Mangrove flourishing/deterioration under the control of the Indian Summer Monsoon over the past ∼3,195 years in Phang Nga Province, Thailand

Mangrove wetlands are strategic locations for mitigating climate changes. In order to address the harm of rapid climate change to mangrove ecosystems, it is necessary to scientifically predict the fate of mangrove ecosystems, which can be achieved by reconstructing the development history of mangrove forests. This study analyzes the contribution of mangrove-derived organic matter (CMOM) from sediment core F in Phang Nga Province, Thailand by using the endmember mixing model based on stable organic carbon isotopes (δ¹³C_org) and C/N (molar) ratio. The variations of CMOM over the past ∼3195 cal yr BP indicate that mangrove forests underwent three periods of flourishing: ∼3195–2620 cal yr BP, ∼2030–1130 cal yr BP, and ∼410–0 cal yr BP, and two periods of deterioration: ∼2620–2030 cal yr BP and ∼1130–410 cal yr BP. Among the potential factors that might affect the development of mangrove forests, relative sea level (RSL), regional hydrodynamics, and human activities do not have notable effects on mangrove flourishment/deteriorating. However, climate factors, particularly air temperature, rainfall, and sea surface salinity are the main factors influencing the flourishing/deterioration of mangrove forests. In the Andaman Sea, these climatic factors are mainly driven by the Indian summer monsoon (ISM).