黄顶菊对不同入侵地植物群落及土壤微生物群落的影响

Effect of Flaveria bidentis invasion on plant community and soil microbial community of different invaded soil

为明确不同入侵地植物群落和土壤生态对黄顶菊入侵的反馈机制,选取天津静海(JH)、河北沧州(CZ)、河北衡水(HS)及河南安阳(AY)4个黄顶菊入侵典型区域,研究黄顶菊对不同入侵地植物群落多样性、土壤理化及土壤微生物群落结构的影响,并进一步揭示植物群落、土壤养分和土壤微生物之间的相关关系。结果表明,黄顶菊入侵显著降低了JH、CZ和HS的植物群落多样性指数(P<0.05),改变了四个地区的土壤理化性质,显著升高了不同入侵地真菌PLFA的含量、总PLFA的含量、真菌/细菌和革兰氏阴性菌/革兰氏阳性菌(P<0.05),降低了土壤微生物的Margalef丰富度指数(P<0.05),但均存在地区间差异;RDA和相关分析的结果表明,硝态氮、全氮的含量对植物群落的影响较大,而铵态氮的含量对土壤微生物群落结构的影响较大,除丰富度指数外,植物群落与土壤微生物群落的多样性指数之间存在显著的负相关关系(P<0.05)。总之,黄顶菊改变了入侵地植物群落多样性,并且对入侵地土壤理化性质和土壤微生物群落结构产生了显著影响,且存在地区差异。本研究将为更好的理解外来植物的入侵机制及制定相应的防控策略提供理论依据。

In order to clarify the feedback mechanism of plant communities and soil ecology in different invasive areas to Flaveria bidentis,four typical invaded regions JH,CZ,HS,and AY(Jinhai in Tianjin,Cangzhou in Hebei,Hengshui in Hebei,and Anyang in Henan,respectively)were selected to determine the effects of invasion on plant community diversity,soil physical and chemical factors,as well as soil microbial community structure,and to further analyse these relationships.The results showed that the plant community diversity index of F.bidentis invaded soil(JH,CZ,and HS)significantly decreased(P<0.05)and the physical and chemical properties of four F.bidentis invaded soils changed.The fungi phospholipid fatty acids(PLFA),total PLFAs,fungi/bacteria and gram negative bacteria/gram positive bacteria in different F.bidentis invaded soil significantly increased due to the plant invasion(P<0.05),while the Margalef richness index of soil microorganisms was significantly reduced(P<0.05).Regional differences were also documented.The results of RDA and correlation analysis showed that the content of nitrate and total nitrogen had a greater influence on plant communities than other physical and chemical properties,while the content of ammonium had a larger impact on soil microbial community structure.Except for the Margalef index,there was a significant negative correlation between the diversity indices of the plant community and the soil microbial community(P<0.05).Overall,F.bidentis changes the diversity of plant communities in invaded habitats and has a significant impact on soil physical and chemical properties as well as soil microbial community structure,and there are regional differences.This study will provide a theoretical basis for a better understanding of the invasion mechanism,and for making corresponding prevention and control strategies for alien plants.