Genetic Diversity and Differentiation in Plathymenia reticulata Benth.: A Comparative Study of Forest and Cocoa Agroforest Systems in the Atlantic Forest Domain

Abstract

Tropical forests, housing about two-thirds of Earth’s terrestrial biodiversity, face significant deforestation and fragmentation, leading to the loss of over half their area. Conservation and restoration efforts are crucial, especially for regions like the Brazilian Atlantic Forest, which suffers with a reduction in biomass and species diversity. The Brazilian agroforest system, typical from the region of Southern Bahia called “cabruca”, are helping to mitigate these effects by combining cocoa cultivation with forest management, enhancing both socio-economic and environmental benefits. In a study focusing on Plathymenia reticulata, a tree species native to the Atlantic Forest, we evaluated the effectiveness of the cabruca agroforest system versus the natural forest for maintaining genetic diversity and landscape connectivity. Results showed that cabruca systems, while managed, exhibit a level of genetic diversity compared to natural forests. However, forest populations remain critical for their genetic reservoirs and adaptability. The cabrucas agroforest system also showed higher inbreeding levels, emphasizing the need for effective management to reduce inbreeding risks.