立枯物对红松洼自然保护区植物物种多样性的影响

以5a定位试验数据为基础,较全面分析了立枯物对山地草甸植物物种多样性的影响,并从立枯物对生态环境的影响角度探讨其影响机制。研究发现,经过连续10a的围封,立枯物对群落多样性指数、物种丰富度和均匀度指数影响较大。植物多样性和均匀度指数的变化是一致的,1999年达到峰值后下降,群落优势度却随时间的延长而增大。研究证明,立枯物是导致植物多样性和均匀度下降及群落优势度上升的主要原因。从生物多样性保护角度看,围封的管理模式仅限于草地退化后的早期管理,待植被恢复后还应有适宜的扰动,以减少立枯物的积累量。

Effect of standing litter on plant species diversity in Hongsongwa Natural Reserve

Based on the five-year orientation experiment,we analyzed the effect of standing litter on floral diversity on meadow,and explored the effect of standing litter on ecological environment.Standing litter exerted a great influence on Shannon-Wiever index,Pielou's index,and Margalef's index after ten year continuous envelop.The changes of floral Shannon-Wiever index and Pielou's index were consistent.The curve starts to decline after the peak in 1999,but the Simpson index increases from the beginning to the end.So,we concluded that standing litter is the main factor which results in the descent of floral Shannon-Wiever index and Pielou's index and the ascend of Simpson index.The administration model of envelop is restricted at an early stage for the degenerative meadow.The appropriate disturbance and mowing are necessary after restoration of vegetation to reduce the accumulation of stand-ing litter.