Tradeoffs, competition, and coexistence in eastern deciduous forest ant communities
Tradeoffs, competition, and coexistence in eastern deciduous forest ant communities
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东部落叶林蚂蚁群落的权衡、竞争与共存
作者：
Katharine L Stuble;M. Rodríguez;Gail L. McCormick;I. Juric;R. Dunn;N. Sanders
长期以来，生态学家一直试图解释多个潜在竞争物种在当地群落中共存的原因。这在物种丰富的组合中尤其具有挑战性，因为在蚂蚁组合中，种间竞争激烈。因此，一套机制已被提出来解释潜在的竞争蚂蚁物种之间的共存：优势发现权衡，优势耐热性权衡，空间隔离，基于温度的生态位分区，和时间生态位分区。通过一系列的观察和实验，我们研究了落叶林蚂蚁组合在北美东部的签名，这些共存机制。我们没有发现任何共同建议的共存机制的证据，有一个显着的例外：蚂蚁物种似乎暂时分区觅食时间，这样的行为优势种觅食更激烈的夜晚，而觅食的次优势种在白天达到高峰。我们的工作，虽然集中在一个单一的集合，表明许多常见的共存机制可能不是一般的所有蚂蚁集合。然而，时间隔离可能在促进蚂蚁物种之间的共存方面发挥作用，至少在某些生态系统中，就像在许多其他生物中一样。
Ecologists have long sought to explain the coexistence of multiple potentially competing species in local assemblages. This is especially challenging in species-rich assemblages in which interspecific competition is intense, as it often is in ant assemblages. As a result, a suite of mechanisms has been proposed to explain coexistence among potentially competing ant species: the dominance–discovery tradeoff, the dominance–thermal tolerance tradeoff, spatial segregation, temperature-based niche partitioning, and temporal niche partitioning. Through a series of observations and experiments, we examined a deciduous forest ant assemblage in eastern North America for the signature of each of these coexistence mechanisms. We failed to detect evidence for any of the commonly suggested mechanisms of coexistence, with one notable exception: ant species appear to temporally partition foraging times such that behaviourally dominant species foraged more intensely at night, while foraging by subdominant species peaked during the day. Our work, though focused on a single assemblage, indicates that many of the commonly cited mechanisms of coexistence may not be general to all ant assemblages. However, temporal segregation may play a role in promoting coexistence among ant species in at least some ecosystems, as it does in many other organisms.