1 Introduction.- 2 Distribution of Meteorological Variables in Forest Canopies.- 2.1 Forest Structure and Utilization.- 2.2 Variation of Meteorological Parameters Within a Stand.- 2.2.1 Radiation.- 2.2.2 Temperature.- 2.2.3 Humidity.- 2.2.4 Wind.- 2.3 Methods of Investigation.- 2.3.1 Field Measurements.- 2.3.2 Wind Tunnel Experiments.- 2.3.3 Analytic Description and Numerical Models.- 3 Air Flow Around and Through Individual Trees.- 3.1 The Numerical Model.- 3.1.1 The System of Equations.- 3.1.2 Boundary Values and Initial Conditions.- 3.1.3 Discretization and Numerical Solution.- 3.1.4 Parameterization of the Stand in the Model.- 3.2 Investigations on Single Trees.- 3.2.1 The Reference Run.- 3.2.2 Variation of Meteorological Input Parameters.- 3.2.3 Variations in Shape of the Individual Tree.- 3.2.4 Dispersion of Air Pollutants Around an Isolated Tree.- 3.3 Studies on Groups of Trees.- 3.4 Investigations of Wind Shelter Hedges.- 4 Air Flow Through and Above Stands.- 4.1 Improvement of the Numerical Model.- 4.2 Investigations in a Horizontally Homogeneous Stand.- 4.2.1 Determination of the Optimum Drag Coefficient.- 4.2.2 Influence of Stand Parameters on Temperature, Humidity, Wind and Turbulence.- 4.3 Investigations in a Horizontally Inhomogeneous Stand.- 4.3.1 The Influence of Deforestation Around the Western Runway of Frankfurt Airport.- 4.3.2 Effects of Complete Deforestation of the Finkenbach Valley (Odenwald) on the Local Climate.- 5 Concluding Remarks.- References.- Symbols.

Starting with the description of meteorological variables in forest canopies and its parameter variations, a numerical three-dimentional model is developed. Its applicability is demonstrated, first, by wind sheltering effects of hedges and, second, by the effects of deforestation on local climate in complex terrain. Scientists in ecology, agricultural botany and meteorology, but also urban and regional lanners will profit from this study finding the most effective solution for their specific problems.