Ecography:中科院版纳植物园发表藤本植物群落结构的系统发育研究

Ecography上发表题为“Phylogenetic clustering increases with succession for lianas in a Chinese tropical montane rain forest ”的研究结果。

应用整合的系统发育数据进行植被调查，不仅可以帮助科学家理解植物群落如何组成，而且还可以探索在近缘植物的生理和生态都是相似的情况下，群落结构是否由环境梯度或者生物的交互作用而成。这也使得科学家可以深入了解次生林等的演替过程。但是目前为止，对于被干扰的森林在该方面的研究仍然较少，特别是针对非树木方面的研究更少。已有研究表明，随着干扰的增加，热带树木群落倾向于由近缘物种组成，这就表明群落组成主要是受早期演替过程中的非生物因素的影响。藤本植物是热带森林的重要组成部分，但是其群落结构的系统发育还未被调查清楚。与热带树木不同，藤本植物在被干扰的森林中也常具有高的多度，而且其多样性在老的次生林中可以达到顶峰。因此，藤本植物的系统发育结构随着干扰梯度的变化也可能不同于热带树木群落。

中国科学院西双版纳热带植物园群落生态与保护研究组Mareike Roeder与其指导老师Ferry Slik以及其他工作人员以勐宋热带山地森林为研究对象，基于DNA条码序列构建了100个不同枝长的等价系统发育树，并对其使用净相似度指数，从而确定该地区22个在不同干扰梯度下样地的系统发育结构。

此外，该研究还比较了三个其他的系统发育指数。当用净相似度指数(NRI)作参数时，藤本植物群落的相关性随着树木基面积减少而减少，这表明在早期演替中藤本植物竞争相互作用占主导，这与之前的研究结果相反。另一方面，藤本植物群落在成熟的森林中是具有系统发育聚类性的，这可能是由于传播限制和/或环境过滤造成的。这三个额外的系统发育指数确定了系统发育群落结构的不同预测因子，表明当仅应用一个系统群落结构指数来进行研究时需谨慎。

原文链接：

PhyloGENEtic clustering increases with succession for lianas in a Chinese tropical montane rain forest

原文摘要：

Previous research found that phylogenetic clustering increased with disturbance for tropical trees, suggesting that community asseMBLy is mainly influenced by abiotic factors during early succession. Lianas are an important additional component of tropical forests, but their phylogenetic community structure has never been investigated. Unlike tropical trees, liana abundance is often high in disturbed forests and diversity can peak in old secondary forest. Therefore, phylogenetic structure along a disturbance gradient might also differ from tropical tree communities. Here we determined phylogenetic community structure of lianas along a disturbance gradient in a tropical montane forest in China, using the net relatedness index (NRI) from 100 equivalent phylogenies with varying branch length that were constructed using DNA-barcode sequences. Three additional phylogenetic indices were also considered for comparison. When NRI was used as index phylogenetic clustering of liana communities decreased with decreasing tree basal area, suggesting that liana competitive interactions dominate during early succession, which is in contrast to the pattern reported for trees. Liana communities in mature forests, on the other hand, were phylogenetic clustered, which could be caused by dispersal limitation and/or environmental filtering. The three additional phylogenetic indices identified different, sometimes contradicting predictors of phylogenetic community structure, indicating that caution is needed when generalizing interpretations of studies based on a single phylogenetic community structure index. Our study provides a more nuanced picture of non-random assembly along disturbance gradients by focusing on a non-tree forest component.

DOI: 10.1111/ecog.01051

作者：Ferry Slik