The effects of colonization, extinction and competition on co-existence in metacommunities

Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford.
Journal of Animal Ecology (Impact Factor: 4.5). 04/2009; 78(4):866-79. DOI: 10.1111/j.1365-2656.2009.01532.x
Source: PubMed


1. The co-existence of competitors in heterogeneous landscapes depends on the processes of colonization, extinction and spatial scale. In this study, we explore the metapopulation dynamics of competitive interactions. 2. Rather than simply evaluating the outcome of interspecific competition in the traditional manner, we focus on both the local population dynamic effects and the regional metapopulation processes affecting species co-existence. 3. We develop a theoretical model of regional co-existence to generate a set of predictions on the patterns of colonization necessary for co-existence and the regional processes that can lead to competitive exclusion. We empirically test these predictions using metacommunity microcosms of the interaction between two bruchid beetles (Callosobruchus chinensis, Callosobruchus maculatus). 4. Using well-replicated time series of the interaction between the bruchids and statistical methods of model fitting, we show how the qualitative and quantitative pattern of interspecific competition between the bruchid beetles is shaped by the structure of the metacommunity. 5. In unlimited dispersal metacommunities, the global exclusion of the inferior competitor is shown to be influenced more by the processes associated with extinction rather than low colonization ability. In restricted dispersal metacommunities, we show how the co-existence of competitors in a spatially heterogeneous habitat (patches connected through limited dispersal) is affected by Allee effects and life-history [colonization (dispersal) - competition] trade-offs.

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Available from: Michael B Bonsall, Oct 03, 2014
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    • "Many studies that have looked for a trade-off have instead found no relationship between traits associated with competition and colonization (e.g., Yu et al. 2004, Limberger and Wickham 2011, Kneitel 2012). Studies that have found trade-offs among only two or three species (e.g., Stanton et al. 2002, Hunt and Bonsall 2009) are inherently limited by statistical power. Documented evidence of competition–colonization trade-offs in multispecies assemblages include a trade-off between competition and dispersal ability in birds (Rodrı´guez et al. 2007), and a trade-off between colonization and competitive ability in laboratory cultures of protozoa (Cadotte et al. 2006). "
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    ABSTRACT: Competition-colonization trade-offs are theorized to be a mechanism of coexistence in communities structured by environmental fluctuations. But many studies that have tested for the trade-off have failed to detect it, likely because a spatiotemporally structured environment and many species assemblages are needed to adequately test for a competition-colonization trade-off. Here, we present a unique 32-year study of rock-dwelling lichens in New Mexico, USA, in which photographs were used to quantify lichen life history traits and interactions through time. These data allowed us to determine whether there were any trade-offs between traits associated with colonization and competition, as well as the relationship between diversity and disturbance in the community. We did not find evidence for a trade-off between competitive ability and colonization rate or any related life history traits. Interestingly, we did find a peak in all measures of species diversity at intermediate levels of disturbance, consistent with the intermediate disturbance hypothesis pattern. We suggest that the coexistence of the dominant species in this system is regulated by differences in persistence and growth rate mediating overgrowth competition rather than a competition-colonization trade-off.
    Full-text · Article · Feb 2014 · Ecology
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    • "An animal's niche is a complex ecological phenomenon that can be subdivided into several dimensions (Pianka 1974 ; Schoener 1974a ) . Differences in the ecological and physiological requirements of Pimm 1993 ; Hunt and Bonsall 2009 ; Dangremond et al . 2010 ) . "
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    ABSTRACT: Competition over spatial niche utilisation is one of most common competitive interactions between species in sympatry. Moreover, competitive interactions may involve age classes, and can fluctuate temporally. Consequently, evasive strategies that enable co-existence are likely to be important in the evolution of species assemblages. Here we investigate a system of two co-existing species of temperate geckos with similar ecologies (the house gecko, Hemidactylus turcicus and the wall gecko, Tarentola mauritanica), providing an opportunity to study the effect of species interactions. Juveniles and adults of both species were investigated throughout their daily and annual cycle to explore the effect of inter- and intra-specific interactions on microhabitat use. The two species showed differences in habitat use for both age classes in sympatry. In sympatry, T. mauritanica uses more open habitats and is more active. In contrast, H. turcicus is found in more closed habitats, closer to the ground and to vegetation cover. In allopatry, H. turcicus was observed in more open habitats, closer to the ground, and to vegetation cover, when compared to the population in sympatry with T. mauritanica. These differences in habitat usage were significant for both age classes. Moreover, there were differences, both in sympatry and in allopatry, between age classes that were dependent on season. In conclusion, the presence of a competitor induces a spatial shift in individuals of both age classes of H. turcicus. Observed plasticity in habitat utilisation in both age classes of H. turcicus is used to argue for the invasive potential of this species.
    Full-text · Article · May 2012 · Ecological Research
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    • "Using animals, some studies confirmed the presence of a CC trade-off (Hanski and Ranta 1983; Lei and Hanski 1998; Cadotte et al. 2006; Rodríguez et al. 2007; Hunt and Bonsall 2009), while others did not (Harrison et al. 1995; Amarasekare 2000; Yu et al. 2004; Guélat et al. 2008). For plants, there is a lot of indirect evidence for a CC trade-off based on seed size (Coomes and Grubb 2003). "
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    ABSTRACT: There is considerable theoretical evidence that a trade-off between competitive and colonization ability enables species coexistence. However, empirical studies testing for the presence of a competition-colonization (CC) trade-off and its importance for species coexistence have found mixed results. In a microcosm experiment, we looked for a CC trade-off in a community of six benthic ciliate species. For each species, we measured the time needed to actively disperse to and colonize an empty microcosm. By measuring dispersal rates and growth rates of the species, we were able to differentiate between these two important components of colonization ability. Competitive ability was investigated by comparing species' growth with or without a competitor in all pairwise species combinations. Species significantly differed in their colonization abilities, with good colonizers having either high growth rates or high dispersal rates or both. Although species showed a clear competitive hierarchy, competitive and colonization ability were uncorrelated. The weakest competitors were also the weakest colonizers, and the strongest competitor was an intermediate colonizer. However, some of the inferior competitors had higher colonization abilities than the strongest competitor, indicating that a CC trade-off may enable coexistence for a subset of the species. Absence of a community-wide CC trade-off may be based on the lack of strong relationships between the traits underlying competitive and colonization ability. We show that temporal effects and differential resource use are alternative mechanisms of coexistence for the species that were both slow colonizers and poor competitors.
    Full-text · Article · May 2011 · Oecologia
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