气候变化影响植物和动物生命中定期发生的事件，如发芽、迁徙和冬眠以及种群动态和形态变化。同时对所有这些相互作用的因素进行监测是困难的，但对一种冬眠型哺乳动物（美国科罗拉多州Upper East River Valley一个亚高山环境中的一种黄腹土拨鼠种群）所做的一项长期生命史研究，提供了适合于完成这项任务的数据。1976–2008年间的气候变化使这些土拨鼠过早从冬眠中苏醒过来，延长了它们的生长季，所以它们现在要比其开始冬眠时重一些。
与此同时，体型较大个体的适应性也增加了，导致种群规模迅速增大。正如Marcel Visser在配发的News & Views文章中所解释的那样，气候变化生态学中的主要挑战是预测未来气候变化对于种群的影响。
关于土拨鼠的这项研究工作提供了实现这一目的所需的数据。本期Nature封面所示为冬天在落基山脉拍摄的黄腹土拨鼠照片。(生物谷Bioon.com)
生物谷推荐原文出处：
Nature doi:10.1038/nature09210
Coupled dynamics of body mass and population growth in response to environmental change
Arpat Ozgul,Dylan Z. Childs,Madan K. Oli,Kenneth B. Armitage,Daniel T. Blumstein,Lucretia E. Olson,Shripad Tuljapurkar& Tim Coulson
Environmental change has altered the phenology, morphological traits and population dynamics of many species1, 2. However, the links underlying these joint responses remain largely unknown owing to a paucity of long-term data and the lack of an appropriate analytical framework3. Here we investigate the link between phenotypic and demographic responses to environmental change using a new methodology and a long-term (1976–2008) data set from a hibernating mammal (the yellow-bellied marmot) inhabiting a dynamic subalpine habitat. We demonstrate how earlier emergence from hibernation and earlier weaning of young has led to a longer growing season and larger body masses before hibernation. The resulting shift in both the phenotype and the relationship between phenotype and fitness components led to a decline in adult mortality, which in turn triggered an abrupt increase in population size in recent years. Direct and trait-mediated effects of environmental change made comparable contributions to the observed marked increase in population growth. Our results help explain how a shift in phenology can cause simultaneous phenotypic and demographic changes, and highlight the need for a theory integrating ecological and evolutionary dynamics in stochastic environments4, 5.
