Impacts of land use change on mangrove blue carbon services: A future perspective in northeastern Brazil

Abstract

Mangroves are important Blue Carbon (BC) ecosystems, providing worldwide climate regulation and other ecosystem services. However, the demand for several economic activities has led to land use changes, which can impact mangrove BC services. This paper aims to analyze the effects of land cover conversion scenarios on mangrove dynamics and BC services delivery along the western South Atlantic coast over 27 years (2023–2050). We developed future scenarios of mangrove conversions by applying the InVEST Scenario Generator tool and using historical conversion rates from analyzing remote sensing hybrid images. Maps of future mangrove species distribution were subsequently used to estimate carbon stocks and emissions, total Net Carbon Sequestration (NCS), and Net Present Value (NPV) by using the InVEST BC model. Based on our results, forest area could decrease by about 7.1% and total carbon stored by 7% by 2050, mainly driven by the expansion of shrimp farms. The total NCS could reach an average value of about 20.1 tCO₂e × ha⁻¹ × yr⁻¹, and the average NPV could get at ≈ US$8000 × ha⁻¹ × yr⁻¹. By 2050, the lowest values of carbon stocks (321 tCO₂e × ha⁻¹) and highest values of carbon emissions (>600 tCO₂e × ha⁻¹), as well as economic losses (>US$200 thousand × ha⁻¹), seem to be concentrated along the mangrove edges, which suffer more from high-impact human activities such as salt extraction and shrimp farming. Results highlight the dynamics of Brazilian mangroves BC services and the need for protective measures and restrictions against the advance of high-impact land uses over these ecosystems.