Collaborative Research: Leveraging the power of ecological modeling and functional ecology to understand spatio-temporal variation in community assembly through the late Quaternary

生物多样性——所有生命形式的多样性——对人类有许多功能，它的丧失是我们这个时代最紧迫的环境问题之一。了解生态群落中物种形成的过程对于在人类影响下描绘生物多样性和生态系统的未来至关重要。迄今为止，对生态群落组成过程的研究主要局限于小（局部）空间尺度和当代（数月至数十年）时间尺度。但是这些过程是复杂的，并且发生在许多不同的尺度上，从地方到大陆的空间尺度，从每月到1000年的时间尺度。为了了解在更长的时间尺度上，哪些过程对构建生态群落是重要的，该项目将使用过去21,000年来小型哺乳动物的化石记录。该项目产生的结果和数据将免费提供给更广泛的科学和教育界使用。该项目将通过培训来自STEM领域代表性不足群体的初高中学生和博士后研究人员，提供劳动力发展机会，扩大对科学的参与。为了阐明群落结构过程的时空非平稳性，该项目将利用晚第四纪小型哺乳动物的化石记录、模拟和物种分布模型（SDM）技术以及特征数据集。该团队将首先对现有化石记录进行全面的时间重新评估，并进行一系列模拟练习，以了解SDMs对化石记录中固有的空间和时间不确定性的敏感性。通过这些步骤获得的知识将指导使用经验化石记录构建近大陆的、动态的（即随时间变化的）物种分布。然后将这些模拟的小哺乳动物的范围分布进行叠加，以获得群落功能和性状组成的评估，这将为群落组装过程的时空变化提供信息。最终，这些发现将有助于理解环境和生物变化对生物多样性和生态系统功能的影响。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Biodiversity—the variety of all forms of life—serves many functions to humans and its loss is one of the most pressing environmental issues of our time. Understanding the processes that shape species within ecological communities is crucial to chart the future of biodiversity and ecosystems in the face of human impacts. To date, studies of processes that are responsible for composition of ecological communities have been largely restricted to small (local) spatial scales and contemporary (months to decades) time scales. But these processes are complex and take place across many different scales, from local to continental spatial scales and monthly to 1000-year time scales. To understand which processes are important to structuring ecological communities at longer time scales, the project will use the fossil record of small mammals from the past 21,000 years. Results from and data generated by the project will be freely available for use by the broader scientific and educational communities. The project will provide workforce development opportunities and broaden participation in science by training middle- and high-schoolers and postdoctoral researchers from groups typically underrepresented in STEM.To elucidate spatial and temporal non-stationarity of processes structuring communities, the project will leverage the fossil record of small mammals across the late Quaternary, simulations and species distribution modeling (SDM) techniques, and trait datasets. The team will first conduct a comprehensive chronological re-assessment of the existing fossil record and carry out a suite of simulation exercises to understand the sensitivity of SDMs to spatial and temporal uncertainty inherent in the fossil record. The knowledge gained through these steps will then guide the construction of near continental, dynamic (i.e., changing through time) species distributions using the empirical fossil record. These modeled range-wide distributions for small mammals will then be stacked to obtain evaluations of community functional and trait composition, which will inform the spatio-temporal variation in community assembly processes. Ultimately, the findings will have implications for understanding the impacts of environmental and biotic change on biodiversity and ecosystem functioning.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.