CAREER: Resolving drivers of variation in grassland community assembly and restoration

人类土地利用对自然生态系统的破坏和改造，如农业，共同对世界生物多样性构成最大威胁。反过来，生态恢复被誉为一种重要的保护工具，因为它能够通过修复受损的生态系统和创造新的栖息地来促进生物多样性。然而，众所周知，恢复结果是不可预测的，这阻碍了土地管理者可靠地修复受损生态系统的能力。该项目将通过调查群落组装过程（物种组装如何随着时间的推移而发展）来评估恢复结果变化的原因。在此过程中，它将指导恢复实践，通过基础生态学理论和生态系统管理的耦合推进恢复生态学领域，并测试长期存在的基本问题，即为什么生态群落的多样性和组成在不同地点存在差异。此外，该项目将培训新的修复科学家，并通过课堂教学、学生和博士后培训以及与进行修复的土地管理机构建立伙伴关系，加强修复研究与实践之间的联系。该项目将在原农业用地上播种原生草原种子，从而恢复草原草原系统。这项工作的一个目标将是了解群落的组装和恢复结果如何受到时空变化的环境条件（土壤肥力和降雨）的影响，以及作为描述生态群落的两个因素的函数——群落内物种数量和每个物种的个体数量。重点问题将通过实验和正在恢复的大型草原网络进行评估，在面向机制的实验和现实世界的组装生态系统之间建立联系。

The destruction and modification of natural ecosystems for human land uses, like agriculture, together pose the greatest threat to the world's biodiversity. In turn, ecological restoration has been hailed as a critical conservation tool for its ability to promote biodiversity through the repair of damaged ecosystems and creation of new habitats. Yet, restoration outcomes are notoriously unpredictable and this hinders land managers' abilities to reliably repair damaged ecosystems. This project will evaluate the causes of variation in restoration outcomes by investigating the process of community assembly - how assemblages of species develop over time - during restoration. In doing so, it will guide restoration practice, advance the field of restoration ecology through the coupling of basic ecological theory and ecosystem management, and test long-standing, fundamental questions about why the diversity and composition of ecological communities vary among locations. Furthermore, this project will train new restoration scientists and strengthen linkages between restoration research and practice through classroom instruction, student and postdoc training, and partnerships with land management agencies conducting restoration.This project will take place within a system of prairie grasslands restored through the sowing of native prairie seeds onto former agricultural lands. A goal of this work will be to understand how community assembly and restoration outcomes are influenced by environmental conditions that vary in space and time (soil fertility and rainfall), and as a function of two factors describing ecological communities - the number of species and number of individuals for each species, within communities. Focal questions will be evaluated experimentally and across a network of large-scale grasslands undergoing restoration, forging a link between mechanism-oriented experiments and real-world assembled ecosystems.