Riparian Deforestation Affects the Structural Dynamics of Headwater Streams in Southern Brazilian Amazonia. (December 2014)

• Record Type: Journal Article
• Authors: Bleich, Monica Elisa; Mortati, Amanda Frederico; André, Thiago; Piedade, Maria Teresa Fernandez
• Is Part Of: Tropical conservation science. Volume 7:Number 4(2014)
• Page Start: 657
• Page End: 676
• Publication Date: 2014-12
• Subjects: riparian zone -- environmental impact -- lotic ecosystems -- temporal variation -- water physical-chemical conditions; Zona ripária -- impactos ambientais -- ecossistemas lóticos -- variação temporal -- condições físico-químicas da água; Rain forest conservation -- Periodicals; Rain forest ecology -- Periodicals; Rain forest conservation; Rain forest ecology; Electronic journals; Periodicals; 577.34
• DOI: 10.1177/194008291400700406
• Languages: English
• ISSNs: 1940-0829

Abstract

Comparative studies of streams with altered versus conserved riparian zones are important to evaluate the degree of alterations caused by inappropriate use of these streams' vital buffer zones. The aim of this study was to determine the impact of riparian deforestation on the habitat structure of southern Brazilian Amazonian headwater streams, as well as to provide elements for impact assessment and the monitoring of these water bodies. We selected ten sites and two headwater streams at each site; one stream was located in an area with preserved riparian vegetation (pristine streams) and the other stream in a deforested riparian zone (altered streams). Stretches of these streams were analyzed across hydrological periods (dry period, beginning of the rainy period, and end of the rainy period) for hydro-morphological aspects, water physical-chemical variables, and habitat integrity (proportion of forestation in buffer zones and habitat integrity index). Compared to pristine streams in all the hydrological periods analyzed, altered streams presented lower oxygen concentration (~1.0 mg/L), an increase of 1 °C in water temperature, and less organic material availability. We found that riparian deforestation affects habitat structure variability among hydrological periods, making them more homogeneous. Therefore, beyond the necessary broadening of the spatial scale of studies in this region, monitoring these understudied headwater stream environments is also crucial for determining the magnitude of deforestation effects on these vulnerable aquatic ecosystems.