Improved model calculation of atmospheric CO₂ increment in affecting carbon stock of tropical mangrove forest

By RAGHAB RAY, CHUMKI CHOWDHURY, NATASHA MAJUMDER,

MANAB KUMAR DUTTA, SANDIP KUMAR MUKHOPADHYAY and

TAPAN KUMAR JANA*, 

*Department of Marine Science, University of Calcutta,

35, B. C. Road, Kolkata-700019, India

(Manuscript received 15 June 2012; in final form 18 March 2013)

Citation: Tellus B, 65, 18981, http://dx.doi.org/10.3402/tellusb.v65i0.18981

ABSTRACT

Because of the difficulties in setting up arrangements in the intertidal zone for free-air carbon dioxide enrichment experimentation, the responses to increasing atmospheric carbon dioxide in mangrove forests are poorly studied.  This study applied box model to overcome this limitation, and the relative changes in present level of reservoirs organic carbon contents in response to the future increase of atmospheric carbon dioxide were examined in the Avicennia dominated mangrove forest at the land-ocean boundary of northeast coast of the Bay of Bengal. The above and below ground biomass (AGB+BGB) and sediment held different carbon stock (53.20±2.87 Mg C ha^-1 (mega gram carbon per hectare) versus 18.52±2.77 Mg C ha^-1). Carbon uptake (0.348 mg C m^-2s^-1) is more than offset by losses from plant emission (0.257 mg C m^-2s^-1) and litter fall (13.52 μg C m^-2s^-1) was more than soil CO₂ and CH₄ emission (8.36 and 1.39 μg C m^-2s^-1, respectively). Across inventory plots Sundarban mangrove forest carbon storage in above and below ground  live trees and soil increased by 18.89 and 5.94 Mg C ha^-1 between June 2009 and December 2011. Box model well predicted the dynamics of above and below ground biomass and soil organic carbon and increasing atmospheric carbon dioxide concentrations could be the cause of 1.1 and 1.57 fold increases in carbon storage in live biomass and soil, respectively across Sundarban mangrove forest rather than recovery from past disturbance.

Keywords: carbon stock, CO₂ sensitivity, box model, mangrove forest, India