Body size and trophic position determine the outcomes of species invasions along temperature and productivity gradients

Abstract

Species invasions are predicted to increase in frequency with global change, but quantitative predictions of how environmental filters and species traits influence the success and consequences of invasions for local communities are lacking. Here we investigate how invaders alter the structure, diversity and stability regime of simple communities across gradients of habitat productivity, temperature, and community size structure. We examine all three-species trophic modules (apparent and exploitative competition, trophic chain and intraguild predation) with empirically derived temperature and body mass scaling of vital rates. We show that the success of an invasion and its effects on community stability and diversity are predictably determined by the effects of environmental factors on each species and the relative strengths of trophic interactions between resident and invading species. We predict that successful invaders include smaller competitors and comparatively small predators, suggesting that species invasions may facilitate the downsizing of food webs under global change.

Effects of temperature and resource level on interspecific interactions in two species of Odonata larvae

“…Few empirical studies have mechanistically examined how temperature and resource levels interact in shaping the effects of interspecific competition in aquatic systems. In contrast, several studies have used an ecosystem-level approach focusing on energy and material flow (Binzer et al, 2012;Cross et al, 2015;Dijoux et al, 2024).…”

“…Few empirical studies have mechanistically examined how temperature and resource levels interact in shaping the effects of interspecific competition in aquatic systems. In contrast, several studies have used an ecosystem‐level approach focusing on energy and material flow (Binzer et al., 2012; Cross et al., 2015; Dijoux et al., 2024). Here, we found an interaction between temperature and resource density, and this interaction term differed between species and time in interesting ways.…”

“…One such variable that affects interspecific interactions is resource density (Hardin, 1960). The interaction between temperature and resource level has been explored theoretically using stoichiometric and ecosystem approaches that have focused on population and communities (Binzer et al., 2012; Cross et al., 2015; Dijoux et al., 2024). However, we know of no explicit theoretical models that have explored how the interaction between temperature and resources affects interspecific interactions using a mechanistic approach, but there could be several possible outcomes.…”