浙江四明山沼泽中植物群落的生长季动态及其环境解释

Dynamics of Plant Communities in Marshes in Siming Mountain of Zhejiang Provience during Growing Season and Its Environmental Interpretation

为了了解浙江省山区沼泽中植物群落的组成、分布和影响因素,在浙江省余姚市四明山上水湖上游的沼泽中,设置了7处调查样地;于2021年5月和7月,在各调查样地,开展了野外植物调查,研究不同季节植物群落的物种组成、分布和α多样性;采用双向聚类分析、网络连接分析和冗余分析方法,分析物种间的关联、植物群落的时空差异及其环境解释率。研究结果表明,在7处调查样地的样方中,共记录20科31属35种野生维管植物,其中,莎草科(Cyperaceae)和禾本科(Poaceae)物种占优势,单属单种科所占比例(40%)较大;5月与7月植物群落的Shannon-Wiener指数、Simpson优势度指数、Menhinick丰富度指数和Pielou均匀度指数的平均值都无显著差异;可以将35种植物划归为萱草群丛(Ass. Hemerocallis fulva)、星花灯芯草+柳叶箬群丛(Ass. Juncus diastrophanthus+Isachne globosa)、三花悬钩子-紫萁+谷精草群丛(Ass. Rubus trianthus-Osmunda japonica+Eriocaulon buergerianum)和龙师草群丛(Ass. Heleocharis tetraquetra);从5月到7月,物种间网络连接拓扑结构的复杂性逐渐加强,体现在最中心节点数、聚集程度和种间关联上;表层土壤中的全氮、全磷和全钾含量是影响5月和7月四明山沼泽中植物群落生长状况的关键因素,坡度和土壤含水量也是其影响因素。

To understand the composition,distribution,and influencing factors of plant communities in the marshes in the mountains of Zhejiang province,7 investigation sites were established in the marshes of upstream of Shangshui Lake in Siming Mountain,Yuyao city,Zhejiang province.In May and July 2021,field surveys for plants were conducted in each investigation site to study the species composition,distribution,andα-diversity of plant communities during growing season.The two-way clustering analysis,network analysis,and redundancy analysis methods were used to analyze the associations between species,spatio-temporal differences in plant communities,and their environmental explanatory variables.The results showed that a total of 35 species of wild vascular plants belonging to 31 genera and 20 families were recorded in the sample plots of 7 investigation sites.Among them,species from the Cyperaceae and Poaceae families were dominant,accounting for a large proportion(40%)of the monogeneric monophyletic families.There were no significant differences in the average values of the Shannon-Wiener diversity index,Simpson dominance index,Menhinick abundance index,and Pielou evenness index between plant communities in May and July.The 35 plant species could be classified into 4 groups,including Ass.Hemerocallis fulva,Ass.Juncus diastrophanthus+Isachne globosa,Ass.Rubus trianthus-Osmunda japonica+Eriocaulon buergerianum and Ass.Heleocharis tetraquetra.From May to July,the complexity of the network connectivity topology among species gradually increased,as reflected in the number of the most central nodes,clustering coefficient,and interspecific associations.The total nitrogen,total phosphorus,and total potassium contents in the surface soil were key factors influencing the growth of plant communities in the marshes in May and July,while slope and soil moisture content were also influence factors.