不同入侵程度紫茎泽兰对草本层物种多样性和功能多样性的影响

Effects of different invasion degrees of Ageratina adenophora on species diversity and functional diversity of herbaceous layer

紫茎泽兰是我国外来入侵物种中危害最为严重的植物之一,为探讨不同入侵程度紫茎泽兰对草本层物种多样性和功能多样性的影响,在楚雄市西山自然保护区内设置紫茎泽兰不同入侵程度样地,调查并分析草本层植物的物种多样性指数和功能多样性指数与环境因子之间的相关性。结果显示:(1)不同程度紫茎泽兰入侵的草本层存在多重动态影响机制;(2)高度入侵的紫茎泽兰会显著降低本地草本层植物的物种多样性;(3)随着入侵程度增加,草本层植物的功能性状结构由聚集走向发散,竞争性排斥的作用逐渐明显;(4)土壤水分含量是影响该区域紫茎泽兰入侵的关键环境因子。因此,草本层的物种多样性和功能多样性均会受到紫茎泽兰入侵的影响,而当地抗干扰能力较强的物种能有效抵抗入侵压力,保持稳定的种群数量。

Ageratina adenophora is one of the most harmful invasive plant species in China.To explore the effects of A.adenophora with different invasion degrees on the species diversity and functional diversity of plant communities,plots with different invasion degrees of A.adenophora were set up in the Xishan Nature Reserve of Chuxiong City,and the correlation between species diversity index and functional diversity index of herbaceous layer plants and environmental factors was analyzed.The results showed that,(1)There were multiple mechanisms dynamically influencing the herbaceous layer with different invasion levels;(2)Highly invasive A.adenophora significantly reduced the species diversity of the native plant community;(3)With the increase of invasion intensity,the functional trait structure of the community moved from aggregation to dispersal,and the role of competitive exclusion was gradually obvious;(4)The soil moisture content was a key environmental factor influencing the invasion of A.adenophora in this region.Therefore,both species diversity and functional diversity in the herbaceous layer were affected by the invasion of A.adenophora,and the local species with strong anti-interference ability can effectively resist the invasion pressure and maintain a stable population.