Contribution of Vegetation Structure on Carbon Assimilation Capacity of Mangrove Ecosystem: A Case Study from Negombo Estuary, Sri Lanka

Abstract

Mangrove ecosystems perform number of important ecological functions and provide a wide range of services at the local or national level and provide a unique combination of both organic matter production and sequestration, which is different from other coastal ecosystems. Mangroves are extensively used to extract twigs and branches for the construction of "Brush piles", the predominant fishing devices in the Negombo estuary, Sri Lanka, believed to have one major impact on the vegetation structure followed by the changes in primary productivity and carbon assimilation capacity of the ecosystem. Present study was conducted with an objective of quantify and relationships between the vegetation structure and Gross Primary Productivity (GPP) of disturbed and natural mangrove stands in the Negombo estuary. Vegetation structural parameters were gathered according to the standard procedures and the measurement of Photosynthetically Active Radiation (PAR) used to calculate the Leaf Area Index (LAI) followed by the GPP. Highest values of vegetation structural parameters, LAI and GPP were recorded from estuarine waterfront and decreased with landwards, which indicated more active vegetation is near by the estuarine waterfront. Comparatively, vegetation structural/structural complexity (CI) and GPP/carbon assimilation capacity were superior in undisturbed/ natural mangrove stands (31.86-36.65

Carbon Cycling in the World’s Mangrove Ecosystems Revisited: Significance of Non-Steady State Diagenesis and Subsurface Linkages between the Forest Floor and the Coastal Ocean

“…Here, the mass balance model of carbon flow through the world's mangrove ecosystems constructed by Alongi [2] is revised, using the data in Sections 2.1-2.3 and in Table 2, and newer data for soil + root burial [3,106], root production [107], mangrove gross primary production (GPP), POC, and DOC export [7,10], and canopy respiration (R c ) [19,66,[108][109][110][111][112][113][114], and extrapolated using the most recent estimate of global mangrove area [115]. The revised carbon flow model ( Figure 5) shows that ∼64% of GPP is respired by the canopy with NPP vested nearly equally in the litter, wood, and belowground root production.…”

Allometric Modelling of the Stem Carbon Content ofRhizophora mucronatain a Tropical Mangrove Ecosystem

“…However, use of destructive methods for this purpose is not advisable as they can disrupt the balance of the carbon removal process. Previous studies conducted in this part of the country to assess the mangrove carbon sequestration capacity have used destructive methods [31,32]. e present study can be considered as the initial attempt to use a nondestructive method to construct an allometric equation to predict the stem carbon content of Rhizophora mucronata in a tropical conserved mangrove forest.…”