Carbon stock assessment of mangrove ecosystems in Batticaloa Lagoon, Sri Lanka, with different degrees of human disturbances

Abstract

This article presents a carbon stock assessment to illustrate the organic carbon distribution and storage within mangrove ecosystems in Sri Lanka. The living tree biomass and soil carbon pools were investigated in three sites with varying degree of human disturbance in Batticaloa Lagoon. Soil carbon content was derived by the Walkley Black method from soil samples and mangrove trees were measured for calculations in general allometric equations. The mangroves that were extremely converted into a shrimp farm in Kokkaddicholai recorded a carbon (C) stock of 100.9 kg m‐2. Dominated by the poisonous Excoecaria agallocha stands, the regenerating mangroves in Manmunai Bridge Island hosted the largest C stock measuring 786.4 kg C m‐2. The Kannankudah site—dominated by Avicennia marina, Lumnitzera racemosa and Excoecaria agallocha stands, recorded a C stock of 593.1 kg C m‐2. Cuts and stumps indicated wood harvesting for local livelihoods. The soil C content pool contributed most significantly to the total C stock, with the top 30 cm containing the largest C concentration in all soil profiles. The soil carbon content was highest (5.1 per cent) in Kannankudah, second highest (3.6 per cent) in the disturbed but regenerating forest at Manmunai Bridge Island, and the lowest (0.3 per cent) at the converted site of Kokkaddicholai.

Potential for Environmental Services Based on the Estimation of Reserved Carbon in the Mangunharjo Mangrove Ecosystem

“…The sampling of tree biomass through the nondestructive method involves recording the tree type and measuring the diameter at breast height. According to Komiyama et al [10] and Lugina et al [11], the retrieval of tree biomass data is done by measuring the diameter (>10 cm) of tree trunks at breast height (1.3 m tree height) and inputting the data into existing allometric equations on the basis of the tree type. Then, the biomass value of mangrove trees is multiplied by 0.47 to obtain the carbon value.…”

Floral and Faunal Diversity in Sri Lankan Mangrove Forests: A Systematic Review

“…This could mean that either the study has underreported some species, or there has been a promising increase in the scientific reporting of invertebrate fauna. Mud lobsters (Thalassina anomala) are unique to the mangrove ecosystems [28]. Marine, Brackish, Fresh WoRMS that are found in the wet zone, but still, it lacks a specific scientific notation and proper ecological survey.…”

Blue carbon stock in sediments of mangroves and seagrass ecosystems at Southeast Sulawesi, Indonesia

“…A recent study reported 121.95 ± 76.11 Mg ha −1 of blue C stocks of the seagrass ecosystem in southeast Asia (Stankovic et al, 2021). Several studies concerning sediment carbon stocks (SCS) have been elucidated for mangroves worldwide including the mangrove ecosystem at the Farasan Islands, Saudi Arabia (Eid et al, 2020), Lagoons, and estuaries in Srilanka (Jonsson & Hedman, 2019; Perera & Amarasinghe, 2019). Coastal ecosystems in Southeast Asia are known to store high amounts of carbon such as mangroves in Vietnam (Mackenzie et al, 2016; Nam et al, 2016; Tinh & Kim, 2020), Cambodia (Sharma et al, 2020), Ubi Island Singapore (Phang et al, 2015), and Sawi Bay, Thailand (Bukoski et al, 2020), but studies regarding SCS both in mangroves and seagrass ecosystems in the coral triangle ecoregions are scarce.…”