Beta diversity in stream macroinvertebrate assemblages: among-site and among-microhabitat components

Abstract

The benthic macroinvertebrate community is an important component of stream diversity, because its members are fundamental connectors among the different trophic levels of running waters. In this study, we assessed alpha and beta diversities of benthic macroinvertebrates in three stream sites and four microhabitats: (i) moss in the air-water interface; (ii) submerged roots of terrestrial plants; (iii) leaf litter deposited in pools; (iv) stones in riffles. We constructed rarefaction curves and compared species richness among microhabitats for each stream site. Additionally, we evaluated which factor, stream site, or microhabitat, was most important in determining variation in assemblage structure, i.e., beta diversity. There was no significant difference among microhabitats in terms of taxa richness evaluated by rarefaction curves. Using partial Constrained Correspondence Analysis (pCCA), we found that microhabitat was most important in determining community composition, accounting for 42.02% of the total variation. Stream sites accounted for 22.27%. In accordance with the pCCA, exploratory multivariate methods (ordination and classification) revealed four distinct groups, corresponding to the four microhabitats, independent of stream sites. Our results indicated that differences among environmental conditions are much more important in the determination of stream assemblage structure than are differences in spatial location. Accordingly, adjacent microhabitats in a single stream site harbor macroinvertebrate assemblages more dissimilar than those found in a single microhabitat at different stream sites.

Spatial and temporal distribution of stream macroalgae in a tropical river basin

“…Even with this information, a precise description of seasonal pattern of macroalgae in relation to environmental factors remains very difficult to be described, especially for tropical streams where rare species represent an important part of the communities' composition. Furthermore, our data support the hypothesis that local characteristics of each stream segment influence the ecological distribution of macroalgae , Costa & Melo 2008). We finally suggest that studies on micro and/or mesohabitat scales of analysis can be fundamental to better understand the ecological distribution of these communities.…”

Rapid ecological assessment of benthic indicators of water quality: a successful capacity-building experience for Brazilian postgraduate students in ecology

“…The availability of microhabitats appears to be an important factor determining of the composition of macroinvertebrate communities (Costa and Melo, 2008), and the difference observed between the two substrate types in the present study appear to further confirm this pattern. The partition analysis revealed a distinct distribution of diversity by substrate type (Figure 2).…”

Diversidade e similaridade entre populações de insetos aquáticos em riachos de primeira e segunda ordem, sul do Brasil

“…-Lima et al (1999), ao estudar a riqueza de peixes em riachos de diferentes ordens, também não verificou uma relação entre a riqueza e a ordem do riacho e os autores afirmam que uma maior riqueza está associada à diversificação de substratos e não à ordem. Para insetos aquáticos, a estruturação das comunidades também parece ser mais influenciada pelas condições ambientais do que pela localização espacial (COSTA; MELO, 2008).…”