主伐对森林景观结构和空间分布格局影响的研究

本文用不同尺度分析了采伐对森林景观的影响。通过对景观组成单元的类型、总体景观比例随海拔梯度的分布格局、景观内各组份水平分布的隔离度等比较表明，采伐后自然重建的景观与原生景观无显著差异，森林景观对采伐干扰具有渐进稳定性。各景观单元均属聚集性分布。景观内部结构的多样性、均匀度有一定提高，景观优势度有所降低。采伐使景观单元破碎化，出现重组现象。采伐引发的景观单元转移概率因类型不同而异；松栎混交林景观单元在其生态区位内稳定性强，对采伐有负反馈效应；华山松为优势的景观单元采伐后明显扩大，以铁杉为主的景观单元也有类似情况；弱度干扰的红桦、云、冷杉景观单元结构稳定并有所扩展。

Influence of Final Cutting on Landscape Structure and Spatial Distribution Pattern of Forests

Effect of cutting on forest landscape is anaIyzed at different scales in the paper. Com-parisons among different types of landscape units, distribution patterns of general landscape pro-portion with elevation gradient and isolation degree of horizontal distribution of different land-scape units showed that there was no significant difference between the original landscape and the natural reestablished landscape after cuttingl forest landscape had progressive stability against cutting disturbance. After cutting, aggergate distribution could be seen in all landscape units. In-ternal structure diversity and well -distributed degree of the landscape were enhanced, domi-nance of the landscape was decreased, though. The landscape units were broken because of cut-ting and reestablishment occurred. The transform probability of the landscape units caused by cutting varied with different types of landscapes; the landscape unit of mixed forest between pine and oak was stable at its niche and had a feed-back reaction to cutting; the unit dominanted by Pinus armandi was extended clearly for cutting, similar situation could also be found in the unit prevailed by Tsuga chinensis; the units of Betula albo-sinensis and Abies as well as Picea slightly disturbed by cutting were stable and enlarged further.