Spatial Bayesian belief networks. A participatory approach for mapping soil vulnerability at the Itatiaia National Park, Brazil

Resumo

The Itatiaia National Park (INP) is a conservation unit, with a multitude of species of the Brazilian fauna and flora, some endemic. The INP is the origin of 12 watersheds that contribute to the rivers Rio Grande and Paraíba do Sul, important rivers in southern and south regions of Brazil. It is one of the parks that receive most visitors in Brazil due to the landscape and biodiversity characteristics. The aim of this study was to assess the soil vulnerability in the INP by integrating the information of physical environment with knowledge of experts, to reconcile demand for public use and of ecosystems conservation. The method used was spatial application of a probabilistic model known as Bayesian Belief Network (BBN). Soil data (such as carbon content, texture, depth, and capacity to store water) were integrated with data derived from remote sensing (e.g. land use) and relief (elevation and slope) and with the expert opinion of land managers, decision makers and researchers that work with the INP or surrounding areas. Integrating environmental factors and expert opinion is a suitable approach to assess the soil vulnerability in INP. The most fragile areas were identified with soils with high levels of carbon, profiles less developed (shallow), with accentuated slopes, and a vegetation cover with herbaceous graminoid plants, with a predominance of Cyperaceae and Poaceae (high altitude fields). This approach will help decision makers to identify priority areas for intervention, in order to reduce soil degradation in the areas with high vulnerability. The results could also be used as a basis to support the INP management plan, as well as to contribute to other researches, especially those related with ecosystem services in the Atlantic Forest Biome.