Does Bark Anatomy Influence the Selection of Woody Medicinal Plants in Seasonal Dry Forests from Brazil?

Abstract

Both human and non-human animals utilize tree bark as a food resource or for medicinal purposes. The preferences of animals can be explained by the nutritional quality of the bark, chemical composition, and ease with which the animals can remove the bark. Humans also exhibit preferences when selecting resources, and factors such as perceived efficacy, species versatility, and bark morphology may favor their use. In this study, we investigated whether the selection of medicinal plants in the Caatinga is based on the anatomical characteristics of the stem bark. To investigate this phenomenon, we tested the hypothesis that more versatile medicinal plants have bark structures that influence their removal. We studied the stem bark anatomy of 20 woody medicinal plants, ten with higher versatility and ten with lower versatility. We observed that the anatomical features of the bark did not predict versatility. Therefore, human selection for these species may be associated with other factors that people consider important.