Country-specific emission factor for developing a tier 3 system of Indonesia’s seagrass carbon inventory

Abstract

Climate action regarding carbon inventory requires baseline assessment, data regarding annual changes, and evaluation of reductions in carbon emissions. However, many studies of seagrass ecosystems have focused only on carbon stock and sequestration, neglecting the importance of the carbon emission factor. It is known that emission factors for land-use change, including those in seagrass ecosystems, can be derived from biomass and sediment carbon stock. Since currently Indonesia only has data for biomass carbon stock, we propose the measurement of province-based emission factors. This study combines the available carbon stock data reported in national or international publications and conducts a meta-analysis to obtain emission factor values. The results show that the biomass standing carbon stock of Indonesia’s seagrass meadows ranges from 0.30 tC/ha (i.e., Special Region of Yogyakarta) to 16.51 tC/ha (i.e., Gorontalo province), while emission factor ranges from 0.012 tC/ha/yr to 0.661 tC/ha/yr (equal to 0.05 t CO2/ha/yr to 2.42 t CO2/ha/yr). These findings will be beneficial for developing Tier 3 carbon inventory since they allow country-specific emission factor for the seagrass ecosystem to be measured.

Seagrass blue carbon stocks and air-sea CO2 fluxes in seagrass meadows Jepara, Indonesia

“…Studies by Wahyudi et al [7], indicate that Indonesia's seagrass carbon uptake ranges from 5.62-8.40 TgC ha −1 y −1 . According to another study by Wahyudi et al [8], the median organic carbon stock (OCS) of aboveground (AG) and below-ground (BG) seagrass was 0.29 and 1.13 MgCorg ha −1 , respectively, while the median organic carbon stock within sediment (OCS-S) was 118.1 MgCorg ha −1 .…”

“…Even though seagrass waters act as a CO2 source, the CO2 flux value of waters containing seagrass ecosystems (vegetated) was lower than those without seagrass (unvegetated) [30] and increase if the seagrass ecosystem contains additional sources of carbonate from algae [29; 30] and mangroves [26; 30; 31]. Central Java waters have the fourth highest seagrass OCS content in Indonesia and more than the average OCS in Indonesia [8] with the largest seagrass distribution in the waters of Karimunjawa and Jepara. There hasn't been any research in Jepara waters connecting CO2 flux and OCS.…”

Seagrass Blue Carbon Stock and Air–Sea CO2 Fluxes in the Karimunjawa Islands, Indonesia during Southeast Monsoon Season

“…Notably, the regions of Gorontalo (16.51 TgC ha −1 ), West Sumatra (13.66 TgC ha −1 ), North Sulawesi (11.38 TgC ha −1 ), and Central Java (4.40 TgC ha −1 ) exhibit the highest levels of carbon stocks and absorption. In particular, the province of Central Java emerges as a standout, boasting elevated seagrass carbon stocks and absorption rates surpassing the national average carbon uptake of Indonesia (which stands at 3.16 TgC ha −1 ) [26]. Referring to Indonesia's seagrass distribution map, the preponderance of seagrass beds in Central Java is notably clustered within the aquatic expanse of Karimunjawa, situated within the Java Sea [24][25][26].…”

“…In particular, the province of Central Java emerges as a standout, boasting elevated seagrass carbon stocks and absorption rates surpassing the national average carbon uptake of Indonesia (which stands at 3.16 TgC ha −1 ) [26]. Referring to Indonesia's seagrass distribution map, the preponderance of seagrass beds in Central Java is notably clustered within the aquatic expanse of Karimunjawa, situated within the Java Sea [24][25][26].…”