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 Pós-Graduação em Biodiversidade Animal, Centro de Ciências 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 redundancy analysis axes were significantly different (F = 2.17, p < 0.001). The first two axes together summarized 40.4% of the variability existing in the abundance data of the macroinvertebrate communities and explained 62.8% of their relationship with the environmental variables (Table 2). The first redundancy analysis axis showed stronger positive correlation with urbanization and land use and a negative correlation with altitude (Table 3, Figure 4). The second axis showed a stronger negative correlation with EC (Table 3, Figure 4). In general, the first axis segregated samples from 3rd and 4th order segments of the VMR and TRR from samples from the IMR microbasin and 1st and 2nd order segments of the VMR and TRR (Figure 4). This segregation was determined especially by urbanization, land use, and RD (Figure 4).
Affiliation: Programa de Pós-Graduação em Biodiversidade Animal, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria. Faixa de Camobi km 9, 97105-900, Santa Maria, RS, Brazil email@example.com.