Relationships between Land-Use Types and Plant Species Used by Traditional Ethno-Medical System.

Aims: The agricultural frontier advances progressively on forested regions in Central Argentina, changing the landscape structure by extremely reducing the extension of native forests. In rural communities that are related to the forests, it is possible that severe changes in the landscapes can have an impact on the knowledge and uses of medicinal plants. The aim of this paper was to evidence some general patterns between the ethnobotanical information recorded in the Chaco region and some characteristics of the landscape. Specifically, we hypothesized that the knowledge on medicinal plants and their type (native or exotic) are related to different types of land use (i.e. different proportions of native forests). Place and Duration of Study: The study was performed 15 rural localities within the Chaco phytogeographic regionin Córdoba, Argentina, conducted between 2004 and 2012. Methodology: A total of 279 interviews were conducted. Plant species were identified according to their status (native or exotic), and a standardized proportion of exotic species was calculated for each site. The different types of land use and their proportions were estimated in 15 rural localities using satellite images. A Principal Component Analysis and a bivariate Spearman correlation were performed to analyze the associations among land-use types, the proportion of native forests and the knowledge of medicinal plants. Results: In general, people had known many native and exotic medicinal plants. Nevertheless, in those localities where landscapes have experienced higher deforestation rates, exotic medicinal plants are more available than native ones (cultivated in gardens and orchards). The tradition of maintaining exotic species in gardens may contribute to maintain the ethno-medical systems in regions of severe forest fragmentation. Conclusion: The disappearance of the forest showed a positive association with losses in the knowledge and use of native medicinal plants.