LTREB: Moose Population Cycles, Ecosystem Properties, and Landscape Patterns on Isle Royale

LTREB：皇家岛上的驼鹿种群周期、生态系统特性和景观格局

• 批准号: 9806313
• 负责人: John Pastor
• 金额: $ 30万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-15 至 2004-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9806313&HistoricalAwards=false
• 关键词: LTREB; Moose; Population; Cycles; Ecosystem

9806313 Pastor The difficulties in developing a general theory of herbivore-ecosystem interactions arise from the long time-scales of population cycles, the complex spatial scaling of interactions between animal and plant populations, and thenon-linear effect of herbivores on carbon and nutrient flows between vegetation and soil. Such theoretical difficulties are compounded by the paucity of long-term, landscape-scale studies. This LTREB research will continue to address these problems by examining the spatial distribution of browse consumption by moose (Alces alces) in relation to browse supply, tree diameter distributions, conifer basal area, and soil nitrogen availability in the boreal forests of two valleys on Isle Royale. A series of alternative hypotheses will be tested: One series of hypotheses states that spatial patterns do not determine ecosystem recovery from the prior period of high moose population densities, while the alternative series of hypotheses invoke a central role of the dynamics of spatial patterns in ecosystem recovery. Changes in mean values of each ecosystem property will be tested by examining trends at grid points through time. This long-term research program covers a period of time in which the system has experienced the both the largest and smallest moose population densities. These extremes in population dynamics will provide valuable information on the effects of herbivores on large-scale plant community dynamics and ecosystem processes.

9806313 Pastor 发展食草动物与生态系统相互作用的一般理论的困难源于人口周期的长时间尺度、动物和植物种群之间相互作用的复杂空间尺度，以及食草动物对植被和土壤之间碳和养分流动的非线性影响。由于缺乏长期的、景观规模的研究，这些理论困难变得更加复杂。 LTREB 的这项研究将继续解决这些问题，通过研究驼鹿 (Alces alces) 采食消耗的空间分布与采食供应、树木直径分布、针叶树断面积和皇家岛两个山谷的北方森林中土壤氮可用性的关系。将测试一系列替代假设：一系列假设指出，空间模式并不决定生态系统从驼鹿种群密度较高的前期恢复，而一系列替代假设则提出了空间模式动态在生态系统恢复中的核心作用。将通过检查网格点随时间变化的趋势来测试每个生态系统属性平均值的变化。这项长期研究计划涵盖了该系统经历了最大和最小驼鹿种群密度的一段时间。这些极端的种群动态将为食草动物对大规模植物群落动态和生态系统过程的影响提供有价值的信息。