A Migratory Ungulate Facilitates Cross-Boundary Nitrogen Transport in Forested Landscapes
A Migratory Ungulate Facilitates Cross-Boundary Nitrogen Transport in Forested Landscapes
复制标题
迁徙的有蹄类动物促进森林景观中的跨界氮运输
作者：
Bryan D. Murray;C. Webster;J. Bump
森林有蹄类动物以多种方式影响生态系统。大多数研究侧重于消耗效应，这种影响可能会波及生态系统的其他组成部分，而且往往是由收获管理或减轻对植被的不良影响所推动的。在这项研究中，我们证明了白尾鹿(Odocoileus Virginianus)，一种北美东部常见的森林有蹄类动物，可能通过排泄含氮废物直接增加氮素的有效性和异质性。我们连续8年每年春季在39块冬季覆盖的栖息地进行粪便颗粒计数，面积从0.04到59.6公顷不等。颗粒计数被用来建立全林和细(10×10)m~2空间尺度上与鹿有关的氮素年输入的异速生长模型。在长期使用的斑块中，按林分规模估计，与鹿有关的氮估计在1-4千克[N]和−1的范围内。一致聚集区的精细估计相当于高达20亿公斤[N]/ha−1。与周围的森林基质相比，这些地区，如垫层地点和步道，经历了更多的N输入。鹿的年使用量和相关的氮输入在空间上变化很大，在林分和精细空间尺度上，使用的空间模式随着时间的推移是一致的。与鹿有关的氮可能代表着跨境氮通量进入针叶树覆盖的斑块，因为鹿在温暖的季节在其他类型的栖息地积累营养，并在冬天失去体重。森林有蹄类动物的含氮废物产生的氮热点和异质性在森林生态学中可能是一个普遍被忽视的现象，其影响因生态环境而异。
Forest ungulates impact ecosystems in a number of ways. Most studies have focused on consumptive effects that may cascade to other components of the ecosystem, and tend to be motivated by harvest management or the mitigation of undesired effects on vegetation. In this study, we demonstrate that white-tailed deer (Odocoileus virginianus), a common forest ungulate in eastern North America, may directly increase availability and heterogeneity of nitrogen due to excretion of nitrogenous wastes. We conducted fecal pellet counts in 39 winter cover habitat patches, ranging in area from 0.04 to 59.6 ha, each spring for eight consecutive years. Pellet counts were used to develop allometric models of annual deer-associated nitrogen inputs at both whole-stand and fine (<10 m2) spatial scales. Deer-associated nitrogen estimates were in the range of 1–4 kg[N] ha−1 in persistently used patches when estimated at the stand scale. Fine-scale estimates in areas of consistent aggregation were equivalent to up to 20 kg[N] ha−1. These areas, such as bedding sites and trails, experienced greater N inputs compared to the surrounding forest matrix. Annual deer use and associated nitrogen inputs were highly variable over space, and spatial patterns in use were consistent over time at both stand and fine spatial scales. Deer-associated nitrogen likely represents a cross-boundary nitrogen flux into patches of conifer cover because deer accumulate nutrients in other habitat types during the warm season, and lose body mass during winter. Nitrogen hotspots and heterogeneity derived from the nitrogenous wastes of forest ungulates may be a generally overlooked phenomenon in forest ecology, with impacts varying according to ecological context.
DOI：
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发表时间：
2015-10
期刊：
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影响因子：
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作者：
Douglas M. Bates;M. Maechler;Ben Bolker;Steven C. Walker
通讯作者：
Douglas M. Bates;M. Maechler;Ben Bolker;Steven C. Walker