RAPID: The role of disturbance in climate-driven hybrid zone dynamics

气候变化是我们这个时代最紧迫的问题之一，但气候变化对物种和生态系统的级联效应仍不清楚。许多物种可能被迫改变它们的地理范围，以逃避不适宜的气候，并寻求更有利的条件。范围的变化可能导致与其他物种的新的相互作用，包括食物或其他资源的竞争，甚至杂交或杂交。这些新的物种相互作用将在决定物种是否能够殖民其他有利的栖息地方面发挥关键作用。此外，间歇性干扰，如火灾可能会改变竞争的平衡范围边缘通过改变栖息地结构和资源的可用性。在这个项目中，PI将研究最近的火灾对两种密切相关的小型哺乳动物（林鼠）之间的范围边缘相互作用的影响。PI先前已经记录了一个物种是如何在气候条件下，特别是干旱条件下超越另一个物种的范围的。然而，他们预测火灾将大大改变物种与环境的相互作用（例如，喂食，筑巢）和彼此（例如，竞争和杂交的趋势），极大地改变，也许扭转了范围边缘运动的方向。PI及其学生将使用捕获标记再捕获来监测人口，以量化个体生存，繁殖，扩散和资源使用，特别是饮食变化。这些信息将用于建立一个预测模型，预测扰动如何与年度天气变化相互作用，以预测物种的分布边界在未来条件下将如何变化。预测物种的分布将如何应对环境变化，需要估计驱动范围边缘动态的机制。当分布边缘也是密切相关的物种之间的parapatric范围边界时，广泛的生态和基因组相互作用可能会控制物种对环境变化的反应。气候在确定范围的边缘边界和混合区动态的作用只是开始被理解在一些陆生脊椎动物系统，几乎没有什么是已知的间断性干扰如何可能改变范围的边缘和混合区动态。在这个项目中，PI利用两个密切相关的物种之间的parapatric范围边界的长期数据收集，对最近的火灾如何通过个体适应度和竞争相互作用的变化来改变范围边缘动态进行明智的预测。PI预测，最近的火灾将大大改变接触区的健身和分散模式，可能导致他们以前记录的范围边缘运动的逆转。PI将使用密集的捕获标记再捕获来量化生存，繁殖，扩散和资源利用来测试这些预测。PI将把这些数据整合到一个预测模型中，预测生态和环境过程如何相互作用，以控制这两个密切相关的物种之间的变化范围。更广泛地说，这项工作将为调查和预测气候变化和局部干扰如何改变基本的物种水平特征提供一个实用和概念性的框架。（范围边缘边界）通过对个体水平特征的差异影响，如生存，繁殖，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准。

Climate change is one of the most pressing issues of our time, yet the cascading effects of climate change on species and ecosystems remain unclear. Many species may be forced to shift their geographic range to escape unsuitable climates and pursue more favorable conditions. Range shifts may lead to novel interactions with other species including competition for food or other resources, and even interbreeding or hybridization. These new species interactions will play a critical role in determining whether or not species are able to colonize otherwise favorable habitats. Furthermore, punctuated disturbances such as fire may change the competitive balance at range edges via altered habitat structure and resource availability. In this project the PIs will examine the impact of a recent fire on the range-edge interactions between two closely related species of small mammals (woodrats). The PIs have previously documented how one species is overtaking the range of the other in response to climate conditions, especially drought. However, they predict the fire will substantially change how the species interact with the environment (e.g., feeding, nest-building) and with each other (e.g., competition and tendency to interbreed), dramatically changing and perhaps reversing the direction of range-edge movement. The PIs and their students will monitor the population using capture-mark-recapture to quantify individual survival, reproduction, dispersal, and resource use, especially dietary changes. This information will be used to build a predictive model of how disturbance interacts with annual weather variation to forecast how species’ distributional boundaries will shift under future conditions. Predicting how species’ distributions will respond to environmental change requires estimation of the mechanisms driving range edge dynamics. When distributional edges are also parapatric range boundaries between closely related species, a wide range of ecological and genomic interactions may govern species’ responses to environmental change. The role of climate in determining range edge boundaries and hybrid zone dynamics is only beginning to be understood in a few terrestrial vertebrate systems; nearly nothing is known of how punctuated disturbance may alter range edge and hybrid zone dynamics. In this project the PIs leverage long-term data collection at a parapatric range boundary between two closely related species to make informed predictions about how a recent fire will alter range edge dynamics via changes in individual fitness and competitive interactions. The PIs predict that the recent fire will substantially alter fitness and dispersal patterns in the contact zone, potentially leading to a reversal of the range edge movements they previously documented. The PIs will test these predictions using intensive capture-mark-recapture to quantify survival, reproduction, dispersal, and resource use. The PIs will integrate these data into a predictive model of how ecological and environmental processes interact to govern the shifting range margin between these two closely-related species. More generally, this work will provide a practical and conceptual framework for investigating and forecasting how climate change and local disturbance can alter a fundamental species-level characteristic (range-edge boundaries) via differential impacts on individual-level characteristics such as survival, reproduction, resource use and dispersal.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.