Influence of Removal of a Non-native Tree Species Mimosa caesalpiniifolia Benth. on the Regenerating Plant Communities in a Tropical Semideciduous Forest Under Restoration in Brazil

Exotic species are used to trigger facilitation in restoration plantings, but this positive effect may not be permanent and these species may have negative effects later on. Since such species can provide a marketable product (firewood), their harvest may represent an advantageous strategy to achieve both ecological and economic benefits. In this study, we looked at the effect of removal of a non-native tree species (Mimosa caesalpiniifolia) on the understory of a semideciduous forest undergoing restoration. We assessed two 14-year-old plantation systems (modified "taungya" agroforestry system; and mixed plantation using commercial timber and firewood tree species) established at two sites with contrasting soil properties in São Paulo state, Brazil. The experimental design included randomized blocks with split plots. The natural regeneration of woody species (height ≥0.2 m) was compared between managed (all M. caesalpiniifolia trees removed) and unmanaged plots during the first year after the intervention. The removal of M. caesalpiniifolia increased species diversity but decreased stand basal area. Nevertheless, the basal area loss was recovered after 1 year. The management treatment affected tree species regeneration differently between species groups. The results of this study suggest that removal of M. caesalpiniifolia benefited the understory and possibly accelerated the succession process. Further monitoring studies are needed to evaluate the longer term effects on stand structure and composition. The lack of negative effects of tree removal on the natural regeneration indicates that such interventions can be recommended, especially considering the expectations of economic revenues from tree harvesting in restoration plantings.

Ethno-medicinal study of plants used for treatment of human ailments, with residents of the surrounding region of forest fragments of Paraná, Brazil

ETHNOPHARMACOLOGICAL RELEVANCE

This study aims to document the traditional knowledge on the use of medicinal plants in the neighborhood of the protected area "Parque Estadual da Cabeça do Cachorro", a fragment of seasonal semideciduous forests. This vegetation is intensely fragmented and disturbed; despite its importance there are few records of the traditional knowledge of medicinal species.

MATERIAL AND METHODS

Twenty-four residents in the neighborhood of the protected area "Parque Estadual da Cabeça do Cachorro" were interviewed. The residents were questioned about preparation techniques, recommended doses, ways of administration and healing properties of various parts of the plants and were invited to walk through the park to collect in situ some species of plants. The recognized medicinal species were identified and traditional knowledge was systematized. Quantitative indices (Informant Consensus Factor - FIC and Use Value - UV) were calculated.

RESULTS

115 species of medicinal plants belonging to 54 botanical families were cited. Asteraceae (n=14), Fabaceae (n=11), Myrtaceae (n=6), Bignoniaceae, Solanaceae and Verbenaceae (n=5) were the most species-rich. The highest use values were calculated for Achyrocline satureioides, Aristolochia triangularis and Bauhinia forficata (0.63). Moreover, the informants consensus about usages of medicinal plants ranges from 0.024 to 0.663, which shows high level of agreements among the informants for gastro-intestinal and respiratory system diseases. Furthermore, for the first time, new traditional medicinal uses of Asteraceae (Chromolaena pedunculosa Hook. & Arn.), Commelinaceae (Tradescantia fluminensis Vell.) and Polypodiaceae (Microgramma vacciniifolia Langsd. & Fisch.) species were reported.

CONCLUSIONS

Present study revealed that the residents of the surrounding region of forest fragments of Paraná are rich in ethno-medicinal knowledge and rely on plant-based remedies for common health problems. As in many parts of Brazil knowledge of the past is combined with new knowledge that has recently been incorporated emphasizing the cultural changes that this area is experiencing. Despite the use of different species of plants are crucial to their way of life, there is concern that these rich popular knowledge may disappear in the future as a result of a possible modernization of this area.