The article offers information and analysis that intend to demonstrate the importance of the Brazilian Forest Act for the protection of the remaining preserved natural vegetation in Brazil, as well as the reasons and guidelines for its revision, in order to reach the possible and desired balance between respect to the natural environment and improved agricultural development.

No-Till System evolution and sediment yield in Rio Grande do Sul Reconcile the increasing demands of agricultural production with the assurance of soil productivity requires quick decisions and supported by reliable information about the expected impact. Understand the effect of large dynamic change of land use maintains future decisions regarding the implementation of sustainable agricultural management practices. This study aimed to evaluate the dynamics of sediment production in Rio Grande do Sul in consequence of the no-till evolution by large scale modeling with easily accessible data. First, the validity of applying a predictive model of erosion on a large scale was tested in the state of Sao Paulo with exogenous variables related to watersheds. Except for the adoption of conservation practices, all factors of Universal Equation of Soil Loss (USLE) were calculated and spatialized in Geographic Information Systems. The soil loss data were combined with parameters related to the shape of river basins, its slope, the occurrence of dams and riparian areas, and used as explanatory variables of the load of sediment in rivers through multivariate regression models. The sediment yield was correlated with the estimated soil loss and the presence of large reservoirs in the lower thirds of the basins (R² = 0.55). In applying the model tested, the soil loss was directly related to land use, focusing high rates of erosion in areas occupied by annual crops. From the proof of the method, this might be used in evaluating the effect of large scale changes in soil management occurred in Rio Grande do Sul from the 80s. Driven by a complex social structure, the no-till system (NT) has been widely adopted in the state. The soil cover factor, which includes the use and management, was obtained through the state Agricultural Censuses and monitoring of the area of SPD of the years 1985, 1996 and 2006. Twenty-nine watersheds were determined from sediment stations and separated into agricultural and pasture. The proportion of agricultural area determines the effect of the NT to control erosion in the basin. The sediment yield did not vary in areas with pasture and was lower than production in the agricultural basin in the years 1985 and 1996. In agricultural areas, the sediment production declined in 1996 and 2006, when it equaled the production of watersheds with pasture. The adoption of the NT showed an average reduction in sediment load of 82%, a value close to the reduction of soil erosion rates tested in experiments with tillage. The suggested method allowed the spatial understanding of the spatial distribution of erosion and its temporal dynamics as a function of land use. Models like this can support the decision-making, with potential for assessing environmental services provided by farmers, determinant tools in the spread of conservation practices.

RESUMOApesar do constante aumento na quantidade e diversidade de publicações acerca da erosão do solo no Brasil e no mundo, as grandes questões dessa ciência ainda não foram respondidas. Os possíveis motivos desse descompasso trazem à tona a necessidade de discutir o papel da pesquisa em erosão. A bibliometria permite uma visão abrangente da ciência, fornecendo perspectivas, contudo estudos que fazem uso dessas técnicas são escassos no mundo, bem como no Brasil. Os objetivos deste trabalho foram analisar as distribuições espacial, temporal, institucional e temática da pesquisa brasileira em erosão acelerada do solo a partir da divisão dos artigos em linhas temáticas e discutir a profundidade da abordagem das questões fundamentais em erosão. Para isso, 225 artigos de instituições brasileiras cujo tema central é a erosão do solo foram digitalizados, cadastrados em banco de dados e classificados em cinco linhas temáticas. Também foram produzidos mapas multitemporais a partir de ferramentas de geoprocessamento. A pesquisa brasileira em erosão, além de recente, está concentrada: (a) em poucas instituições, localizadas nas regiões Sul e Sudeste; e (b) em dois temas, centrados na Equação Universal de Perda de Solo e em comparações de manejos agrícolas quanto à perda de solo, com grande influência do nível de consolidação dos núcleos de pesquisa, que têm nesses dois temas centrais sua iniciação na pesquisa em erosão acelerada do solo. Termos de indexação: erosão hídrica, banco de dados, história.

The Caratinga Biological Station (CBS) is an important preserve of the Brazilian Atlantic Rain Forest, defined as a national priority for the conservation of this highly fragmented biome and shelter to the largest existing population of the northern muriqui, the critically threatened largest monkey species of the Americas. Extensive research on the demography of this population has indicated favorable conditions for growth, pointing out the importance of promoting expansion of the locally available habitat. In the present study, rural establishments neighboring the CBS were involved in a participatory program for wildlife corridor restoration, by means of the application of a 'System for Weighted Environmental Impact Assessment of Rural Activities' (APOIA-NovoRural), which consists of 62 indicators integrated in five sustainability dimensions: i) Landscape ecology; ii) Environmental quality; iii) Socio-cultural values; iv) Economic values; and v) Management and administration. Results regarding the Landscape ecology indicators (those most related with fauna protection) attested to the adequate performance of productive activities in the studied establishments, while pointed out the need for improvements in natural habitats conservation. The Environmental Management Reports issued to the farmers included mapped recommendations for forest restoration and wildlife corridors implementation, favoring the connection of the main preserved area of CBS with the second largest forest fragment in the region.

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