Data from: Species interactions and the effects of climate variability on a wetland amphibian metacommunity

Disentangling the role that multiple interacting factors have on species responses to shifting climate poses a significant challenge. However, our ability to do so is of utmost importance to predict the effects of climate change on species distributions. We examined how populations of three species of wetland breeding amphibians, which varied in life history requirements, responded to a six-year period of extremely variable in precipitation. This interval was punctuated by both extensive drought and heavy precipitation and flooding, providing a natural experiment to measure community responses to environmental perturbations. We estimated occurrence dynamics using a discrete hidden Markov modeling approach that incorporated information regarding habitat state and predator-prey interactions. This approach allowed us to measure how metapopulation dynamics of each amphibian species was affected by interactions among weather, wetland hydroperiod, and co-occurrence with fish predators. The pig frog, a generalist, proved most resistant to perturbations, with both colonization and persistence being unaffected by seasonal variation in precipitation or co-occurrence with fishes. The ornate chorus frog, an ephemeral wetland specialist, responded positively to periods of drought owing to increased persistence and colonization rates during periods of low-rainfall. Low probabilities of occurrence of the ornate chorus frog in long-duration wetlands were driven by interactions with predators due to low colonization rates when fishes were present. The mole salamander was most sensitive to shifts in water availability. In our study area, this species never occurred in short-duration wetlands and persistence probabilities decreased during periods of drought. At the same time, negative effects occurred with extreme precipitation because flooding facilitated colonization of fishes to isolated wetlands and mole salamanders did not colonize wetlands once fishes were present. We demonstrate that the effects of changes in water availability depend on interactions with predators and wetland type and are influenced by the life history of each of our species. The dynamic species occurrence modeling approach we used offers promise for other systems when the goal is to disentangle the complex interactions that determine species responses to environmental variability.厘清多重交互因子对物种气候响应的作用机制，是一项极具挑战性的工作。然而，实现这一目标对于预测气候变化对物种分布的影响至关重要。本研究针对三种生活史需求各异的湿地繁殖两栖动物，探究其种群对六年降水极度波动时段的响应。该时段兼具大范围干旱、强降水与洪涝事件，为探究群落对环境扰动的响应提供了天然实验场景。我们采用整合了栖息地状态与捕食者-猎物交互信息的离散隐马尔可夫模型（discrete hidden Markov model），估算物种出现动态。该方法使我们得以量化每种两栖动物的集合种群动态，如何受气候、湿地水文周期以及与鱼类捕食者共存等交互作用的影响。作为泛化物种的猪蛙，对环境扰动的抗性最强，其定殖率与种群存续率均不受降水季节波动或与鱼类共存的影响。临时湿地特化物种饰纹丛蛙，在低降水时段的存续率与定殖率均有所提升，因此对干旱时段呈现正向响应。饰纹丛蛙在长周期湿地中的出现概率较低，这是因为当鱼类存在时其定殖率低下，与捕食者的交互作用主导了这一现象。鼹钝口螈对水资源可利用性的变化最为敏感。在本研究区域内，该物种从未出现在短周期湿地中，且在干旱时段的存续概率有所下降。与此同时，极端降水也会带来负面影响：洪涝会促使鱼类扩散至孤立湿地，而一旦湿地中出现鱼类，鼹钝口螈便无法完成定殖。本研究表明，水资源可利用性变化的影响，取决于与捕食者的交互作用以及湿地类型，同时也受各研究物种的生活史特征调控。我们所采用的动态物种出现建模方法，为旨在厘清调控物种对环境波动响应的复杂交互机制的其他研究系统，提供了可行的研究范式。