Sibly Richard M, Barker Daniel, Denham Michael C, Hone Jim, Pagel Mark
School of Animal and Microbial Sciences, University of Reading, Whiteknights, Reading RG6 6AJ, UK.
Science. 2005 Jul 22;309(5734):607-10. doi: 10.1126/science.1110760.
A key unresolved question in population ecology concerns the relationship between a population's size and its growth rate. We estimated this relationship for 1780 time series of mammals, birds, fish, and insects. We found that rates of population growth are high at low population densities but, contrary to previous predictions, decline rapidly with increasing population size and then flatten out, for all four taxa. This produces a strongly concave relationship between a population's growth rate and its size. These findings have fundamental implications for our understanding of animals' lives, suggesting in particular that many animals in these taxa will be found living at densities above the carrying capacity of their environments.
种群生态学中一个关键的未解决问题涉及种群规模与其增长率之间的关系。我们针对1780个哺乳动物、鸟类、鱼类和昆虫的时间序列估计了这种关系。我们发现，在低种群密度下，种群增长率很高，但与之前的预测相反，随着种群规模的增加，增长率迅速下降，然后趋于平稳，这一现象适用于所有这四类生物。这在种群增长率与其规模之间产生了一种强烈的凹形关系。这些发现对我们理解动物的生活具有根本性的意义，尤其表明在这些生物分类中的许多动物会被发现生活在高于其环境承载能力的密度之下。
