Impact of agricultural landscape structure on energy flow and water cycling1

In long term studies the following climatological characteristics were measured or calculated: air and soil temperature, sunshine, wind speed, vapor pressure, saturation deficit, precipitation, humidity, incoming and reflected solar energy, energy emitted by active surfaces and primary production. Taking into account the relationships between climatological characteristics, the growth stages of vegetation, and relations between heat balance components, the fluxes of energy used for evapotranspiration, air, and soil heating were estimated in various ecosystems composing the agricultural landscape. The energy contained in biomass production of various crops was estimated also. Aggregate estimates of energy flow connected with evapotranspiration, and soil and air heating were calculated for eight model landscapes which differed by the plant cover structure. A higher variability of energy fluxes was observed for individual ecosystems than for agricultural landscapes. It was shown that the structure of the plant cover has an important bearing on energy flow and water cycling both by direct and indirect influences. Shelterbelts are especially important in their influence on energy flow and water cycling.