加拿大一枝黄花和小飞蓬共同入侵对植物群落的影响OACSTPCD

In order to clarify the coexistence mechanism of invasive plants and native plants under the co-invasion of two invasive plants,this study took the plant communities invaded by Solidago canadensis and Erigeron canadensis as the research object.The composition,diversity,niche width and functional traits of plant communities under different invasion levels were analyzed by quadrat method,and the effects of the co-invasion of two invasive plants on the diversity of aboveground plant communities were explained.The results showed that:(1)There were some differences in plant community composition between the invaded and uninvaded regions of S.canadensis and E.canadensis.Compared with single invasion,co-invasion increased the number of plant species in plant communities by 20.00%-66.67%.(2)Both single invasion and co-invasion significantly reduced the plant community diversity,and the number of species decreased by 18.75%-37.50%;the Shannon diversity in-dex decreased by 29.33%-65.33%,and the Pielou evenness index decreased by 38.60%-52.31%.(3)The domi-nant species in the co-invasion area of S.canadensis and E.canadensis were 1-3 more than those in the single invasion area.Under the condition of co-invasion,the niche overlap between invasive species and companion species was higher than that between companion species.(4)Compared with single invasion,co-invasion in-creased the five functional traits of coexisting plant species,including stem diameter,leaf area,leaf length,leaf width and belowground biomass,and increased the leaf area and leaf length of the two invasive plants by 13.70%-684.95%and 32.10%-71.55%,respectively.This study showed that the co-invasion antagonism of S.Canadensis and E.canadensis affects the plant community diversity,which can provide a theoretical basis for elucidating the coexistence mechanism of invasive plants and other plant species under the co-invasion of two invasive plants.