Testing trade-offs and the dominance-impoverishment rule among ant communities

Aim: Ant communities are believed to be structured by competition, with dominant species competitively excluding subordinates (the dominance-impoverishment rule). However, a high number of seemingly similar species coexist, possibly due to interspecific trade-offs. Here, we examine the evidence for the dominance-impoverishment rule across a broad latitudinal gradient and explore whether trade-offs explain coexistence within and among ant communities. Location: 40 sites in 19 countries across Europe, western North America and northern South America. Taxon: Formicidae. Methods: We conducted 2-h baiting experiments at each site. Three dominance scores were calculated for each species at each site where it occurred. We then examined the relationship between ant dominance and diversity and tested for the generality of three trade-offs (dominance-discovery, dominance-thermal tolerance and dominance-generalism) within and among ant communities along with the possible effects of enviro...研究目的：蚂蚁群落被认为由竞争作用塑造，优势物种可通过竞争排除从属物种，即优势-贫乏法则（dominance-impoverishment rule）。然而，大量形态相似的物种能够稳定共存，这一现象可能源于物种间的权衡效应（interspecific trade-offs）。本研究旨在探究不同纬度梯度下优势-贫乏法则的实证依据，并探讨权衡效应能否解释蚂蚁群落内部以及群落间的物种共存机制。 研究区域：涵盖欧洲、北美西部与南美北部的19个国家内的40个采样位点。 研究类群：蚁科（Formicidae）。 研究方法：我们在每个采样位点开展了时长2小时的诱饵诱集实验（baiting experiments）。针对每个在该采样点出现的蚂蚁物种，计算3项优势度得分。随后我们分析了蚂蚁优势度与物种多样性之间的关联，并检验了3种权衡效应：优势度-发现能力权衡（dominance-discovery）、优势度-耐热性权衡（dominance-thermal tolerance）以及优势度-泛化性权衡（dominance-generalism）在蚂蚁群落内部及群落间的普适性，同时探讨环境因子的潜在影响……