The influence of natural and anthropic environmental variables on the structure and spatial distribution along longitudinal gradient of macroinvertebrate communities in southern Brazilian streams.
Bottom Line: A total of 42 families and 129 taxa were found, with predominance of environmentally tolerant taxa.However, changes in anthropic variables were not affected by these geological differences and therefore did not correlate with patterns of spatial distribution in macroinvertebrate communities.Richness as a whole tended to be higher in 3(rd) to 4(th) order set of segments, but this trend was a result of local anthropic environmental disturbances.
Affiliation: Programa de PĆ³s-GraduaĆ§Ć£o em Biodiversidade Animal, Centro de CiĆŖncias Naturais e Exatas, Universidade Federal de Santa Maria. Faixa de Camobi km 9, 97105-900, Santa Maria, RS, Brazil firstname.lastname@example.org.Show MeSH
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Mentions: The three studied microbasins are located in the central region of the state of Rio Grande do Sul, Brazil, and are about 30 km from each other (Figure 1). The VacacaĆ-Mirim River (VMR) is located in the Municipality of Santa Maria, which has ca. 270,000 inhabitants. The river is 6th order, has a drainage area of ca. 1136 km2 (Marchesan et al. 2007), and belongs to the JacuĆ River basin (drainage area of 71,600 km2) (Figure 1). The watershed area is primarily given over to farming and ranching (Cargnin 2010). The IbicuĆ-Mirim River (IMR) and the TororaipĆ River (TRR) belong to the IbicuĆ River basin (drainage area of 47,740 km2; Paiva et al. 2000). The IMR is 5th order, drains an area of 33.1 km2 (Sampaio et al. 2010), and is also located in Santa Maria Municipality, but far from the urban area. The TRR is 4th order, has a drainage area of 0.15 km2, and is located in Mata Municipality, which has ca. 6,000 inhabitants. The three microbasins drain agricultural landscapes, however their headwaters suffer less influence from agriculture.
Affiliation: Programa de PĆ³s-GraduaĆ§Ć£o em Biodiversidade Animal, Centro de CiĆŖncias Naturais e Exatas, Universidade Federal de Santa Maria. Faixa de Camobi km 9, 97105-900, Santa Maria, RS, Brazil email@example.com.