甘南白龙江上游小流域主要林分地被物层的持水特性分异

在甘南白龙江上游林区内，采用实地踏测和浸水法，对林区内主要的4种不同林分类型（冷杉原始林、云杉、落叶松和华山松人工林）林下地被物持水性能进行了研究分析。结果表明:（1）4种不同类型树种林下地被物的总蓄积量为11.75～28.96 t/hm²，其冷杉林（28.96 t/hm²）>落叶松林（16.17 t/hm²）>华山松林（14.36 t/hm²）>云杉林（11.75 t/hm²）；（2）不同林分类型地被物的持水量、吸水速率与浸泡时间之间的动态变化基本相似，持水量与浸水时间存在对数关系，其吸水速率与浸水时间呈幂函数关系。（3）不同树种林下地被物的总有效拦蓄量为21.00～41.99 t/hm²，其中冷杉林最大，其次是落叶松林，最后是华山松林和云杉林；最大拦蓄量、最大持水量、有效拦蓄量和总有效拦蓄深的变化与总有效持水量变化一致。

Water-holding Performance of Major Forest Litter Layer in Bailong River Upstream Watershed of Gannan

By the methods of field survey and soaking extraction, an investigation on the water-holding capacity of the litters under four main forests (fir forest, spruce forest, larch forest, Pinus armandi forest) was conducted in Bailong River of Gansu. The accumulation amount of the litters under forests ranged from 11.75 t/hm² to 28.96 t/hm², and followed the order:fir forest(28.96 t/hm²) > larch forest(16.17 t/hm²) > Pinus armandi forest(14.36 t/hm²) > spruce forest(11.75 t/hm²); the litter, water-holding capacity changed logarithmically with their soaking time, the water-absorption rate of the litter presented a power function with immersing time. The effective retaining amount of the litter decreased in order:fir forest > larch forest > Pinus armandi > spruce forest.