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.

该项目的目的是确定驼鹿在几个不同的空间和时间尺度上如何影响驼鹿如何影响植物物种分布，生态系统和景观的长期动态。 这将允许将个人行为与人群和生态系统生态学结合在一起。 先前的工作表明，驼鹿对硬木的选择性浏览会增加云杉的优势，进而降低土壤氮的可用性，因为垃圾质量差。 还发现这些效应在整个景观中分布非随机分布，并源自浏览对植物竞争，种子雨和种子库动力学的影响。 通过觅食驼鹿的明确空间仿真模型，已经表明：1）通过单个驼鹿浏览最初随机景观的结构； 2）结构以及驼鹿的能量状态在很大程度上取决于所使用的觅食策略（例如，马尔可夫觅食与根据边际价值定理觅食）：3）3）觅食策略会影响驼鹿的能量状态。 三年的研究表明，情节，环状和过渡过程决定了生态系统如何响应浏览以及如何改变觅食决策的序列。 这些过程在从短期到长期的连续体沿着非常不同的时间尺度出现。 从短期到长期的此类过程包括驼鹿对浏览植物的重新审视，种子雨的环状模式，具体取决于桅杆年，募集和植物的募集和死亡率，这些植物的募集和死亡率决定了未眉毛的植物侵入灌输斑块的序列，以及通过生育和垃圾降落而导致的土壤N供应变化。 短期事件的序列部分决定了长期轨迹。 相反，长期趋势可能与某些本地短期事件相反。 至关重要的是，短期结果放在长期趋势的背景下。 对这种性质的研究是对复杂生态系统的更好理解的基础。 获得的知识几乎立即适用于生活资源的管理；还有更多用于可持续狩猎，木材资源和水质的信息。