Preliminary evaluation of organic carbon sedimentation rates in Asian mangrove coastal ecosystems estimated by ²¹⁰Pb chronology

¹ Ecosystem Analysis Group, Biological Environment Sector, Environmental Science Research Laboratory, CRIEPI., 270-1194 Abiko, Chiba, Japan
² Center for Radiation Protection and Environment Monitoring, INST., PO Box 5T-160, Hoang Quoc Viet, Hanoi, Virtnam
³ Department of Marine Science, Chulalongkorn University, 10330 Bangkok, Thailand
⁴ Technology Development Dept. ENAA., 105-0003 Minato-ku, Tokyo, Japan

Abstract

The organic carbon accumulation rate in mangrove ecosystem was reported to be important sink of carbon as well as that in boreal peat accumulation. For the estimation of 10 years scale organic carbon accumulation rates at mangrove plantation coastal area, the ²¹⁰Pb is expected to be suitable for decades scale estimation by its half-life, though it has possibility of bio-/physical- turbation effect in applying ²¹⁰Pb chronology, especially in Asian mangrove ecosystem where the anthropogenic physical turbation by coastal fishery is vigorous. We studied the organic carbon and ²¹⁰Pb accumulation rates in subtropical mangrove coastal ecosystems in Japan, Vietnam and Thailand to remove the effect of bio- anthropogenic turbation on organic carbon accumulation. We finally concluded that ²¹⁰Pb was applicable to estimate organic carbon accumulation rates in these ecosystems. The measured organic carbon accumulation rates using ²¹⁰Pb in mangrove coastal ecosystems of Japan, Vietnam and Thailand were t-C ha^-1 y^-1.