摘要
From the biological point of view the value of autotrophy plant association is determined by the carbon fixation and the carbon cycle. Among the plant associations of Hungary, forest has the largest biological carbon fixation and carbon cycle. In general, the annual water cycle is the key factor in the organic material production of the Hungarian forests. The most intensive water con- sumption and organic material production take place from May till July, which period is named main water consumption and respec- tively main growing period, In Hungary the categories of the forest climate are characterized by main tree species and based on the characteristic meteorological data （Jaro and Tatraaljai, 1985）. In Hungary the forest area covered by stand is 1,650,000 hm2. Beech forest climate covers 8% of the forest area, hornbeam-oak forest climate covers 22%, sessile oak-Turkey oak forest climate covers 48% and forest steppe climate covers 22%. Partly in the frame of ICP-Forests, the Department of Ecology in the Forest Research Institute carries out long term, complex ecophysiological investigations on several sample plots （so-called basic plots） throughout the whole country. The organic material production （growth）, the nutrient and water cycle, the measurements of air pollutants and mete- orological parameters, as well as chemical analyses are all part of the investigations. As a comparison the figure of two basic plots （Sopron Pasp0kladfiny） shows the water cycles of a good growing beech stand in beech climate and a wcak pedunculate oak stand in forest steppe climate in the hydrological year of 2001-2002. In the Hungarian forest 60% 70% of the precipitation is used for inter- ception, evaporation, and in the vegetation season, for the transpiration both in beech and forest steppe climate. From other point of view, only 30%-40% of the open air precipitation infiltrates into the soil and can be utilized by the forest.
From the biological point of view the value of autotrophy plant association is determined by the carbon fixation and the carbon cycle. Among the plant associations of Hungary, forest has the largest biological carbon fixation and carbon cycle. In general, the annual water cycle is the key factor in the organic material production of the Hungarian forests. The most intensive water con- sumption and organic material production take place from May till July, which period is named main water consumption and respec- tively main growing period, In Hungary the categories of the forest climate are characterized by main tree species and based on the characteristic meteorological data （Jaro and Tatraaljai, 1985）. In Hungary the forest area covered by stand is 1,650,000 hm2. Beech forest climate covers 8% of the forest area, hornbeam-oak forest climate covers 22%, sessile oak-Turkey oak forest climate covers 48% and forest steppe climate covers 22%. Partly in the frame of ICP-Forests, the Department of Ecology in the Forest Research Institute carries out long term, complex ecophysiological investigations on several sample plots （so-called basic plots） throughout the whole country. The organic material production （growth）, the nutrient and water cycle, the measurements of air pollutants and mete- orological parameters, as well as chemical analyses are all part of the investigations. As a comparison the figure of two basic plots （Sopron Pasp0kladfiny） shows the water cycles of a good growing beech stand in beech climate and a wcak pedunculate oak stand in forest steppe climate in the hydrological year of 2001-2002. In the Hungarian forest 60% 70% of the precipitation is used for inter- ception, evaporation, and in the vegetation season, for the transpiration both in beech and forest steppe climate. From other point of view, only 30%-40% of the open air precipitation infiltrates into the soil and can be utilized by the forest.
