Beaver, Succession, and Ecosystem Dynamics Across the BorealLandscape

北方景观中的海狸、演替和生态系统动态

• 批准号: 9119614
• 负责人: Carol Johnston
• 金额: $ 68万
• 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: 1992
• 资助国家: 美国
• 起止时间: 1992-06-01 至 1996-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9119614&HistoricalAwards=false
• 关键词: Beaver; Succession; Ecosystem; Dynamics; Across

The spatial patterns and properties of beaver ponds change abruptly during population expansion, and there are scale- dependent pathways of pond establishment and abandonment. Thus, ecosystem properties of beaver ponds are not randomly distributed across the landscape nor do they change randomly through time. This research project suggests the following hypothesis: Ecosystem dynamics in valleys occupied by beaver are determined by 1) the geomorphology, hydrologic regimes, and carbon and nutrient pools antecedent to pond establishment, 2) changes in food supply in uplands as beaver forage, and 3) changes in the hydrologic regimes and nutrient cycles during pond creation and abandonment. The relative importance of each of theses factors changes during beaver population cycles, resulting in multiple successional pathways and multiple stable states across the landscape. This project will test this hypothesis at landscape and ecosystem scales by: 1) analyses of spatial patterns of ponds and adjacent riparian forests using a 65 year sequence of air photos, geographic information systems, geostatistics, and percolation theory: 2) manipulating nutrient availabilities in mixed species communities in the field and manipulating nutrients, water, and litter in monoculture mesocosms; and 3) constructing a scale- dependent model of the dynamics of boreal landscapes influenced by beaver.

海狸池塘的空间模式和特性在人口扩张期间突然变化，并且存在池塘建立和遗弃的规模依赖途径。 因此，海狸池塘的生态系统特性不是随机分布在整个景观中，也不会随着时间的流逝而随机变化。 该研究项目提出了以下假设：海狸占用的山谷中的生态系统动态由1）1）1）地貌学，水文制度以及碳和营养池前提是池塘建立，2）2）在海狸饲料中的粮食供应变化，以及Beaver饲料的粮食供应变化，以及3）在水文方面和营养cretiment and Prist and pond and pond and pond and pond and pond and pond and pond and pond and pond。 在海狸种群周期期间，每个这些因素的相对重要性都会发生变化，从而导致多个继任途径和整个景观中多个稳定状态。 该项目将通过：1）使用65年的空气照片，地理信息系统，地统计学和percolations和percolation：2）在池塘和邻近的河林森林中测试这一假设，分析池塘和邻近的二维里亚林林的空间模式：2）在混合物种社区中操纵了野生和养分的养分，并在水中进行了养分，并在水中养成了较高的水平，并养成了水。 3）构建一个受海狸影响的北方景观动力学的量表依赖模型。