Thermal mismatches explain consumer–resource dynamics in response to environmental warming

Abstract

Changing temperatures will impact food webs in ways we yet to fully understand. The thermal sensitivities of various physiological and ecological processes differ across organisms and study systems, hindering the generation of accurate predictions. One step towards improving this picture is to acquire a mechanistic understanding of how temperature change impacts trophic interactions before we can scale these insights up to food webs and ecosystems. Here, we implement a mechanistic approach centered on the thermal sensitivity of energetic balances in pairwise consumer-resource interactions, measuring the thermal dependence of energetic gain and loss for two resource and one consumer freshwater species. Quantifying the balance between

Thermal environment and ecological interactions modulate the importance of evolution in response to warming

“…Organisms originated from a long-running mesocosm experiment in Dorset, England. This mesocosm experiment has been the subject of multiple previous publications (e.g., Yvon-Durocher et al 2015, Álvarez-Codesal et al 2023. Briefly, at the time of sampling in 2019, open-air experimental ponds of 1 m 3 water of mixed freshwater phytoplankton and zooplankton had been continuously maintained since 2005 (i.e., approximately 14 years).…”

“…We sampled two phytoplankton resource species, the algae C. reinhardtii and Desmodesmus sp. from each treatment in January 2019, as well as a consumer species, Daphnia pulex in October 2019 (for further details see Álvarez-Codesal et al 2023). The discrepancy in dates occurred because we were unsuccessful in isolating consumers on the first attempt.…”

“…In consequence, we expect that when shifts in thermal performance occur in traits that affect how species interact, such as resource acquisition or metabolism, this could affect overall fitness of populations that interact and respond to warming. Specifically, 1) different life history traits within a species can have different thermal dependencies (Dell et al 2011, Huey andKingsolver 2011), 2) consumer and resource species have documented differences in these thermal dependencies (O'Connor et al 2009, Álvarez-Codesal et al 2023, and 3) evolutionary potential can differ across trophic levels (Terhorst et al 2010, Hague andRoutman 2016). Therefore, it follows that evolution in response to warming has the potential to alter consumer-resource dynamics, while also being reciprocally influenced by them (Faillace et al 2021), and that the effects of evolution may additionally depend upon current thermal environment.…”

The effects of warming on the stability of consumer-resource interactions

“…Such organism- and population-level responses scale up to ecological communities and ecosystems via interspecific interactions (Montoya & Raffaelli, 2010, O’Connor et al ., 2011, Thomas et al ., 2004). Therefore, to predict how increasing ambient temperatures (IPCC, 2021) will alter communities, we first need to understand how interspecific interactions will respond to warming (Alvarez-Codesal et al ., 2023, Bideault et al ., 2021).…”

“…A reduction with warming in either energetic efficiency or interaction strength has been associated with increased stability via the dampening or elimination of oscillations (Vasseur & McCann, 2005, Rall et al ., 2008). Lower energetic efficiency or weaker interaction strength due to warming have also been argued to increase the risk of consumer extinction due to starvation (Sentis et al ., 2012, Rall et al ., 2012, Alvarez-Codesal et al ., 2023). However, the latter would imply the proximity of the dynamics to the consumer extinction boundary and, therefore, a loss of stability associated to consumer persistence.…”