DISSERTATION RESEARCH: Consequences of habitat fragmentation for biodiversity and invasive species

该项目研究了栖息地破碎化（斑块）对本地植物多样性和非本地入侵草的传播的直接和间接影响。 破碎化一直很难研究，因为它通常发生在同一时间的栖息地丧失。 该项目利用得克萨斯州中部稀树草原和林地的自然斑块来研究破碎化的影响，并将其与栖息地丧失的影响分开。 理论预测，破碎化和外来物种入侵都会减少物种多样性。 一些模型表明，破碎化可能会直接限制具有有限传播能力的入侵植物的传播，但通过减少多样性间接促进它们的建立。 将对这些假设进行检验。 该项目将结合联合收割机分析航空照片，实地观察，种子传播的测量，和多样性的实验操作，以量化本地生物多样性，入侵草的存在和传播，栖息地破碎化之间的关系。 生物多样性面临的两个主要威胁是生物多样性的破碎化和入侵物种的扩散。 这项研究将测试这些过程的理论预测，并提供景观结构的管理，以保护生物多样性的见解。 该补助金将支持一名研究生，并为几名本科生提供研究经验。

This project examines both the direct and indirect effects of habitat fragmentation (patchiness) on native plant diversity and the spread of a non-native invasive grass. Fragmentation has been difficult to study because it is usually occurs at the same time as habitat loss. This project takes advantage of the natural patchiness of central Texas savannas and woodlands to study the effects of fragmentation separate from the effects of habitat loss. Theory predicts that both fragmentation and invasive non-native species will reduce species diversity. Some models suggest fragmentation may directly limit the spread of invasive plants with limited dispersal ability, but indirectly facilitate their establishment by reducing diversity. These hypotheses will be tested. The project will combine analysis of aerial photographs, field observations, measurements of seed dispersal, and experimental manipulation of diversity to quantify the relationships among native biodiversity, the presence and spread of an invasive grass, and habitat fragmentation. Fragmentation and the spread of invasive species are two of the leading threats to biological diversity. This research will test theoretical predictions about these processes and provide insights for the management of landscape structure to preserve biodiversity. The grant will support a graduate student and provide research experience for several undergraduate students.