Biology Department, McGill University, 1205 Docteur Penfield Avenue, Montreal H3A 1B1, Canada.
Ecology. 2012 May;93(5):1183-93. doi: 10.1890/11-0275.1.
Climate, habitat, and species interactions are factors that control community properties (e.g., species richness, abundance) across various spatial scales. Usually, researchers study how a few properties are affected by one factor in isolation and at one scale. Hence, there are few multi-scale studies testing how multiple controlling factors simultaneously affect community properties at different scales. We ask whether climate, habitat structure, or insect resources at each of three spatial scales explains most of the variation in six community properties and which theory best explains the distribution of selected community properties across a rainfall gradient. We studied a Neotropical insectivorous bat ensemble in the Isthmus of Panama with acoustic monitoring techniques. Using climatological data, habitat surveys, and insect captures in a hierarchical sampling design we determined how much variation of the community properties was explained by the three factors employing two approaches for variance partitioning. Our results revealed that most of the variation in species richness, total abundance, and feeding activity occurred at the smallest spatial scale and was explained by habitat structure. In contrast, climate at large scales explained most of the variation in individual species' abundances. Although each species had an idiosyncratic response to the gradient, species richness peaked at intermediate levels of precipitation, whereas total abundance was very similar across sites, suggesting density compensation. All community properties responded in a different manner to the factor and scale under consideration.
气候、生境和物种相互作用是控制不同空间尺度上群落特征(如物种丰富度、丰度)的因素。通常,研究人员研究少数几个特征在一个尺度下受到一个因素的影响。因此,很少有多项研究测试多个控制因素如何同时影响不同尺度上的群落特征。我们研究了巴拿马地峡的三种空间尺度上的气候、生境结构或昆虫资源,以解释六个群落特征的大部分变异,以及哪种理论能最好地解释选择的群落特征在降雨量梯度上的分布。我们使用声学监测技术研究了巴拿马地峡的新热带食虫蝙蝠群。通过气候数据、生境调查和昆虫在分层抽样设计中的捕获,我们使用两种方差分解方法确定了三个因素解释了多少群落特征的变异。我们的结果表明,物种丰富度、总丰度和摄食活动的大部分变异发生在最小的空间尺度上,由生境结构解释。相比之下,大尺度的气候解释了大多数单个物种丰度的变异。尽管每个物种对梯度都有独特的反应,但物种丰富度在降水的中间水平达到峰值,而总丰度在不同地点非常相似,表明密度补偿。所有的群落特征都以不同的方式对所考虑的因素和尺度做出反应。