Trait-similarity and trait-hierarchy jointly determine fine-scale spatial associations of resident and invasive ant species

Interspecific competition, a dominant process structuring ecological communities, is influenced by species' phenotypic differences. Limiting similarity theory holds that species with similar traits should compete intensely (\"trait-similarity\"). In contrast, competing theories including modern coexistence theory emphasize that species with traits conferring competitive advantages should outcompete others (\"trait-hierarchy\"). Either or both of these mechanisms may drive competitive exclusion, but their relative importance and interacting effects are rarely studied. Here, we explore empirically whether trait-similarity and trait-hierarchy can explain fine-scale spatial associations observed between invasive and native ant species in a tropical assemblage. We find that pairwise co-occurrences between the invasive red imported fire ant Solenopsis invicta and 28 other species across relatively homogenous grasslands can be explained largely by an interaction of trait-similarity and trait-hiera...种间竞争是塑造生态群落结构的主导过程，其强度受物种种间表型差异的调控。限制相似性理论（Limiting similarity theory）认为，性状相似的物种种间竞争更为激烈，即“性状相似性（trait-similarity）”机制。与之相对，包括现代共存理论（modern coexistence theory）在内的竞争性理论则强调，携带有赋予竞争优势性状的物种会排挤其他物种，即“性状层级（trait-hierarchy）”机制。上述两种机制中的任意一种或二者共同作用均可引发竞争排斥，但目前鲜有研究探讨二者的相对重要性及其交互效应。本研究通过实证分析，验证性状相似性与性状层级机制是否能够解释热带蚁类集合群落中入侵蚁与本土蚁之间的精细尺度空间关联。研究发现，在相对均质的草原生境中，入侵性红火蚁（Solenopsis invicta）与其余28个物种种间的成对共存模式，在很大程度上可通过性状相似性与性状层级的交互作用予以解释