Suchergebnisse

Abstract The municipality of Sorriso-MT has become the largest grain producer in the country in the last 40 years, which has caused important economic, social and local changes. Thus, we seek to analyze and understand the dynamics of these transformations. We evaluate the growth of agricultural activity in the Municipality, the reduction of areas of natural vegetation and relate the growth of production with aspects of economic and social development. In order to verify the temporal transformations in the landscape, maps of soil occupation were elaborated from satellite images, in a five-year time scale (1985 to 2015). In 2015, 24.97% of the area of the Municipality covered by natural vegetation. Soy is the main crop, present in 68.6% of the area of the Municipality. If, on the one hand, agricultural activities generate taxes that are fundamental to municipal obligations, on the other hand, they also generate relevant socioenvironmental impacts.

Agricultural landscapes sometimes include natural habitats which can support the ecosystem by enhancing the pollination of crops, thus boosting the productivity. This research was conducted between May and July 2017, in the municipality of Tangará da Serra, Mato Grosso, Brazil, to assess the Cerrado from the perspective of it being a crucial habitat to sustain the sunflower-pollinating bees (Helianthus annuus L.). The bees were sampled using entomological nets and pan traps, in specifically marked out plots (20 m x 150 m), in the Cerrado, and in a sunflower crop, at different distances from the Cerrado border. The assessment was done in terms of the composion and species richness, abundance of individuals and the mass (g) of the sunflower chapters exposed and isolated from the floral visitors. While species richness showed no differences between the Cerrado and sunflower crop, a difference was observed for abundance, with more numbers of individuals in the sunflower crop, most likely because of the food source supply. In the sunflower crop, the bee diversity decreased proportionally as the distance from the border increased. The seed mass of the sunfl ower chapters was significantly higher in the flowers open to visitors than in those of the isolated chapters open for visitation. From the results, it was evident that the bees presente in the Cerrado visit the sunflower crop to gather pollen and nectar, and thus assist in cross-pollinating them and raising the productivity.