兴安落叶松老龄林分幼苗天然更新及微生境特点

对落叶松老龄林幼苗天然更新及微生境研究采用样线法，沿样线设置样方，调查样方内幼苗数、测定环境变量。结果表明，原始老龄林各环境变量中地表层的作用最突出，光照的作用最小，灌木层居中。一般，枯落物、根系盘结层和苔藓的作用较大，其中枯落物对苔藓的发育有抑制作用。抑制兴安落叶松更新的主要因素：在丛桦落叶松林中主要是草本植物、赤杨落叶松林为苔藓厚度、杜香落叶松林为苔藓厚度和根系盘结层厚度。

Natural Regeneration of Larix gmelini Seedlings and Micro-habitat in old-growth Larix gmelini Forests

In the old-growth Larix gmelini forests, natural seedlings and their microhabitat were studied by using line transect method.The quadrats, in which the number of seedlings and habitat variate were measured,were set up along the line.The results show that forest floor plays the most important role,shrub layer the second,and light the last. As for the forest floor,the litter, root layer and mosses occupy a remarkable position. The litter inhibites the mosses developrnent.The major factors that inhibit natural regeneration were grasses in L. gmelini-Betula fruticosa forest,moss thickness in L.gmelini-Alnus mandshurica forest,moss thickness and root layer in L.gmelini-Ledum palustre forest.