Data from: Tradeoffs and coexistence in fluctuating environments: evidence for a key dispersal-fecundity tradeoff in five nonpollinating fig wasps

The ecological principle of competitive exclusion states that species competing for identical resources cannot coexist, but this principle is paradoxical because ecologically similar competitors are regularly observed. Coexistence is possible under some conditions if a fluctuating environment changes the competitive dominance of species. This change in competitive dominance implies the existence of tradeoffs underlying species' competitive abilities in different environments. Theory shows that fluctuating distance between resource patches can facilitate coexistence in ephemeral patch competitors given a functional tradeoff between species dispersal ability and fecundity. We find evidence supporting this tradeoff in a guild of five ecologically similar nonpollinating fig wasps, and subsequently predict local among patch species densities. We also introduce a novel `colonization index' to estimate relative dispersal ability among ephemeral patch competitors. We suggest that a dispersal ability-fecundity tradeoff and spatiotemporally fluctuating resource availability commonly cooccur to drive population dynamics and facilitate coexistence in ephemeral patch communities.

竞争排除原理（competitive exclusion principle）指出，争夺相同资源的物种无法共存，但该原理存在悖论——生态相似的竞争物种常被观测到共存。在部分条件下，若波动环境改变物种的竞争优势，即可实现物种共存。这种竞争优势的变化，意味着不同环境下物种的竞争能力存在权衡（tradeoff）。理论研究表明，若物种在扩散能力与繁殖力间存在功能权衡，那么资源斑块间的距离波动可促进临时斑块竞争者的物种共存。我们在包含5种生态相似非传粉榕小蜂的功能群（guild）中找到了支持该权衡的证据，并据此预测了斑块间物种的局域密度。此外，我们提出了一种新型定殖指数（colonization index），用以估算临时斑块竞争者间的相对扩散能力。我们认为，扩散能力-繁殖力权衡与时空动态波动的资源可获得性通常共同作用，驱动临时斑块群落的种群动态并促进物种共存。