The Water Balance of Wet Grassland Sites with Shallow Water Table Conditions in the North-Eastern German Lowlands in Extreme Dry and Wet Years

In recent years, Germany has experienced an increasing number of extreme wet and dry years. the North German lowlands, grassland sites with shallow water table conditions are widespread landscape elements. They characterized by a special nutrient balance that reacts very sensitively to changes in hydrological system. Studies on evapotranspiration (ETa) development groundwater levels were carried out at two typical conditions. A weighable lysimeter system Spreewald wetland (SPW) eddy covariance station Havelländisches Luch (HL) used measure ETa. The results show even these cannot sufficiently meet vegetation’s demands drop values deeper than 1 m below surface. As result, supply vegetation is temporarily limited. mean crop coefficients (Kc) reach 1.1 period sufficient supply, but around 0.8 years when Areas small catchment areas, such as HL, more seriously affected meteorological areas inflows from larger SPW.