基于植物多样性的喀纳斯景区山地草甸生态系统恢复力评价

Evaluation of Mountain Meadow Ecosystem Resilience Based on Plant Diversity of Kanas Scenic Area

在明晰草地生态系统恢复力涵义的基础上,建立一个基于植物多样性的草地生态系统恢复力评价体系,从维持自身结构与功能能力、恢复能力、抵抗能力3个方面定量测度草地生态系统恢复力,并对受到人类活动干扰而受损的新疆喀纳斯景区山地草甸生态系统的恢复力进行定量评估,以期为景区草地生态系统的科学管理提供依据。结果表明:随着人类活动强度及频度的增加,山地草甸生态系统维持自身结构与功能能力和恢复能力在物种多样性、功能群多样性及群落多样性层次均呈下降趋势,且背景区、缓冲区均显著高于活动区与强烈活动区(P<0.05);抵抗能力在物种多样性层次也随着人类活动强度及频度的增加而呈下降趋势,多年生植物是物种多样性层次恢复力的主要贡献者;但在功能群多样性和群落多样性层次则由于功能群与群落的功能冗余作用,稳定了群落的生产力和生态系统过程,虽呈下降趋势,但下降程度和变化幅度减缓。这反映了利用单一指标或单一植物多样性组织层次评价草地生态系统恢复力的不足之处。因此,多尺度草地生态系统恢复力评价体系避免了单项指标评价的偏差,使得评价更加合理。

In order to provide evidence for grassland ecosystem scientific management of Kanas Scenic Area,a more clear definition with associated evaluation of ecosystem resilience is suggested.Plant diversities of damaged mountain meadow ecosystem by human disturbance（tourism,grazing and other human activities） were investigated using the indices of ecosystem（community） structure,function maintenance,recovery capability,and resistance ability.Results showed that the maintenance of ecosystem（community） structure and function as well as recovery capability all had a decreasing trend with human disturbance increasing.There were significant differences between buffer zone and intense activity zone,background zone and activity zone,as well as background zone and intense activity zone（P0.05）.The resistance ability of species diversity decreased while human disturbance increased.Perennial plants were the main contributors of the resistance ability of species diversity.However,trend and change amplitudes of resistance ability were slowed in functional diversity and community diversity due to the functional redundancy of functional groups and community.The stability of community productivity and ecological processes could resist human disturbance.Therefore,the evaluation system of grassland ecosystem resilience is more rational and avoids the deficiency of evaluating deviation of single index.