种间关系对物种多样性-可入侵性关系的影响

Effect of Interspecific Interactions on the Relationship Between Diversity and Invasibility

物种多样性在群落抵抗外来生物入侵中的作用一直存在争论,种间关系如何影响物种多样性在抵抗入侵中的作用至今仍不清楚。该研究选择4个被喜旱莲子草入侵的自然草地群落(标注为A,B,C和D),分析不同环境特征条件下种间关系特征及其对群落物种多样性与可入侵性关系的影响。研究结果显示A和B区域土壤全氮含量低,本土植物植株密度低,群落本土物种丰富度与喜旱莲子草生物量呈现正相关;C区域群落土壤全氮含量高,本土植物植株密度高,本土物种丰富度与喜旱莲子草生物量呈现负相关;D区域群落土壤全氮含量高,本土植物植株密度高,群落本土物种丰富度与喜旱莲子草生物量无相关关系。在A和B区域优势物种植株数量与喜旱莲子草生物量呈现显著正相关,C区域呈现显著负相关,D区域呈现无相关。研究结果为解释物种多样性在群落抵抗外来生物入侵中作用存在的争论提供了一条新的理论解释途径。

The role of species diversity in invasion resistance has been debated.However,how how interspecific interaction affect the role of species diversity is unclear.Four natural grassland communities(labeled A,B,C,and D)invaded by Alternanthera philoxeroides were selected,and analyze interspecific interactions under different environments and their effect on the relationship between species diversity and invasibility.Results showed that A and B regions had low soil total nitrogen and plant density,and species richness positively correlated with biomass of invader.C region had high soil total nitrogen and plant density,and had a negative relationship.D region had high soil total nitrogen and plant density,and had no significant relationship.In A and B regions,plants number of dominant species positively correlated with invader biomass,while in C and D regions,plants number of dominant species negatively correlated with or have no significant relationship with invader biomass.Results provide a new theoretical explanation for the debate on the role of species diversity in invasion resistance.