Vinícius Andrade Maia, Natália de Aguiar-Campos, Fernanda Coelho de Souza, Cléber Rodrigo de Souza, Jamir Prado-Junior, Camila Laís Farrapo, Tainá Mamede Cirne-Silva, Jean Daniel Morel, Fernanda Moreira Gianasi, Gabriela Gomes Pires de Paula, Nathalle Cristine Alencar Fagundes, Alisson Borges Miranda Santos, Wilder Bento da Silva, Felipe de Carvalho Araújo, Fernanda de Oliveira, André Maciel da Silva Sene, Lidiany Carolina Arantes da Silva, Leony Aparecido Silva Ferreira, Miguel Gama Reis, Denise Moura Madeira, Rafaella Tavares Pereira, Vinvivenci Filipe Pereira de Lima E Silva, Ana Lívia de Carvalho Rodrigues, Renan de Soldi Matzner, Michael de Oliveira Alves Braga, Marco Aurélio Leite Fontes, Ana Carolina Silva, Pedro Higuchi, Rubens Manoel Dos Santos
Recent evidence indicates that Brazilian forests are shifting from persistent carbon sinks to emerging carbon sources, with important implications for the global climate. To investigate this trend, we analyse long-term census data from 49 forest sites spanning southeast and southern Brazil, including tropical and subtropical forests. We examine above-ground carbon dynamics and its relationship with tree diversity and functional traits that are tightly linked with species' carbon processing and storage capacities. Our findings reveal a long-term trend of taxonomic, functional and phylogenetic homogenisation and a decline in the forests' above-ground carbon sink. Specifically, homogeneous forests have lower carbon losses, whilst forests with more conservative species are associated with greater carbon gains and lower carbon losses. Overall, our study establishes a baseline to understand and predict the above-ground carbon sink in the face of ongoing climate change in this region.