Abstract
Temperature extremes are predicted to increase in frequency, intensity and duration under global warming and are believed to significantly affect community composition and functioning. However, the effect of extreme climatic events on communities remains difficult to predict, especially because species can show dissimilar responses to abiotic changes, which may affect the outcome of species interactions. To anticipate community responses we need knowledge on within and among species variation in stress tolerance. We exposed a soil arthropod community to experimental heat waves in the field and measured heat tolerance of species of different trophic levels from heated and control plots. We measured the critical thermal maximum (CTmax) of individuals to estimate inter- and intraspecific variation in heat tolerance in this community, and how this was affected by experimental heat waves. We found interspecific variation in heat tolerance, with the most abundant prey species, the springtail Isotoma riparia, being more sensitive to high temperatures than its predators (various spider species). Moreover, intraspecific variation in CTmax was substantial, suggesting that individuals within a single species were unequally affected by heat extremes. However, heat tolerance of species did not increase after being exposed to an experimental heat wave. We conclude that interspecific variation in tolerance traits potentially causes trophic mismatches during extreme events, but that intraspecific variation could lessen these effects by enabling partial survival of populations. Therefore, ecophysiological traits can provide a better understanding of abiotic effects on communities, not only within taxonomic or functional groups, but also when comparing different trophic levels.
Highlights
Most terrestrial ecosystems irregularly experience sudden and severe changes in environmental conditions, for example, due to extreme weather events, such as heat waves, drought spells, and floods
In this paper we investigate the extent of inter- and intraspecific variation in heat tolerance of several species from a soil arthropod community that was exposed to experimental heat waves
We focus on a thermal trait that is related to temperature extremes: the critical thermal maximum (CTmax), which reflects the heat tolerance of an individual when exposed to a gradually increasing temperature (Lutterschmidt and Hutchison 1997; Terblanche et al 2007; Mitchell and Hoffmann 2010)
Summary
Most terrestrial ecosystems irregularly experience sudden and severe changes in environmental conditions, for example, due to extreme weather events, such as heat waves, drought spells, and floods. When extreme conditions affect only a particular age or size class, such as small-sized juveniles or reproductively active adults, severe consequences for the population can be expected This may alter size distributions and population dynamics with cascading effect on higher trophic levels (e.g., through reduced prey density) or lower trophic levels (e.g., through reduced predation pressure). Another important source of intraspecific variation in trait values is phenotypic plasticity (DeWitt and Scheiner 2004), by which previous exposure to stressful conditions may lead to a rapid increase in tolerance to subsequent exposures, which may even act across generations (e.g., Bateson et al 2014; Zizzari et al 2016). We will discuss the ecological consequences of the inter- and intraspecific variation in heat tolerances in terms of species interactions within our soil community
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
