Atlantic Oscillation on the water level in this lake. Phytoplankton biomass was significantly lower in years of high water level and the changes were unrelated to nutrient loading. The share of filamentous blue-greens among phytoplankton followed the changes in the water level while there was a succession of dominants. Planktolyngbya limnetica reached its maximum in the low water period in the middle of the 1970s. Limnothrix redekei and L. planktonica started to dominate in the high water period in the 1980s while the total biomass decreased substantially in spite of high nutrient loading. During the low water period in the 1990s, the role of the nitrogen-fixing species Aphanizomenon skujae increased. The succession was caused by changes in light and nutrient availability in the fully mixed environment. As low light species, filamentous Limnothrix spp. were most successful in competition for light and phosphorus in deeper water while A. skujae was favoured by high light intensities and a low N/P ratio in shallow water.

Hydrology: water level / Leconte, R., Peters, D., Pietroniro, A. & ...

Climate Region	cold
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Hydrology: water level

Reference

Leconte, R., Peters, D., Pietroniro, A. & T. Prowse (2006): Modelling climate change impacts in the Peace and Athabasca catchment and delta: II - variations in flow and water levels with varying winter severity. Hydrological Processes 20(19): 4215-4230.

Description

In general, a reduction of winter severity lowered lake levels and river flows. While the winter severity effect is of relatively short duration in the rivers, the subsequent reduction in lake levels extends over the summer months. High river flows predispose flow reversal conditions, and water enters the lakes at the outlet as the water levels in the rivers feeding the PAD increase significantly over a short period of time. This flow reversal effect is suppressed during milder winters. Numerical modelling results indicate that extending the ice-cover season (severe winter) by 14 days resulted in an increase of up to 5 cm in water level of large takes in the PAD, while reducing it by 28 days lowered the levels by almost 10 cm. Short-term variations in river levels reached up to 1.5 m as a result of varying the extent of the ice-cover season. As the simulation runs did not consider ice-jam events and neglected the effect of ice thickness on water levels, the reported quantitative results must be interpreted with prudence.

Nutrients: minerlisation, release (sediment) / Kankaala, P., A. Ojala, T. Tulonen & L. A ...

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

Reference

Kankaala, P., A. Ojala, T. Tulonen & L. Arvola (2002): Changes in nutrient retention capacity of boreal aquatic ecosystems under climate warming: a simulation study. Hydrobiologia 469: 67-76.

Description

Abiotic indicators: Higher P release in the experimental greenhouse pond than in the reference pond. Accelerated eutrophication. Uptake of phosphate from sediment and phosphate released from decaying plants: under warmer climate accelerated. Utilized by littoral algal communities.

Uptake of phosphate from sediment and phosphate released from decaying plants: under warmer climate accelerated.

Early Warning Indicators: Later freezing earlier thawing of ice cover. Earlier / later mixing: changes in heat transfer.

Bacterioplankton: Higher P release in the experimental greenhouse pond than in the reference pond. Accelerated eutrophication. Uptake of phosphate from sediment and phosphate released from decaying plants: under warmer climate accelerated. Utilized by littoral algal communities.

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

Climate Region	cold
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.

Thermal structure, water temperature, epilimnion thickness / Keller, W., J. Heneberry, L. Leduc, J. Gunn & ...

Climate Region	cold
Ecosystem type	shallow
Parameter group	Abiotic indicators
Indicator	Thermal structure, water temperature, epilimnion thickness

Reference

Keller, W., J. Heneberry, L. Leduc, J. Gunn & N. Yan (2006): Variations in epilimnion thickness in small Boreal Shield Lakes: Relationships with transparency, weather and acidification. Environmental Monitoring and Assessment 115(1-3): 419-431.

Description

Dissolved organic carbon (DOC) was the best individual predictor of late summer epilimnion thickness (r2 = 0.69). Total chlorophyll a, the number of days between ice-out and late-summer stratification, and lake area collectively explained an additional 14% of the variation in epilimnion thickness. The three attributes of summer weather that we examined, mean daily temperature, mean daily wind speed, and mean daily hours of bright sunshine, did not add to the predictive ability of our regression model. Lake acidity also did not add directly to the predictive ability of the model, likely because DOC concentrations already reflected the effects of pH. Our study supports an increasing body of evidence indicating that the dominant effects of climate change on lake thermal structure in small lakes will be through effects on processes that affect lake transparency.

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

Climate Region	cold
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 %deg;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 / Straile, D. (2002): ...

Climate Region	cold
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	cold
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, mixis timing/type change / Kankaala, P., A. Ojala, T. Tulonen & L. A ...

Climate Region	cold
Ecosystem type	shallow
Parameter group	Early warning indicators
Indicator	Ice cover timing, mixis timing/type change

Reference

Kankaala, P., A. Ojala, T. Tulonen & L. Arvola (2002): Changes in nutrient retention capacity of boreal aquatic ecosystems under climate warming: a simulation study. Hydrobiologia 469: 67-76.

Description

Uptake of phosphate from sediment and phosphate released from decaying plants: under warmer climate accelerated.

Early Warning Indicators: Later freezing earlier thawing of ice cover. Earlier / later mixing: changes in heat transfer.

Food webs

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

Climate Region	cold
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.

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

Climate Region	cold
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.

Primary production

Bacterial biomass, bacterioplankton / Tulonen, T., P. Kankaala, P. Kankaala, A. Oja ...

Climate Region	cold
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Bacterial biomass, bacterioplankton

Reference

Tulonen, T., P. Kankaala, P. Kankaala, A. Ojala & L. Arvola (1994): Factors controlling production of phytoplankton and bacteria under-ice in a humic, boreal lake. Journal of Plankton Research 16(10): 1411-1432.

Description

Changes in ice cover, and light conditions: The importance of light as the factor controlling primary production in winter: additions of phosphorus and DOM did not enhance the primary production, higher growth rates and production of bacteria. Bacterioplankton was simultaneously controlled by heterotrophic flagellates (laboratory experiments: exclusion of flagellates always resulted in higher yields of bacteria of increased cell size). The importance of temperature was highlighted with the significant correlation (r(2) = 0.59) between bacterial production and temperature within the range 0.6-2.1 °C. Thus, on the boreal zone the possible warming of climate may lead to enhanced microbial activities in winter, but under unchanged light conditions no effects on primary production will be expected.

Bacterioplankton / Kankaala, P., A. Ojala, T. Tulonen & L. A ...

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

Reference

Kankaala, P., A. Ojala, T. Tulonen & L. Arvola (2002): Changes in nutrient retention capacity of boreal aquatic ecosystems under climate warming: a simulation study. Hydrobiologia 469: 67-76.

Description

Uptake of phosphate from sediment and phosphate released from decaying plants: under warmer climate accelerated.

Early Warning Indicators: Later freezing earlier thawing of ice cover. Earlier / later mixing: changes in heat transfer.

Community composition, indicator species / Noges, T., P. Noges & R. Laugaste (2003): ...

Climate Region	cold
Ecosystem type	shallow
Parameter group	Primary production
Indicator	Community composition, indicator species

Reference

Noges, T., P. Noges & R. Laugaste (2003): Water level as the mediator between climate change and phytoplankton composition in a large shallow temperate lake. Hydrobiologia 506(1-3): 257-263.

Description

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

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

Reference

Description

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

Climate Region	cold
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 / Rooney, N. & J. Kalff (2000): ...

Climate Region	cold
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	cold
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 community composition / Anneville, O., S. Gammeter & D. Straile ( ...

Climate Region	cold
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 / Strecker, A.L., T.P. Cobb & R.D. Vinebroo ...

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

Reference

Description

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

Climate Region	cold
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.

Secondary production - fish

Growth, production, survival change / Grant, S.C.H. & W.M. Tonn (2002): ...

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

Reference

Grant, S.C.H. & W.M. Tonn (2002): Effects of nutrient enrichment on recruitment of age-0 fathead minnows (Pimephales promelas): potential impacts of environmental change on the Boreal Plains. Canadian Journal of Fisheries and Aquatic Sciences 59(5): 759-767.

Description

Fathead minnows (Pimephales promelas): Experimental nutrient enrichment increased phytoplankton biomass (chlorophyll a) sevenfold in treatment compared to reference systems. In response, fish laid more eggs and survival of age-0 fish was enhanced, both of which contributed to a more than fivefold increase in total number of age-0 fish that survived to the end of the growing season in treatment versus reference systems. A complementary enclosure experiment suggested that enhanced growth and decreased susceptibility to starvation contributes to the greater survival of age-0 fish when food resources are increased. Furthermore, overwinter mortality of age-0 fathead minnows in experimental ponds was strongly size-selective; no fish smaller than 20 mm survived winter. Because of these effects on egg production and growth and survival of age-0 fish, environmental changes predicted for the Boreal Plains could significantly alter the dynamics of fish populations.

Growth, production, survival change / Gunn, J.M. (2002): ...

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

Reference

Gunn, J.M. (2002): Impact of the 1998 El Niño event on a lake charr, Salvelinus namaycush, population recovering from acidification. Environmental Biology of Fishes 64(1-3): 343-351.

Description

Lake charr, Salvelinus namaycush: The warm years triggered by the El Nino event exposed fish to bottom water temperatures of 20 °C for several weeks and resulted in the loss of all hatchery-reared juveniles that were released in 1998. A few adults survived the warm years by making use of cold water refuge areas (groundwater seepage). This study shows how climate change can eliminate charr populations at the margins of their range. It also illustrates the potential confounding effects of climate warming on aquatic ecosystems already subject to other stressors.

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

Climate Region	cold
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	cold
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 - zooplankton

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

Climate Region	cold
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	cold
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.

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

Climate Region	cold
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

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

Climate Region	cold
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	cold
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., Nõges, 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.

Lakes in general

Abiotic incidators

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

Climate Region	cold
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	cold
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

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.

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

Climate Region	cold
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.

Paleolimnological research (organic-inorganic carbon content) / Anderson, N. J., Brodersen, K. P., Ryves, D. ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Abiotic incidators
Indicator	Paleolimnological research (organic-inorganic carbon content)

Reference

Anderson, N. J., Brodersen, K. P., Ryves, D. B., McGowan, S., Johansson, L. S., Jeppesen, E., Leng, M. J. (2008): Climate Versus In-Lake Processes as Controls on the Development of Community Structure in a Low-Arctic Lake (South-West Greenland). Ecosystems 11(2): 307-324.

Description

The dominant processes determining biological structure in lakes at millennial timescales are complex. In this study, we used a multi-proxy approach to determine the relative importance of in-lake versus indirect processes on the Holocene development of an oligotrophic lake in SW Greenland (66.99 °N, 50.97 °W). A 14C and 210Pb-dated sediment core covering approximately 8500 years BP was analyzed for organic?inorganic carbon content, pigments, diatoms, chironomids, cladocerans, and stable isotopes (δ13C, δ18O). Relationships among the different proxies and a number of independent controlling variables (Holocene temperature, an isotope-inferred cooling period, and immigration of Betula nana into the catchment) were explored using redundancy analysis (RDA) independent of time. The main ecological trajectories in the lake biota were captured by ordination first axis sample scores (18-32% variance explained). The importance of the arrival of Betula (ca. 6500 years BP) into the catchment was indicated by a series of partial-constrained ordinations, uniquely explaining 12-17% of the variance in chironomids and up to 9% in pigments. Climate influences on lake biota were strongest during a short-lived cooling period (identified by altered stable isotopes) early in the development of the lake when all proxies changed rapidly, although only chironomids had a unique component (8% in a partial-RDA) explained by the cooling event. Holocene climate explained less variance than either catchment changes or biotic relationships. The sediment record at this site indicates the importance of catchment factors for lake development, the complexity of community trends even in relatively simple systems (invertebrates are the top predators in the lake) and the challenges of deriving palaeoclimate inferences from sediment records in low-Arctic freshwater lakes.

Abiotic incidators/ Secondary production - zooplankton

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

Climate Region	cold
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 / Posch, M., Aherne, J., Forsius, M., Fronzek, ...

Climate Region	cold
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 confounding influence 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	cold
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Acidification: deposition

Reference

Description

Acidification: deposition / Dillon, P.J., K.M. Somers, J. Findeis & M ...

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

Reference

Dillon, P.J., K.M. Somers, J. Findeis & M.C. Eimers (2003): Coherent response of lakes in Ontario, Canada to reductions in sulphur deposition: the effect of climate on sulphate concentrations. Hydrology and Earth Sytem Sciences 7(4): 583-595.

Description

Sulphate concentrations in lakes strongly predicted by regional/global scale climate indices (SOI, ENSO) and sulphate deposition indices. Large-scale climate factors play a major role in determining the response of lakes to sulphate deposition, recovery may be delayed.

Acidification: import (wetlands) / Dillon, P.J., L.A. Molot & M. Futter (199 ...

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

Reference

Dillon, P.J., L.A. Molot & M. Futter (1997): The effect of El Niño-related drought on the recovery of acidified lakes. Environmental Monitoring and Assessment 46: 105-111.

Description

Stored reduced S in anoxic zones (wetlands) oxidized during drought, sulphate export rates after droughts high. Elevated sulphate concentrations in streams and lakes (in spite of decreased atmospheric sulphate deposition).

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

Climate Region	cold
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	cold
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) / Dillon, P.J. & Molot, L.A. (2005): ...

Climate Region	cold
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) / Temnerud, J., Weyhenmeyer, G.A. (2008): ...

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

Reference

Temnerud, J., Weyhenmeyer, G.A. (2008): Abrupt changes in air temperature and precipitation: Do they matter for water chemistry ? Global Biogeochemical Cycles 22: 39661.

Description

We analyzed 120 years long time series of air temperature and precipitation from 29 respective 44 sites distributed all over Sweden and determined abrupt changes by using three methods. For air temperature we found significant changes in 1930 and 1989 and for precipitation in 1920, 1979, and 1998. Analyzing more than 30 yearlong time series of ice cover (333 sites), discharge and watercourses chemistry (87 sites), we observed abrupt changes in 1977, 1989, and 1998 for discharge but first in 1998 for watercourses chemistry, most pronounced for organic matter and sulfate concentrations. We suggest that the abrupt increase in air temperature in 1989 liberated more easily mobilized organic matter in the catchments, which, for water chemistry, was first detected in 1998 as a consequence of increased discharge. We conclude that increases in air temperatures can make ecosystems more sensitive to further changes in precipitation.

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

Climate Region	cold
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

Trends 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	cold
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.

Eutrophic zone - size, nutrients / Findlay, D.L., S.E.M. Kasian, M.P. Stainton, ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Eutrophic zone - size, nutrients

Reference

Findlay, D.L., S.E.M. Kasian, M.P. Stainton, K. Beaty & M. Lyng (2001): Climatic influences on algal populations of boreal forest lakes in the Experimental Lakes Area. Limnology and Oceanography 46(7): 1784-1793.

Description

Duration of stratification increased, depth of eutrophic zone increased. Length of ice-free season increased. Nutrient input decreased. Light extinction increased. Number of phytoplankton species increased. Shift in species composition: Greater abundances of dinoflagellates and large chrysophytes. Biomass increased.

Methane / Walter, K.M., S.A. Zimov, J.P. Chanton, D. Ve ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Methane

Reference

Walter, K.M., S.A. Zimov, J.P. Chanton, D. Verbyla & F.S. Chapin (2006): Methane bubbling from Siberian thaw lakes as a positive feedback to climate warming. Nature 443: 71-75.

Description

We find that thawing permafrost along lake margins accounts for most of the methane released from the lakes, and estimate that an expansion of thaw lakes between 1974 and 2000, which was concurrent with regional warming, increased methane emissions in our study region by 58%. Furthermore, the Pleistocene age (35,260-42,900 years) of methane emitted from hotspots along thawing lake margins indicates that this positive feedback to climate warming has led to the release of old carbon stocks previously stored in permafrost.

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

Climate Region	cold
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.

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

Climate Region	cold
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.

Thermal structure, water temperature, epilimnion thickness / Keller, W., J. Heneberry, L. Leduc, J. Gunn & ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Abiotic indicators
Indicator	Thermal structure, water temperature, epilimnion thickness

Reference

Description

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

Climate Region	cold
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	cold
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	cold
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. (2002): ...

Climate Region	cold
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	cold
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, stratification characteristics / Findlay, D.L., S.E.M. Kasian, M.P. Stainton, ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Early warning indicators
Indicator	Ice cover timing, stratification characteristics

Reference

Description

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

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

Reference

Livingstone, D.M., Padisák, 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	cold
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, stratification characteristics / McCormick, M.J. (1990): ...

Climate Region	cold
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	cold
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

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

Climate Region	cold
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.

Primary production

Bacterial biomass, bacterioplankton / Tulonen, T., P. Kankaala, P. Kankaala, A. Oja ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Bacterial biomass, bacterioplankton

Reference

Description

Bacterioplankton / Arnott, S.E., Keller, B., Dillon, P.J, Yan, N ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Bacterioplankton

Reference

Arnott, S.E., Keller, B., Dillon, P.J, Yan, N., Paterson, M. & D. Findlay (2003): Using temporal coherence to determine the response to climate change in boreal shield lakes. Environmental Monitoring and Assessment 88: 365-388.

Description

Only weak effect on phytoplankton, zooplankton. Acidification pulses due to draught (El Nino). Effect on phyto- and zooplankton: Changes in phytoplankton richness related to pH (acidification), only weak relation to surface water temperature.

Bacterioplankton / Findlay, D.L., S.E.M. Kasian, M.P. Stainton, ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Bacterioplankton

Reference

Description

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

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

Reference

Description

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

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

Reference

Description

Phytobenthos (epilithon) / Watkins, E.M., D.W. Schindler,M.A. Turner &am ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Primary production
Indicator	Phytobenthos (epilithon)

Reference

Watkins, E.M., D.W. Schindler,M.A. Turner & D. Findlay (2001): Effects of solar ultraviolet radiation on epilithic metabolism, and nutrient and community composition in a clear-water boreal lake. Canadian Journal of Fisheries and Aquatic Sciences 58(10): 2059-2070.

Description

The absence of UVR increased epilithic photosynthetic rates 37-46% above epilithon exposed to ambient UVR, increased cellular carbon and nitrogen content, and consequently lowered C:P. UVR effects on algal metabolism were dependent on seasonal trends. Epilithic respiration rates and chlorophyll a concentrations were not significantly different among treatments. A reduction in UV induced taxonomic shifts in epilithon, with diatoms increasingly favoured under low UV conditions. Species richness and diversity were not affected. Overall, the results of this study, considered together with previous research, suggest that the epilithic community is sensitive to changes in the UVR environment of aquatic ecosystems.

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

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

Reference

Description

Phytoplankton community composition / Xenopoulos, M.A. & P.C. Frost (2003): ...

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

Reference

Xenopoulos, M.A. & P.C. Frost (2003): UV radiation, phosphorus, and their combined effects on the taxonomic composition of phytoplankton in a boreal lake. Journal of Phycology 39(2): 291-302.

Description

Principal components analysis ordination separated phytoplankton that were negatively affected by UV radiation and/or positively affected by P treatments (e.g. small chrysophytes, Cryptomonas rostratiformis, T. flocculosa) from those that generally were unaffected by either treatment (e.g. desmids, some Cyanobacteria). Richness, Shannon-Weaver diversity, and evenness were significantly higher in phytoplankton communities shielded from UVAR and UVBR. The relationship between diversity and richness was positive in all phytoplankton samples except in those exposed to UVBR. Thus, UVBR-exposed phytoplankton communities were dominated by a few species even though the number of taxa remained relatively unchanged. Consequently, alterations in the UV environments of lakes resulting from climate warming (e.g. drought) and land-use change (e.g. increased P export) will likely promote shifts in the community composition of lake phytoplankton.

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

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

Reference

Description

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

Climate Region	cold
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	cold
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	cold
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	cold
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	cold
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

Growth, production, survival change / Borgstrom, R. & J. Museth (2005): ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Growth, production, survival change

Reference

Borgstrom, R. & J. Museth (2005): Accumulated snow and summer temperature - critical factors for recruitment to high mountain populations of brown trout (Salmo trutta L.). Ecology of Freshwater Fish 14(4): 375-384.

Description

brown trout (Salmo trutta L.): recruitment failure depended significantly on the accumulated snow depth in April, whereas the mean August temperature in the year of birth was significant for the appearance of strong year-classes. Size of the young-of-the-year (YOY) trout at onset of the winter seemed to be crucial for survival. Also little snow and low temperatures during the winter may have led to recruitment failure, as small nursery streams may freeze completely under such conditions, as happened during the winter of 1995/1996. Thus, the recruitment to brown trout populations in western high mountain areas of Norway seemed to be strongly affected by accumulated snow depth and summer temperatures. A climate change with more winter precipitation, as predicted for the present century, may therefore be detrimental to recruitment. However, warmer summers may increase recruitment to levels that lead to overpopulation, but also to establishment of brown trout populations at higher elevations than today.

Growth, production, survival change / Grant, S.C.H. & W.M. Tonn (2002): ...

Climate Region	cold
Ecosystem type	lakes in general
Parameter group	Secondary production - fish
Indicator	Growth, production, survival change

Reference

Description

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

Climate Region	cold
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.

Secondary production - zooplankton

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

Climate Region	cold
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	cold
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	cold
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	cold
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	cold
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 confounding, nongenetic factors. Our results provide solid proof for a rapid microevolutionary 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. (2002): ...

Climate Region	cold
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

Zooplankton biomass, diversity, composition change / Arnott, S.E., Keller, B., Dillon, P.J, Yan, N ...

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

Reference

Description

Susceptibility ecosystem

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

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

Reference

Description

Carbon budget / Kankaala, P., L. Arvola, T. Tulonen & A. ...

Climate Region	cold
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Carbon budget

Reference

Kankaala, P., L. Arvola, T. Tulonen & A. Ojala (1996): Carbon budget for the pelagic food web of the euphotic zone in a boreal lake (Lake Paajarvi). Canadian Journal of Fisheries and Aquatic Sciences 53(7): 1663-1674.

Description

Production of phytoplankton and bacteria enchanced by additions of phosphorus, and of phosphorus and humic matter together. Effects on zooplankton less clear: short time of the experiments, also loss of carbon through respiration in several steps of the microbial food chain. Protozoans: key roles as grazers; heterotrophic nanoflagellates: most important grazers of bacteria; ciliates: more important algal grazers than metazooplankton. Indirect evidence: ciliates formed a considerable proportion of the food of metazooplankton. The amount of carbon released through respiration exceeded the sum of that fixed by primary producers and lost through sedimentation. If the climate change in the boreal zone increases loading of nutrients and humic matter into lakes, this imbalance between respiration and fixation of carbon can be expected to increase.

Hydrology: water level / Gibson, J.J., T.D. Prowse & D.L. Peters ( ...

Climate Region	cold
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Hydrology: water level

Reference

Gibson, J.J., T.D. Prowse & D.L. Peters (2006): Partitioning impacts of climate and regulation on water level variability in Great Slave Lake. Journal of Hydrology 329(1-2): 196-206.

Description

The effect of flow regulation has been to dampen annual water level variability by about 20 ±2 cm, to reduce annual maximum water Levels by about 14 ±3 cm and to shift peak water levels earlier in the season by about 30 ±8 days. Meanwhile, climate forcing has tended to enhance water level variability by 8 ± 2 cm, to enhance maximum water levels by 10 ±3 cm and to advance the timing of maximum water levels slightly (11 ±8 days). Climatic and regulation impacts appear to have generally counter-balanced changes in amplitude of water level changes and magnitude of peak levels but have cumulatively contributed to a seasonal shift toward earlier peak water levels in the lake.

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

Climate Region	cold
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	cold
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	cold
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	cold
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.

Residence time dependent (suscepibility) / Malmaeus, J.M., T. Blenckner, H. Markenstenb ...

Climate Region	cold
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Residence time dependent (suscepibility)

Reference

Malmaeus, J.M., T. Blenckner, H. Markenstenb & I. Perssonb (2006): Lake phosphorus dynamics and climate warming: A mechanistic model approach. Ecological Modelling 190(1-2): 1-14.

Description

Model results: In the phosphorus model water mixing, mineralization, diffusion and biouptake are temperature dependent. In the simulations, Lake Erken is much more sensitive to climate warming than the two basins of Lake Malaren: much longer water residence time in Lake Erken (7 years), stressing the importance of internal lake processes. In Galten and Ekoln the water residence times are less than I year, and the effects of water temperature changes are small. In Lake Erken the concentration of epilimnetic-dissolved phosphorus is almost doubled in spring and autumn in the warmest climate scenario. Since the lake is mostly phosphorus limited, this means that the potential for phytoplankton production is almost doubled. The implication would be that in Lake Erken, and in other eutrophic lakes with long water residence times, eutrophication problems may become serious in the future, and that managers may need to take action today in order to maintain good water quality in these lakes.

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

Climate Region	cold
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.

Thermal structure, water temperature, epilimnion thickness / Keller, W., J. Heneberry, L. Leduc, J. Gunn & ...

Climate Region	cold
Ecosystem type	deep
Parameter group	Abiotic indicators
Indicator	Thermal structure, water temperature, epilimnion thickness

Reference

Description

Early warning indicators

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

Climate Region	cold
Ecosystem type	deep
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 / Goedkoop, W. & E. Törnblom (1996): ...

Climate Region	cold
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	cold
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	cold
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, climatic memory hypolimnion, mixis timing/type change / Pettersson, K. & K. Grust (2002): ...

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

Reference

Description

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

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

Reference

Description

Food webs

Food web and carbon budget, eutrophication / Kankaala, P., L. Arvola, T. Tulonen & A. ...

Climate Region	cold
Ecosystem type	deep
Parameter group	Food webs
Indicator	Food web and carbon budget, eutrophication

Reference

Description

Primary production

Bacterial biomass, bacterioplankton / Tulonen, T., P. Kankaala, P. Kankaala, A. Oja ...

Climate Region	cold
Ecosystem type	deep
Parameter group	Primary production
Indicator	Bacterial biomass, bacterioplankton

Reference

Description

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

Climate Region	cold
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	cold
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

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

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

Reference

Description

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

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

Reference

Description

Secondary production - fish

Growth, production, survival change / Grant, S.C.H. & W.M. Tonn (2002): ...

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

Reference

Description

Secondary production - zooplankton

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

Climate Region	cold
Ecosystem type	deep
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

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

Climate Region	cold
Ecosystem type	deep
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

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

Climate Region	cold
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

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

Climate Region	cold
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.

Freshwater type.

Lakes in cold ecoregions

– Case studies –

Shallow

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Lakes in general

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