Impactos do extrativismo de cascas do caule de Stryphnodendron rotundifolium Mart. e estratégias de forrageio de coletores locais no semiárido do nordeste do Brasil

Abstract

Many rural populations still collect plant resources for their livelihoods. Some researchers believe that this collection follows a cost/benefit rationale, in which the extractor always seeks to obtain the best possible return. With that in mind, the question that motivated the development of this thesis was to understand the process of collecting a medicinal resource, which includes from the strategies adopted by the extractors when selecting their areas to obtain the resource, up to the moment the resource is ready to be explored again. To access this scenario, this thesis was divided into two axes. The first comprises the analysis of the behavior of the extractors in the bark collection of Stryphnodendron rotundifolium Mart. based on the Optimum Foraging Theory (TFO). The second analyzes the influence of the impacts of the collection on the regeneration of stem bark of the same species. The species is well known and exploited by the communities around the Araripe National Forest, more specifically in the Horizonte district, Ceará, Brazil. Within the set of medicinal plants used by this community, "barbatimão" as it is popularly known, is one of the plants most used in the treatment of inflammation and wound healing. We conducted excursions with 38 extractivists in order to collect information on the selection of areas and individuals for collection, the amount of bark collected and the distance traveled from the community to its collection site. Concomitantly, in two distinct areas of Cerrado, experiments were set up to follow the process of regeneration of bark under different intensities of damages. Our results showed that extractivists do not behave according to the variables predicted by TFO. Extractors do not follow behavior oriented towards the continuous maximization of resources. This is probably due to the collection being executed according to the demand of the trade, which is not always high. Along with this, there is the inspection of the protection organs and the competition for resources by different extractivists. These three variables combined cause frequently that the extractivists do not adopt the optimal behavior predicted by the theory. The results relative to the impacts of the collection on bark regeneration showed that the individuals with the highest damage intensities were those that obtained the highest regeneration rates. Although it occurs, no individual has presented a complete regeneration of its bark. Considering the above, it is concluded that, based on the non-optimization of collection by the extractivists because it is based on the individual demand, this means that the strategies are variable and uncertain, since they fluctuate directly in conjunction with this commercial demand. This, together with the fact that S. rotundifolium individuals take more than two years to fully regenerate their bark, and considering that the simulated cuts are much smaller than those performed in real practice, it is assumed that this practice deserves greater attention in order to achieve its sustainability.