Ecological stability in response to warming

Abstract

That species' biological rates including metabolism, growth and feeding scale with temperature is well established from warming experiments(1). The interactive influence of these changes on population dynamics, however, remains uncertain. As a result, uncertainty about ecological stability in response under warming remains correspondingly high. In previous studies, severe consumer extinction waves in warmed microcosms(2) were explained in terms of warming-induced destabilization of population oscillations(3). Here, we show that warming stabilizes predator-prey dynamics at the risk of predator extinction. Our results are based on meta-analyses of a global database of temperature effects on metabolic and feeding rates and maximum population size that includes species of different phylogenetic groups and ecosystem types. To unravel population-level consequences we parameterized a bioenergetic predator-prey model(4) and simulated warming effects within ecological, non-evolutionary timescales. In contrast to previous studies(3), we find that warming stabilized population oscillations up to a threshold temperature, which is true for most of the possible parameter combinations. Beyond the threshold level, warming caused predator extinction due to starvation. Predictions were tested in a microbial predator-prey system. Together, our results indicate a major change in how we expect climate change to alter natural ecosystems: warming should increase population stability while undermining species diversity.