Estoque de carbono na biomassa e na necromassa de florestas de mangue conservadas e degradadas no estuário do Rio Mamanguape, Paraíba

Abstract

Despite the well-established importance of mangrove ecosystems in mitigating the impacts of climate change, significant knowledge gaps remain regarding carbon stocks in specific ecosystem compartments, particularly necromass. In this context, the present study aimed to quantify and compare carbon stocks in the biomass and necromass of conserved and degraded mangrove forests in the Mamanguape River estuary, Paraíba, northeastern Brazil. Carbon stocks were estimated for aboveground and belowground biomass, as well as aboveground and belowground necromass, at two conserved forest sites and four degraded forest sites. The results showed that total carbon stocks (biomass + necromass) ranged from 2.9 ± 2.3 to 129.3 ± 15.2 Mg C/ha. In the conserved forests, biomass accounted for the largest proportion of the total carbon stock, whereas necromass predominated in the degraded areas. Furthermore, the conserved sites exhibited significantly higher carbon stocks than the degraded sites, highlighting the importance of maintaining vegetation structural integrity for the preservation of blue carbon. Mangrove forest degradation in the Mamanguape River estuary is primarily associated with alterations in hydrological connectivity, which impair the ecosystem's capacity to store carbon. These findings emphasize the need to implement hydrological restoration as a strategy to recover ecosystem functioning and enhance the carbon sequestration potential of mangrove forests. Keywords: mangrove forest, carbon stock, conservation