Impact of Sundarban mangrove biosphere on the carbon dioxide and methane mixing ratios at the NE Coast of Bay of Bengal, India
TL;DR: In this paper, the authors measured the diurnal and seasonal variations in carbon dioxide and methane fluxes between Sundarban biosphere and atmosphere using micrometeorological method during 1998-2000.
About: This article is published in Atmospheric Environment.The article was published on 2002-02-01. It has received 64 citations till now. The article focuses on the topics: Atmospheric methane & Carbon dioxide.
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TL;DR: In this article, the authors review 72 published articles to elucidate characteristics of biomass allocation and productivity of mangrove forests and also introduce recent progress on the study of MANGEO to solve the site and species-specific problems.
688 citations
TL;DR: The impact of increasing N deposition on natural ecosystems is poorly understood, and further understanding is required regarding the use of drainage as a management tool, to reduce CH4 emissions from wetlands and to increase GHG sink from the restoration of degraded lands, including saline and sodic soils.
Abstract: Besides water vapour, greenhouse gases CO2, CH4, O3 and N2O contribute ~60%, 20%, 10% and 6% to global warming, respectively; minor contribution is made by chlorofluorocarbons and volatile organic compounds (VOC). We present CO2, CH4 and N2O fluxes from natural and relatively unmanaged soil–plant ecosystems (the ecosystems minimally disturbed by direct human or human-induced activities). All natural ecosystems are net sinks for CO2, although tundra and wetlands (including peatlands) are large sources of CH4, whereas significant N2O emissions occur mainly from tropical and temperate forests. Most natural ecosystems decrease net global warming potential (GWP) from –0.03 ± 0.35 t CO2-e ha–1 y–1 (tropical forests) to –0.90 ± 0.42 t CO2-e ha–1 y–1 (temperate forests) and –1.18 ± 0.44 t CO2-e ha–1 y–1 (boreal forests), mostly as CO2 sinks in phytobiomass, microbial biomass and soil C. But net GWP contributions from wetlands are very large, which is primarily due to CH4 emissions. Although the tropical forest system provides a large carbon sink, the negligible capacity of tropical forests to reduce GWP is entirely due to N2O emissions, possibly from rapid N mineralisation under favourable temperature and moisture conditions. It is estimated that the natural ecosystems reduce the net atmospheric greenhouse gas (GHG) emissions by 3.55 ± 0.44 Gt CO2-e y–1 or ~0.5 ppmv CO2-e y–1, hence, the significant role of natural and relatively unmanaged ecosystems in slowing global warming and climate change. However, the impact of increasing N deposition on natural ecosystems is poorly understood, and further understanding is required regarding the use of drainage as a management tool, to reduce CH4 emissions from wetlands and to increase GHG sink from the restoration of degraded lands, including saline and sodic soils. Data on GHG fluxes from natural and relatively unmanaged ecosystems are further compounded by large spatial and temporal heterogeneity, limited sensitivity of current instruments, few and poor global distribution of monitoring sites and limited capacity of models that could integrate GHG fluxes across ecosystems, atmosphere and oceans and include feedbacks from biophysical variables governing these fluxes.
287 citations
TL;DR: The atmospheric fluxes of N(2)O, CH(4) and CO(2), from the soil in four mangrove swamps in Shenzhen and Hong Kong, South China were investigated in the summer of 2008 and were positively correlated with the soil organic carbon, total nitrogen, total phosphate, total iron and NH(4)(+)-N contents, as well as the soil porosity.
158 citations
Cites background from "Impact of Sundarban mangrove biosph..."
...Some mangrove soil emitted a significant amount of greenhouse gases (e.g. Mukhopadhyay et al., 2002; Allen et al., 2007)....
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TL;DR: In this article, the authors measured diurnal and seasonal variations of air-water CO2 exchange in relation to the occurrence of phytoplankton during January-December 2001.
Abstract: The Sundarban mangrove forest (4,264 km 2 ) constitutes about 3% of the total area of the world mangrove. We measured diurnal and seasonal variations of air‐water CO2 exchange in relation to the occurrence of phytoplankton during January‐December 2001. Diurnal variations of airflows showed that the minimum and maximum CO2 flux of 216.2 mmol m 22 h 21 and 49.9 mmol m 22 h 21 , respectively, occurred during the higher sea breeze. The average ratio of dissolved inorganic nitrogen (DIN 5 13.85 6 7.19 mmol L 21 ) to dissolved inorganic phosphorus (DIP 5 1.23 6 0.57 mmol L 21 ) was 11 6 4 and the surface water was undersaturated with respect to dissolved oxygen. The mean value of 0.1 6 0.08 for the ratio of phytoplankton production (P) to community respiration (R) indicated that the ecosystem was heterotrophic. The saturation of dissolved carbon dioxide with respect to the atmosphere varied seasonally between 59% and 156%, with minimum levels in postmonsoon and maximum levels in premonsoon/early monsoon (June/July). Out of the 36 genera of diatoms, 1 blue green alga, and 3 dinoflagellates that occurred throughout the year, only 6 reached bloom proportions in postmonsoon, when mangrove water was a sink of atmospheric CO2. Although 59.3% of the emitted CO2 was removed from the atmosphere by biological processes, on an annual basis, the Sundarban mangrove forest supplies 13.8 kg C ha 21 yr 21 of CO2 from water surface to the atmosphere. Even though it is important to compare all in and out fluxes, there is no direct link between CO 2 emission and the later CO2 removal by biological processes.
130 citations
Cites background from "Impact of Sundarban mangrove biosph..."
...Sometimes it is not clear if an ecosystem is a net source or sink of CO2 (Mukhopadhyay et al. 2002b)....
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...Anthropogenic processes, responsible for the conversion of a productive estuary to a heterotrophic one (Frankignoulle et al. 1998; Mukhopadhyay et al. 2002a), further complicate the uncertainty of the estimation of unaccounted sinks....
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...Mukhopadhyay et al. (2002b) observed a positive correlation of fCO2(air) with Richardson number (Ri) and its values were found to be increasing in the atmosphere when there was an inversion condition in the Sundarban mangrove forest....
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TL;DR: In this paper, seasonal and spatial variation of dissolved and atmospheric methane (CH 4 ) was measured in the estuaries of the Sundarban mangrove ecosystem from January to December 2003.
115 citations
References
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TL;DR: In this paper, the authors investigated the magnitude of CH4 emissions to the troposphere from the Amazon River floodplain and the mechanism of these emissions were investigated using the data of 94 individual flux measurements made along a 1700-km stretch of the river during July/August 1985.
Abstract: The magnitudes of CH4 emissions to the troposphere from the Amazon River floodplain and the mechanism of these emissions were investigated using the data of 94 individual flux measurements made along a 1700-km stretch of the river during July/August 1985. The overall average rate of CH4 emission from wetlands was found to be 390 mg CH4/sq m per day, with the highest emissions (590 mg CH4/sq m per day) attributed to the water surfaces covered by aquatic macrophytes. Ebullition was the dominant mechanism of emission, accounting for 85 percent of the total. Surface-water CH4 concentrations were highly supersaturated, averaging 6.4 micromolar. The annual emission of CH4 from the Amazon Basin to the troposphere, estimated from the area and the known emission rate, is about 10 CH4 Tg/yr, indicating the importance of the area in the global atmospheric CH4 cycle.
217 citations
TL;DR: In this paper, a new method for estimating scalar fluxes, called surface renewal analysis, was developed and successfully tested with air temperature data from a maize crop, an orchard, and a forest canopy.
214 citations
TL;DR: In this article, the authors found that rice fields are a major source of methane emissions to the atmosphere, with an average emission rate of 60 mg m{sup {minus}2} h{sup{minus}1} from rice fields at TuZu in the Sczhuan Province of China.
Abstract: Methane emissions from rice fields in China are found to be 4-10 times higher than emission rates from rice fields in the United States and Europe. Average emission rates during the growing season were {approximately}60 mg m{sup {minus}2} h{sup {minus}1} from rice fields at TuZu in the Sczhuan Province of China. These results show that rice fields are a major source of methane to the atmosphere.
175 citations
TL;DR: A correlation between the CH 4 oxidation activity and the number of methanotrophs was only observed at high (1000 ppmv) CH 4 mixing ratios as discussed by the authors, which indicates that the counted methanophores were not the bacteria which are oxidizing atmospheric CH 4 (≤17 ppmv).
Abstract: CH 4 oxidation activities from various soils and freshwater sediments were measured at low (≤2 parts per million by volume (ppmv)) and high (≥1000 ppmv) CH 4 mixing ratios Most of the tested soils acted as sinks for atmospheric CH 4 A correlation between the CH 4 oxidation activity and the numbers of methanotrophs was only observed at high (1000 ppmv) CH 4 mixing ratios This indicates that the counted methanotrophs were not the bacteria which are oxidizing atmospheric CH 4 (≤17 ppmv) The CH 4 oxidation was due to prokaryotic microorganisms active only under oxic conditions
167 citations
TL;DR: A seasonal study of methane release from adjoining salt, brackish and fresh marsh sediment and adjacent open water areas in Louisiana's Barataria Basin indicates that methane emission is a significant process in the carbon and energy flow of the ecosystem.
Abstract: A seasonal study of methane release from adjoining salt, brackish and fresh marsh sediment andthe adjacent open water areas in Louisiana’s Barataria Basin indicates that methane emission isa significant process in the carbon and energy flow of the ecosystem. Methane emission wasinversely related to salinity and sulfate concentration, with methane increasing and salinity andsulfate decreasing with increasing distance from the coast. The annual amounts of methaneevolved were 4.3, 73 and 160 g C m -2 for the salt, brackish and fresh marshes, respectively. Invitro experiments show that methane production is sensitive to the addition of sulfate, highconcentrations (10 mM SO,) inhibiting methane evolution. DOI: 10.1111/j.1600-0889.1983.tb00002.x
157 citations