LTREB: Long-term Dynamics of Moose Populations, Community Structure, and Ecosystem Properties on Isle Royale

LTREB：皇家岛驼鹿种群、群落结构和生态系统特性的长期动态

• 批准号: 9306368
• 负责人: John Pastor
• 金额: $ 25万
• 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: 1993
• 资助国家: 美国
• 起止时间: 1993-07-01 至 1998-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9306368&HistoricalAwards=false
• 关键词: LTREB; Long; term; Dynamics; Moose

The objective of this project is to determine the long-term dynamics of how moose affect plant species distribution, ecosystems, and landscapes at several different spatial and temporal scales. This will allow integration individual behavior with population and ecosystem ecology. The previous work has demonstrated that selective browsing by moose on hardwoods increases dominance of spruce, which in turn depresses soil nitrogen availability because of poor litter quality. It has also been found that these effects are distributed non-randomly across the landscape, and derive from the effects of browsing on plant competition, seed rain and seed bank dynamics. Through an explicitly spatial simulation model of a foraging moose it has been shown that: 1) browsing by individual moose imposes structure on initially random landscapes; 2) that structure as well as the energetic status of the moose depends greatly on the foraging strategy used (e.g. Markovian foraging vs. foraging according to the marginal value theorem): and 3) the foraging strategy affects the energetic status of the moose. Three years of study have suggested that episodic, cyclic, and transitional processes determine the sequence of how ecosystems change in response to browsing and how foraging decisions are subsequently altered. These processes occur at very different time scales along a continuum from short-term to long-term. Such processes, ranging from short to long-term, include revisitation of browsed plants by moose, cyclic patterns of seed rain depending on mast years, recruitment and mortality of plants determining the sequence of invasion of browsed patches by unbrowsed plants, and changes in soil N availability resulting from manuring and changes in litterfall. The sequences of short-term events partially determine long-term trajectories. Conversely, long-term trends may be in opposite directions from that of some local short-term events. It is crucial that short-term results be placed in the context of long-term trends. %%% Research of this nature is fundamental to the better understanding of complex ecological systems. Such knowledge, as it is gained, is almost immediately applicable to the management of living resources; more for sustainable hunting, timber resources, and water quality as well.

该项目的目标是确定长期 驼鹿如何影响植物物种分布的动态， 生态系统和景观在几个不同的空间和 时间尺度 这将允许集成个人行为 人口和生态系统生态学。 以前的工作有 证明了驼鹿对硬木的选择性浏览 增加了云杉的优势，这反过来又抑制了土壤 氮的有效性，因为不良的凋落物质量。 它还 发现这些效应是非随机分布的， 景观，并从浏览植物的影响 竞争、种子雨和种子库动态。 通过 一只觅食驼鹿的明确空间模拟模型， 研究表明：1）个体驼鹿的浏览会影响结构 在最初的随机景观; 2）该结构以及 驼鹿的精力状态在很大程度上取决于觅食 使用的策略（例如，马尔可夫觅食与根据 边际价值定理）; 3）觅食策略影响 驼鹿精力充沛的状态 三年的学习 表明，情节，循环，和过渡过程， 确定生态系统如何响应 浏览和觅食的决定如何随后改变。 这些过程发生在沿着不同的时间尺度上， 从短期到长期的连续性。 这些过程， 从短期到长期，包括重新访问浏览过的植物， 驼鹿，种子雨的周期模式取决于桅杆年份， 植物的补充和死亡决定了 未被浏览的植物入侵被浏览的斑块， 施肥对土壤氮素有效性的影响及其变化 垃圾 短期事件的序列部分地 确定长期轨迹。 相反，长期趋势 可能与某些地方短期 事件 关键是要把短期结果放在 长期趋势的背景下。 %%% 这种性质的研究对于更好地理解 复杂的生态系统。 这样的知识，因为它是获得， 几乎可以立即应用于生活管理， 资源;更多的可持续狩猎，木材资源， 水质也是。