Warming at the population level: effects on age structure, density, and generation cycles.

The impact of climate change on strongly age-structured populations is poorly understood, despite the central role of temperature in determining developmental rates in ectotherms. Here we examine the effect of warming and its interactions with resource availability on the population dynamics of the pyralid moth Plodia interpunctella, populations of which normally show generation cycles, a consequence of strong and asymmetric age-related competition. . Warming by 3°C above the standard culture temperature led to substantial changes in population density, age structure and population dynamics. Adult populations were some 50% larger in warmed populations, probably because the reduced fecundity associated with warming leads to reduced larval competition, allowing more larvae to develop to adulthood. Warming also interacted with resource availability to alter population dynamics, with the generation cycles typical of this species breaking down in the 30° populations when standard lab. diet ...尽管温度在决定变温动物（ectotherms）的发育速率方面发挥核心作用，但气候变化对强年龄结构种群的影响仍未得到充分阐明。本研究探讨了升温及其与资源可获得性的交互作用对螟蛾科昆虫印度谷螟（Plodia interpunctella）种群动态的影响；该物种种群通常呈现世代周期，这是强且不对称的年龄相关竞争的直接结果。将温度较标准饲养温度升高3℃后，种群密度、年龄结构与种群动态均发生显著改变。升温组种群的成虫种群规模较对照组高出约50%，这可能是因为升温伴随的繁殖力下降降低了幼虫竞争压力，使得更多幼虫能够发育至成虫阶段。此外，升温还与资源可获得性产生交互作用以改变种群动态：在采用标准实验室饲料的30℃种群中，该物种典型的世代周期出现瓦解……