加拿大一枝黄花入侵对地上植被及土壤种子库的影响

Effects of Solidago canadensis invasion on aboveground vegetation and soil seed banks

为了探究外来植物对入侵地植物群落的影响,对加拿大一枝黄花(Solidago canadensis L.)入侵和未入侵地的地表植被和土壤种子库进行了样方调查和取样分析。结果表明:(1)加拿大一枝黄花入侵地地上植被的Shannon-Wiener多样性指数、Simpson优势度指数、Margalef丰富度指数、Pielou均匀度指数均低于未入侵地,且加拿大一枝黄花入侵后有利于野豌豆、加拿大一枝黄花等草本植物成为优势种。(2)与非入侵地相比,加拿大一枝黄花入侵地土壤种子库种子密度降低了58.36%,且入侵导致0~5 cm和5~10 cm土层的种子密度显著降低,分别降低了58.66%和68.75%;入侵地种子库的Shannon-Wiener多样性指数、Simpson优势度指数、Pielou均匀度指数在浅土层显著低于未入侵地。(3)入侵地和非入侵地土壤种子库都以多年生草本植物为主,但是入侵地的一年生草本植物明显低于非入侵地;土层越深土壤种子库与地上植被的相似性越低;入侵地各土层土壤种子库与地上植被的相似性高于未入侵地。明确了加拿大一枝黄花入侵改变植物群落结构特征,为本地植物群落的植被恢复和重建提供一定的科学依据。

In order to explore the impact of exotic plants on plant communities in invasive areas, sample surveys and sampling analyses were carried out on the aboveground vegetation and soil seed banks in invasive and uninvaded areas of Solidago canadensis L.. Our results showed that:(1) Shannon-wiener diversity index, Simpson dominance index, Margalef richness index and Pielou evenness index of the aboveground vegetation of the invasion of Solidago canadensis were all lower than those of uninvaded sites, the invasion of Solidago canadensis was beneficial to Vicia, and Solidago canadensis became the dominant species.(2) Compared with uninvaded plots,the seed bank density of Solidago canadensis invasion plots decreased by 58.36%, and the invasion caused a significant decrease in seed density of 0-5 cm and 5-10 cm soil layers, which decreased by 58.66% and 68.75%,respectively;Shannon-wiener diversity index, Simpson dominance index and Pielou evenness index of the seed bank of the invasive area were significantly lower than those of the uninvaded soil in the shallow soil.(3) Perennial herbaceous plants dominated the soil seed banks in both invasive and uninvaded plots, but annual herbaceous plants in invasive plots was significantly lower than that in uninvaded plots. The deeper the soil layer, the lower the similarity between soil seed bank and aboveground vegetation. The similarity between soil seed banks and aboveground vegetation in each soil layer of the invaded land was higher than that of the uninvaded land. The study showed that the invasion of Solidago canadensis changed the structure of the plant community, reduced the diversity of the local plant community and the seed density and diversity of the soil seed bank, and adversely affected the vegetation restoration and reconstruction of the local plant community.