Long-term studies of the influence of biogeochemical barriers (shelterbelts and stretches of meadows) on water cycling and control of ground water pollution in an agricultural landscape have shown that more solar energy is used for evapotranspiration in shelterbelts than in cultivated fields or meadows. Therefore, annual water runoff from cultivated fields is about 170% higher than from coniferous forest, 60% higher than deciduous forest and 16% higher than meadows. The differences in

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... piration rates between shelterbelts and meadows increases when additional energy input for evapotranspiration is provided by transport of heat from cultivated fields to these habitats by advection. The average water percolation time through the unsaturated zone of soils varies by 100%. A shelterbelt, having a mixed species composition, more effectively screens the passage of chemical compounds dissolved in ground water than shelterbelts composed of one tree species. Peat soils have a very high cation exchange capacity which increases the efficiency of riparian meadows for the control of ground water pollution. Natural landscape features which assist in controlling matter cycles are of great importance for modifying chemical outputs from agricultural watersheds.