Blue carbon sequestration following mangrove restoration: evidence from a carbon neutral case in China

ABSTRACT Sequestration of blue carbon (C) in mangrove plantations depends on site characteristics and plantation management. This study evaluated the effects of plantation management on C sequestration at a C-neutral site in Xiamen, China. A field study was conducted on 10-year-old Sonneratia apetala and Kandelia obovata plantations (mono-Sa, mono-Ko) and a 15-year-old mixed plantation-. We found that mono-Ko had a significantly higher ecosystem C sequestration rate (3.32 ± 0.62 kg C m−2 yr−1) than others when planted in the indirect shade of pioneer species. As a non-native species, Sonneratia performed better (0.57 ± 0.01 kg C m−2 yr−1) when planted with Kandelia than in monotypic plantations. The temporary and long-term certified emission reduction (tCER and lCER) of the 12.98 ha mono-Ko was 4103.89 and 3693.50 net CO2-e within 10 years, respectively. A literature review was conducted to show the compatibility of this study with other natural and plantation sites of China and Bangladesh (the native habitat for Sonneratia). The C sequestration of Sonneratia plantation sites in China is comparable with those in Bangladesh. However, the soil C accumulation rate for a Sonneratia monotypic plantation in Bangladesh decreased with age, yet the same did not occur in the plantations of China.