inland water systems outline: introduction area and distribution excursion: peatlands services...
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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 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
• Hydrologic regulation
• Sediment retention and water purification
Services
• Hydrologic regulation
• Sediment retention and water purification
• Recharge/ discharge of groundwater
Services
• Hydrologic regulation
• Sediment retention and water purification
• Recharge/ discharge of groundwater
• Climate-change mitigation
Services
• Hydrologic regulation
• Sediment retention and water purification
• Recharge/ discharge of groundwater
• Climate-change mitigation
• Products from IWS
Services
• Hydrologic regulation
• Sediment retention and water purification
• Recharge/ discharge of groundwater
• Climate-change mitigation
• Products from IWS
• Recreation and tourism
Services
• Hydrologic regulation
• Sediment retention and water purification
• Recharge/ discharge of groundwater
• Climate-change mitigation
• Products from IWS
• 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
Indirect drivers:• Expanding of population, welfare
Direct drivers:• Physical change• hydrologic modification• Invasive species• Fisheries/ harvesting
Drivers of change
Indirect drivers:• Expanding of population, welfare
Direct drivers:• Physical change• hydrologic modification• Invasive species• Fisheries/ harvesting• Water pollution and eutrophication
Drivers of change
Indirect drivers:• Expanding of population, welfare
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