Dissertation Research: Effects of the aquatic:terrestrial habitat ratio on an amphibian predator and its prey

论文研究：水生：陆地生境比例对两栖动物捕食者及其猎物的影响

• 批准号: 1011433
• 负责人: Tiffany Knight
• 金额: $ 1.16万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-15 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1011433&HistoricalAwards=false
• 关键词: Dissertation; Research; Effects; aquatic; terrestrial

Habitat destruction can change the degree of isolation and shape of remaining habitats, and thus can have dramatic consequences for biodiversity and the functioning of ecosystems. Although less appreciated, disproportionate destruction of one type of habitat will also change the ratio of distinct habitat types in a landscape. For example, wetland draining will not only decrease the amount of aquatic habitat in a landscape, but will also decrease the ratio of aquatic to terrestrial habitats. For organisms that require the use of both aquatic and terrestrial habitat types, such as amphibians, changes in the ratio of aquatic to terrestrial habitats can alter their abundance in either habitat, as well as their overall population dynamics. Preliminary surveys of a long lived amphibian, Ambystoma maculatum (the spotted salamander), indicate that the abundance of larval A. maculatum in aquatic habitats depends critically upon the ratio of aquatic to terrestrial habitat available. Because larval A. maculatum are top predators in small fishless ponds, they can have dramatic effects on community composition and diversity of their prey; alterations to the ratio of aquatic to terrestrial habitats can alter the strengths of this effect. This research seeks to elucidate the relationship between the ratio of aquatic to terrestrial habitats in a landscape and the impacts of larval A. maculatum on the aquatic community. It will specifically focus on the influence, of A. maculatum predation on the population dynamics of two frog species that utilize terrestrial and aquatic habitats to different extents, using mark-recapture and demographic modeling approaches.Studies of declining populations of amphibians typically focus on aquatic habitat and factors that affect larval survivorship and growth therein. Yet, there is increasing evidence of the importance of terrestrial habitat for many amphibian populations. Understanding how amphibians will respond to different types of habitat destruction (e.g., deforestation, draining of wetlands) requires consideration of the entire life-cycle of amphibians, and the ratio of aquatic to terrestrial habitats within the landscape. This research will be a timely contribution to the conservation literature and to management efforts aimed at preventing future extinctions of amphibians.

生境的破坏可能会改变剩余生境的孤立程度和形状，从而对生物多样性和生态系统的功能产生严重后果。虽然不太受重视，但对一种生境的不成比例的破坏也会改变景观中不同生境类型的比例。例如，湿地排水不仅会减少景观中水生栖息地的数量，还会降低水生栖息地与陆地栖息地的比例。对于需要使用水生和陆生生境类型的生物，如两栖动物，水生生境与陆生生境比例的变化可能会改变它们在任一生境中的丰度，以及它们的总体种群动态。对一种长寿的两栖动物斑点钝口蝾螈（Ambystoma maculatum）的初步调查表明，maculatum在水生生境中的数量取决于水生生境与陆地生境的比例。因为幼虫A.在无鱼的小池塘中，斑节蜱是顶级捕食者，它们可以对其猎物的群落组成和多样性产生巨大影响;改变水生生境与陆地生境的比例可以改变这种影响的强度。本研究旨在阐明景观中水生生境与陆生生境的比例与幼虫A。maculatum对水生群落的影响。它将特别关注的影响，A。maculatum捕食的两种青蛙的种群动态，利用陆地和水生栖息地在不同程度上，使用标记-再捕获和人口模型approaches.Studies的两栖动物种群下降通常集中在水生栖息地和影响幼虫生存和生长的因素。然而，越来越多的证据表明陆地栖息地对许多两栖动物种群的重要性。了解两栖动物如何应对不同类型的栖息地破坏（例如，森林砍伐、湿地排水）需要考虑两栖动物的整个生命周期以及景观中水生生境与陆生生境的比例。这项研究将是一个及时的贡献，以保护文献和管理工作，旨在防止未来的两栖动物灭绝。