Population genetics studies are widely recognized for generating useful knowledge for biodiversity conservation. To date, however, little is known about the levels and distribution of genetic diversity of Drymis brasiliensis (Miers LC), a tree species from the Atlantic Rainforest. Therefore, in this study, we investigated how genetic diversity is distributed within and among populations of D. brasiliensis from southern Brazil using allozyme markers to genotype reproductive trees (8 populations) and seedlings (3 populations). Furthermore, in two populations, we established two permanent plots (5.1 and 1 ha) to analyze fine-scale genetic structure (FSGS). Studied populations presented low levels of genetic diversity (reproductive = 0.085; seedlings = 0.054) and high fixation indexes (reproductive = 0.396; seedlings = 0.231). Genetic divergence among populations was equal to 0.05, which is significant, signaling that few populations can conserve large portions of the species total genetic diversity. FSGS was only detected for one population, when reproductive individuals were separated by less than 40 m. Low genetic diversity combined with high fixation indexes clearly signal a risk of losing diversity. Therefore, conservation efforts should be aimed at enhancing gene flow within the studied populations.

Drimys brasiliensis Miers, locally known as cataia or casca-de-anta, is a native tree species of the Atlantic Rainforest. Its bark is harvested from natural populations. This study examined the recovery capacity of the bark of D. brasiliensis under different bark harvesting methods, as well as the influence of these approaches on its population dynamics and reproductive biology. While none of these treatments resulted in changes in phenological behavior or the rate of increase of diameter at breast height and tree height, the removal of wider bark strips resulted in lower rates of bark recovery and higher rates of insect attack and diseases. Accordingly, the results recommend using strips of bark 2 cm wide and 2 m long, with 4 cm between strips, for effective rates of bark regrowth and for lower susceptibility to insect attack and diseases. From these studies, we concluded that D. brasiliensis has a high potential for sustainable management of its natural populations, demonstrating the possibility of generating an important supplementary income for farmers and contributing to the use and conservation of the Atlantic Rainforest.

http://dx.doi.org/10.5902/1980509816598Drimys brasiliensis Miers, conhecida como cataia ou casca-de-anta, é uma árvore nativa da Floresta Ombrófila Mista. Sua casca tem sido utilizada medicinalmente a partir da exploração de árvores em populações naturais. O objetivo deste trabalho foi a realização de estudos de biologia reprodutiva de Drimys brasiliensis visando fundamentar estratégias de exploração sustentável e conservação, possibilitando a geração de renda a partir da exploração deste recurso florestal não madeireiro. Foram realizados estudos de fenologia reprodutiva (296 árvores acompanhadas por 30 meses), ecologia de polinização e dispersão de sementes, e biologia floral. O período de florescimento ocorre durante o verão, com pico em janeiro. Frutos verdes estão presentes o ano inteiro, amadurecendo com o aumento das temperaturas. Ocorre uma sobreposição das fenofases fruto verde e fruto maduro oriundas de florescimentos de anos diferentes. Com isso, frutos maduros estão disponíveis o ano inteiro para a fauna. Os himenópteros são os visitantes florais com maior potencial de fluxo gênico via pólen, porém, a sua frequência é baixa, assim como a dos demais visitantes, apesar da alta produção de flores e da alta viabilidade dos grãos de pólen. Com isso, a alta produção de frutos observada é possivelmente decorrente da autofecundação. Os dispersores primários de frutos são raros, tendo sido observados pássaros. Entretanto, a dispersão secundária das sementes que chegam ao solo por barocoria é alta.

Drimys brasiliensis Miers, locally known as cataia or casca-de-anta, is a native tree of Floresta Ombrofila Mista, in Brazil. Its bark has been used for medicine, through the exploitation of plants of natural populations. The present work aimed to study aspects of reproductive biology of Drimys brasiliensis in order to establish strategies for sustainable management and conservation, in order to generate alternative income from the exploitation of this non-timber forest product. Studies about reproductive phenology (296 plants during 2 years and a half), pollination and dispersal ecology, and floral biology were realized. The flowering season occurred the summer, with its peak in January. There are unripe fruits throughout the year, becoming ripe fruits as the temperature increases. There is a superposition of unripe and ripe fruit phenology from different flowering seasons. Ripe fruits are then, available for animals throughout the year. Hymenopteras are flower visitors with major potential for gene flow via pollen, but their frequency is low, like others flowers visitors, despite the high flowers production and pollen viability. Therefore, the highest fruit production which was seen comes from self-fecundation. The primary fruit dispersers are rare, birds being observed. However, the secondary dispersal of seeds that reach the ground by barocory is high.

Departamento de Fitotecnia Centro de Ciencias Agrarias Univ. Federal de Santa Catarina, Caixa Postal 476, CEP 88040-900, Florianopolis, SC