Species assortment or habitat filtering: a case study of spider communities on lake islands

Abstract

Competition theory predicts that species of similar ecological niches are less likely to coexist than species with different niches, a process called species assortment. In contrast, the concept of habitat filtering implies that species with similar ecological requirements should co-occur more often than expected by chance.Here we use environmental and ecological data to assess patterns of co-occurrence of regional communities of spiders distributed across two assemblies of lake islands in northern Poland. We found aggregated and random co-occurrences of species of the same genus and a significant tendency of species segregation across genera. We also found that species of the same genus react similarly to important environmental variables. A comparison of ecological traits of species of the local communities with those expected from a random sample from the regional Polish species pool corroborated partly the habitat filtering hypothesis. On the other hand, we did not find evidence for species assortment.Our results also imply that at least some observed species co-occurrences result from niche differentiation.

Stygobiotic crustacean species richness: a question of numbers, a matter of scale

“…This answer may apparently be in line with classic community assembly theories which are synthetically focused on interspecific competition and niche differentiation among species which built up the community (Gotelli & Graves, 1996;Losos, 2008). The analysis of patterns of species richness at the local scale may hypothetically suggest that some (if not all) of the groundwater habitats may offer a small range of successful strategies (Cornwell et al, 2006;Ulrich et al, 2009), which, together with oligotrophy, may led to poor species assemblages, composed by phylogenetic related species. Only a further approach, dealing with analysis of the functional diversity (Stegen & Swenson, 2009) in groundwater communities, together with the evaluation of phylogenetic diversity within and among groundwater assemblages (Hardy & Senterre, 2007;Graham & Fine, 2008;Ricklefs, 2008), will clarify the more significant ecological processes responsible for the observed patterns of point-species richness.…”

Niche distribution and influence of environmental parameters in marine microbial communities: a systematic review

“…In contrast, niche theory is based on the assumption that the species composition of an ecosystem is entirely determined by environmental conditions, a process known as habitat filtering ( Dumbrell et al, 2010 ; Pontarp et al, 2012 ). This process results in communities of co-existing organisms with largely overlapping ecological niches, meaning that they respond similarly to environmental conditions of their habitats and possibly compete for resources ( Ulrich et al, 2009 ; Maire et al, 2012 ). In contrast, niche partitioning, allows co-occurring microorganisms to avoid competition by using different strategies to exploit the diversity of resources available at their environment ( Macalady et al, 2008 ).…”

Fifty years after the ‘‘Homage to Santa Rosalia’’: Old and new paradigms on biodiversity in aquatic ecosystems

“…The almost widespread truncated food webs in ground water (Gibert & Deharveng, 2002), together with different habitat preferences of stygobiotic species, may represent the coarse-grained explanations of the crucial question governing this contribution: why are there so few species in ground water? The analysis of patterns of species richness at the local scale may hypothetically suggest that some (if not all) of the groundwater habitats may offer a small range of successful strategies (Cornwell et al, 2006;Ulrich et al, 2009), which, together with oligotrophy, may led to poor species assemblages, composed by phylogenetic related species. The analysis of patterns of species richness at the local scale may hypothetically suggest that some (if not all) of the groundwater habitats may offer a small range of successful strategies (Cornwell et al, 2006;Ulrich et al, 2009), which, together with oligotrophy, may led to poor species assemblages, composed by phylogenetic related species.…”