Effects of global warming on wetland ecosystems
Wetlands belong among our most species-rich and most complex environments and their values have been recognized in both national environmental objectives and EU directives. Wetlands are threatened by global warming that affects directly through effects on physiology and behavior of species, and indirectly through changed hydrology and nutrient circulation and changed landuse. The distribution limits for many species are assumed to become displaced since the species try to find their climatic optima. This implies a risk for local extinctions and invasions. Reduced water runoff during spring is expected to lead to an areal reduction of wetlands, implying risks for a reduction of species richness. More frequent runoff peaks during summer can be expected to disturb plant growth and reduce their production. These hypotheses are tested in a series of experiments on wetland plants.