Increased temperature variation poses a greater risk to species than climate warming

Abstract

Increases in the frequency, severity and duration of temperature extremes are anticipated in the near future. Although recent work suggests that changes in temperature variation will have disproportionately greater effects on species than changes to the mean, much of climate change research in ecology has focused on the impacts of mean temperature change. Here, we couple finegrained climate projections (2050-2059) to thermal performance data from 38 ectothermic invertebrate species and contrast projections with those of a simple model. We show that projections based on mean temperature change alone differ substantially from those incorporating changes to the variation, and to the mean and variation in concert. Although most species show increases in performance at greater mean temperatures, the effect of mean and variance change together yields a range of responses, with temperate species at greatest risk of performance declines. Our work highlights the importance of using fine-grained temporal data to incorporate the full extent of temperature variation when assessing and projecting performance.

Effects of acute and chronic temperature changes on the functional responses of the dogfish Scyliorhinus canicula (Linnaeus, 1758) towards amphipod prey Echinogammarus marinus (Leach, 1815)

“…The rate of warming, and subsequently environmental variation, affects maximum feeding estimates; consequently variation from the mean temperature is likely to have an impact upon predation pressure (Dell et al 2011;Paaijmans et al 2013;Vasseur et al 2014). Furthermore, patchiness of prey populations could confer a benefit against predation, despite increased predation pressured conferred through decreased handling time.…”

“…The effects of temperature change can be discernable on an individual level (Huey et al 1999;Calosi et al 2013;Vasseur et al 2014), and on population and community levels (Le Quesne and Pinnegar 2011;Rall et al 2012). Furthermore, thermal change may manifest as long-term chronic temperature increase or as acute temperature variations over short periods of time .…”

Micro-scale environmental variation amplifies physiological variation among individual mussels

“…Mean temperatures and the frequency of extreme weather events are predicted to continue increasing [2,3], likely reducing the mean performance of species [4,5]. Such global trends will interact with regional factors, such as spatial variation in climatic patterns or the timing of low tides [6,7], in sometimes complex and nonlinear ways [8].…”

Increasing frequency of low summer precipitation synchronizes dynamics and compromises metapopulation stability in the Glanville fritillary butterfly

“…Most ecological studies related to climate change have analysed changes in species' geographical ranges [11][12][13][14] and abundances [11,13,15], where the driving forces are thought to be the mean values of climatic variables, typically some measure of temperature. Many recent theoretical [16], modelling [17,18], experimental [17,[19][20][21][22] and observational [23][24][25] studies indicate that climatic variability and climatic extremes may have a similar or even stronger impact than the respective mean values on species dynamics. Once again, however, these studies have generally examined the impact of environmental variation on the geographical ranges and mean abundances of species, whereas practically no studies have analysed the impact of climatic variability on more complex aspects of population dynamics, such as the amplitude or spatial synchrony of population dynamics.…”