Metacommunity patterns in larval odonates

Abstract

The growth of metacommunity ecology as a subdiscipline has increased interest in how processes at diVerent spatial scales structure communities. However, there is still a signiWcant knowledge gap with respect to relating the action of niche-and dispersal-assembly mecha nisms to observed species distributions across gradients. Surveys of the larval dragonXy community (Odonata: Ani soptera) in 57 lakes and ponds in southeast Michigan were used to evaluate hypotheses about the processes regulating community structure in this system. We considered the roles of both niche-and dispersal-assembly processes in determining patterns of species richness and composition across a habitat gradient involving changes in the extent of habitat permanence, canopy cover, area, and top predator type. We compared observed richness patterns and species distributions in this system to patterns predicted by four general community models: species sorting related to adap tive trade-oVs, a developmental constraints hypothesis, dis persal assembly, and a neutral community assemblage. Our results supported neither the developmental constraints nor the neutral-assemblage models. Observed patterns of rich ness and species distributions were consistent with patterns expected when adaptive tradeoVs and dispersal-assembly mechanisms aVect community structure. Adaptive trade oVs appeared to be important in limiting the distributions of species which segregate across the habitat gradient. How ever, dispersal was important in shaping the distributions of species that utilize habitats with a broad range of hydroperi ods and alternative top predator types. Our results also sug gest that the relative importance of these mechanisms may change across this habitat gradient and that a metacommu nity perspective which incorporates both niche-and dis persal-assembly processes is necessary to understand how communities are organized.

Metacommunity theory as a multispecies, multiscale framework for studying the influence of river network structure on riverine communities and ecosystems

“…Numerous theoretical and empirical examples illustrate the utility of the metacommunity approach for simultaneous consideration of processes at multiple spatial scales. These examples come from a variety of organisms and systems including laboratory experiments (Cadotte 2006, Davies et al 2009), mesocosm experiments (Howeth and Leibold 2010a), lakes (Beisner et al 2006, McCauley et al 2008, ponds , Urban 2004, Werner et al 2007, Chase et al 2009), coral reefs (MacNeil et al 2009), forests (Jabot et al 2008), grasslands (Cronin 2007), savannahs (Debout et al 2009), agricultural landscapes (Driscoll and Lindenmayer 2009), and riverine systems (discussed below). However, despite several studies addressing meta-FIG.…”

Consumptive effects of fish reduce wetland crayfish recruitment and drive species turnover

“…A byproduct of these correlations is the observation that predatory interactions between vertebrate predators and invertebrate species with which they do not coexist tend to be stronger than interactions between those predators and coexisting species (Wellborn et al 1996;Wissinger et al 1999b; Garcia and Mittelbach 2008). Recent studies suggest that the presence of large-bodied Wshes may be more important than Wsh presence (i.e., small or large-bodied Wsh) for determining the life histories of co-existing invertebrates (Dorn 2008;McCauley 2008;McCauley et al 2008).…”

Setting boundaries: Environmental and spatial effects on Odonata larvae distribution (Insecta)

“…Thus, this variable did not have a structuring effect on Odonata (and its suborders) composition. Another factor, discussed by McCauley et al (2008), is that in lentic systems niche and dispersal are factors that affect Odonata larvae spatial distribution processes and species richness.…”