Using Spatial and Genetic Tools to Understand Functional Connectivity in a Patchy Landscape

本项目研究了栖息地破碎化对早期演替栖息地专家新英格兰棉尾鼠在斑块景观中的扩散和连通性的影响。人类活动在地球仪上最普遍的影响是土地使用和土地覆盖的变化以及相关的生境破碎化。了解自然种群如何对景观特征做出反应，并恢复景观尺度上的连通性，对于当今有效的生物多样性保护以及规划应对气候变化的管理至关重要。景观结构和连通性问题以及动物运动与景观异质性的关系也是景观生态学领域的中心主题。通过研究早期演替和灌木栖息地的生态系统中的景观连接性，该项目将把破碎化理论扩展到森林生态系统之外。景观组成的早期演替的栖息地提出了一个理想的框架，用于测试假设动物的扩散和破碎化理论，因为它们是短暂的和斑块的性质，并严重影响了人类的修改景观和土地利用的变化。本项目将应用遥感和空间分析的地理工具，结合种群遗传技术，以景观遗传学方法，查明景观特征对促进和阻碍棉尾鼠扩散的影响。将利用包括无源光学、激光雷达和雷达在内的中高分辨率遥感器的数据集，对早期演替生境和灌木生境进行定性和制图。景观和扩散建模将使用最低成本路径，隔离电阻，和图论。通过多个不同程度的栖息地破碎化和人口密度的复制景观的比较，本研究将测试的遗传结构，分散距离和性别偏见的分散模式，以及关于道路的分散障碍和促进剂的早期演替栖息地专家的双管齐下的影响碎片化和有效人口规模的影响的假设。结果将综合开发一个模型的棉尾草基因流景观结构和预测模型，以确定热点的连接，并估计补丁特定的殖民化概率恢复景观。该项目有助于实现减轻人类改变景观对自然种群和生态系统的影响的社会目标。通过关注一个受威胁的物种，新英格兰棉尾鼠，在一个不断下降的栖息地，早期演替森林，这个项目将产生的信息，将直接用于恢复一个脆弱的生态系统。保持一个包括所有演替阶段的森林景观镶嵌图，将增强生物多样性，保持这一继续经历大规模人为景观变化的地理区域的生态完整性。通过确定景观如何影响棉尾鼠的扩散模式和连通性，并确定维持种群持续性的关键走廊，该项目将为栖息地恢复和保护这一受威胁物种提供关键见解。通过与州和联邦机构生物学家建立伙伴关系，该项目的成果与利益相关者共享，确保它们将产生最大的保护影响。该项目将有助于培训一名研究生和几名本科生，并促进自然资源、地理和计算机科学等学科之间的跨学科培训。该项目中开发的空间工具及其在保护管理中的应用也将纳入本科生和研究生课程。

This project investigates the effects of habitat fragmentation on the dispersal and connectivity of an early successional habitat specialist, the New England cottontail, in a patchy landscape. Among the most pervasive effects of human activities across the globe are changes in land use and land cover and the associated fragmentation of habitat. Understanding how natural populations respond to landscape features and restoring connectivity on a landscape scale are critical for effective biodiversity conservation today as well as planning for management that accounts for climate change. Issues of landscape structure and connectivity and the relationship of animal movements and landscape heterogeneity are also central themes in the field of landscape ecology. By investigating landscape connectivity in an under-studied ecosystem of early successional and shrub habitats, this project will extend fragmentation theory beyond forested ecosystems. Landscapes consisting of early successional habitats present an ideal framework for testing hypotheses about animal dispersal and fragmentation theory because they are ephemeral and patchy by nature and are heavily impacted by human modifications of the landscape and changes in land use. This project will apply geographic tools of remote sensing and spatial analyses with population genetic techniques, in a landscape genetics approach, to identify the influence of landscape features in facilitating and impeding cottontail dispersal. Early successional and shrub habitats will be characterized and mapped using data sets from moderate to high-resolution remote sensors that include passive optical, LiDAR and radar. Landscape and dispersal modeling will be conducted using least cost path, isolation-by-resistance, and graph theory. By comparison across multiple, replicated landscapes with varying degrees of habitat fragmentation and population density, this study will test hypotheses about the effects of fragmentation and effective population size on genetic structure, dispersal distances and sex-biased dispersal patterns and also about the two-pronged effects of roads as dispersal barriers and facilitators for early successional habitat specialists. Results will be synthesized to develop a model of cottontail gene flow in relation to landscape structure and a predictive model to identify hot spots of connectivity and to estimate patch-specific colonization probabilities in restoration landscapes. This project contributes to the societal goal of mitigating consequences of human modifications of the landscape on natural populations and ecosystems. By focusing on a threatened species, the New England cottontail, in a declining habitat, the early successional forest, this project will generate information that will be directly used in the restoration of a vulnerable ecosystem. Maintaining a mosaic of forested landscapes that includes all successional stages will enhance biodiversity and maintain ecological integrity of this geographic region that continues to experience large-scale anthropogenic landscape change. Through identifying how the landscape influences the dispersal patterns and connectivity of cottontails and identifying key corridors to maintain population persistence, this project will provide key insight for habitat restoration and the conservation of this threatened species. Through established partnerships with state and federal agency biologists, the results of this project are shared with stakeholders, ensuring they will have maximal conservation impact. This project will contribute to the training of one graduate and several undergraduate students and foster cross-disciplinary training among the disciplines of natural resources, geography, and computer science. Spatial tools developed in this project and their application in conservation management will also be incorporated into undergraduate and graduate curricula.