Predation by wolves interacts with the North Pacific Oscillation (NPO) on a western North American elk population
Predation by wolves interacts with the North Pacific Oscillation (NPO) on a western North American elk population
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DOI：
10.1111/j.1365-2656.2004.00909.x
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发表时间：
2005-03
影响因子：
4.8
通讯作者：
M. Hebblewhite
中科院分区：
文献类型：
--
作者：
M. Hebblewhite
摘要1最近的研究揭示了北大西洋涛动（NAO），一个大规模的气候变化，对北方有蹄类动物种群的广泛影响。然而，人们对北太平洋涛动（NPO）（一种类似的气候指数）对有蹄类动物的影响知之甚少。2使用暴露于不同程度狼捕食的三个麋鹿亚群的15年时间序列，研究了NPO对班夫国家公园（BNP）麋鹿种群动态的影响。NPO与当地的气候数据密切相关，包括雪深（r =+0.51）和冬季温度（r =-0.51）。3较高的NPO值反映了冬季严酷程度的增加，降低了麋鹿的种群增长率，而与捕食压力无关。麋鹿的人口增长率，但是，下降更强烈的狼捕食的地区，通过与冬季的严重程度，指数NPO的相互作用。在没有狼捕食的情况下，NPO的作用较弱。4雪和NPO的作用差异取决于捕食压力。在没有狼捕食的情况下，NPO降低了麋鹿的种群增长率，这表明整体气候很重要。与狼捕食，雪的深度比NPO更重要，这表明在更深的雪中增加的捕食率的机制。5这项研究首次证明了太平洋气候对北美西部有蹄类动物种群动态的影响作用，并进一步证明了大规模气候变化在陆地生态系统动态中的作用。
Summary 1 Recent research reveals the widespread influence of the North Atlantic Oscillation (NAO), a large-scale climatic variation, on northern ungulate populations. Little is known, however, about the influence of the North Pacific Oscillation (NPO), a similar climatic index, on ungulates. 2 The influence of the NPO on elk population dynamics in Banff National Park (BNP) was examined using a 15-year time-series of three elk subpopulations exposed to different levels of predation by wolves. NPO was strongly related to local climate data including snow depth (r =+0·61) and winter temperatures (r = −0·51). 3 Higher NPO values reflected increasing winter severity, reducing elk population-growth rate irrespective of wolf-predation pressure. Elk population-growth rate, however, declined more strongly in areas with wolf predation through the interaction with winter severity, indexed by NPO. Effects of NPO were weaker in the absence of wolf predation. 4 Differences between the effects of snow and NPO were revealed that depended on wolf-predation pressure. Without wolf predation, NPO reduced elk population-growth rate, suggesting overall climate was important. With wolf predation, snow depth was more important than NPO, suggesting a mechanism of increased wolf-predation rates in deeper snow. 5 This study is the first to demonstrate the influential role of Pacific climate on western North American ungulate population dynamics and provides further evidence of the role of large-scale climatic variation in terrestrial ecosystem dynamics.