【摘要】 长期定位观测研究青海云杉林调节水分变化规律表明 :森林林冠层截留降水使到达林内的降水量减少、强度降低 ;林冠层遮蔽减弱了林内太阳辐射 ,降低了林内土壤蒸发 ,保持林内湿度较高、土壤含有较多水分 ;森林的蒸发散使同一高度林区上空的湿度比草地或裸地高。更多还原

【Abstract】 Through long term and located observation, the law and function of forests on hydrologic cycle, forest on the water evaporation, humidity and soil water of catchments areas were summarized. The forests influence the amount of precipitation and intensity, reduce evaporation in forest by canopy interception, which refrains from runoff and soil and water erosion. Forests reduce water evaporation of forests-land since canopy shadow, which keeps a full air humidity and water in the soil, provide shadow environment and full water conditions for hydrophilous vegetation growth. The air humidity of forests at the same height is higher than grasslands or bare lands due to the forests evaporation, and forests change the parts of air circulation, so make use of the favourable factors for precipitation and take effect for increasing rainfalls in forests area.更多还原