加拿大一枝黄花和小飞蓬共同入侵对植物群落的影响

Effects of the co-invasion of Solidago canadensis and Erigeron Canadensis on aboveground plant communities

为阐明两种入侵植物共同入侵下入侵植物和其他植物的共存机理,以加拿大一枝黄花(Solidago canadensis)和小飞蓬(Erigeron canadensis)共同入侵的植物群落为研究对象,通过样方调查法分析不同入侵程度条件下植物群落的组成、多样性、生态位宽度和功能性状,阐释2种入侵植物共同入侵对地上植物群落多样性产生的影响。结果表明:(1)2种入侵植物在入侵地与未入侵地的植物群落组成存在一定的差异;与单一入侵相比,共同入侵增加了植物群落的植物种类数,增幅为20.00%~66.67%。(2)无论是单一入侵还是共同入侵,均显著降低了植物群落多样性,其中物种数目减少18.75%~37.50%;Shannon多样性指数降低29.33%~65.33%;Pielou均匀度指数降低38.60%~52.31%。(3)加拿大一枝黄花和小飞蓬共同入侵地的优势种比单一入侵地的多1~3种;共同入侵条件下,入侵种和伴生种间的生态位重叠度高于伴生种之间。(4)与单一入侵相比,共同入侵增加了共存植物种的5种功能性状:茎粗、叶面积、叶长、叶宽和地下生物量,也增加了2种入侵植物的叶面积和叶长,增幅分别为13.70%~684.95%和32.10%~71.55%。该研究表明加拿大一枝黄花和小飞蓬共同入侵拮抗性影响了植物群落多样性,可为阐明两种入侵植物共同入侵下的入侵植物和其他植物种的共存机理提供理论基础。

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 index decreased by 29.33%–65.33%,and the Pielou evenness index decreased by 38.60%–52.31%.(3)The dominant 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 increased 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.