Diversity in Caatinga is continuously decreasing due to indiscriminate harvesting practices, deforestation and burning, mainly caused by farming and cattle activities. Studies concerning people’s perceptions about the importance of natural resources generate important information to decision making on local biodiversity conservation, by favoring collective spaces which can allow a dialog with the community, in a process of valorization of local knowledge. Therein, the present work sought to study local representations about landscape transformations and the plant resources which supply the community medical system, coming from people’s perceptions of the environment and rescuing traditional knowledge about resource availability. In the first stage of the study, interviews were performed with all the Carão community, in the semi-arid of Pernambuco state (NE Brazil), in order to get information about the known medicinal plants and the dynamics of this knowledge among local specialists, their families and the rest of the community. By means of participatory methods we sought to understand the processes of transformation of the community’s medicinal resources and the surrounding environment, considering the community’s production systems and natural resources and proportioning an overview about the importance of landscape and plant species to the community. The main problems related to these transformations were diagnosed, as well as the main alternatives pointed by the participants. The applied methodologies included local interviews and participatory approaches as “historical graphic”, “scoring exercises” and “problematizations”. Community’s knowledge about medicinal plants is expressively represented by local specialists, although it seems like this knowledge is being shared with their families, especially to what concerns native species. The medicinal resources supply unity represented by the “serra” that around the community was emphasized by specialists as the most important source of forest resources for medicinal uses. However, the more anthropogenic unities were considered by the community as the main sources of harvesting for medicinal species. Among the most representative species it can be emphasized: Myracrodruon urundeuva Allemão, Caesalpinia ferrea Mart. and Amburana cearensis (Allemão) A.C. Sm.. A number of factors influence people’s perceptions on choosing the most important medicinal species and these factors are mainly related to its therapeutic efficiency, its variety of medicinal uses, its use frequency by the informants in their daily routines, its flavor, its use popularity, its environmental availability and its variety of non-medicinal uses. The supply of these resources in the environment goes through a stability process, what suggests a positive community view concerning resource abundance. Nevertheless, it is important to stand out that deforestation and environmental degradation occurred in the past, mainly in the community terrain areas, where this process was performed with higher intensity. The current decreasing of agricultural and cattle practices is a consequence of the workers leaving the countryside and this factor is indirectly responsible for the conservation of forest species which, in other occasions, would have been substituted by agricultural practices.
