Spatial and environmental effects on a rock-pool metacommunity depend on landscape setting and dispersal mode
Spatial and environmental effects on a rock-pool metacommunity depend on landscape setting and dispersal mode
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DOI：
10.1111/fwb.12920
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发表时间：
2017-06-01
影响因子：
2.7
通讯作者：
Mesquita-Joanes, Francesc
中科院分区：
文献类型：
--
作者：
Castillo-Escriva, Andreu;Aguilar-Alberola, Josep A.;Mesquita-Joanes, Francesc
关于元社区结构机制的实证研究通常集中于环境过滤和扩散的主要作用。最近的研究表明，这些结构机制的相对重要性在不同体型、分类隶属和扩散能力的生物体之间有所不同，并且还取决于空间范围和环境异质性。然而，在现场元社区研究中，很少明确考虑站点之间的物理连通性和分散模式的影响。我们分析了一个岩石水池动物元群落，比较了山谷环境中具有短暂连接水道的一组水池和山地环境中没有这种连接的一组水池之间的环境和空间影响。我们还分析了影响元社区中主动和被动分散者的结构机制的相对作用。我们使用排列多元方差分析和群体分散的多元同质性分析来比较景观设置之间的环境和物种变化。应用变异划分来确定由环境和空间变量解释的物种变异的百分比。结构机制的相对影响取决于景观连通性背景和物种扩散模式。物种分选在孤立的和水路相连的水池中驱动了活跃的分散元群落，这表明这些动物在环境适宜的地点具有一定的分散率，足以补偿我们考虑的空间尺度上的灭绝。此外，在环境更加异质且通过水道连接的山谷岩石池组中，活性分散剂的β多样性和物种分选效应较高。相比之下，物种分类仅在具有连接水道的水池组中构建被动分散器元群落，而空间限制对相对更孤立的山坡水池中的被动分散器的影响更为强烈。总体而言，在我们研究的规模上，环境变量比空间变量对岩石池元群落的影响更大，但与水道无关的岩石池中的被动扩散器确实往往具有空间受限的分布。
Empirical studies on structuring mechanisms of metacommunities usually focus on the major roles of environmental filtering and dispersal. Recent works suggest that the relative importance of these structuring mechanisms differs among organisms with different body size, taxonomic affiliation, and dispersal abilities, and also depends on spatial extent and environmental heterogeneity. However, the effects of physical connectivity among sites and dispersal mode are less commonly considered explicitly in field metacommunity studies. We analysed a rock-pool animal metacommunity, comparing both environmental and spatial effects between a set of pools in a ravine setting, with ephemeral connecting waterways, and another in a hill setting, without such connections. We also analysed the relative role of structuring mechanisms influencing active versus passive dispersers in the metacommunity. We used permutational multivariate analysis of variance and analysis of the multivariate homogeneity of group dispersions to compare environmental and species variation between landscape settings. Variation partitioning was applied to determine the percentage of species variation explained by environmental and spatial variables. The relative influence of the structuring mechanisms depended on both the landscape connectivity context and species dispersal mode. Species sorting drove active-disperser metacommunities in both isolated and waterway connected pools, suggesting that these animals had a dispersal rate among the environmentally suitable sites that was adequate to compensate for extinctions at the spatial scale we considered. In addition, beta diversity of active dispersers and species-sorting effects were higher in the set of ravine rock pools that were more environmentally heterogeneous and connected by waterways. In contrast, species sorting structured passive-disperser metacommunities only in the set of pools with connecting waterways, whereas spatial constraints more strongly affected passive dispersers in the relatively more isolated hillside pools. Overall, environmental variables had a greater effect than spatial variables on rock-pool metacommunities at the scale we studied, with the exception that passive dispersers in rock pools unconnected by waterways did tend to have spatially constrained distributions.