Rodrigo de Jesus Silva

Factors influencing the food transition in riverine communities in the Brazilian Amazon

The objective of this study was to determine the main patterns and factors influencing food transition in riverine people in the Brazilian Amazon. Through interviews with a semi-structured questionnaire, we inferred their food habits and provide information about general demographic, socioeconomic, resource use and environmental context. Data from the questionnaires were categorized and analyzed using a logistic regression model to assess the relative influence of socioeconomic and environment factors on the local diet. Based on a logistic regression data analysis, it was found a greater consumption of processed food significantly associated with multiple factors such as market participation, sex (female and male), government aid to forest conservation and environment context (upland and wetland). Although the local diet is composed mainly of local resources such as fish and cassava flour, increasing incomes due to direct government subsidy programs and marketing of cassava flour have influenced these local practices and habits. Through the analysis of factors influencing food transition, it was possible to evaluate those having the greatest effect on this Amazon region and propose an alternative method to subsidy food policy grounded in local opinion surveys.

ESSAY ABOUT ISOTOPIC ECOLOGY (δ13C AND δ15N) OF FISH FARMING SPECIES: POSSIBLE CONSEQUENCES FOR HUMAN CONSUMPTION

This study aims to assess changes of the isotopic signal - δ 13 C and δ 15 N - of muscle tissue among fish species of natural and breeding environments as a way to understand the relationship between habitat, diet and trophic composition of these watersports animals. Thus, we used four different species of fishes, being the peacock bass and tuna from different natural environments and the salmon and tilapia of breeding environments or fattening farms. From this, excepting the species of tuna the values of δ 13 C of Tilapia was significantly larger than others - peacock bass, salmon and tambaqui - while for the values of δ 15 N the species of Tilapia were significantly the lowest of all. Furthermore, the hatchery species of Tilapia and Salmon considerably had the lower variability. These results together suggest a significant difference in isotopic signal between species of hatchery and natural environments, reflecting different diets and composition of food chains according to the source environment of species.

ECOLOGICAL RESTORATION INDICATORS IN AGROFORESTRY SYSTEMS IN THE ATLANTIC FOREST

The Agroforestry Systems (SAF) are forms of land use and land occupation in which woody plants are managed in association with herbaceous and agricultural ones. They present the possibility to recover degraded areas, as comprehended in legislation. Thus, the monitoring and assessment of areas recovered with Agroforestry Systems are extremely important, seeking to evaluate if their environmental functions can be equivalent to areas recovered only with native species. Thereby, the objective of this study was to evaluate, through forest restoration indicators, the recovery of ecosystem functions in SAF implanted in Ribeirao Grande, Sao Paulo State. The sample design was randomized by 3 installments (15 x 15 m each) randomly allocated in a SAF area and other 3 installments in a reforestation area with native species only (RN), both five years old, in the same watershed. The indicators were crown diameter, forest litter stock, height and diameter above the base of the individual trees, temperature, and humidity. The assumptions of normality and homogeneity of variance were verified through the Waste Analysis, with subsequent analysis using the nonparametric Wilcoxon-Mann-Whitney test. Statistical analyzes were performed using the R software (R Delopment Core Team, 2012) with a significance level of 5% (α = 0.05). It is concluded that the recovery area only with native species presents better development of vertical structure, with greater canopy closure. For soil indicators there were no differences. SAF, run by natural succession, can be presented as an alternative to the recovery of degraded areas, because they are more similar to the structure of native forests.