基于熵权法建立了草原旅游点植被退化评价流程,以甘肃夏河县桑科草原旅游点为例进行了实例研究。首先,建立了包括草群高度、植被密度和盖度以及物种丰富度指数、物种多样性指数和均匀度指数6个指标的草原旅游点植被退化评价体系。结果表明:桑科草原旅游点植物生长对旅游活动干扰的敏感性较高,植物物种对旅游活动干扰的敏感性较低;车辆碾压对植被破坏最为严重,各样区植被退化程度随着与破坏点(带/区)中心距离的增大而降低。随着草原旅游点植被退化程度的降低,植物科、属、种的数量均有较明显的增加,植物种间竞争关系增强;大车前(Plantago major)和鹅绒委陵菜(Potentilla anserina)逐渐失去竞争优势,萹蓄(Polygonum aviculare)的竞争力得到显著增强。利用熵权法对桑科草原旅游点植被退化程度的评价结果与前人关于旅游点植被破坏的研究规律相符,且桑科草原旅游点干扰区植物群落特征与植被退化评价结果相一致,说明建立的草原旅游点植被退化评价方法是合理准确的。
Vegetation on grasslands has been disturbed distinctly by the development of tourist resources. In this paper,the assessment process of vegetation degeneration at tourist spots in grasslands was established,and a case study on assessment of vegetation degeneration in the Snankoh Grasslands was carried out. At first,the assessment system of vegetation degeneration in the grasslands was established,which included the height of grass group,density,coverage,richness index,diversity index and evenness index of plants. The results of assessment revealed that the vegetation growth at the tourist spots in the Snankoh Grasslands was highly sensitive to the disturbance of tourist activities. Vehicle rolling was the most serious damage to vegetation. As the increase of the distance to the center of inference,the degree of vegetation degeneration was decreased obviously. As the reduction of degree of vegetation degeneration,the quantities of plant species,genera and families were increased obviously,the competition among plant species was more significant,Plantago major and Potentilla anserine lost their competitiveness gradually,and the competitiveness of Polygonum aviculare was enhanced significantly. The assessed results of vegetation degeneration at the tourist spots in the grasslands based on entropy-weight method consisted with the previous study results.