New insights from multidimensional trait space responses to competition in two clonal plant species
New insights from multidimensional trait space responses to competition in two clonal plant species
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DOI：
10.1111/1365-2435.13220
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发表时间：
2019-02-01
影响因子：
5.2
通讯作者：
Mony, Cendrine
中科院分区：
文献类型：
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作者：
Bittebiere, Anne-Kristel;Saiz, Hugo;Mony, Cendrine
性状种内变异决定群落动态和物种共存。为了应对竞争，植物可以表现出种内变异性，以增强其竞争能力或稳定其与竞争对手的生态位差异。这种反应是多方面的，因为它涉及沿着不同功能轴的变化和不可避免的特质之间的权衡。在这里，我们将最近的概念的多维性状空间的种内植物竞争反应的分析。我们具体测试了以下内容：（a）在没有竞争者的情况下，植物多维性状空间将被包装为促进植物定殖的策略;以及（B）与竞争者一起，植物多维性状空间将被导向竞争，其大小和形状特征取决于竞争者物种丰富度。研究了两个无性系植物Brachypodium pinnatum（L.）P. Beauv。和偃麦草Elytrigia repens（L.）古尔德，为了应对竞争。我们分析了植物的反应，在没有竞争对手和竞争。竞争处理包括种内和种间的实验混合物，增加物种丰富度。对于每个目标物种和每个处理，我们基于三维竞争中涉及的六个性状（即，分株和连接性状）。我们测量了这些超体积的大小，相似性和特征在其形成中的贡献。在没有竞争对手的情况下，对于这两个物种，我们展示了一个多维度的性状空间包装的殖民策略。在竞争条件下，两个目标物种的多维性状空间最宽的丰富度梯度的极端，即种内和种间的高丰富度竞争处理。高的种内变异性，促进生态位分化的个体相似的物种或反映了大范围的竞争反应部署时，植物面临着许多不同的竞争对手的身份。多维响应过程的基础上，根据周围的邻里组成，更具体地说，在竞争对手的功能相似性与目标物种的各种性状的微调。这项研究强调了物种竞争反应的多维性，也强调了迄今为止被忽视的重要性，竞争物种丰富度的性状种内变异性和随后的社区组装。
Trait intraspecific variability determines community dynamics and species coexistence. In response to competition, plants can display intraspecific variability to enhance their competitive ability or stabilise their niche differences with competitors. This response is multidimensional because it involves changes along different functional axes and inevitable trade-offs between traits. Here, we transposed the recent concept of the multidimensional trait space to the analysis of intraspecific plant response to competition. We specifically tested the following: (a) in the absence of competitors, the plant multidimensional trait space will be packed towards strategies promoting plant colonisation; and (b) with competitors, the plant multidimensional trait space will be directed towards competition with its size and shaping characteristics dependent on competitor species richness. We studied trait intraspecific variability of two clonal species, Brachypodium pinnatum (L.) P. Beauv. and Elytrigia repens (L.) Gould, in response to competition. We analysed plant response in the absence of competitors and in competition. Competition treatments included intraspecific and interspecific experimental mixtures with increasing species richness. For each target species and each treatment, we built an hypervolume based on six traits involved in the three-dimensional competition (i.e., ramet and connection traits). We measured these hypervolumes for their size, similarity and the contribution of traits in their shaping. In the absence of competitors and for both species, we demonstrated a multidimensional trait space packing towards a colonisation strategy. Under competition, the multidimensional trait spaces of the two target species were the widest at the extremes of the richness gradient, that is, intraspecific and interspecific high richness competition treatments. High intraspecific variability either promoted niche differentiation from individuals of similar species or reflected the large range of competitive responses deployed when plants were faced with many different competitor identities. The multidimensional response process was based on fine adjustments of various traits depending on the surrounding neighbourhood composition and more specifically, on the competitor functional similarity with the target species. This study emphasises the multidimensionality of species competitive response, and also underlines the so far neglected importance of competitor species richness for trait intraspecific variability and subsequently community assembly.