踩踏干扰对滇西北高寒草甸的影响/响应机制研究

According to the stand protocol for controlled trampling experiments (i.e. Before-After-Impact-Control,BAIC) proposed by Cole and Bayfield, as well as investigation results of vegetation degradation and habitat characteristics, trampling experiments were conducted in three types of alpine meadows (namely alpine meadow, rocky meadow and forest edge meadow) in the northwest of Yunnan province. Quantitative analysis on vegetation and soil changes under different trampling densities were carried out in terms of four indices including vegetation appearance (vegetation height and coverage), vegetation structure (species richness and frequency), function (vegetation resilience and resistance) and habitat characteristics (soil thickness and compaction), so as to determine the responses of different alpine meadows to trampling disturbances. Significant and representative indices were selected to build TRAMPLING DENSITY-VEGETATION RESPONSE model, and analysis of variance (ANOVA) were adopted to identify the threshold value of vegetation response to trampling intensity. Such quantitative research on vegetation response to trampling is not only helpful in understanding the process of trampling disturbance,but also beneficial to relevant researches on alpine meadow recovery in northwestern Yunnan as well as nationwide.Moreover, the identification of reponse threshold under trampling intensities would provide new theoretical and data support for tourism capacity assessment in alpine meadow region.

参照Cole和Bayfield（1993）提出的踩踏实验标准设计（BACI），结合草甸植被退化和生境调查的结果，在滇西北选择3个不同类型的高寒草甸区（高山草甸、高寒石质草甸和林缘草甸）开展踩踏实验。定量分析不同踩踏强度下高寒草甸植被外观（物种高度、盖度）、结构（物种丰富度、频度）、功能（恢复力、抵抗力）、生境特征（土层厚度、土壤紧实度等）等植被土壤参数的变化和差异，以确定不同高寒草甸类型对踩踏干扰的响应规律。选择变化明显、具代表性的指标，与踩踏强度一起构建"踩踏强度-植被响应"模型，结合方差分析确定参数发生转变的阈值。通过对踩踏干扰的响应特征的量化研究,进而实现对"踩踏干扰-植被响应"机制的定量分析，弥补国内研究不足，同时为滇西北高寒草甸的恢复研究提供数据。通过确定不同草甸类型在不同踩踏干扰强度下的响应阈值，为高寒草甸旅游承载力的计算提供新的理论和数据的支撑。