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

Implication of Organic Matter on Arsenic and Antimony Sequestration in Sediment: Evidence from Sundarban Mangrove Forest, India.

S. K. Mandal, R. Ray, C. Chowdhury, N. Majumder, T. K. Jana

Bull Environ Contam Toxicol, 2013, DOI 10.1007/s00128-012-0934-y

Abstract

This study reports the measurement of stability constants for the interaction of As (V and III) and Sb (V and III) with humic substances extracted from aquatic sediments of the Sundarban mangrove forest ecosystem. It was observed that As and Sb formed a slightly more stable association with fulvic acid (FA) than with its humic acid (HA) counterpart. Quenching of fluorescence at increasing As (III and V) or Sb (III and V): FA or HA ratios was obtained that ideally correspond to a 1:1 complexation model. Quite strong complexation of As and Sb by FA and HA occurs at neutral pH, indicating that HA and FA probably markedly affect the mobility of As and Sb in the mangrove environment.

Key words: Arsenic, Antimony, Humic substances, stability constant

NOx UPTAKE BY MANGROVE PLANTS AND ITS EFFECT ON MANGROVE DNA BASE HETEROGENEITY

AOGS-AGU (WPGM) JOINT ASSEMBLY,2012

INTERNATIONAL CONFERENCE, SINGAPORE 13-17TH AUGUST,2012

NOx Uptake by Mangrove Plants and Its Effect on Mangrove DNA Base Heterogeneity
Natasha MAJUMDER^1#+, Tapan Kumar JANA^1
1University of Calcutta, India
^#Corresponding author: natasha.majumder@gmail.com ⁺Presenter

Mangroves can use atmospheric NO_x as a source of nitrogen under soil nitrogen source constrain. In the atmosphere over Sundarban mangrove, progressive decrease of NOx was observed from a maximum of 4.34 ± 1.49 ppbv in January to a minimum of 1.57 ± 0.19 ppbv at 10 m in the month of September. During the period of September to February, the biosphere atmosphere NOx exchange rates of -0.84 to -1.63 ng N m^-2 s^-1 in the day and -0.36 to 5.19 ng N m^-2 s^-1 in the night were observed. However, during the period of March to August, the ecosystem showed NOx emission without any uptake and ranged from 0.34 to 2.13 ng N m^-2 s^-1 in the day and from 0.88 to 3.26 ng N m^-2 s^-1 in the night. The mean DNA concentrations in mangrove plant leaves were found to be 32.57 ± 6.12 mg g ^-1with 0.22 - 0.25 µg µg^-1DNA nitrogen in leaf DNA. in January during the max uptake of NOx, while 0.16 - 0.20 µg µg^-1DNA nitrogen in September when mangrove exhibited  minimum uptake of NO x from the atmosphere. The percentage of G-C base pairs in leaves (58.42-64.38%) was found greater than the percentage of A-T-base pairs (35.58-41.57%) which indicate the presence of N rich nucleotides. Statistical analysis revealed significant correlation between leaf protein and independent variables (TIN, NOx flux) tested (R = 0.92, p = 0.016) with 85.2% explained variability. Which supports the hypothesis that the leaf stomata can contribute to the atmospheric NOx uptake and its can shape the DNA base composition of the mangrove leaves.

IMPLICATION OF ORGANIC MATTER ON ARSENIC AND ANTIMONY SEQUESTRATION IN SEDIMENT:EVIDENCE FROM SUNDARBAN MANGROVE FOREST,INDIA

AOGS-AGU (WPGM) JOINT ASSEMBLY,2012

International Conference,Singapore 13-17th August 2012.

Implication of Organic Matter on Arsenic and Antimony Sequestration in Sediment: Evidence from Sundarban Mangrove Forest, India
Sanjay Kumar MANDAL^1#+, Tapan Kumar JANA^1
1University of Calcutta, India
^#Corresponding author: mandal.sanjaykumar@gmail.com ⁺Presenter

This study reports the measurement of stability constant for the interaction of As (V and III) and Sb (V and III) with humic substances extracted from Sundarban mangrove sediment, India. It was observed that As & Sb formed a more stable association with fulvic acid (FA) than its counterpart humic acid (HA), but the difference of stability with respect to oxidation state of As and Sb were less prominent. Quenching of fluorescence at increasing As (III & V) / Sb (III & V): FA /HA ratio was obtained that ideally correspond to one type of binding site (1:1 complexation model). Quite strong complexation of As & Sb (logarithm of the conditional stability constant between 5.13-5.68) by FA & HA occurs at neutral pH (7) indicating that HA & FA probably affect markedly the mobility of As & Sb in the mangrove environment. The sediment is silty clay loam type with 5.93% clay. FA and HA show excitation at 313 and 392 nm with the occurrence of maximum emission at 425 and 484 nm, respectively. This suggests that humification results in the shifting of λ_em (emission max.) towards longer wavelength (lower energy), which can be related to an increase aromatic condensation. The synchronous fluorescence spectra (SyF) of HA and FA are observed for FA at 346, 386 and 420nm and those for HA at 347, 394, 425 and 445nm.

CARBON SEQUESTRATION BY MANGROVE FOREST: ONE APPROACH FOR MANAGING CARBON DIOXIDE EMISSION FROM THERMAL POWER PLANTS

AOGS-AGU (WPGM) JOINT ASSEMBLY,2012

International Conference, Singapore,13-17th August 2012.

Carbon Sequestration by Mangrove Forest: One Approach For Managing Carbon Dioxide Emissions from Thermal Power Plants

Raghab RAY^1#+, Tapan Kumar JANA^1
1University of Calcutta, India
^#Corresponding author: raghab.ray@gmail.com ⁺Presenter

In the past decade, anthropogenic emissions of CO₂, primarily as a result of fossil fuel burning, increased at a rate of 3.4% per year and fossil fuel combustion as well as cement industry contribute 7.7 ± 0.5 giga ton of carbon annually to the atmosphere. Tropical forests processes about six times as much carbon as the anthropogenic emission. Mangrove forest accounts 2.4% of tropical forest and in the coastal area it could be one of the possible sink for the anthropogenic carbon dioxide. In this study total amount of coal converted to carbon dioxide by a thermal power plant near the northeast coast of India has been considered and it was found that 2.83 million ton of carbon is added to the atmosphere for the generation of 7469732 MW annually. Indian Sundarban mangrove forest (4264 km²) stores 0.41% of the total carbon storage in the Indian forest (6621 million tone carbon) and uptakes 2.79 million ton carbon annually which is 0.55 % of the annual fossil fuel emission (504.6 million ton carbon per annum) from India. Based on this study, about 4328 km² forest coverage is needed to sequester all carbon dioxide emitted from the thermal power plants. This study would help in great extent for future planning of aforestation program and management of the mangrove forest in the perspective of the use of forest for neutralizing anthropogenic CO₂ emitted during the course of development of Industries in and around Indian coast.

STIMULATION OF ESTUARINE BIOLOGICAL PUMP FOR CO2 USING GIBBERELIC ACID

AOGS-AGU (WPGM) JOINT ASSEMBLY,2012

International conference, Singapore,13-17th August 2012.

Stimulation of Estuarine Biological Pump for CO2 Using Gibberelic Acid

Chumki CHOWDHURY^1#+, Tapan Kumar JANA^1
1University of Calcutta, India
^#Corresponding author: chowdhurychumki@gmail.com ⁺Presenter

An estuary can be a source for CO₂ when heterotrophic production predominates over phytoplankton production, resulting significant change of regional atmosphere composition with respect to carbon dioxide. For example, flux of carbon dioxide from the Mahanadi estuary to the atmosphere was found to be 52.87- 2472.16 µM.m^-2.h^-1 which is greater than that of Saptamukhi estuary (4.7-810.62 µM.m^-2.h^-1). Both the estuaries show heterotrophism and act as source for CO2. However, in case of excess nutrient input cultural eutrophication could transfom an estuary as a sink for CO₂. But the effect of nutrients on phytoplankton production could soon reach saturation level at low concentration, For example half saturation concentration for inorganic nitrogen and phosphorous are 2.0-10 μM and 0.02-0.5 μM, respectively. Therefore estuaries can act as a sink for CO₂ for limited period of time.  To find an alternative process to gear up the biological pump could be a noble approach. This study reports the removal of excess CO₂ from medium by mixed culture of phytoplankton collected from Saptamukhi estuaruy and exposed to plant growth stimulator gibberelic acid other than nutrients. The increased growth of phytoplankton further resulted into the uptake of bicarbonate and carbonate ions from the system. Gibberelic acid promoted the growth of phytoplankton upto 33% in the culture while the culture without gibberelic acid control culture showed maximum no of cell increase of 24% and 21% respectively. Cultures added with gibberelic acid showed greater uptake of bicarbonate and carbonate ions from culture than the culture without gibberelic acid and the control.

Aerosol, Sundarbans: Fine mode aerosol chemistry over a tropical urban atmosphere: characterization of ionic and carbonaceous species, A. Chatterjee & C. Dutta & T. K. Jana & S. Sen, J Atmos Chem DOI 10.1007/s10874-012-9231-8, 2012. An extensive aerosol sampling program was conducted during January-December 2006 over Kolkata (22º33′ N and 88º20′ E), a mega-city in eastern India in order to understand the sources, distributions and properties of atmospheric fine mode aerosol (PM2.5). The primary focus of this study is to determine the relative contribution of natural and anthropogenic as well as local and transported components to the total fine mode aerosol loading and their seasonal distributions over the metropolis. The average concentrations of fine mode aerosol was found to be 71.2±25.2 μgm-3 varying between 34.5 μgm-3 in monsoon and 112.6 μgm-3 in winter. The formation pathways of major secondary aerosol components like nitrate and sulphate in different seasons are discussed. A long range transport of dust aerosol from arid and semiarid regions of western India and beyond was observed during pre-monsoon which significantly enriched the total aerosol concentration. Vehicular emissions, biomass burning and transported dust particles were the major sources of PM2.5 from local and continental regions whereas seasalt aerosol was the major source of PM2.5 from marine source regions.