Spatial and temporal variability modify density dependence in populations of large herbivores.
Spatial and temporal variability modify density dependence in populations of large herbivores.
复制标题
空间和时间的变化改变了大型食草动物种群的密度依赖性。
DOI：
10.1890/05-0355
复制
发表时间：
2006
期刊：
影响因子：
4.8
通讯作者：
Kenneth L. Hamlin
中科院分区：
文献类型：
--
作者：
Guiming Wang;N. Thompson Hobbs;Randall B. Boone;A. Illius;Iain J. Gordon;John E. Gross;Kenneth L. Hamlin
生态学的一个核心挑战是了解内部和外部控制对人口增长的相互作用。我们研究了气候的时间变化和植被的空间变化对大型食草动物种群密度依赖性的影响。我们将模型ln（Nt）= a +（1 + B）x ln（N（t-1））+ c x ln（N（t-2））的三个子集拟合到美国落基山脉有蹄类动物丰度估计值（Nt）的五个时间序列。密度依赖性的强度通过系数B的大小来估计。我们回归估计的B的时间异质性指标的天气和空间异质性的资源。这些回归的斜率的95%后验间隔表明，时间异质性加强了密度依赖的人口增长的反馈，而空间异质性削弱了它们。这一发现提供了第一个经验证据表明，密度依赖以不同的方式响应空间异质性和时间异质性。
A central challenge in ecology is to understand the interplay of internal and external controls on the growth of populations. We examined the effects of temporal variation in weather and spatial variation in vegetation on the strength of density dependence in populations of large herbivores. We fit three subsets of the model ln(Nt) = a + (1 + b) x ln(N(t-1)) + c x ln(N(t-2)) to five time series of estimates (Nt) of abundance of ungulates in the Rocky Mountains, USA. The strength of density dependence was estimated by the magnitude of the coefficient b. We regressed the estimates of b on indices of temporal heterogeneity in weather and spatial heterogeneity in resources. The 95% posterior intervals of the slopes of these regressions showed that temporal heterogeneity strengthened density-dependent feedbacks to population growth, whereas spatial heterogeneity weakened them. This finding offers the first empirical evidence that density dependence responds in different ways to spatial heterogeneity and temporal heterogeneity.