Considering the effects of temperature × nutrient interactions on the thermal response curve of carrying capacity

Abstract

Citation: Lemoine, N. P. 2019. Considering the effects of temperature 9 nutrient interactions on the thermal response curve of carrying capacity. Ecology 100(4):Abstract. Climate warming will likely destabilize populations or drive consumers locally extinct. These predictions arise from consumer-resource models incorporating temperaturedependent parameters, and the accuracy of these predictions hinges on the validity of temperature scalings for each parameter. Among all parameters, carrying capacity (K) is the most ill-defined and the temperature scaling of this parameter has no empirically verified foundation. Most studies assume that K declines exponentially with warming, but others have assumed a positive or no relationship between K and temperature. Here, I developed a theoretical foundation for a temperature scaling of K based on physiological principles of temperature and nutrient limitation of phytoplankton growth. The trade-off between thermodynamics and nutrient uptake yields a unimodal thermal response curve for K, and this prediction is supported by empirical data on both phytoplankton and insects. Analyses of consumer-resource models demonstrate the primacy of K in determining predictions of coexistence and stability. Since K exerts a dominant influence on model predictions, ecologists should carefully consider the temperature scaling of K for the species and region in question to ensure accurate estimates of population stability and extinction risk.

Effects of Warming on Intraguild Predator Communities with Ontogenetic Diet Shifts

“…as metabolic demands increase and we assume a temperature independent nutrient supply (Savage et al 2004, but see Lemoine 2019). The combination of increased metabolism and intake rate and decreased resource production captures reductions in energetic efficiency of food webs via the warming-induced mismatch between respiration and biomass production (O'Connor et al 2009).…”

Fish life histories in a warming climate: a mechanistic basis of change and a community context

“…As body size determines the energy demand and temperature sensitivity of energetic efficiency, size differences between trophic levels can determine how system carrying capacity (a system's ability to hold standing biomass based on environmental conditions) respond to warming (Arim et al 2007;Binzer et al 2012). Because of responses in primary production, carrying capacity should be unimodal over the full biological temperature range, and thus decrease in the higher temperature range (Lemoine 2019;Uszko et al 2022). Consequently, food web responses to warming are predicted to depend on the temperature range examined, how warming changes energetic efficiency across trophic levels, on effects on primary production but also on biomass loss via mortality affecting competition for resources (Vasseur & McCann 2005;Binzer et al 2012).…”

Resource limitation determines realized thermal performance of consumers in trophodynamic models

“…More recent work (Lemoine, 2019) has stressed the non‐linear and often unimodal shapes of temperature dependence on biological rates as a reason to investigate the same functional dependence for . Since is the result of the joint expression of many biotic and abiotic processes, the manner in which these processes align can lead to a variety of different functional forms over the biologically relevant range (Lemoine, 2019; Uszko et al, 2017). As we endeavour to describe temperature's effect at the scale of communities, it is important to consider a broader range of temperatures, including those that could lead to negative rates of population growth.…”

“…This result was also confirmed more recently by Bernhardt et al ( 2018 ). More recent work (Lemoine, 2019 ) has stressed the non‐linear and often unimodal shapes of temperature dependence on biological rates as a reason to investigate the same functional dependence for . Since is the result of the joint expression of many biotic and abiotic processes, the manner in which these processes align can lead to a variety of different functional forms over the biologically relevant range (Lemoine, 2019 ; Uszko et al, 2017 ).…”