Invertebrates diversity in mountain Neotropical quartzite caves: which factors can influence the composition, richness, and distribution of the cave communities?

Abstract

Twenty caves located in a high altitudinal quartzite area in Brazil were examined for invertebrate richness and composition and in terms of environmental factors that determine community structure. We evaluate how distance, altitude, cave extension, environmental stability, number and size of cave entrances and stream presence can act on species composition and richness. The caves presented a high richness of troglophilic (463 spp.) and troglobitic species (6 spp.) in relation to other siliciclastic caves around the world. The average richness was 39.55 species per cave (sd = 21.87), the quantitative similarity among caves was 41% and turnover was βrepl. = 0.769. Araneae (20% of the sampled species), Diptera (18%) and Coleoptera (14%) were the dominant orders regarding species richness. Only twenty percent of the caves were placed out of the confidence interval of the average taxonomic distinctness (∆+); however, the ∆+ decreased with the increase of environmental stability. Cave extension and stream presence were the main factors determining the variation of species composition among caves. Cave extension also influenced species richness variations. Furthermore, the total richness and richness of troglobitic species increased with cave extension. The threats to these habitats further revealed that the fauna is at risk due to tourism, trampling and natural soil erosion that can promote microhabitat alterations. Therefore, quartzite caves also require special attention regarding conservation actions in order to keep their natural biological dynamics.

Epigean and hypogean drivers of Neotropical subterranean communities

“…(2015) and Souza‐Silva et al. (2020). Additionally, cave entrances play a key role in structuring subterranean communities as they represent the interface between epigean and hypogean ecosystems.…”

“…However, several important factors for structuring cave fauna in temperate regions, such as climatic features, ecoregions and primary productivity, and the influence of epigean ecosystems over subterranean communities, have not yet been tested in Neotropical regions (Bregović & Zagmajster, 2016;Christman et al, 2016;Culver et al, 2006;Mammola, Piano, Malard, Vernon, et al, 2019;Niemiller & Zigler, 2013). Similarly, some patterns observed for Neotropical regions have not been documented for temperate areas, such as the influence of streams and entrance features over the diversity of the terrestrial cave fauna (Prous et al, 2015;Simões et al, 2015;Souza-Silva et al, 2020a, 2020b. This is possibly due to the fact that most studies of cave fauna in temperate regions are focused on troglobitic species (Moldovan et al, 2018).…”

“…As a result, some previously proposed patterns, such as lowered troglobitic richness in Neotropical regions (Deharveng & Bedos, 2012), have been rejected as more data have emerged (Ferreira et al., 2018). Ecological studies on cave communities both in temperate and tropical regions have also shown that extrinsic and intrinsic caves variables are key drivers of hypogean biodiversity (Mammola, Cardoso, Angyal, et al., 2019; Souza‐Silva et al., 2020; Zagmajster et al., 2018). As an example, the positive relationship between cave size and richness is recurrent and documented in different regions of the world (Jaffé et al., 2018; Mammola, Cardoso, Angyal, et al., 2019; Souza‐Silva et al., 2020; Zagmajster et al., 2018).…”

“…Ecological studies on cave communities both in temperate and tropical regions have also shown that extrinsic and intrinsic caves variables are key drivers of hypogean biodiversity (Mammola, Cardoso, Angyal, et al., 2019; Souza‐Silva et al., 2020; Zagmajster et al., 2018). As an example, the positive relationship between cave size and richness is recurrent and documented in different regions of the world (Jaffé et al., 2018; Mammola, Cardoso, Angyal, et al., 2019; Souza‐Silva et al., 2020; Zagmajster et al., 2018). However, several important factors for structuring cave fauna in temperate regions, such as climatic features, ecoregions and primary productivity, and the influence of epigean ecosystems over subterranean communities, have not yet been tested in Neotropical regions (Bregović & Zagmajster, 2016; Christman et al., 2016; Culver et al., 2006; Mammola, Piano, Malard, Vernon, et al., 2019; Niemiller & Zigler, 2013).…”

Between darkness and light: spring habitats provide new perspectives for modern researchers on groundwater biology

“…Our results further demonstrate that stygofauna are reported in springs more frequently than surface fauna are reported in groundwater, in terms of both number of papers and overall numbers of species. In recent years, a growing body of literature has shown that even the occurrence of surface species in caves is often not accidental (Lunghi, Manenti & Ficetola, 2014b, a finding that has important implications for the communities of shallow subterranean habitats (Kozel et al, 2019;Lunghi, 2018;Lunghi et al, 2020;Salvidio et al, 2020;Silva, Iniesta & Ferreira, 2020). If stygofauna occur in springs and adjacent microhabitats more commonly than surface fauna occur underground, it is likely that, at least for some stygobionts, the use of the surface environment is not accidental.…”