Environmental predictors of macroinvertebrate communities in coastal wetlands of southern Brazil

Abstract

The rapid degradation of wetlands worldwide accentuates the urgent need for ecological data to help manage and protect the threatened biodiversity in the remaining often-fragmented wetlands. In the Neotropics where fragmentation is common, environmental factors structuring aquatic macroinvertebrate communities are poorly known. We tested the hypothesis that physical features, such as wetland area, habitat diversity, water depth and temperature, and water and sediment chemistry are important correlates with richness, density and composition of wetland macroinvertebrate assemblages in Brazil. If so, do these correlations differ between summer and winter? A total of 16 895 individuals across 61 families were collected. Richness was positively associated with habitat diversity and water depth and negatively associated with water temperature. Macroinvertebrate density was negatively associated with water depth, and positively correlated with habitat diversity, percentage of sediment organic matter and water conductivity. Macroinvertebrate composition was associated mainly with wetland area and habitat diversity in the wetlands studied; these relationships persisted in both seasons. Our data illustrate environmental factors that potentially structure and maintain aquatic macroinvertebrate biodiversity in southern Brazil wetlands, and should be managed because 90% of these ecosystems have already been lost as a result of human activities.

Aquatic macrophyte and macroinvertebrate diversity and conservation in wetlands of the Sinos River basin

“…The positive relationship between area and macrophyte and macroinvertebrate richness has been found in Southern Brazil wetlands (Rolon and Maltchik, 2006;Stenert and Maltchik, 2007;Rolon et al, 2008). However, for the macroinvertebrate community, the influence of the area is controversial (Panatta et al, 2007;Stenert et al, 2008). In the Sinos River basin, wetland area influenced macrophyte richness.…”

“…The principle that a large area supports more species (Rosenzweig, 1995) has been put into practice in conservation planning. The species-area relationships have also been applied to wetland conservation programs in Southern Brazil, mainly for wetlands fragmented by rice cultivation expansion (Guadagnin et al, 2005;Rolon and Maltchik, 2006;Guadagnin and Maltchik, 2007;Panatta et al, 2007;Stenert and Maltchik, 2007;Rolon et al, 2008;Stenert et al, 2008). However, little has been done for wetlands drained by the urban expansion in basins of high demographic density.…”

Spatio-temporal attributes of water temperature and macroinvertebrate assemblages in the headwaters of the Bushmans River, southern Drakensberg

“…In addition, water conductivity levels remained low at all sites and during all seasons (mean = 0.09 mS/m). Water conductivity, in particular, influences macroinvertebrate richness and diversity (Miserendino, 2001;Azrina et al, 2006;Stenert et al, 2008). In South Africa, Dallas et al (1999) have established pH and conductivity tolerance levels for macroinvertebrate families, including Heptageniidae (Table 1), which was present in the Bushmans River.…”

Responses of freshwater molluscs to environmental factors in Southern Brazil wetlands

“…The macroinvertebrate structure in wetlands has been associated with area and habitat heterogeneity (Oertli et al, 2002;Batzer et al, 2004;Panatta et al, 2006;Studinski and Grubbs, 2007;Stenert et al, 2008); hydroperiod (Tarr et al, 2005;Whiles and Goldowitz, 2005;Stenert and Maltchik, 2007); altitude (Oertli et al, 2002;Jacobsen, 2004); water chemistry (Heino, 2000;Batzer et al, 2004), and water depth and temperature (Zimmer et al, 2000;Hall et al, 2004;Tarr et al, 2005;Studinski and Grubbs, 2007). However, most of these surveys were developed in the North Hemisphere and Australia.…”