Mangrove Ecosystem Carbon Stocks: Insights from Setiu Lagoon, Malaysia

Mangroves are coastal vegetated blue carbon ecosystems that efficiently sequester CO2 and store large carbon stocks, yet lagoon-fringing mangrove systems remain less represented in regional inventories despite restricted exchange and long sediment residence times that can enhance soil carbon persistence. We quantified above- and below-ground biomass (AGB, BGB) and 0-50 cm soil organic carbon stocks (SCS) in Rhizophora mucronata and Bruguiera gymnorrhiza dominated mangroves fringing Setiu Lagoon, Malaysia, comparing an undisturbed stand with an aquaculture-impacted stand to assess the effects of land-use change. Biomass carbon was estimated from species-specific allometries and measured tissue %C; and SCS was determined by dry combustion after carbonate removal. In these blue carbon ecosystems, soil physicochemical properties, rather than forest structural variables (diameter at breast height- DBH and tree density), explained most variation in SCS, highlighting a lagoon-fringing pattern in which sediment characteristics drive ecosystem carbon storage. Mean biomass carbon was higher at the undisturbed site than at the aquaculture-influenced site (AGB: 39.17 vs. 36.53 Mg C ha(- 1); BGB: 21.36 vs. 16.48 Mg C ha(- 1)). Mean SCS was 163.21 Mg C ha(- 1), approximately threefold greater than tree-biomass carbon, indicating that soils are the dominant, longer-lived carbon pool in this lagoon setting. Total ecosystem stocks corresponded to similar to 736-884 Mg CO(2)e ha(- 1). These findings support prioritizing restoration of lagoon-fringing mangroves and routine monitoring of the ecosystem properties (e.g., DBH, density and associated environmental variables), to safeguard carbon benefits.

Journal

ESTUARIES AND COASTS

Year

2026

Volume

49

Issue

4

ISSN

1559-2723

eISSN

1559-2731

DOI

10.1007/s12237-026-01707-4

WoS UID

WOS:001730751900002