摘要:从物种多样性和功能多样性探讨沉水植物群落对水深的响应可深刻揭示水深对群落构建的影响机制。以南四湖不同水深沉水植物群落为研究对象，对比分析了群落的9个加权功能性状（株高、茎分支数、茎节数、茎直径、根长、根围直径、生物量分配比、比叶面积、植物体磷含量）、5个物种多样性指数（Berger-Parker生态优势度指数、Margalef丰富度指数、Simpson多样性指数、Shannon-Wiener多样性指数和Pielou均匀度指数）和5个功能多样性指数（功能丰富度FRic指数、功能均匀度FEve指数、功能离散度FDiv指数、功能分散度FDis指数和二次熵Rao指数）以及物种多样性和功能多样性关系对水深的响应规律。研究结果表明：（1）水深可显著改变群落株高、根长、根围直径、比叶面积、生物量分配比和植物体磷含量6个加权功能性状；群落茎分支数、茎节数和茎直径3个加权功能性状对水深变化无显著响应；（2）水深可显著影响群落物种多样性和功能多样性，中等水深处沉水植物群落具有较高的Margalef丰富度指数、Shannon-Wiener多样性指数、Berger-Parker生态优势度指数、Pielou均匀度指数以及功能丰富度FRic指数、功能均匀度FEve指数、功能离散度FDis指数、二次熵Rao指数；（3）水深可改变5个物种多样性指数与功能丰富度FRic指数、功能均匀度FEve指数、功能离散度FDiv指数3个功能多样性指数间的相关关系，但对5个物种多样性指数与功能离散度FDis指数、二次熵Rao指数2个功能多样性指数间的相关关系无显著影响。研究结论为：群落不同测度的物种多样性和功能多样性指数及其相关关系对水深变化的响应迥异，在探讨水深对沉水植物群落构建的影响机制时应从多个方面综合考量。



Abstract:Understanding how traits and multiple diversity of plant community change along with environment gradient can profoundly reveal the mechanism of environment factors on plant community assembly. Water depth is a critical factor affecting the community assembly of submerged macrophytes in lakes. In this study, we aim to examine how the community weighted functional traits, species diversity, functional diversity and the association of the two facets diversity respond to water depth gradients. We collected the submerged macrophytes samples at 300 sampling points along 10 transects in Nansi Lake, which crossed the water depth of the submerged macrophytes colonized in the lake. Then, we measured nine community weighted functional traits (plant height, branch number, internode number, stem diameter, root length, rhizosphere diameter, aboveground weight/underground weight ratio, specific leaf area and plant phosphorus content), five species diversity indexes (Berger-Parker dominance index, Margalef richness index, Simpson diversity index, Shannon-Weiner diversity index and Pielou evenness index), and five functional diversity indexes (FRic functional volume index, FEve functional evenness index, FDiv functional division index, FDis dispersion index and Rao functional division two-times entropy index) for these samples. The results showed that: (1) community weighted height, root length, rhizosphere diameter, aboveground weight/underground weight ratio, specific leaf area and plant phosphorus content differed significantly among different water depths, while branch number, internode number and stem diameter were not significantly different among different water depths. (2) The submerged macrophytes community at moderate water depths showed the highest species diversity and functional diversity. (3) Correlations between five species diversity indexes and three of the functional diversity indexes (FRic index, FEve index, and FDiv index) were dependent on water depth, while the correlations between five species diversity indexes and FRic index, FDiv index were independent on water depth. Our results suggested that species diversity, functional diversity of the submerged macrophytes in Nansi Lake showed a similar trend in response to water depth gradients, but their associations varied along with water depth. Therefore, simultaneous considering the two facets of diversity would be essential for revealing the mechanism of water depth on submerged macrophyte community assembly.





PDF全文下载地址:

https://www.ecologica.cn/stxb/article/pdf/stxb201904100715