围封对荒漠草原典型植物群落特征及多样性的影响OA北大核心

[Objective]This study aims to elucidate the impact of enclosure on the characteristics and diversity of typical plant communities in desert grasslands,to provide scientific evidence for the conservation of plant resources,biodiversity,and the sustainable utilization and management of grassland resources in Ningxia desert grasslands.[Methods]Four typical plant communities,including Artemisia scoparia,Stipa breviflora,Sophora alopecuroides,and Artemisia ordosica,widely distributing in the desert grasslands of Ningxia,were selected as research objects to investigate the impact of enclosure measures on the structure and functional characteristics of different plant communities.[Results]Enclosure did not alter the dominant status of key species in the four plant communities but changed their functional group composition and importance values.Enclosure increased the total number of species in the annual plant community(Artemisia scoparia)by 13.33％but decreased the total number of species in perennial plant communities(Stipa breviflora,Sophora alopecuroides,Artemisia ordosica)by 30％,34.78％,and 40％,respectively.It reduced the number of perennial miscellaneous grass species in all four plant communities and increased the importance values of perennial miscellaneous grasses and perennial graminoids in perennial plant communities.Enclosure increased the height and aboveground biomass of the four plant communities and increased the canopy cover of Artemisia scoparia,Stipa breviflora,and Artemisia ordosica communities.Enclosure decreased the Margalef richness index of all four plant communities,the Shannon-Wiener and Simpson indices of perennial herbaceous plant communities(Stipa breviflora,Sophora alopecuroides),but increased the Shannon-Wiener,Simpson,and Pielou indices of the annual plant community.From the perspective of tne analysis on life form of key species in the communities,alpha diversity showed the order:perennial herbaceous＞subshrub＞annual herbaceous plant communities.Aboveground biomass was significantly positively correlated with canopy cover and height(p＜0.001),and significantly negatively correlated with the Margalef richness index(p＜0.001)and the Shannon-Wiener index(p＜0.05).[Conclusion]Enclosure can positively influence the canopy cover,height,and aboveground biomass of communities by altering the species composition of different plant communities.However,the sensitivity of diversity characteristics of different plant communities to enclosure measures varies.