青海省大通县主要造林树种枯落物水文效应研究

Hydrological Effects Study of Main Forestation Litters in Datong County,Qinghai Province

枯枝落叶在森林生态系统中占有极其重要的地位。本文对青海省大通县主要植被类型的枯落物，从持水能力、失水特性以及有效拦蓄量3方面分析。结果表明：（1）大通县鹞子沟主要造林地枯落物最大持水量变动范围为5．85～34．16t／hm^2，其中最大的云杉天然次生林为34．16t／hm^2，最小的华北落叶松林为5．85t／hm^2。云杉林下的枯落物最大持水量和最大持水率普遍高于沙棘林和华北落叶松林下的枯落物。（2）枯落物的持水量在失水实验开始的1～2h内迅速下降，之后速度变慢。说明枯落物拦蓄地表径流后，随着枯落物湿润程度的减小．失水能力降低，至达到枯落物的自然含水量。（3）在对枯落物有效拦蓄量的比较中发现，云杉林有效拦蓄量最大．其次是沙棘天然次生林，最小的为沙棘人工林。

Forest litters play an important role in forestry ecological system. The essay discussed forest litters of main plants in Datong county, Qinghai province. Three subjects were discussed, which is preserving capacity, losing water trait and effective holding quantity of rainfall. The results show： （1）The annual accumulation of different forest litter is about 5.85 - 34. 16 t/hm^2 , and the account of natural spruce is higher than others, the account of northern larch is the least. （2）The containing water quantity of forest litters dramatically dropped within 1 or 2 hours and then slowed down. It illustrates forest litters can reach natural containing water quantity with wetness of litters declining. （3）Comparing effective holding capacity of this three types of forest litters, the research found natural spruce was the best, and sea buckthorn followed, northern larch was the last.