Predation leads to assembly rules in fragmented fish communities

Abstract

Diamond [Assembly of species communities. In: Ecology and Evolution of Communities (eds Cody, M.L. & Diamond, J.M.). Harvard University Press, Cambridge, pp. 342-444] proposed that resource competition leads to checkerboard-like distributions of competing species. This proposal prompted research that revealed checkerboard patterns within a wide range of communities, but the mechanisms that generate such patterns are still poorly understood. Here we present whole-lake natural experiments and analyses of species-environment relationships in small coastal lake fish communities that were fragmented when land uplift isolated these lakes from the Baltic Sea, showing that a combination of predation and habitat suitability generated checkerboard distributions. Checkerboard patterns developed because two piscivores, northern pike and Eurasian perch, caused the extinction of several prey species in deep lakes. Conversely, low oxygen levels in shallow lakes caused extinction of the piscivores, and these areas served as a refuge for tolerant prey species. Based on these findings, we suggest that habitat suitability and biotic interactions should be viewed simultaneously in null models of assembly rules.

Evaluating macroinvertebrate community shifts in the confluence of freestone and limestone streams

“…However, interspecific competition or predation between different species of macroinvertebrates cannot be conclusively eliminated as a source of variation in community structure. Competitive exclusion can influence macroinvertebrate communities (Gotelli and McCabe, 2002;Florencio et al, 2013) and the distribution of predator species can depend on the distribution of prey (Englund et al, 2009;Florencio et al, 2013). These effects may be stronger on smaller spatial scales, where there tends to be less spatial heterogeneity (Englund et al, 2009).…”

“…Competitive exclusion can influence macroinvertebrate communities (Gotelli and McCabe, 2002;Florencio et al, 2013) and the distribution of predator species can depend on the distribution of prey (Englund et al, 2009;Florencio et al, 2013). These effects may be stronger on smaller spatial scales, where there tends to be less spatial heterogeneity (Englund et al, 2009). The effects of competitive exclusion and habitat segregation, when taxa segregate due to different preferences for non-overlapping habitats, are difficult to disentangle (Gotelli and McCabe, 2002).…”

Assembling an ant community: species functional traits reflect environmental filtering

“…However, a range of other processes (e.g. competition, predation) can also generate patterns of spatial segregation, emphasizing the need to test processes underlying observed patterns (Englund et al 2009;Gotelli and McCabe 2002;Hausdorf and Hennig 2007). To this end, we investigated the links between environmental factors and ant functional traits.…”

“…It has been hypothesized that environmental conditions may Wlter species: species arriving from the regional species pool only persist in local habitats if functional physiological, morphological, and/or life-history traits are compatible with habitat characteristics (Keddy 1992;Southwood 1988). A range of other processes (e.g., competition, predation) can also generate patterns of species segregation along environmental gradients (Englund et al 2009;Gotelli and McCabe 2002;Hausdorf and Hennig 2007), and multiple processes may operate simultaneously (Englund et al 2009). As a result, quantifying the links between a habitat's conditions and the functional traits of its species represents a Wrst, necessary step in determining the processes governing species distributions.…”

The birth and death of lakes on young landscapes

“…Data on maximum depth were available for 108 small lakes (0.01-0.1 km 2 , depth >1 m, 5.5% of all lakes). This sample of lakes was selected by Englund et al [2009] to ensure that lake area was orthogonal to lake age (r = 0.09), allowing us to examine the relationship between depth and lake age independently of lake area.…”