晋西黄土区不同树种配置对林下植被物种多样性的影响

摘要

以晋西黄土区的油松林、刺槐林和油松刺槐混交林3种人工林群落为研究对象,通过地表植被调查,分析了不同树种配置对林下层物种多样性的影响.结果表明:在晋西黄土区,针阔叶树种的配置更有利于林下层植被多物种的共存;油松和刺槐的搭配种植显著提高了森林土壤的养分质量分数和林下植物群落的生物量,这些生态因子的改善又有利于其林下植被物种多样性的增加.因此,建议在该地区可适当扩大油松和刺槐混交林的种植面积,在充分发挥其水土保持功能的基础上提高地表植被的物种组成多样性.%The understory plant communities were investigated in pure plantations of Pinus tabulaeforrnis, Robinia pseudoacacia and a P. tabulaeformis-R. pseudoacacia mixed plantation in the Loess Plateau of west Shanxi Province in 2008. Effects of allocation of tree species on species diversity of forest floor were analyzed. Results show that the mixed allocation of conifer and broadleaf is favorable to the coexistence of more understory species. P. tabulaeformis-R. pseudoacacia mixed plantation could enhance the mass fraction of soil nutrients and the biomass of understory plant communities, which is propitious to increase the understory species diversity. Therefore, the planting area of P. tabulaeformis-R. pseudoacacia mixed plantations should be extended properly to increase the diversity of forest floor based on the full exertion of water and soil conservation functions.