Trait-based community assembly of epiphytic diatoms in saline astatic ponds: a test of the stress-dominance hypothesis
Trait-based community assembly of epiphytic diatoms in saline astatic ponds: a test of the stress-dominance hypothesis
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DOI：
10.1038/s41598-019-52304-4
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发表时间：
2019-10-31
影响因子：
4.6
通讯作者：
Botta-Dukat, Zoltan
中科院分区：
文献类型：
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作者：
Acs, Eva;Foldi, Angela;Botta-Dukat, Zoltan
压力优势假说（SDH）认为，强烈的环境梯度驱动群落特征趋同，而不是限制相似性。以前的研究主要是对陆生植物群落进行的，发现了有争议的证据来支持这一预测。我们在这里提供附生硅藻SDH的第一个测试。我们研究了静水塘硅藻群落的群落聚集。这些水体表现出各种环境因素的应力梯度，是测试SDH的良好模型系统。硅藻群落的功能多样性评价基于4个性状：(1)反映胁迫耐受性与竞争优势权衡的组合性状，(2)细胞大小，(3)需氧量和(4)氮吸收策略。根据我们的研究结果，盐度、pH值和大型植物带的宽度似乎是特征收敛/发散模式的重要预测因子，可能是通过影响二氧化碳和浊度的有效性来起作用的。浑浊、多盐水和多碱性的池塘性状多样性较低，透明、少盐水和少碱性的池塘功能多样性较高。总的来说，我们的结果支持压力优势假说。在环境压力增加的生境中，环境过滤是最重要的群落聚集规则，而在更有利的条件下，限制相似性成为主导。
The stress dominance hypothesis (SDH) postulates that strong environmental gradients drive trait convergence in communities over limiting similarity. Previous studies, conducted mostly with terrestrial plant communities, found controversial evidence for this prediction. We provide here the first test for SDH for epiphytic diatoms. We studied community assembly in diatom communities of astatic ponds. These water bodies serve as a good model system for testing SDH because they exhibit stress gradients of various environmental factors. Functional diversity of diatom communities was assessed based on four traits: (1) combined trait reflecting the trade-off between stress tolerance and competitive dominance, (2) cell size, (3) oxygen requirement and (4) N-uptake strategy. According to our results, salinity, pH and the width of the macrophyte belt appeared as significant predictors of the trait convergence/divergence patterns presumably acting through influencing the availability of carbon dioxide and turbidity. Lower trait diversity was found in turbid, more saline and more alkaline ponds and functional diversity was higher in transparent, less saline and less alkaline ponds. Overall, our results supported the stress dominance hypothesis. In habitats representing increased environmental stress, environmental filtering was the most important community assembly rule, while limiting similarity became dominant under more favourable conditions.