Effects of riparian vegetation on the structure of the marginal aquatic habitat and the associated fish assemblage in a tropical Brazilian reservoir

Abstract

Effects of riparian vegetation removal on the structure of the marginal aquatic habitat and the associated fish fauna in a tropical Brazilian reservoir. Biotra Neotrop., 9(4): http://www.biotaneotropica.org.br/v9n4/en/abstract?article+bn00709042009.Abstract: Riparian zones represent areas of strong biological, physical and chemical interaction between terrestrial and aquatic ecosystems. These areas are usually typified by high diversity of fauna, flora and environmental processes. The present study evaluates the littoral habitat structure and its fish fauna related to associations between presence and absence of natural riparian vegetal cover, in a reservoir in northeastern Brazil. Sampling was performed on marginal areas where riparian vegetation was present and where it had been removed for the plantation of sugar cane. For each type of marginal area three replicate sites were sampled during the wet season. Data on the habitat structure (submerged elements and substrate composition), fish and water quality were collected. The data was analyzed using Shannon-Wiener's diversity index and Pielou's equitability. Non-metric Multidimensional Scaling and the Multi-Response Permutation Procedure were used to evaluate similarities between sites. The structure of the habitat was more diverse in sites were natural riparian vegetation was still present. Muddy substrate was more abundant in areas with riparian vegetation whereas sandy substrate was more abundant in areas where riparian vegetation had been removed. Measured physico-chemical parameters and nutrients remained nearly constant across all sites. Metynnis lippincottianus and Crenicichla menezesi were more associated with the habitat in areas where riparian vegetation was removed, whereas Cichlasoma orientale and Cichla ocellaris were strongly correlated to forested areas. Keywords: riparian zone, habitat structure, water management, conservation.BELTRÃO, G. B. M., MEDEIROS, E. S. F. & RAMOS, R. T. C. Efeitos da cobertura vegetal ripária na estrutura do habitat aquático marginal e na fauna de peixes associada em um reservatório tropical brasileiro. Biotra Neotrop., 9(4): http://www.biotaneotropica.org.br/v9n4/pt/abstract?article+bn00709042009.Resumo: A zona ripária representa uma área de importantes interações, sejam biológicas, físicas ou químicas, entre o ecossistema terrestre e aquático. Essas áreas são geralmente caracterizadas por uma alta diversidade de fauna, flora e processos ecológicos. Este estudo avalia a estrutura do habitat aquático e a fauna de peixes com relação à presença e ausência da mata ciliar natural em um reservatório no Nordeste brasileiro. Amostragens foram realizadas em áreas marginais onde a mata ciliar estava presente e onde esta havia sido removida para o plantio de cana-de-açúcar. Em cada área, três pontos de coleta foram amostrados durante o período chuvoso. Dados sobre a estrutura do habitat (elementos submersos e composição do substrato), peixes e qualidade da água foram coletados. Os dados foram analisados usando o índice de divers...

Impact of riparian trees shade on aquatic plant abundance in conservation islands

“…Riparian zones represent areas of strong biological, physical and chemical interaction between terrestrial and aquatic ecosystems. Habitat structure is more diverse in sites where natural riparian vegetation is present (BELTRÃO et al 2009). Water shaded by riparian trees is cooler and contains more dissolved oxygen; roots of riparian vegetation provide spawning sites for fish and the associated invertebrates are a significant food resource for them (HARPER et al 1995); however, too dense a tree cover completely eliminates submerged macrophytes and hence other aquatic biota associated with them.…”

Spatial and temporal heterogeneity in a subtropical reservoir and their effects over the benthic macroinvertebrate community

“…Several authors reported the importance of the interaction between the water body and the ground (Beltrão et al, 2009;Kobayashi et al, 2010;Salemi et al, 2012). This interaction is considered relevant to the aquatic environment because provide nutrients, organic matter, minerals and pollutants and as can modulate other variables as light and temperature (Falkenmark, 2011;Tsatsaros et al, 2013).…”

Macroinvertebrados bentônicos e a estrutura do habitat em um rio intermitente do semiárido brasileiro

“…Precipitation is higher between April and June, with an annual average of 1095.9 mm (Rodal et al, 1998). Maximum altitudes in the area range between 650 and 1000 m (Beltrão et al, 2005) and average annual temperatures are 25 ºC. The vegetation in the area is the Caatinga/Agreste, a mostly deciduous open forest (Beltrão et al, 2005).…”

“…Maximum altitudes in the area range between 650 and 1000 m (Beltrão et al, 2005) and average annual temperatures are 25 ºC. The vegetation in the area is the Caatinga/Agreste, a mostly deciduous open forest (Beltrão et al, 2005). At each river reach, three subsamples of 40 x 40 x 2.5 cm of sediment were randomly taken using a D-shaped net (40 cm wide and 250 μm mesh).…”

“…Some studies show that the main factors that affect the macroinvertebrate community distribution are associated with the stability, heterogeneity and granulometry of sediment, dissolved oxygen concentrations, pH, water velocity and temperature and food availability (Palmer et al, 1994;Hynes, 2001), besides water flow and hydroperiod. Other studies mention that the riparian vegetation can affect macroinvertebrate assemblages by increasing the availability of underwater structures for colonization, resulting in greater densities and diversity of organisms (Trivinho-Strixino and Strixino, 1993;Beltrão et al, 2009). The role of the extreme variations in water flow in the spatial dynamics of the macroinvertebrate assemblages and their association with habitat structure in semi-arid intermittent streams has received little attention.…”