Ecosystem carbon losses following a climate-induced mangrove mortality in Brazil

Abstract

Drought events may induce mangrove mortality and dieback events worldwide as a result of climate extremes. As mangroves sequester large quantities of carbon, quantifying the losses of these stocks following climate disturbances may guide wetland governance strategies globally. In Southeast Brazil, we determined the total ecosystem carbon stocks (TECS) of pristine mangroves that were up to 1851 Mg of carbon per hectare (Mg C ha−1), which are the highest stocks measured from South American and raising estimates of Brazil's mangrove TECS to 0.52 Pg C. A mangrove mortality event in the same estuary resulted in a 14.6 % decrease in TECS (270.5 Mg C ha−1) and loss of 20 % of mangrove soil carbon within less than 2-years. Carbon dioxide emissions from this impact were 992.8 Mg CO2e ha−1, which are slightly lower than emissions from land use disturbances on mangroves worldwide. Our results suggest that climate effects on mangroves can become significant sources of greenhouse gases globally.