Systematic variation in the temperature dependence of physiological and ecological traits

Abstract

To understand the effects of temperature on biological systems, we compile, organize, and analyze a database of 1,072 thermal responses for microbes, plants, and animals. The unprecedented diversity of traits (n = 112), species (n = 309), body sizes (15 orders of magnitude), and habitats (all major biomes) in our database allows us to quantify novel features of the temperature response of biological traits. In particular, analysis of the rising component of within-species (intraspecific) responses reveals that 87% are fit well by the Boltzmann-Arrhenius model. The mean activation energy for these rises is 0.66 ± 0.05 eV, similar to the reported acrossspecies (interspecific) value of 0.65 eV. However, systematic variation in the distribution of rise activation energies is evident, including previously unrecognized right skewness around a median of 0.55 eV. This skewness exists across levels of organization, taxa, trophic groups, and habitats, and it is partially explained by prey having increased trait performance at lower temperatures relative to predators, suggesting a thermal version of the life-dinner principlestronger selection on running for your life than running for your dinner. For unimodal responses, habitat (marine, freshwater, and terrestrial) largely explains the mean temperature at which trait values are optimal but not variation around the mean. The distribution of activation energies for trait falls has a mean of 1.15 ± 0.39 eV (significantly higher than rises) and is also right-skewed. Our results highlight generalities and deviations in the thermal response of biological traits and help to provide a basis to predict better how biological systems, from cells to communities, respond to temperature change. I nvestigation of the thermal response of diverse biological processes should reveal general mechanisms by which life responds to Earth's complex and rapidly changing thermal landscape (1). General patterns of how temperature affects biological systems can be deduced in at least two ways. First, physiological and ecological traits (e.g., metabolic rate, encounter rate) can be measured for each species at its optimal temperature and plotted together to construct a single curve across species (2, 3). This interspecific approach has been used extensively (2-8), including studies of how climate affects biological systems (8-11). Second, a curve can be constructed by measuring trait values across a range of temperatures for a single species (intraspecific) (12, 13). In both intra-and interspecific cases, each curve can be characterized by its Q 10 value or activation energy (4, 6). These parameters, along with optimal temperature and response breadth for intraspecific responses, can be contrasted to explore effects of taxa, traits, and habitats. Indeed, for nearly a century, intraspecific studies have been conducted on a huge diversity of physiological and ecological traits (3,6,12,(14)(15)(16)(17). Comparative studies of these intraspecific data have tended to focus on a subset of available data (16,...

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)

“…This may be due to the temperature rise increasing the metabolism of the prey and causing a consequent increase in prey velocity and increased boldness (van Baalen et al 2001;Nowicki et al 2012). As a result, more stimuli are provided to the predator and the encounter rate is increased, leading to a higher attack rate when the prey is acclimated (Curio 1976;Taylor 1984). However, when the predator was acclimated the attack rate was higher toward nonacclimated prey and lower toward prey that were acclimated.…”

“…When the predator was acclimated the handling time was longer towards prey that were non-acclimated. This may again be related back to encounter rate (Curio 1976;Taylor 1984) and an increased metabolism and digestion speed due to acclimation of the predator (Dell et al 2011). Therefore, when predator and prey are both acclimated to the same temperature there is a decrease in handling time which implies that consumption rates will also increase with temperature warming.…”

Unifying ecological stoichiometry and metabolic theory to predict production and trophic transfer in a marine planktonic food web

“…Although different species can have distinct values for E a [30], our estimations did not reveal any significant difference between the two consumers in the range below 208C and we thus used the same value for both species. Note however, that at higher temperature the growth rate of Euplotes reaches a saturation level and does not follow the Arrhenius law (see the electronic supplementary material, figure S3).…”

Metabolic theory predicts whole-ecosystem properties

“…2A). Theory and available data suggest that E is ∼0.65 eV (i.e., rates increase about 2.5 times with every 10°C) (17,(27)(28)(29), meaning that uptake rates increase and residence times decrease exponentially with temperature, varying by about 40-fold over the range 0-40°C (Fig. 2D).…”