落叶松人工林采伐前后下层植被的演替

随着兴安落叶松人工要的林龄不同，林下小生境也随之变化，从而，导致了林下植被的演替。３０多年来，通过对落叶松人工林下层植被演替的定位研究表明：随着林龄的增加，林分郁闭度加大，原次生林下的草本植物在种类、盖度１高度和多度上相对减少，而阴性杂草增加；当落叶松人工林实行皆伐作业皇，阳性杂草又随之大量侵入。鉴于林下植被演替的这一特点，营造落叶松人工林后应及时进行间伐透光，为草本植物的生长发育创造有利条件。有

THE UNDERGROWTH SUCCESSION IN LARCH PLANTATIONS BEFORE AND AFTER CUTTING

With the increase in stand age. the micro-environment under the forest waschanged. and the undergrowth succession occured consequently. More than 30years of research proved that, with the increase in stand age and canopy density,herbs pre-occured in the natural sencondary forest diminished in speciescomposition, coverage, height, and abundance. But, shade-demanding grassesflourished. When clear-cutting system was employed the the larch plantations.light-demanding grasses recurred abundantly. The study results are ofimportance to the practice and theory of forest management.