Abstract:
In this study, the mobile sandy land in Zoige county in northwest Sichuan that has not been treated and treated for 5, 10, and 20 years were selected as the research object, and the chang process of plant community species composition, species diversity and spatial distribution pattern at different restoration times of mobile sandy land in northwest Sichuan were analyzed, so as to explore the stability of vegetation community structure after ecological restoration in this area, and provide scientific guidance for ecological restoration of sandy land in northwest Sichuan. The results showed that: (1) With the extension of the recovery time, the number of species in mobile sandy land increased. After 20 years of treatment, the number of plant species increased from about 3 in the untreated plot to about 21, and the vegetation coverage increased from below 5% to 75%. (2) The species diversity index of dominant population generally showed an upward trend with the extension of treatment time. After 20 years of treatment, the richness index, Simpson index, Shannon-Wiener index and evenness index increased by 172.51%, 49.45%, 123.79%, and 54.03% respectively. Among them, the richness index and Shannon-Wiener index increased the most, and the evenness index also increased significantly. (3) At different treatment time, the dominant population formed an aggregation distribution pattern, and the aggregation intensity of the same dominant population showed a significant upward trend with the extension of the treatment time. After 10 years of treatment, the species diversity index and aggregation intensity of dominant populations such as
Leymus secalinus and
Carex moorcroftii were higher, and the aggregation intensity index of dominant population of Kobresia in open sandy land was slightly different. Therefore, it can be concluded that the plant community has basically reached a relatively stable state after 10 years of artificial management of the mobile sandy land. It is proposed that the restoration measures such as setting up willow barriers, planting shrubs and grass, fertilizing, and prohibiting livestock disturbance can effectively promote the vegetation recovery in the ecological restoration of mobile sandy land in the alpine region of northwest Sichuan.