Species turnover in Amazonian frogs: low predictability and large differences among forests

Abstract

The factors explaining species turnover at different spatial scales have been intensively studied, but most work in Amazonia has mainly focused on plants. For animals, it is not as obvious which environmental variables most affect differences in species composition among sites. We sought to identify what causes anuran turnover in Amazonian terra firme forests, and how the effectiveness of these factors varies among regions and across spatial scales. We sampled frogs in 56 plots along ponds and streams distributed over three terra firme forest areas in Eastern Amazonia. Using multiple regressions on distance matrices, we partitioned the variation in species turnover into components explained by variation in environmental and spatial distances. This was done in parallel for each area separately, and for all areas together, to assess the consistency of results between scales and across areas at the same scale. Each community seemed to respond to a set of factors specific to that area, and the identity of the variables that emerged as significant differed among areas and scales. Both geographical distances and environmental differences had larger explanatory power at the regional scale than at the local scale. The large differences among results from different areas caution against making broad generalizations about species turnover patterns from a single community, as real differences may exist among areas.

The Program for Biodiversity Research in Brazil: The role of regional networks for biodiversity knowledge, dissemination, and conservation

“…Much of the PPBio effort directly concerns the distribution of species, but given the broad scope of the network, no taxonomic group dominates the research agenda. As biodiversity conservation is the ultimate goal of PPBio, many studies are on surveys and monitoring of populations and biological assemblages (e.g., Almeida-Gomes et al 2015, Moreira et al 2016, Bitar et al 2017, natural history (e.g., Magalhães et al 2013, Simões et al 2019, and description and analysis of the distribution of new species (e.g., Tourinho et al 2010Bellini et al 2013Aldrete & Neto 2014), filling critical knowledge gaps in all Brazilian biomes. A preliminary evaluation of output indicated that the Amazon still accounts for 55% of publications, followed by Atlantic Forest (17%), Caatinga (10%), Pantanal (6%), South Brazilian Grasslands (3%) and Cerrado (3%), but differences among biomes reflects to some extent biases in data reporting.…”

Soil and forest structure predicts large-scale patterns of occurrence and local abundance of a widespread Amazonian frog

“…A persistent problem is explaining how abiotic and biotic factors affect the distributions of species across spatial scales which are hierarchical in nature ( Fraterrigo, Wagner & Warren, 2004 ). Recent work has disentangled historical and environmental determinants for the spatial turnover of species assemblage compositions ( Ricklefs & Schluter, 1993 ; Holyoak, Leibold & Holt, 2005 ; Bitar et al, 2017 ). However, for single species, the main focus has been on predicting entire ranges by extrapolating from local data on habitat requirements (e.g., using species distribution models, see Elith & Leathwick, 2009 ; Zurell et al, 2016 ), for which an understanding of the potential hierarchy of controls on species’ niches is critically important ( Araujo & Luoto, 2007 ; Fraterrigo, Wagner & Warren, 2004 ).…”

“…While sharp environmental boundaries clearly influence the abundance and occurrence of organisms, the effect of more gradual clines of biotic and abiotic features are less appreciated ( Quesada et al, 2012 ; Cintra et al, 2013 ; Emilio et al, 2013 ; Schietti et al, 2016 ). Under such a scenario, the abundance of organisms and patterns of local adaptation are shaped by continuous environmental changes across the landscape ( Endler, 1977 ; Leite & Rogers, 2013 ; Dias-Terceiro et al, 2015 ; Bitar et al, 2017 ).…”

“…Anurans are useful models to evaluate biogeographic and ecological determinants of species assemblages in tropical ecosystems owing to their high diversity, low vagility and specific environmental requirements ( Zimmerman & Bierregaard, 1986 ; Ernst & Rödel, 2008 ; Menin et al, 2007 ; Keller et al, 2009 ). Furthermore, based on their life histories, groups of species can be assigned to specific guilds (e.g., lotic and lentic aquatic breeders, forest-floor dwellers and canopy species; for case studies from Amazonia see Zimmerman & Simberloff, 1996 ; Menin et al, 2007 ; Rojas-Ahumada, Landeiro & Menin, 2012 ; Landeiro, Waldez & Menin, 2014 ; Dias-Terceiro et al, 2015 ; Bitar et al, 2017 ). Related species may share behavioral, physiological, and morphological traits because of common ancestry, rather than as a result of being exposed to similar selection pressures and convergent evolution ( Huey, 1987 ; Losos, 1990 ; Cadle & Greene, 1993 ; Zimmerman & Simberloff, 1996 ).…”

Do flood pulses structure amphibian communities in floodplain environments?

“…The differences in richness may also result from nestedness that occurs when species in a less rich locality are a subset of species of a richer community (Almeida-neto et al 2008). Understanding these patterns can provide insights into the processes that maintain biodiversity in communities subjected to frequent disturbances and help delineate conservation strategies (G omez-Rodr ıguez et al 2010, Machado et al 2012, Bitar et al 2017.…”