Wetlands in cold ecoregions
– Indicators for Climate Change Impacts –
Interactions between Climate Change, other stressors and the biota are complex. What are the main impacts? Which simple parameters are suited to detect them?
Here we suggest indicators, which reflect the main effects of Climate Change on freshwater ecosystems.
Within the Euro-Limpacs consortium there is an ongoing discussion about the best suited indicators. On this page you find a first selection, which will frequently be updated and improved within 2008.
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Biological parameters
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Bird migration
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Biological parameters Responding parameter Bird migration Response description
Spring migrations start earlier with warming. This is more pronounced early in the season and with terrestrial and wetland birds than with waterfowl.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Beginning of spring migration period
Reference(s)
Zalakevicius M. & R. Zalakeviciute (2001): Global climate change impact on birds: a review of research in Lithuania. Folia Zoologica 50(1): 1-17.
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Ecosystem maintenance
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Biological parameters Responding parameter Ecosystem maintenance Response description
Ecosystems potentially will suffer if detritus and species are lost to severe flooding and runoff events, and if drought levels exceed the tolerance limits of species.
Specification of relevant ecosystem type
Riverine wetlands
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Frequency and severity of storms
Justification of indicator
Reduction of biomass and species due to wash out.
Suggested indicator 2
Soil/sediment moisture content
Justification of indicator 2
Tolerance of species to drought may lead to extinctions, leaving the system open to invasions by exotic species
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Food web support I
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Biological parameters Responding parameter Food web support I Response description
Plant production supports production by other plants and various species of animals, either directly through food chains or indirectly via consumer organisms. Increased temperature may influence primary production and water availability, thus having consequential impacts across the ecosystem.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Air temperature
Justification of indicator
Increased temperature may result in increased rates of primary production.
Suggested indicator 2
Height of water table
Justification of indicator 2
Adequate water availability enhances primary production
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Food web support II
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Biological parameters Responding parameter Food web support II Response description
Drought and flooding both contribute to mineralisation and release of nutrients from organic matter. This can increase the build up of plant-available nutrients in the sediments, which are readily washed into water courses and wetlands in runoff.
Secondary effects
Eutrophication
Specification of relevant ecosystem type
All types of wetlands
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Frequency and severity of storms
Justification of indicator
Increase in eutrophication may result from large runoff events.
Suggested indicator 2
Height of water table
Justification of indicator 2
Desiccation may lead to oxidation and mineralisation of bound nutrients, which can then wash into water bodies and wetlands in runoff
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Insect species
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Biological parameters Responding parameter Insect species Response description
Changing climate has direct effects on the distributions of both terrestrial and aquatic insect species. Milder winters and hot summers are important factors in the survival of temperature-sensitive species. This will probably alter the tolerable ranges of some species, including pest species, and may lead to increased invasions into new areas by exotic species.
Secondary effects
Probable increased impacts on agriculture and biodiversity
Specification of relevant ecosystem type
Wetlands and open water
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Taxonomic composition and abundance of insect species, especially butterflies and aquatic insects
Justification of indicator
Indicates impacts on habitat integrity.
Reference(s)
Thomas J.A. (2005): Monitoring change in the abundance and distribution of insects using butterflies and other indicator groups. Philosophical Transactions of the Royal Society B-Biological Sciences 360(1454): 339-357.
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Tree survival
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Biological parameters Responding parameter Tree survival Response description
Increase in flooding can lead to progressive replacement of forest with bogs.
Specification of relevant ecosystem type
Forested wetlands
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Water table height
Justification of indicator
Water table height and tree survival are directly correlated.
Reference(s)
Crawford R.M.M., C.E. Jeffree & W.G. Rees (2003): Paludification and forest retreat in northern oceanic environments. Annals of Botany 91: 213-226.
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Vegetation assemblages I
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Biological parameters Responding parameter Vegetation assemblages I Response description
Elevated water table led to increase in bryophytes and reduction of shrubs in the bog, but increase in graminoids and forbs in the fen.
Secondary effects
In both the bog and the fen, below-ground biomass will increase compared with above-ground biomass.
Specification of relevant ecosystem type
Bog, fen
Relevant ecoregion(s) according to Illies
19 (Iceland), 20 (Borealic Uplands), 21 (Tundra), 22 (Fenno-Scandian Shield)
Suggested indicator
Height of water table; Vegetation assemblages
Justification of indicator
Water table height and vegetation assemblages are directly correlated.
Suggested indicator 2
Air temperature
Justification of indicator 2
Impacts of species and drought
Reference(s)
Weltzin J.F., J. Pastor, C. Harth, S.D. Bridgham, K. Updegraff & C.T. Chapin (2000): Response of bog and fen plant communities to warming and water-table manipulations. Ecology 81(12): 3464-3478.
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Vegetation assemblages II
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Biological parameters Responding parameter Vegetation assemblages II Response description
Lowered water table leads to increased proportion of dicotyledonous plant species.
Secondary effects
Increased risk of fire likely to lead to increased incidence of invasive plant species.
Relevant ecoregion(s) according to Illies
19 (Iceland), 20 (Borealic Uplands), 21 (Tundra), 22 (Fenno-Scandian Shield), 23 (Taiga)
Suggested indicator
Height of water table
Justification of indicator
Indicator for risk of vegetation assemblage change. This will have knock-on effects on other species.
Reference(s)
Hogenbirk, J.C. & R.W. Wein (1991): Fire and drought experiments in northern wetlands – a climate change analog. Canadian Journal of Botany 69(9): 1991-1997.
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Vegetation type
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Biological parameters Responding parameter Vegetation type Response description
Lowered water table leads to succession to forest-type vegetation from the graminoids and mosses occurring in pristine conditions.
Secondary effects
Nutrient cycling and carbon storage are affected because litter quality and quantity is different between the two vegetation types.
Specification of relevant ecosystem type
Wet boreal peatlands
Relevant ecoregion(s) according to Illies
19 (Iceland), 20 (Borealic Uplands), 21 (Tundra), 22 (Fenno-Scandian Shield), 23 (Taiga)
Suggested indicator
Water table height, occurrence of higher plant species
Justification of indicator
Water table height and vegetation assemblages are directly correlated.
Reference(s)
Laiho R., H. Vasander, T. Penttila & L. Laine (2003): Dynamics of plant-mediated organic matter and nutrient cycling following water-level drawdown in boreal peatlands. Global Biogeochemical Cycles 17(2).
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Hydromorphological parameters
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Flood water retention
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Hydromorphological parameters Responding parameter Flood water retention Response description
Increased temperature may lead to increased rates of evaporation.
Secondary effects
Reduced mean rates of runoff.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Height of water table
Justification of indicator
Retention of flood water will be enhanced if the water table is lowered but reduced if the water table is higher.
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Groundwater recharge
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Hydromorphological parameters Responding parameter Groundwater recharge Response description
Ability to recharge aquifers is affected by desiccation.
Secondary effects
Discharge of groundwater is likely to be reduced where drought occurs or abstractions are increased.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Height of water table
Justification of indicator
If the water table is high, the rate of recharge of groundwater (if any) will be increased.
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Ice cover duration
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Hydromorphological parameters Responding parameter Ice cover duration Response description
Increased air temperatures lead to a later thaw.
Secondary effects
Thickness of ice
Specification of relevant ecosystem type
Wetlands with open water
Relevant ecoregion(s) according to Illies
20 (Borealic Uplands), 21 (Tundra), 22 (Fenno-Scandian Shield), 23 (Taiga)
Suggested indicator
Date of ice break up
Justification of indicator
Indicates direct temperature effects. Influences length of season.
Suggested indicator 2
Thickness of ice
Justification of indicator 2
Indicates direct temperature effects. Influences length of season.
Reference(s)
Marszelewski W. & R. Skowron (2006): Ice cover as an indicator of winter air temperature changes: case study of the Polish Lowland lakes. Hydrological Sciences Journal 51(2): 336-349.
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Sediment retention
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Hydromorphological parameters Responding parameter Sediment retention Response description
Scouring of sediments by extreme weather events.
Secondary effects
Oxidation of sediments due to desiccation can lead to loss of sediments.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Frequency and severity of storms
Justification of indicator
Storms and associated flash floods and spates may wash away sediments and detritus, reducing their retention.
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Physico-chemical parameters
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Carbon acquisition I
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Physico-chemical parameters Responding parameter Carbon acquisition I Response description
Warm and wet conditions together increase C acquisition.
Specification of relevant ecosystem type
Fen
Relevant ecoregion(s) according to Illies
21 (Tundra)
Suggested indicator
Temperature and precipitation
Justification of indicator
Indicates gross C dynamics.
Reference(s)
Griffis T.J. & W.R. Rouse (2001): Modelling the interannual variability of net ecosystem CO2 exchange at a subarctic sedge fen. Global Change Biology 7(5): 511-530.
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Carbon acquisition II
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Physico-chemical parameters Responding parameter Carbon acquisition II Response description
Early snow melt followed by wet and warm conditions led to high carbon acquisition through photosynthesis.
Specification of relevant ecosystem type
Fen
Relevant ecoregion(s) according to Illies
21 (Tundra)
Suggested indicator
Date of snow melt, temperature and precipitation
Justification of indicator
A combination of early spring plus wet and warm weather promotes vegetation growth. Photosynthesis sequesters carbon, while rates of respiration remain comparatively stable year to year. Thus, carbon is accumulated in these conditions.
Reference(s)
Griffis T.J., W.R. Rouse & J.M. Waddington (2000): Interannual variability of net ecosystem CO2 exchange at a subarctic fen. Global Biogeochemical Cycles 14(4): 1109-1121.
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Carbon retention
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Physico-chemical parameters Responding parameter Carbon retention Response description
Retention of carbonaceous material will be enhanced if warmer temperatures increase primary production while water availability is sufficient, but will be reduced if runoff events increase in frequency.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Rate of primary production
Justification of indicator
Retention of carbon in vegetation and detritus will be enhanced by increased production.
Suggested indicator 2
Runoff
Justification of indicator 2
Increased runoff will reduce the conservation of organic matter
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Mineralisation
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Physico-chemical parameters Responding parameter Mineralisation Response description
Lowered water table stimulates enzyme activity leading to increased mineralisation.
Relevant ecoregion(s) according to Illies
19 (Iceland) 20 (Borealic Uplands)
Suggested indicator
Rates of enzyme activity
Justification of indicator
Indicates carbon loss from peat.
Reference(s)
Freeman C., G. Liska, N.J. Ostle, M.A. Lock, B. Reynolds & J. Hudson (1996): Microbial activity and enzymic decomposition processes following peatland water table drawdown. Plant and Soil 180(1): 121-127.
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Nutrient export
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Physico-chemical parameters Responding parameter Nutrient export Response description
Increased production leads to greater provision of organic detritus, which is then available for export downstream.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Production of litter
Justification of indicator
Export of nutrients will increase if detritus production is high.
Suggested indicator 2
Runoff
Justification of indicator 2
High rates of runoff will facilitate the export of nutrients
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Nutrient retention
Climate Region Cold Ecosystem type Wetlands Stressor type Temperature Responding parameter group Physico-chemical parameters Responding parameter Nutrient retention Response description
Longer season and warmer temperatures can lead to increased primary production.
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Rate of primary production
Justification of indicator
Retention of nutrients is potentially greater where production is high.
Suggested indicator 2
Oxidation rate
Justification of indicator 2
High rates of oxidation and mineralisation can liberate nutrients, and reduce their retention in the wetland
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Organic carbon export
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Physico-chemical parameters Responding parameter Organic carbon export Response description
Organic carbon is provided for downstream ecosystems in runoff water.
Specification of relevant ecosystem type
Riverine wetlands
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Height of water table
Justification of indicator
Organic carbon can be released as dissolved organic carbon (DOC) in runoff water.
Suggested indicator 2
Incidence of storms
Justification of indicator 2
Increased runoff will increase the export of organic matter
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Release of CH4
Climate Region Cold Ecosystem type Wetlands Stressor type Hydrology Responding parameter group Physico-chemical parameters Responding parameter Release of CH4 Response description
Lowered water table reduced CH4 emission.
Specification of relevant ecosystem type
Wetland forest
Relevant ecoregion(s) according to Illies
All Nordic ecoregions
Suggested indicator
Water table height
Justification of indicator
Water table height and greenhouse gas emission are directly correlated.
Reference(s)
Werner C., K. Davis, P. Bakwin, C. Yi, D. Hurst & L. Lock (2003): Regional-scale measurements of CH4 exchange from a tall tower over a mixed temperate/boreal lowland and wetland forest. Global Change Biology 9(9): 1251-1261.
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