林分密度对生态公益林群落结构和物种多样性的影响——以新津文峰山马尾松为例

Effects of Stand Density on Community Structure and Species Diversity of Ecological Non-Commercial Forest——A Case Study on Pinus massoniana in Wenfeng Mountain,Xinjin District,Sichuan Province

【目的】为给新津县文峰山马尾松生态公益林寻求一个合适的林分密度,以发挥当地生态公益林的综合效益,并实现其可持续发展。【方法】采用典型样地法,以四川新津文峰山5种不同林分密度(A:1 000株/hm2;B:1 125株/hm2;C:1 250株/hm2;D:1 375株/hm2;E:1 500株/hm2)25 a生马尾松人工生态公益林为研究对象,对该地物种多样性指数及群落径级、高度级结构进行综合分析。【结果】(1)共记录植物122种,隶属57科98属;(2)不同林分密度对乔木层径级和高度级结构的影响不显著,对乔木层优势种有显著影响,但对灌草层植被的优势种无明显影响;(3)林分密度对灌草层植物多样性指数呈显著(P<0.05)或极显著(P<0.01)相关。随着密度的增大,林下物种多样性均先增大后减小,且在密度为1 125株/hm2时取得最大值。【结论】研究认为当地林分密度为1 125株/hm2时,能显著提高新津文峰山马尾松生态公益林群落的稳定性和物种多样性。

【Objective】The aim of the study was to select a suitable stand density for the ecological noncommercial forest of Wenfeng Mountain Pinus massoniana in Xinjin County,which might be beneficial for local ecological forest and sustainable development.【Method】25-year-old P. massoniana forest with5 density classes（A： 1 000 plant/hm^2;B： 1 125 plant/hm^2;C： 1 250 plant/hm^2;D： 1 375 plant/hm^2;E： 1 500 plant/hm^2） were chosen in this study. The plant diversity index,population diameter and height structure were comprehensively analyzed.【Result】（1）122 species were identified,belonging to 98 families and 98 genera;（2）Plant density had no significant effect on tree diameter and height structure,but had an effect on main dominant species of arbor layer vegetation. Similarly,plant density had no significant effects on main dominant species of shrub and grass layer;（3）Plant density was significantly correlated with plant diversity index. With an increase of density,the diversity of forest species increased first and then decreased. And,the maximum value exited in the P. massoniana stand with 1 125 plant/hm^2 density. 【Conclusion】The stability and species diversity of P. massoniana community was relatively well in Wenfeng Mountain of Xinjin County when the density was about 1 125 plant/hm^2.