大狼毒型亚高山草甸植被演替对围封的响应

Response of Vegetation Succession to Enclosure in Euphorbia jolkinii Subalpine Meadow

在青藏高原南缘香格里拉县,采用野外植被调查的方法,开展围封1至7年大狼毒型退化亚高山草甸物种组成、多样性及群落结构的研究。研究结果显示:经5年以上围封,大狼毒型亚高山草甸的优势物种组成由之前的“大狼毒(Euphorbia jolkinii)+西南委陵菜(Potentilla fulgens)+绶草(Spiranthes sinensis)”演替为“大狼毒(E.jolkinii)+草地早熟禾(Poa pratensis L.)+西南委陵菜(P.fulgens)”。围封后群落中优良牧草优势地位显著增加,毒害草优势地位下降。草地地上生物量、密度、盖度、物种多样性和均匀度显著增加,生态优势度显著下降(P<0.05)。综上所述,围封有利于青藏高原南缘大狼毒型退化亚高山草甸的植被恢复。

The species composition,diversity and community structure of degraded Euphorbia jolkinii subalpine meadow enclosure for one to seven years were studied in Shangri-La county,southern edge of Qinghai-Tibet Plateau,by using the method of field vegetation survey.The results showed that after more than 5 years of enclosure,the dominant species composition of E.jolkinii subalpine meadow changed from“E.jolkinii+Poa pratensis L.+Potentilla fulgens”to“E.jolkinii+P.fulgens+Spiranthes sinensis”.After enclosure,the domination of high-quality forages in the community increased significantly,while that of weeds dramatically declined.The aboveground biomass,density,coverage,species diversity and evenness increased significantly,while the ecological dominance decreased significantly(P<0.05).In conclusion,the enclosure is beneficial to the vegetation restoration of degraded E.jolkinii subalpine meadow in the southern edge of Qinghai-Tibet Plateau.