History predicts contemporary community diversity within a biogeographic province of freshwater fish

Abstract

AbstractAimHistorical biogeography and community ecology both seek to uncover the patterns and processes governing the structure and composition of communities, though typically at different temporal and spatial scales. Recent work has called to integrate these two fields; however, it is typically assumed that history plays little role in assembling contemporary, local communities. We incorporated phylogeographic data into traditional metacommunity analyses of freshwater fish communities to analyse if history can shape local community structure.LocationStreams in the Nicaraguan Depression in north‐eastern Costa Rica.TaxonFreshwater fish communities.MethodsWe sampled community composition in 14 streams of the San Juan River Basin during the dry season of 2019 and evaluated variability in community composition in response to local and landscape‐scale environmental variability, spatial distance and historic processes using redundancy analyses. We measured environmental and spatial variables using typical methods utilized in metacommunity studies and approximated the effects of history with samova genetic groupings of three livebearing fishes native to the area. We also used PERMANOVAs to test if community composition exhibits similar spatial structure as seen in the genetic data of the three livebearing fishes used as historical proxies.ResultsLarge‐scale patterns of genetic diversity predicted the patterns of local community diversity with community composition showing similar spatial structuring. Additionally, history variables were the only variables that significantly explained community composition and accounted for 20.6% of the total variability.Main ConclusionsSpecies‐specific incidence patterns within Costa Rican freshwater fish communities vary according to biogeographic history, indicating that history can impact local community assembly. These observed patterns are likely due to colonization history following eustatic sea level change. Phylogeography can bridge the gap between classical biogeography and community ecology by enhancing inferences regarding community assembly through time and space, therefore studies should incorporate both genetic and local community data when assessing community assembly.