Aquatic macroinvertebrate diversity and composition in streams along an altitudinal gradient in Southeastern Brazil

Abstract

Aquatic macroinvertebrate diversity and composition in streams along an altitudinal gradient in Southeastern Brazil. A study concerning taxonomic richness and composition of the aquatic insect fauna in streams within the same catchment basin along an altitudinal gradient in Southeast Brazil, was conducted to test the hypothesis that there is a faunal discontinuity in the biocenotic composition, related to differences in altitude and latitude. In Southeastern Brazil, around latitude 22°, this faunal transition from rhithron to potamon biocenosis should occur at 500 m above sea level. Eighteen tributaries of the Mambucaba River, at Serra da Bocaina National Park, SP-RJ, Brazil, were studied. The streams were separated into 6 altitudinal zones (zone 1: above 1500 m; zone 2: 1200-1300 m; zone 3: 900-1000 m; zone 4: 400-700 m; zone 5: 100-300 m; and zone 6: 0-100 m) each including three streams. The aquatic insects were identified at the lowest possible taxonomic level. The highest richness was observed in altitudes between 1200-1300 m, while the lowest occurred in altitudes below 100 m. The Indicator Value method indicated taxa characteristic for four of the six altitudinal zones considered in this paper. Sorensen's Index and CCA results showed that distribution and composition of aquatic insect fauna of Serra da Bocaina National Park was influenced primarily by altitude and temperature rather than stream size. The absence of indicator species and the lower abundance in altitudes between 400-700 m suggest a transition from rhithral to potamal fauna, which is distinct at 200 m. Resumo: Riqueza de macroinvertebrados aquáticos em riachos ao longo de um gradiente altitudinal no Sudeste do Brasil. Um estudo da riqueza e composição da fauna de insetos aquáticos de uma bacia hidrográfica com ênfase no gradiente altitudinal foi conduzido com o objetivo de testar a hipótese de que existe uma descontinuidade na composição da fauna relacionada à altitude e latitude. Na região Sudeste do Brasil, próxima à latitude 22°, a transição da fauna ritral-potamal deveria ocorrer em torno de 500 m. Com este objetivo central foram estudados 18 afluentes do Rio Mambucaba, Parque Nacional da Serra da Bocaina, SP-RJ, divididos em 6 faixas altitudinais (faixa 1: acima de 1500 m; faixa 2: 1200-1300 m; faixa 3: 900-1000 m; faixa 4: 400-700 m; faixa 5: 100-300 m e faixa 6: 0-100 m), sendo amostrados três riachos por faixa de altitude. Os insetos aquáticos foram identificados até o menor nível taxonômico possível. A maior riqueza foi observada nas altitudes entre 1200-1300 m, enquanto a menor riqueza ocorreu em altitudes inferiores a 100 m. O teste de espécies indicadoras mostrou táxons característicos para quatro das seis zonas altitudinais consideradas no presente trabalho. Os resultados do índice de Similaridade de Sorensen e da CCA mostraram que a comunidade de insetos aquáticos do Parque Nacional da Serra da Bocaina foi influenciada primariamente pela altitude e temperatura mais do que o tamanho do rio. A ausência de táxons indicat...

The Veliidae (Hemiptera: Heteroptera: Gerromorpha) from São Paulo State, Brazil: new species, description of the male ofMicrovelia ioanaDrake & Hottes, 1952, and synonymical and distributional notes

“…Based on the above-mentioned material, the species is recorded for the first time from Sa˜o Paulo State. Specimens collected on Serra da Bocaina have been previously identified as Microvelia costaiana Drake & Hussey (1951) by Henriques-Oliveira and Nessimian (2010).…”

Stability of environmental reference conditions as indicated by stream macroinvertebrate communities: a case study in the central United States

“…Contrary to our expectations, richness levels (total and EPT) were generally greater at the latter site than at the two former sites, suggesting that distance up the watershed was as important as forested land cover in these cases. Elevation and drainage area probably did not present enough of a range at the 16 sites to demonstrate the effects reported by other researchers (Tate & Heiny 1995;Grubaugh et al 1996;Henriques-Oliveira & Nessimian 2010).…”

Madicolous Chironomidae from the Brazilian Atlantic Forest: a checklist with notes on altitudinal distributions (Diptera, Insecta)

“…Compositional changing in chironomid assemblages along altitudinal gradients have been verified by many researchers worldwide (McKie et al 2005, Tejerina and Malizia 2012, Henriques-Oliveira and Nessimian 2010, Scheibler et al 2014, Robinson et al 2016, Matthews-Bird et al 2016). In mountain ecosystems the occurrence of chironomid species can be influenced by environmental changes related to altitude variation, such as temperature and oxygen availability (Oliver 1971, Pinder 1986, Eggermont and Heiri 2012), dispersal capacity (Ashe et al 1987), historical events (McKie et al 2005, Allegrucci et al 2006, Krosch et al 2011) or other regional particularities (Körner 2007).…”