长江上游亚高山针叶林土壤水分入渗性能及影响因素

Water Infiltration and the Influential Factors of Soils Under Subalpine Coniferous Forests in the Upper Reaches of the Yangtze River

森林土壤水分入渗性能是森林生态系统水分循环的基本环节 ,直接影响森林 水文生态效应。本文研究了长江上游支流大渡河的水源地—贡嘎山东坡亚高山针叶林分布区土壤水分入渗性能及其影响因素 ,结果表明 :研究区土壤稳渗率均较大 ;其中混交成熟林土壤稳渗率最大 ,林木皆伐后土壤稳渗率最小 ,其它森林类型介于其间 ;土壤稳渗率与 >0 2 5mm水稳性团聚体含量、水稳性团聚体平均重量直径 (MWDw)、非毛管孔隙度呈极显著相关 ,与水稳性团聚体分形维数 (Fdw)呈显著性相关 ,另与森林类型、枯落物层、容重、砾石含量有一定相关性。

Water infiltration property is one of basic processes of water cycle of forest ecosystem and exerts influence on forest hydro-ecosystem directly.Water infiltration property and the influential factors of soils under subalpine coniferous forests on east slope of the Gongga Mountain,which is the water source of the Dadu River and lies in the Upper Reaches of the Yangtze River,were studied in this paper.The results showed that:the stable water infiltration rates of samples were large wholly and the largest were soil under mixed-mature forest,followed by soils under secondly forest,middle-aged forest,over-mature forest and slash;the stable water infiltration rates and percent of water stable aggregates(>0 25 mm),mean weight diameter(MWDw)of water stable aggregates and non-capillary porosity were all most significantly correlated(α=0 01),and those were significantly correlated with fractal dimension(FDw)(α=0 05)and correlated with type of forest,thickness of litter moss,bulk density and gravel at some degree.