Breaking down the components of the competition‐colonization trade‐off: New insights into its role in diverse systems

Abstract

Performance trade‐offs between competition and colonization can be an important mechanism facilitating regional coexistence of competitors. However, empirical evidence for this trade‐off is mixed, raising questions about the extent to which it shapes diverse ecological communities. Here, we outline a framework that can be used to improve empirical tests of the competition‐colonization trade‐off. We argue that tests of the competition‐colonization trade‐off have been diverted into unproductive paths when dispersal mode and/or competition type have been inadequately defined. To generate comparative predictions of associations between dispersal and competitive performance, we develop a conceptual trait‐based framework that clarifies how dispersal mode and type of competitor shape this trade‐off at the stage of dispersal and establishment in a variety of systems. Our framework suggests that competition‐colonization trade‐offs may be less common for passively dispersing organisms when competitive dominants are those best able to withstand resource depletion (competitive response), and for active dispersers when traits for dispersal performance are positively associated with resource pre‐emption (competitive effect). The framework presented here is designed to provide common ground for researchers working in different systems in order to prompt more effective assessment of this performance trade‐off and its role in shaping community structure. By delineating key system properties that mediate the trade‐off between competitive and colonization performance and their relationship to individual‐level traits, researchers in disparate systems can structure their predictions about this trade‐off more effectively and compare across systems more clearly.

Similar trait‐based successional assembly in native and introduced plants despite species pool differences

“…Based on these results, mean seed mass of native species would be expected to increase over time, which was indeed observed (Figure 4b,e). Since seed mass is linked to seedling competition–colonization trade‐offs (Coomes & Grubb, 2003; Ferzoco & McCauley, 2023; Rees, 1996; Turnbull et al., 1999), these patterns likely represent the transition from good colonizers that arrive early to competitively superior species that dominate in later stages. Similarly, taller native species had higher incidence and abundance in late succession as compared to shorter ones (Figures 2 and 3).…”

“…For native species, we confirmed that height and seed mass, in particular, significantly explained species composition, consistent with the predictions of deterministic community assembly. In the early stages of succession, small-seeded native species were more likely to be present in the community is linked to seedling competition-colonization trade-offs (Coomes & Grubb, 2003;Ferzoco & McCauley, 2023;Rees, 1996;Turnbull et al, 1999), these patterns likely represent the transition from good colonizers that arrive early to competitively superior species that dominate in later stages. Similarly, taller native species had higher incidence and abundance in late succession as compared to shorter ones (Figures 2 and 3).…”

A Mechanistically Integrated Model of Exploitative and Interference Competition over a Single Resource Produces Widespread Coexistence

“…Our modeling of interference competition as a delay before a motile organism “gives up” is not an obvious fit to sessile plants, although it is, following precedent in classic game theory (Maynard Smith and Price, 1973), a good fit for motile animals (Stanton, Palmer and Young 2002, Rodríguez, Jansson and Andrén 2007, Ferzoco and McCauley 2023). Specifically, temporal investment in interference incurs an opportunity cost to foraging, facilitating coexistence.…”

The importance of regeneration processes on forest biodiversity in old-growth forests in the Pacific Northwest

“…Numerous theoretical models highlight the critical role of regeneration processes in shaping forest ecosystems. Competition–colonization models propose that the coexistence of tree species is influenced by their competitive abilities for resources and colonization capacities in different environmental niches [ 24 ]. Species with strong competitive traits may dominate resource-rich areas, while others with efficient colonization mechanisms thrive in less favourable conditions.…”