Land cover and conservation state of a region in the Southern limit of the Atlantic Forest (river Maquiné basin, Rio Grande do Sul, Brazil)

Abstract

The state of conservation of Atlantic Forest in the Maquiné river basin was assessed using land cover data obtained from Landsat TM 5 satellite imagery (October 1995). The initial analysis examined the distribution of the relative areas of each land-cover type according to landscape slope classes, potential vegetation zones, and a 90 m riparian buffer. Land-cover classes were then regrouped into categories representing "low", "intermediate", and "high" degree of anthropogenic alteration. Results indicate that about 70% of the land cover of the Maquiné river basin has been highly altered as a consequence of replacement of natural forests by agriculture. Presently, a recovery process seems to be underway, contrasting with the historical trend towards deforestation. There are large areas of secondary vegetation in intermediate (34.8%) and advanced successional stages (20.2%), particularly across the range of the montane forest and of forest formations that occur at elevations higher than 800 m (high-montane dense ombrophilous forest and mixed ombrophilous forest). The geographical location at the southern limit of the Atlantic Forest stricto sensu and comparison of the results with data on the state of conservation of the Atlantic Forest in Rio Grande do Sul indicate that the Maquiné river basin is an important area for conservation. Some points regarding future research and conservation management are also discussed.

Relief influence on the spatial distribution of the Atlantic Forest cover on the Ibiúna Plateau, SP

“…This has caused them to be more frequently abandoned for regeneration, although the declivities observed in Caucaia are not so high. The same pattern can be observed in other areas of the Atlantic Forest, as in the basin of Maquiné, State of Rio Grande do Sul, where the abandonment of the lands and further forest regeneration occurred preferably in more remote areas or in areas less appropriate for farming (Becker et al, 2004). In a similar way, in the semi-decidual montane forests of São José Mountain Range, Tiradentes (MG), the original cover was reduced to scattered fragments, most of them situated in areas whose topography makes their use difficult (Oliveira-Filho and Machado, 1993).…”

A fish-based biotic integrity index for assessment of lowland streams in southeastern Brazil

“…The benefits to water bodies of the presence of riparian vegetation are numerous (Pusey & Arthington, 2003, and authors cited therein) and may yet represent a great opportunity to increase connectivity between terrestrial habitats (Becker et al, 2004). The current cost of restoring one hectare of riparian forest in the Rio Piracicaba basin in State of São Paulo, for example, was estimated to be approximately US$3,350 (Silva et al, 2007).…”

Stream fish, water and habitat quality in a pasture dominated basin, southeastern Brazil

“…Based on our cursory analysis in this pasture dominated landscape, mitigation efforts should be centered on reversing the degradation in the physical quality of the streams, specifically those of the first order, minimizing physical habitat losses of aquatic biota by rehabilitating riparian vegetation, controlling siltation, and conserving soil. Specifically in the case of riparian zones restoration, this could be an important opportunity for improving connectivity between terrestrial habitats (Becker et al, 2004). In addition, effluents should be treated and land use controls must be developed for, at least, the most populous municipalities in the system.…”