Abstract
Under field conditions, most of rainfall drops on the surface of vegetation cover (canopy), not directly on the soil surface. Chemical properties of drops are changed when rainfall passes through the canopy. Dry deposition accumulated on the canopy between rain events is washed by rainfall. K+, Mg2+, Ca2+ and other materials are leached from internal plant tissues. NO3-, NH4+ and other solutes, gases and particles are taken from leaf surfaces covered with cuticle layer. Basically, dry deposition is an important nutrient source for plant growth. But sometimes these processes have harmful effects. Excessive leaching causes nutrient deficit and excessive deposition causes various disorders of plant growth. Therefore, the physiological processes on leaf surfaces are important to understand the nutrient cycling of terrestrial ecosystem. In alpine ecosystems, most of nitrogen is taken from leaf surfaces and considerable amount of water is absorbed from leaf surfaces. Dew and fog have important roles.
