东灵山风景区草甸资源退化评价及管理措施

Assessing Meadow Vegetation Degradation in the Tourist Attraction Dongling Mountain of Beijing

将样带与样方调查方法相结合,对北京东灵山山顶草甸风景区进行实地取样。采用盖度、高度、物种多样性、地上生物量、一年生、二年生植物所占比例、土壤理化特征等参数,通过去趋势典范对应排序分析(DCCA)对草甸退化状况进行数量化评价,辨识草甸退化的不同等级。结果表明,草甸退化分为常规干扰草甸、轻度退化草甸、中度退化草甸及重度退化草甸等4个等级,草甸退化等级的划分一方面表现为盖度、高度、地上生物量、物种多样性、土层厚度等降低,同时也表现为一年生、二年生植物相对数量的增加和优势种的变化过程。在风景区管理中,鉴于常规干扰草甸与轻度退化草甸的群落特征,在管理方面不需要采取特殊保护措施,应以定期监测为主,控制大规模游人活动。在利用方面,可以继续向游人开放,并可以用于适当放牧,但应该采取适当短期休牧,以保持或恢复草甸植被正常生产力;对中度和重度退化草甸,应采取人工建植乡土植被、分期封育以及规范旅游区商贩和游客行为等措施,防止草甸资源进一步退化,促进草甸植被恢复。

Dongling Mountain, located in the western part of Beijing municipality（115°27′ - 115°29′N, 40°1″- 40°3″E）and with precious natural heritage of Beijing＇ s biodiversity and the most famous scenic spots, is sensitive to environmental change due to over-exploitation and lack of management. Meadow vegetation with subalpine features, which located in the area from 1 791m to 2 140m above sea level high, was the key research area. Through analyzing the field survey data collected from 49 quadrats, the degradation of the tourist attraction meadow in Dongling Mt of Beijing has been assessed. Coverage, height, species diversity, aboveground biomass, percentage of annual and biannual plants in total species and soil parameters were recorded during the sampling, and applied to ordination process by two calculation steps of the Detrended Canonical Correspondence Analysis （DCCA） with CANOCO （version 4.5 ） to differentiate different degradation groups. By the first step, serious degraded meadow was easily differentiated from other groups, and other three degraded meadows, moderate degraded meadow, mild degraded meadow, conventional interfered meadow, were respectively differentiated by the second calculation step. The results show that there are four degradation groups, which can be recognized through the gradients of increase of percentage of annual and biannual plants and of reduction of the coverage, the height, the aboveground biomass, the species diversity and the soil depth, combining with the change of dominant species. Conventionally interfered meadow and mild degraded meadow can be opened to tourists, but with taking appropriate short-term exclosure to restore normal meadow vegetation productivity. Artificial restoration measures by planting indigenous plants, fencing periodically the serious and moderate degraded meadow from tourists and animals, and keeping the peddlery away from the core area of meadow should be effective for protecting the meadow from further degradation and for the conservation of meadow resource.