Dissertation Research: The Ecological Implications of HabitFragmentation: A Field Manipulation of Patch Size and Connectivity

栖息地破碎化的现象， 原生植被的面积缩小， 从邻近的连续的栖息地， 这是最严重的威胁之一， 地球的生物多样性。 生态 对栖息地碎片的观察表明， 一般来说，物种多样性随着斑块大小的增加而减少 减少。 碎片之间的植被连接 经常被动物使用，并被认为可以增加 物种在片段中持续存在的概率。 然而，迄今为止发表的研究有几个主要的 局限性：补丁通常不事先测量 与世隔绝;很少有证据表明， 优先使用贴片之间的连接;以及 生物的基本生活史特征通常是 未就其对下列问题的数字答复进行审查： 生境破碎化 没有发表的研究， 已经通过实验操纵了碎片的大小， 现场条件下的连通性，并比较 种的反应，在操纵样地， 相邻的控制区。 本研究拟在本地区进行， 美国科罗拉多博尔德附近的一片草地草原， 实验性地创造了三种大小的栖息地斑块 并操纵连接的存在或不存在， 相邻的连续的栖息地 该研究还将 模拟四种基本的空间结构 土地变化和破碎化的顺序： 边缘条带序列，廊道序列，离散斑块 序列、散斑序列和四个核 顺序 四个序列将同时 将相同面积的草地从未开垦的草地改为开垦的草地 栖息地，但完整的空间配置 栖息地在不同序列中会有所不同。 通过研究昆虫 动态，他将能够检查的程度， 哪些动物种群受到阻碍或增强 碎片化过程。 除了审查 植物和昆虫物种丰富度的总体格局 和多样性的实验和控制地块，他 将比较三个焦点的运动反应， 表现出不同程度的昆虫物种 和进食方式。 结果将 有助于他们理解生态 特定空间配置的影响，以及 将有可能指导生态学家和设计师 和规划者在他们的土地使用决策 项目

The phenomenon of habitat fragmentation, when remnants of native vegetation are reduced in size and separated from adjacent, continuous habitat, is extremely widespread and poses one of the most serious threats to the earth's biological diversity. Ecological observations of habitat fragments have shown that in general, species diversity decreases as patch size decreases. Vegetated connections between fragments are often used by animals, and are presumed to increase the probability of species' persistence in fragments. However, studies published to date have several major limitations: Patches are typically not measured prior to isolation; it has rarely been shown that animals preferentially use connections between patches; and organisms' basic life history characteristics are often not examined in relation to their numerical response to habitat fragmentation. No studies are published which have experimentally manipulated both fragment size and connectivity under field conditions and compared species' responses in the manipulated plots to those in adjacent control plots. The research proposed here, to be done in native mixed- grass prairie near Boulder, Colorado, USA, involves experimentally creating habitat patches of three sizes and manipulating presence or absence of connectivity to adjacent, continuous habitat. The research will also simulate the spatial configurations in four basic sequences of land transformation and fragmentation: edge strip sequence, corridor sequence, dispersed patch sequence, dispersed patch sequence and four nuclei sequence. The four sequences will simultaneously convert equal areas of grassland from intact to cleared habitat, but the spatial configuration of the intact habitat will vary among sequences. By studying insect dynamics, he will be able to examine the extent to which animal populations are impeded or enhanced by fragmentation processes. In addition to examining overall patterns of plant and insect species richness and diversity in experimental and control plots, he will compare the movement responses of three focal insect species which exhibit different degrees of vagility and modes of feeding. The results will contribute to their understanding of the ecological implications of particular spatial configurations, and will potentially guide ecologists as well as designers and planners in their decisions regarding land use projects.