Global patterns in mangrove soil carbon stocks and losses

Abstract

Mangrove soils represent a large sink for otherwise rapidly recycled carbon (C). However, widespread deforestation threatens the preservation of this important C stock. It is therefore imperative that global patterns in mangrove soil C stocks and their susceptibility to remineralization are understood. Here, we present patterns in mangrove soil C stocks across hemispheres, latitudes, countries and mangrove community compositions, and estimate potential annual CO2 emissions for countries where mangroves occur. Global potential CO2 emissions from soils as a result of mangrove loss were estimated to be ∼7.0 Tg CO2 e yr-1. Countries with the highest potential CO2 emissions from soils are Indonesia (3,410 Gg CO2 e yr-1) and Malaysia (1,288 Gg CO2 e yr-1). The patterns described serve as a baseline by which countries can assess their mangrove soil C stocks and potential emissions from mangrove deforestation. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved

Coastal morphology explains global blue carbon distributions

“…Our results indicated that for those latter countries, many of which have mostly carbonate coastal settings, the global mean reference value of mangrove SOC stocks suggested by Atwood et al . () was about 50% lower than estimates based on coastal morphology (Figure , a and b).…”

“…; 2.6 Pg C in Atwood et al . ), we found that mangrove SOC stocks varied markedly across different types of coastal environmental settings, increasing from river‐dominated to tide/wave‐dominated to carbonate coastlines. A single nation may have different types of coastal environmental settings contiguously where mangroves exist, so that using a mean average of mangrove C storage per nation or latitude does not capture the variability associated with coastal morphology.…”

“…For example, a global estimate recently provided by Atwood et al . () used a country‐level mean mangrove SOC stock of 283 Mg C ha −1 based on values from 48 countries to extrapolate global patterns for the remaining 57 countries that lack data on mangrove SOC. Our results indicated that for those latter countries, many of which have mostly carbonate coastal settings, the global mean reference value of mangrove SOC stocks suggested by Atwood et al .…”

“…In contrast to previous studies (eg Jardine and Siikamäki ; Atwood et al . ), this dataset only included soil profiles that were at least 0.3 m in depth and mangrove SOC density estimates obtained via elemental analyses or chemical determination (ie wet oxidation). Each site in this dataset was previously classified into distinct coastal environmental settings according to a conceptual model (Thom ; see Rovai et al .…”

Carbon Stocks of Coastal Wetland Ecosystems on Hainan Island, China

“…The result is similar to that reported for Yingluo Bay [34]. The study demonstrated that there were significant differences in C stocks among mangrove types, which was opposite to those along the Pacific and Caribbean coasts of Honduras [35]. For different plant structures, root biomass occupied 26.5~42.9% vegetation C stocks.…”