Spider sociality and community assembly

是什么决定了植物和动物群落的组成是生态学的核心问题，但考虑到大的空间尺度和大多数系统的难以操作，这个问题不容易解决。社会性蜘蛛和在其网络上定居的蜘蛛是一种可处理的系统，可以在多个尺度上解决社区和元社区生态学中的关键问题。美洲的社会蜘蛛属Anelosimus群落在大陆尺度上表现出独特的环境过滤特征，而在局部尺度上则限制了相似性。我们已经表明，环境过滤器反映了昆虫大小、降水强度和捕食风险的广泛尺度模式，这将社会和亚社会物种的发生限制在某些栖息地。我们将测试资源分配、环境和时间异质性在这些群落生态位分化中的作用。我们假设，环境的异质性为不同体型或社会水平的物种提供了不同的微栖息地，反过来，它们捕获的猎物的大小也不同。为了验证环境异质性和物种丰富度正相关的假设，我们将对哥斯达黎加/巴拿马、厄瓜多尔和巴西的1-5种群落所占据的栖息地进行表征。在选定的群落中，我们将进行互惠巢移植实验，以验证在给定的微生境中，大多数功能不同的物种表现出最大的性能差异的预测。这些群居蜘蛛和其他蜘蛛组成的三维网络，孕育着具有足够独特性和稳定性的栉蛛节肢动物群落，可以作为元群落的模型。我们将调查决定这些社区组成的地方和全球过程的相互作用。我们认为，三维尺度作为宿主网络大小的函数，与环境生产力相互作用，决定资源流向宿主和幼虫。这些因素可能不仅会影响翼虫的密度，还会影响它们的多样性。寄主蜘蛛的行为，如巢的卫生，也可能影响某些类型的inquiline的发生率。为了验证这些假设，我们将评估厄瓜多尔蛭形生物群落的组成、宿主-蛭形生物的相互作用以及跨越海拔和降水梯度的资源流向宿主和蛭形生物。通过人为地建立新的宿主网络，我们将评估这些社区组成中的地方和空间过程的作用。这些项目在解决社区构成问题上追求两个新颖的方向——认识到社区聚集中社会性水平的重要性，并利用三维蜘蛛网中的inquiline社区作为元社区分析的新经验系统。这两个易于处理的系统构成了一个强大的组合，可以在多个尺度上解决生态学的核心问题之一。

The question of what determines the composition of plant and animal communities is central to ecology, but one not easily addressed given the large spatial scales and difficult manipulation of most systems. Social spiders, and the inquilines that colonize their webs, are tractable systems to address key questions in community and metacommunity ecology at multiple scales. Communities of the social spider genus Anelosimus across the Americas exhibit the distinct signatures of environmental filtering at the continental scale and limiting similarity at the local scale. We have shown that the environmental filter reflects broad scale patterns of insect size, precipitation intensity and predation risk, which limit the occurrence of social and subsocial species to certain habitats. We will test the roles of resource partitioning and environmental and temporal heterogeneity in niche differentiation in these communities. We hypothesize that environmental heterogeneity opens up diverse microhabitats to species that differ in body size or level of sociality, which, in turn, differ in the size of prey they capture. To test the hypothesis that environmental heterogeneity and species richness are positively associated, we will characterize the habitats occupied by communities ranging from 1-5 species in Costa Rica/Panama, Ecuador, and Brazil. Within select communities, we will perform reciprocal nest transplant experiments to test the prediction that most functionally dissimilar species exhibit the greatest performance difference in a given microhabitat. The three-dimensional webs of these social and other spiders harbour inquiline arthropod communities of sufficient distinctness and stability to serve as models for metacommunities. We will investigate the interplay of local and global processes in determining the make up of these communities. We suggest that three-dimensional scaling as a function of host web size interacts with environmental productivity to determine flow of resources to hosts and inquilines. These factors may impact not only the density of inquilines, but also their diversity. Behaviours of the host spiders, such as nest hygiene, may also influence the incidence of certain inquiline types. To test these hypotheses we will assess the composition of inquiline communities, host-inquiline interactions, and flow of resources to hosts and inquilines across elevation and precipitation gradients in Ecuador. By artificially establishing new host webs we will assess the role of local and spatial processes in the make up of these communities. The proposed projects pursuit two novel directions to address the question of community composition-recognizing the importance of level of sociality in community assembly and using the inquiline communities in 3D spider webs as a new empirical system for metacommunity analysis. These two tractable systems make for a powerful combination to tackle one of the central questions in ecology at multiple scales.