Britaldo Silveira Soares Filho

The Distribution of Biomphalaria spp. in Different Habitats in Relation to Physical, Biological, Water Contact and Cognitive Factors in a Rural Area in Minas Gerais, Brazil

A total of 256 sites in 11 habitats were surveyed for Biomphalaria in Melquiades rural area (State of Minas Gerais) in August and November 1999 and in March 2000. Of the 1,780 Biomphalaria collected, 1,721 (96.7%) were B. glabrata and 59 (3.3%) B. straminea. Snails were found in all habitats except in wells, with the largest mean numbers in tanks, seepage ponds and canals, and the smallest numbers in springs, rice fields and fishponds. Peoples knowledge of the occurrence of Biomphalaria at the collection sites and the presence of Biomphalaria ova were strongly correlated with the occurrence of snails, and distance between houses and collection sites, as well as water velocity were inversely correlated with Biomphalaria occurrence (p < 0.001). The strongest predictor o f Biomphalaria occurrence was the presence of tilapia fish in fishponds. Fourteen Biomphalaria (0.8% of all snails) found at 6 sites were infected with Schistosoma mansoni. Suggestions are made for the utilization of local peoples knowledge in snail surveys and further studies are recommended on the possible use of tilapia for biological control of Biomphalaria in fishponds, as well as modeling of S. mansoni transmission and reinfection.

A Combined Biophysical and Economic GIS Framework to Assess Sugarcane Cropping Potential in Brazil

Recently, the increasing demand for biofuels triggered a new phase for the sugar-alcohol sector. In Brazil, as well as in other tropical countries, this process raised worries regarding the possible direct and indirect effects of the crops expansion on the conversion of native vegetation coverings. Therefore, the modeling of spatial-economic surfaces, representing the potential rent variation in its spatial component, for eco- nomic activities, may be a useful tool in the decision-making process. Hence, here we propose and present the results of a combined framework composed of two modules using the modeling platform Dinamica EGO. The first module simulates sugarcanes growth, calculating the daily response of the crop to envi- ronmental conditions during the stages of the plants development. The second module estimates rents for sugarcane cultivation in Brazil, identifying areas where this activity would bring higher economic return, looking at simulated productivity, production costs and selling prices in a way that is spatially explicit for Brazil. Two different scenarios for production costs were tested, and results ranged from negative values to maxima of R

Mapping Socio-biodiversity: Do Old Modelling Tools Suit New Challenges?

/ha 929 and R

A Suite of Tools for ROC Analysis of Spatial Models

/ha 1176 for standard and efficient costs of production, respectively. The model successfully indicated non-profitable and profitable areas, and regions where high expected eco- nomic return overlaps endangered ecosystems.

Challenges for Low- Carbon Agriculture and Forest Conservation in Brazil

This work shows an original use of classical methods in land change modelling. The aim of this study is to model yields (productivity) and economic importance (annual rents) of rubber and Brazil nut in the Brazilian Amazon. Biophysical variables related to rubber and Brazil nut yields as well as market access (commercialization) were used to model favorability of productivity using Weights of Evidence (WofE) method. To favorability of productivity were assigned yields base on case study data. The economic model then combines the map of yields with output prices and costs of collection, processing, and transport to estimate annual rents per hectare for a specific forest plot. For estimating transport costs we used cost friction surface modelling tools. Our results show that yields for Brazil nut averages 8.19±7.41 kg hayear and rent averages US

Is It Possible to Make Rubber Extraction Ecologically and Economically Viable in the Amazon? The Southern Acre and Chico Mendes Reserve Case Study

5.05±7.49 hayear. Rubber average yields is of 3.53 kg/ha/year and rubber rents average US

ESTUDO DA MUDANÇA DE USO E COBERTURA DO SOLO NA BACIA DO RIO FORMIGA - MG

0.56±0.7hayear. Coupling biophysical and economic models allowed us to explore which environmental and governance improvements are needed to avoid deforestation and forest degradation in the Brazilian Amazon. Our results also show that despite some methodological issues and the recurrent call for “new” modelling approaches for addressing the complexity of socio ecological systems, “old” modelling tools such as Weight of Evidence and Cost Friction Surface, are still suited for addressing the challenge of mapping