云顶山亚高山草甸植物物种多样性对模拟增温的响应

Responses of subalpine meadow species diversity to simulated warming in the Yunding Mountain

为了研究气候变暖背景下亚高山草甸植被群落物种多样性对温度升高的响应,将云顶山亚高山草甸作为研究区,采用开顶式增温箱(OTC)进行模拟增温样地布设,随机设置对照(CK)、低度增温(OTC1)和高度增温(OTC2)3种试验处理。结果表明:(1)该区禾草、莎草、杂草三种功能型植物当中,以杂草类植物为主;禾草类植物在低度增温下重要值增加12.92%,在高度增温下增加20.66%;杂草类植物在低度增温下的重要值减小13.15%,在高度增温下减小10.73%;而莎草类植物在低度增温下重要值增加0.23%,在高度增温下其重要值减小9.93%。(2)该区各物种多样性指数在不同增温处理下变化趋势不同,过度增温对草甸物种多样性产生一定的负面影响。可见,在全球变暖的背景下,云顶山亚高山草甸禾草类植物对温度升高的响应更加迅速,物种多样性趋于降低,因此需要对亚高山草甸植物进行保护。

In order to study the response of species diversity of subalpine meadow vegetation to temperature rise in the context of climate warming,this study regarded the Lvliang Mountain as a research area and its subalpine meadow as the object.We adopted open-top chambers as a main method in a simulated warming experiment to research the relationship between the increasing temperature and the vegetation diversity.Three plots in simulated warming were set at different areas;they were control,low temperature increase(OTC1),and high temperature increase(OTC2).The results showed that:(1)Among the three functional plants of grass,sedge and weeds in this area,the weeds were represented by Rosaceae and Compositae dominantly.The importance value of grass in the community increased by 12.92%at low temperature and 20.66%at high temperature.The importance value of weeds decreased by 13.15%at low temperature and decreased by 10.73%at high temperature.But the importance value of sedge increased by 0.23%at low temperature and decreased by 9.93%at high temperature.(2)Variations of species diversity indices were different under different warming treatments in this area.The over increased temperature had some negative effects on the species diversity of the subalpine meadow.It can be seen that under the background of global warming,the species diversity tends to decrease and its grass respond more rapidly to the increasing temperature in the subalpine meadow of Yunding Mountain,so it is necessary to protect the subalpine meadow plants.