Cabruca agroforests in southern Bahia, Brazil: tree component, management practices and tree species conservation

In southern Bahia, Brazil, cabrucas are the traditional agroforests in which cacao trees are planted under thinned-out native forests. To analyze the role of cabrucas in tree species conservation, we inventoried the non-cocoa trees in 1.0 ha plots of cabruca in 16 cocoa farms and compared our results with a similar survey undertaken in the early 1960s in the same region to analyze the long term changes. We also interviewed 160 cocoa farmers to investigate their preferences for species and the main practices used in managing shade trees. The cabrucas showed high levels of tree diversity for an agroforestry system (Shannon index ranging from 2.21 to 3.52) and also high variation in structure and composition among the different farms. Forest specialist trees accounted for most species (63.9%) in the survey and were among the species most preferred by the farmers, although we found evidence that some of these trees are gradually being replaced by other species. Our results indicate that cabrucas are poor substitutes for undisturbed forests in terms of tree species richness, but their presence in human-altered landscapes is of utmost importance to the conservation of forest tree species as they increase overall heterogeneity and may serve as ecological corridors, additional habitats, and buffer zones.