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

使用空间和遗传工具了解斑驳景观中的功能连通性

• 批准号: 1263601
• 负责人: Adrienne Kovach
• 金额: $ 7.5万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1263601&HistoricalAwards=false
• 关键词: Using; Spatial; Genetic; Tools; Understand

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.

本项目调查了栖息地破碎化对早期演替栖息地专家——新英格兰棉尾猴在斑块状景观中的分散和连通性的影响。人类活动在全球范围内最普遍的影响之一是土地利用和土地覆盖的变化以及与之相关的生境破碎化。了解自然种群如何对景观特征做出反应，并在景观尺度上恢复连通性，对于当今有效的生物多样性保护以及考虑气候变化的管理规划至关重要。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生境生态系统的景观连通性，该项目将把破碎化理论扩展到森林生态系统之外。由早期演替生境组成的景观为检验动物分散和破碎化理论的假设提供了理想的框架，因为它们本质上是短暂的和不完整的，并且受到人类对景观的改造和土地利用变化的严重影响。该项目将在景观遗传学方法中运用遥感地理工具和人口遗传技术的空间分析，以确定景观特征在促进和阻碍棉尾虫扩散方面的影响。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代和灌木生境进行表征和绘制。景观和分散建模将使用成本最低的路径、电阻隔离和图论进行。通过对不同程度栖息地破碎化和人口密度的多个复制景观进行比较，本研究将验证破碎化和有效种群规模对遗传结构、扩散距离和性别偏向扩散模式的影响，以及道路作为早期演替栖息地专家的扩散障碍和促进因素的双重效应。综合研究结果，建立与景观结构相关的棉尾草基因流模型和预测模型，以识别连通性热点，并估计修复景观中斑块特异性定殖概率。该项目有助于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。通过关注一个濒临灭绝的物种，新英格兰棉尾，在一个逐渐减少的栖息地，早期演替森林，这个项目将产生信息，将直接用于恢复脆弱的生态系统。保持包括所有演替阶段的森林景观的马赛克将增强生物多样性，并保持该地理区域继续经历大规模人为景观变化的生态完整性。通过确定景观如何影响棉尾虫的扩散模式和连通性，并确定维持种群持续性的关键通道，该项目将为生境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的生物学家建立伙伴关系，这个项目的结果与利益相关者分享，确保它们将产生最大的保护影响。该项目将有助于培养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养。本项目开发的空间工具及其在养护管理中的应用也将纳入本科和研究生课程。