Plant species’ coexistence relationships may shift according to life history traits and seasons
Plant species’ coexistence relationships may shift according to life history traits and seasons
复制标题
植物物种的共存关系可能会根据生活史特征和季节而变化
作者：
T. Osawa;H. Mitsuhashi;A. Ushimaru
摘要虽然已有研究表明干扰对物种多样性有贡献，但对与生活史性状相关的物种共存机制的研究却很少。在这项研究中，我们比较了物种的丰富度和组成的河流汇流周围的植物群落，探讨干扰如何促进不同生活史性状的物种共存。汇合的上游和下游的网站是理想的这种比较，因为它们借鉴了相同的物种的游泳池，并有类似的环境条件，但在洪水干扰的程度显着不同。我们比较了上游和下游的汇合点，计算物种丰富度和群落相似性指数的几个生活史特征在夏季和春季。在夏季，所有的物种，一年生和夏季开花的物种的综合丰富度，下游汇合比上游，但这是不是多年生植物的情况。相似性分析表明，植物群落是根据一个中性的过程，即共存物种之间的相互作用是中性的。而春季各生活史特征的物种丰富度在汇流区上游和下游基本一致。相似性分析表明，在这种情况下，群落是通过物种分类过程构建的;即，每个生活史特征都有不同的生境偏好。因此，不同群落集结过程的相对强度可能会随季节而变化。我们的结论是，物种群体不同的干扰反应可能共存于一个单一的社会。因此，干扰后的群落结构可能涉及两个过程：一个中性过程和一个物种分类过程。每一个的相对重要性可能会有所不同物种的生活史性状和季节之间的相互作用可能会导致目前的社区结构。
Abstract Although several studies have demonstrated that disturbance contributes to species’ diversity, little emphasis has been placed on the identification of species’ coexistence mechanisms related to life history traits. In this study, we compared species’ richness and components of plant communities around river confluences to explore how disturbance promotes the coexistence of species with different life history traits. Sites upstream and downstream of confluences are ideal for such comparisons because they draw on the same species’ pools and have similar ambient conditions, but differ markedly in the extents of flooding disturbance. We compared sites upstream and downstream of confluences by calculating species’ richness and community similarity indices for several life history traits in both summer and spring. In summer, the combined richness of all the species, of annual- and summer-flowering species, was higher downstream from confluences than upstream, but this was not the case for perennials. Similarity analyses suggested that plant communities are constructed according to a neutral process, whereby interactions between the coexisting species are neutral. However, in spring, species’ richness was similar upstream and downstream of confluences for all life history traits. Similarity analyses suggested that under these circumstances, the communities were constructed through a species-sorting process; i.e., each life history trait had a distinct habitat preference. Thus, the relative strengths of different community assembly processes may change seasonally. We concluded that species groups differing in their responses to disturbance may coexist in a single community. Thus, community structuring following disturbance may involve two processes: a neutral and a species-sorting process. The relative importance of each may vary between species’ life history traits and between seasons, and the interaction may account for current community structures.