白洋淀湿地不同生境植物群落功能生态位及影响因素分析

Functional niche of plant communities and its influencing factors in different habitats of Baiyangdian wetland

为研究白洋淀湿地不同生境植物群落功能生态位特征及主要限制性环境因素,以白洋淀水生植物群落和洲滩草本植物群落为研究对象,利用功能生态位超体积量化不同生境植物群落功能生态位,利用Sørensen指数计算不同生境植物群落功能生态位超体积重叠程度,并探究影响不同生境植物群落功能生态位超体积的关键环境因子。结果发现,不同生境植物群落功能生态位超体积差异明显,表现为水生植物群落大于洲滩草本植物群落。2种生境植物群落功能生态位重叠程度为0.32。碱解氮、全磷是影响洲滩草本植物群落功能生态位超体积的主要环境因子,而影响水生植物群落功能生态位超体积的关键环境因子是碱解氮、速效磷和铵态氮。2种生境植物群落功能生态位超体积均表现为与生境氮元素含量呈显著正相关,与磷元素含量显著负相关。综上所述,白洋淀湿地不同生境植物群落功能生态位分化明显,洲滩草本植物群落功能生态位空间收敛程度更高,生境中有效氮元素含量和磷元素含量是植物群落功能生态位的主要驱动力。

In order to study the functional niche characteristics and main limiting environmental factors of plant communities in different habitats of Baiyangdian wetland.This study takes the floodplain herbaceous plant community and the aquatic plant community in Baiyangdian as the research objects.Functional niche hypervol-ume was hired to quantified the functional niche under different habitats in Baiyangdian wetland.Sørensen index was used to calculate the overlap degrees of functional niche hypervolumes for plant communities in different habitats.And then,this study explored the key environment factors affecting the functional niche hypervolumes of plant communities in different habitats.The results showed that the functional niche hypervolumes of plant com-munities in different habitats was significantly different,the functional niche hypervolumes of aquatic plant com-munity were higher than those of floodplain herbaceous plant community.The overlap degree of functional niche hypervolumes was small between plant communities in the two habitats with overlap index 0.32.Alka-line-hydrolyzable nitrogen and total phosphorous were the main environmental factors affecting the functional niche hypervolumes of floodplain herbaceous plant community.The key environmental factors affecting the func-tional niche hypervolumes of aquatic plant community included alkaline-hydrolyzable nitrogen,available phos-phorous and ammonia nitrogen.The functional niche hypervolumes were significantly positively correlated with the content of nitrogen,and negatively correlated with the content of phosphorous of plant communities in the two habitats.In conclusion,the plant communities showed obvious functional niche differentiation in different habitats,and the convergence degree of functional niche space of floodplain herbaceous plant community was higher than aquatic plant community.The content of available nitrogen and phosphorus in the habitats were the main driving force of functional niche of plant community in Baiyangdian wetland.