56 Economic dimensions and socio-cultural patterns
Essen
City
ForestFreiburg
im
BergwaldFrankfurt
City
ForestBerlin
City
Forest
Recreation Wildlife Forest
ProductionWater
ProductionMining
reclamationClimate
& noise
Figure 3.1Urban forests providing valuable ecosystem services in Germany. Relative
intensity of use: 100 % black, very high; 75 % high; 50 % medium; 25 % low; 0 % very
low. Adapted from Osband (1984).Unmentioned above and poorly represented in most economic models are
natural systems.Yet these address major stated objectives of society and provide
enormous value (Daily1997,Atkinsonet al.1999,Dailey and Ellison2002,Ravetz
2000, White2002,Millennium Ecosystem Assessment2005).Most natural-systems
values are quite familiar and taken for granted, until they are in short supply or
runout. Clean water supply is a big and rapidly growing problem in numerous
growing urban regions. Natural vegetation covering an aquifer is arguably the
best way to sustain a clean-water supply (Figure3.1). The natural vegetation
provides this key ‘‘service” to society, and requires protection. Long-term natural-
systems protection is a small cost compared with the service value provided to
millions of people in the city.
Nature’sservices(natural-systems services, natural capital, nature’s values) or
ecosystem services(those where natural organisms play central roles) are wide-
spread (Daily1997,Millennium Ecosystem Assessment2005,National Research
Council2005)andareespecially provided by diverse types of greenspace. Nearby
natural recreation areas, especially forested, provide a valuable service to city
residents. Wetlands that absorb stormwater and reduce flooding provide a ser-
vice to the city. Vegetated stream corridors reduce erosion and sedimentation.
Natural soils absorb and break down chemical pollutants. The list of ecosystem
services in urban regions goes on and on, each providing a key value to society