Department of Natural Resources Management, Texas Tech University, Lubbock, TX, 79409, USA.
Museum of Texas Tech University, Lubbock, TX, 79409, USA.
Oecologia. 2020 Jul;193(3):645-654. doi: 10.1007/s00442-020-04683-z. Epub 2020 Jun 24.
Despite extensive focus on numerous mechanisms that potentially structure Neotropical bat communities, understanding of the relative importance of any is still illusive. Recently, it has been demonstrated that all mechanisms used to explain community organization can be conceptualized as one or a combination of the few higher-level processes of dispersal, drift, selection and speciation. These four higher-level processes have not been addressed equally by Neotropical bat community ecologists. In particular, predictions formulated from a hypothesis of ecological drift have not been tested for any Neotropical bat community. Herein we contrast efficacy of predictions based on the higher-level processes of drift and selection in describing community structure of bats in the Atlantic Forest of eastern Paraguay. Predictions apply to species-environment interactions, patterns of trait variation and beta-diversity, predictability of dominant competitors and responses to seasonality. At best, there was inconsistent support for the operation of either drift or selection within this bat community. Selection, however, had more various forms of support including strong species-environment relationships, predictable patterns of dominant competitors and strong responses to seasonality. Despite stronger support for selection, a number of predictions of drift were supported as well. It is likely that a combination of both of these processes operates across the variable environments experienced in Atlantic Forest. Predictions of both processes are difficult to make operational. Support for drift often comes from failure to demonstrate a significant pattern and should not be considered strong support of a prediction. Similarly, many predictions of selection predict phenotypic patterns among species without specifying a particular trait. This is problematic because the phenotype is multifaceted and a lack of pattern in one measured trait might mask a strong pattern in some other unmeasured trait. Distilling mechanisms of community organization into four higher level processes is a substantial innovation in community ecology. Nonetheless, efforts need to be made to develop a suite of mutually exclusive and falsifiable predictions to facilitate future and more rapid understanding of community organization.
尽管人们对可能构成新热带蝙蝠群落结构的众多机制进行了广泛关注，但对任何机制的相对重要性仍然难以捉摸。最近，已经证明，用于解释群落组织的所有机制都可以被概念化为扩散、漂移、选择和物种形成等少数几个更高层次过程的一种或组合。这些四个更高层次的过程并没有被新热带蝙蝠群落生态学家平等对待。特别是，从生态漂移假说中得出的预测尚未在任何新热带蝙蝠群落中进行测试。本文中，我们对比了基于漂移和选择这两个更高层次过程的预测在描述巴拉圭东部大西洋森林蝙蝠群落结构时的效力。这些预测适用于物种-环境相互作用、性状变异和β多样性模式、优势竞争者的可预测性以及对季节性的响应。最好的情况下，在这个蝙蝠群落中，漂移或选择的运作存在不一致的支持。然而，选择具有更多形式的支持，包括物种-环境关系较强、优势竞争者的可预测模式以及对季节性的强烈响应。尽管对选择的支持更强，但漂移的一些预测也得到了支持。这两种过程可能在大西洋森林所经历的多变环境中共同作用。这两种过程的预测都很难付诸实践。对漂移的支持通常来自未能证明存在显著模式，因此不应被视为对预测的有力支持。同样，许多选择的预测预测了物种之间的表型模式，而没有指定特定的特征。这是有问题的，因为表型是多方面的，一个测量特征中没有模式可能掩盖了一些其他未测量特征中的强烈模式。将群落组织的机制提炼为四个更高层次的过程是群落生态学的重大创新。尽管如此，仍需要努力制定一套相互排斥且可证伪的预测，以促进对群落组织的未来和更快速的理解。
