Collaborative Research: Testing for Cascading Effects of Habitat Fragmentation

合作研究：测试栖息地破碎化的级联效应

• 批准号: 0316798
• 负责人: Douglas Bolger
• 金额: $ 34.5万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-10-01 至 2006-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0316798&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; Cascading; Effects

Collaborative Research: Testing for Cascading effects of Habitat FragmentationBolger, Douglas T.Dartmouth CollegeFood web theory provides a useful framework for management of ecosystems, and compliments well the more traditional population-level approach. However, the applicability of food web concepts, including keystone species and top-down cascades, to ecosystems of conservation concern is unclear. This project will study changes in predator-prey interactions in the coastal sage scrub ecosystem of southern California cause by habitat fragmentation, associated with urban development. This project focuses on four landscape treatments in coastal San Diego County that vary in the degree of exposure to urban edge and fragmentation: interior of large habitat blocks (1000ha), urbanized edge of large blocks, large habitat fragments (50-100 ha) and small fragments (5-20 ha). The proposed research will expand previous work by continuing demographic studies on birds, but with simultaneously estimation of mesocarnivore, snake, and raptor abundance and activity to estimate their impacts and examine how these vary with habitat fragmentation. The work will determine if nest predation, juvenile and adult bird survival, as well as small mammal abundance and survival vary with fragment size and predator composition. In addition, it will investigate the role of snakes, and raptors and determine their impact relative to mammalian predators by comparisons across experimental treatments and by path analysis. By comparing bird responses to small mammals this project will address the question of whether all primary consumers are vulnerable to cascades, or if the biological differences between taxa make one group more susceptible to top-down regulation than another. Overall, this project will train 18-25 undergraduates, 3 graduate students and a post-doctoral student, and will creating research opportunities for underrepresented students participating in an NSF Undergraduate Mentoring in Environmental Biology teaching program. In addition, this research will directly benefit ongoing management and reserve design objectives of local wildlife agencies and nonprofit, land management organizations.

合作研究：栖息地碎片化的级联效应测试道格拉斯·t·博尔格达特茅斯学院食物网理论为生态系统管理提供了一个有用的框架，并且很好地补充了更传统的种群水平方法。然而，包括关键物种和自上而下的级联在内的食物网概念对保护生态系统的适用性尚不清楚。该项目将研究南加州沿海鼠尾草灌丛生态系统中由栖息地破碎引起的捕食者-猎物相互作用的变化，与城市发展有关。该项目重点研究了圣地亚哥沿海地区的四种景观处理方法，它们对城市边缘和破碎化的暴露程度不同：大型栖息地块体内部（1000公顷）、大型栖息地块体的城市化边缘、大型栖息地块体（50-100公顷）和小碎片体（5-20公顷）。拟议的研究将通过继续对鸟类进行人口统计研究来扩展先前的工作，但同时估计中食肉动物、蛇和猛禽的丰度和活动，以估计它们的影响，并检查它们如何随着栖息地的破碎而变化。这项工作将确定巢捕食，幼鸟和成年鸟的生存，以及小型哺乳动物的丰度和生存是否随着碎片大小和捕食者的组成而变化。此外，它将调查蛇和猛禽的作用，并通过实验处理和路径分析的比较来确定它们相对于哺乳动物捕食者的影响。通过比较鸟类和小型哺乳动物的反应，该项目将解决以下问题：是否所有的初级消费者都容易受到级联反应的影响，或者分类群之间的生物差异是否使一个群体比另一个群体更容易受到自上而下的监管。总体而言，该项目将培养18-25名本科生，3名研究生和1名博士后，并将为参加NSF本科生环境生物学教学指导计划的代表性不足的学生创造研究机会。此外，这项研究将直接有利于当地野生动物机构和非营利土地管理组织的持续管理和保护区设计目标。