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Sandip Mukhopadhyay

Bio: Sandip Mukhopadhyay is an academic researcher from University of Calcutta. The author has contributed to research in topics: Mangrove & Biogeochemical cycle. The author has an hindex of 17, co-authored 57 publications receiving 1258 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, the authors studied the fluvial fluxes and estuarine transport of nutrients from a tropical river (Mahanadi River) in Northeastern India and compared select nutrient and water quality parameters between 1983 and 2008.
Abstract: Ongoing climate change and anthropogenic activities are introducing stressors that affect the structure and function of coastal ecosystems. This paper focuses on the fluvial fluxes and estuarine transport of nutrients from a tropical river (Mahanadi River) in Northeastern India and compares select nutrient and water quality parameters between 1983 and 2008. This estuary acts as a perennial source of CO2 with a net annual flux to the atmosphere of about 135 tons. The non-conservative fluxes showed a net annual removal of 650 and 140 tons of phosphorus and nitrogen from the water column, respectively. Negative biogeochemical feedbacks that decreased the availability of N and P in 2008 relative to 1983 levels indicate major changes in biogeochemical responses towards fluvial fluxes of nutrient.

17 citations

Journal Article
TL;DR: An attempt has been made for the individual measurement of CO 2 fluxes in the Sundarban forest and in the water ways near Jambu Island by using micrometeorological method, and a negative linear correlation was obtained between wind speed andCO 2 flux from atmosphere to the forest.
Abstract: Attempt has been made for the individual measurement of CO 2 fluxes in the Sundarban forest and in the water ways near Jambu Island by using micrometeorological method during 12-13 February 1998. The gas fluxes were measured directly over a short enough time period at variable flux controlling conditions. This environment has been found to be sink for CO 2 during study period. A negative linear correlation was obtained between wind speed and CO 2 flux from atmosphere to the forest (F af ). The atmosphere to surface water flux (F aw ) was found to be due to undersaturated condition of water with respect to solubility of CO 2 . Measured values for the fluxes of CO 2 from the atmosphere to the forest and water areas were found to be at a rate of 24 x 10 9 and 16 x 10 6 kg C year -1 , respectively.

16 citations

Journal ArticleDOI
TL;DR: In vitro propagation of Hemidesmus indicus (L) R Br through bud multiplication and subsequent plant regeneration and Chromosome number stability with no detectable structural changes was observed in the regenerates.
Abstract: The present study involves in vitro propagation of Hemidesmus indicus (L) R Br through bud multiplication and subsequent plant regeneration. The buds multiplied to produce numerous shoots at variable rates in presence of a-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP) as well as NAA and kinetin. The best response in bud multiplication was obtained in Murashige and Skoog’s (MS) basal medium supplemented with 0.1 mg I-1 NAA and 2.0 mg I-1 BAP (7-8 shoots per explant) and the bud break time was only 4 days after inoculation. The multiplication rate was low when the buds were cultured in NAA and kinetin media and the shootlets regenerated were very thin, weak and elongated. The shoots regenerated were further cultured on MS and half strength MS basal media with variable levels of indole-3-butyric acid (IBA) for initiation of roots. Culture of shootlets for 34 weeks in one half strength of MS medium followed by culturing in the same medium with 1.5 mg 1-1 IBA induced highest production of roots (3-5 roots per shoot) within 2 weeks. Chromosome number stability with no detectable structural changes was observed in the regenerates. The rooted plants were successfully established in the soil with 85% survival rate.

16 citations

Journal ArticleDOI
TL;DR: The histological and biochemical studies showed vigorous development of corm like structures and shoot organogenesis from callus tissues cultured in MG supplemented media and higher content of δ-aminolaevulinic acid and of chlorophyll.
Abstract: The aim of this study was to evaluate the influence of methylglyoxal (MG) on organogenesis and regeneration of tobacco (Nicotiana tabacum L.) plants from callus in media containing glycine or succinate. The best improvement in shoot proliferation and shoot length was obtained in the medium supplemented with 0.1 mM MG and 0.5 mM glycine or 0.25 mM succinate. The histological studies showed vigorous development of corm like structures and shoot organogenesis from callus tissues cultured in MG supplemented media. Biochemical studies also revealed higher content of δ-aminolaevulinic acid (a precursor of chlorophyll) and of chlorophyll.

15 citations

Journal ArticleDOI
TL;DR: The present study involves in vitro propagation of Iphigenia indica (Kunth.) through multiplication of whole corms and corm buds to produce numerous shoots at variable rates in presence of α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP).
Abstract: The present study involves in vitro propagation of Iphigenia indica (Kunth.) through multiplication of whole corms and corm buds. The whole corms produced very small micro-corms, which developed plants individually whereas corm buds multiplied to produce numerous shoots at variable rates in presence of α-naphthaleneacetic acid (NAA) and 6-benzylaminopurine (BAP). The best response in corm and bud multiplication was obtained in Murashige and Skoog's basal medium (MS) supplemented with 2.69 μM NAA and 8.88 μM BAP. The shoots regenerated were further cultured on MS medium containing NAA and indole-3-butyric acid (IBA) for initiation of roots. MS medium with 5.38 μM NAA and 4.92 μM IBA induced highest percentage of roots (81%) within 2 weeks in culture.

13 citations


Cited by
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Journal ArticleDOI
TL;DR: The unaccounted carbon sink is conservatively estimated at 112 ± 85 Tg C a 1, equivalent in magnitude to 30-40% of the global riverine organic carbon input to the coastal zone as mentioned in this paper.
Abstract: results in a conservative estimate of 218 ± 72 Tg C a 1 . When using the best available estimates of various carbon sinks (organic carbon export, sediment burial, and mineralization), it appears that >50% of the carbon fixed by mangrove vegetation is unaccounted for. This unaccounted carbon sink is conservatively estimated at 112 ± 85 Tg C a 1 , equivalent in magnitude to 30–40% of the global riverine organic carbon input to the coastal zone. Our analysis suggests that mineralization is severely underestimated, and that the majority of carbon export from mangroves to adjacent waters occurs as dissolved inorganic carbon (DIC). CO2 efflux from sediments and creek waters and tidal export of DIC appear to be the major sinks. These processes are quantitatively comparable in magnitude to the unaccounted carbon sink in current budgets, but are not yet adequately constrained with the limited published data available so far.

918 citations

Journal ArticleDOI
TL;DR: Of immediate concern are potential carbon losses to deforestation that are greater than these ecosystems' rates of carbon storage, and large reservoirs of dissolved inorganic carbon in deep soils are a large loss of carbon.
Abstract: Mangroves are ecologically and economically important forests of the tropics. They are highly productive ecosystems with rates of primary production equal to those of tropical humid evergreen forests and coral reefs. Although mangroves occupy only 0.5% of the global coastal area, they contribute 10–15% (24 Tg C y−1) to coastal sediment carbon storage and export 10–11% of the particulate terrestrial carbon to the ocean. Their disproportionate contribution to carbon sequestration is now perceived as a means for conservation and restoration and a way to help ameliorate greenhouse gas emissions. Of immediate concern are potential carbon losses to deforestation (90–970 Tg C y−1) that are greater than these ecosystems' rates of carbon storage. Large reservoirs of dissolved inorganic carbon in deep soils, pumped via subsurface pathways to adjacent waterways, are a large loss of carbon, at a potential rate up to 40% of annual primary production. Patterns of carbon allocation and rates of carbon flux in mangrove f...

890 citations

Journal Article
TL;DR: The unaccounted carbon sink is conservatively estimated at 112 ± 85 Tg C a 1, equivalent in magnitude to 30-40% of the global riverine organic carbon input to the coastal zone.
Abstract: results in a conservative estimate of 218 ± 72 Tg C a 1 . When using the best available estimates of various carbon sinks (organic carbon export, sediment burial, and mineralization), it appears that >50% of the carbon fixed by mangrove vegetation is unaccounted for. This unaccounted carbon sink is conservatively estimated at 112 ± 85 Tg C a 1 , equivalent in magnitude to 30–40% of the global riverine organic carbon input to the coastal zone. Our analysis suggests that mineralization is severely underestimated, and that the majority of carbon export from mangroves to adjacent waters occurs as dissolved inorganic carbon (DIC). CO2 efflux from sediments and creek waters and tidal export of DIC appear to be the major sinks. These processes are quantitatively comparable in magnitude to the unaccounted carbon sink in current budgets, but are not yet adequately constrained with the limited published data available so far.

797 citations

Journal ArticleDOI
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

Journal ArticleDOI
TL;DR: In this article, the authors upscaled air-water CO2 fluxes to take into account the latitudinal and ecosystem diversity of the coastal ocean, based on an exhaustive literature survey.
Abstract: [1] Air-water CO2 fluxes were up-scaled to take into account the latitudinal and ecosystem diversity of the coastal ocean, based on an exhaustive literature survey. Marginal seas at high and temperate latitudes act as sinks of CO2 from the atmosphere, in contrast to subtropical and tropical marginal seas that act as sources of CO2 to the atmosphere. Overall, marginal seas act as a strong sink of CO2 of about −0.45 Pg C yr−1. This sink could be almost fully compensated by the emission of CO2 from the ensemble of near-shore coastal ecosystems of about 0.40 Pg C yr−1. Although this value is subject to large uncertainty, it stresses the importance of the diversity of ecosystems, in particular near-shore systems, when integrating CO2 fluxes at global scale in the coastal ocean.

562 citations