Inland Water Systems Outline: introduction area and distribution excursion: peatlands Services...

Inland Water Systems

Outline:

• introduction• area and distribution

excursion: peatlands• Services• Condition• Drivers of change• conclusions

Inland Water Systems

IWS are: All inland aquatic habitats, whether fresh, brackish or saline, as well as

inland seas• Lakes• Rivers • marshes• Swamps• Floodplains• Small streams• Ponds• Cave waters

also rice-fields, aquaculture ponds, reservoirs

Special attributes of IWS

• Variety in time and extent difficult to assess

• Biggest species-richness compared to Marine and terrestrial ecosystems

• Maybe worst threatened of all systems in MA

• IWS are affected by- but also influence climate change feedback

• Multiple services from healthy IWS intensive use

Source: http://ga.water.usgs.gov/edu/watercyclesummarytext.html

Area

530 million to 1280 million hectares

2.6% of earth´s surface ; 8.5% of landsurface covered by IWS

Global distribution

http://www.peatlandsni.gov.uk/formation/global.htm#globalmap

global peatlands

peatlands

• Peat: organic material which is acumulated but not decomposed due to anoxic conditions in swamps/ marshes

Peatlands cover 400 million hectares

Source:http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=17423

peatlands

• Carbon-accumulation of intact peatlands

Feedback with climate

Services

• Hydrologic regulation

Services


• Sediment retention and water purification

Services



• Recharge/ discharge of groundwater

Services




• Climate-change mitigation

Services





• Products from IWS

Services






• Recreation and tourism

Services






• Recreation and tourism

• Cultural value

Condition of IWS

• Agricultural drainage: 56-65% of IWS suitable for agriculture• Wetland-loss: 50% during 20eth century (speculation)

• Status of IWS species: dramatic

Table 20.5. Relative Species Richness of Different Ecosystems

(McAllister et al. 1997)

Ecosystems Freshwater Marine Terrestrial

Habitat Extent 0.8 70.8 28.4

(percent of

world)

Species Diversity 2.4 14.7 77.5

(percent of

known species)

Relative Species 3.0 0.2 2.7

Richness

source: Millenium ecosystem Assessment chapter 20

Drivers of change

Indirect drivers:• Expansion of population, welfare

Direct drivers:• Physical change, hydrologic modification

hydrologic modification

DAMS:• 700% increase in water stored in river-systems immense change of flowing-patterns impact on sediment-transport and waste-processing capacity

(residence time doubled/ tripled) impact on fish-migration floodplains alterated

Drivers of change

Indirect drivers:• Expanding of population, welfare

Direct drivers:• Physical change• hydrologic modification• Invasive species

Drivers of change


Direct drivers:• Physical change• hydrologic modification• Invasive species• Fisheries/ harvesting

Drivers of change


Direct drivers:• Physical change• hydrologic modification• Invasive species• Fisheries/ harvesting• Water pollution and eutrophication

Drivers of change


Direct drivers:• Physical change• hydrologic modification• Invasive species• Fisheries/ harvesting• Water pollution and eutrophication• Climate change

conclusions

• Deep examination often reveals: greater economic benefits from intact IWS than of those beeing converted (holistic approach)

essential to consider information about full range of benefits

• Special agreements needed due to connectivity of IWS (linkage between countries)

• People who benefit most from intact IWS are local residents, especially poor people

Use of local knowledge and consideration of local people required

Inland Water Systems Outline: introduction area and distribution excursion: peatlands Services...

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