Dissipation of solar energy in landscape-controlled by management of waterand vegetation

Man (farmers, forest managers) by dealing with water and vegetation changes substantially the distribution of solar energy. Differences in sensible he at (warming) and latent heat (cooling by evapotranspiration) on drained and wetland areas, and the air conditioning effect of a single tree are demons trated. It is shown that the energy produced in all power stations of the C zech Republic is several orders of magnitude lower than the sensible heat r eleased from the drained and urban areas of the country. A single tree tran spiring about 400 1 of water a day has an air-conditioning efficiency of ab out 20 kW. Whereas photosynthesis (biomass production) uses less than 1% of incoming solar energy, by evapotranspiration (latent heat) more than 50% c an be used in water saturated vegetation. Distribution of temperatures (hea t potentials) in large areas is shown on satellite pictures. Land managers influence local climate and their important role should be considered in po licy-making decisions. (C) 2001 Elsevier'Science Ltd. All rights reserved.