Mangrove Methane Biogeochemistry in the Indian Sundarbans: A Proposed Budget
نویسندگان
چکیده
Biogeochemical cycling of CH4 was investigated at Lothian Island, one of the relatively pristine islands of Indian Sundarbans and its adjacent Saptamukhi estuary, during June 2010 to December 2012. Intertidal mangrove sediments were highly anoxic and rich in organic carbon. Mean rates of methanogenesis were 3,547 and 48.88μmol m−3 wet sediment d−1, for intertidal (up to 25 cm depth) and sub-tidal sediments (first 5 cm depth), respectively. CH4 in pore-water was 53.4 times more supersaturated than in adjacent estuarine waters. This resulted in significant CH4 efflux from sediments to estuarine waters-via advective and diffusive transport. About 8.2% of the total CH4 produced in intertidal mangrove sediments was transported to the adjacent estuary through advective flux, which was 20 times higher than diffusive CH4 flux. Mean CH4 concentrations in estuarine surface and sub-surface waters were 69.9 and 56.1 nM, respectively, with a dissolved CH4 oxidation rate in estuarine surface waters of 20.5 nmol L −1 d−1. An estimated 0.09 Gg year−1 of CH4 is released from estuaries of Sundarbans to the regional atmosphere. The mean CH4 mixing ratio over the forest atmosphere was 2 ppmv. On annual basis, only 2.75% of total supplied CH4 to the forest atmosphere was transported to the upper atmosphere via biosphere-atmosphere exchange. Mean CH4 photo-oxidation rate over the forest atmosphere was 3.25 × 10 −9mg cm−3 d−1. Using new and previously published data we present for the first time, a CH4 budget for Sundarbans mangrove ecosystem which in part, revealed the existence of anaerobic CH4 oxidation in the mangrove sediment column.
منابع مشابه
Atmospheric Ozone And Its Biosphere - Atmosphere Exchange In A Mangrove Forest Ecosystem: A Case Study From Sundarbans, NE Coast Of India
Temporal variation of atmospheric O3 and its biosphere – atmosphere exchange were monitored in the Sundarbans mangrove forest from January 2011 to December 2011 on bimonthly basis. O3 mixing ratios at 10 m and 20 m heights over the forest atmosphere ranged between 14.66 ± 1.88 to 37.90 ± 0.91 and 19.32 ± 6.27 to 39.80 ± 10.13 ppbv, respectively; having maximal premonsoon and minimal monsoon per...
متن کاملDaytime Ozone Variation in Surface Air in a Subtropical Mangrove Estuary at Manakudy, South India
Surface ozone (SOZ) can be very harmful if it exceeds the threshold limit. It can accumulate over sea and can return back to the land along with the breeze. Rural and vegetation rich areas often record elevated levels of surface ozone because of the variations in Volatile Organic Compound (VOC) levels, wind velocity and direction. Similarly methane is also an important greenhouse gas and plays ...
متن کاملDaytime Ozone Variation in Surface Air in a Subtropical Mangrove Estuary at Manakudy, South India
Surface ozone (SOZ) can be very harmful if it exceeds the threshold limit. It can accumulate over sea and can return back to the land along with the breeze. Rural and vegetation rich areas often record elevated levels of surface ozone because of the variations in Volatile Organic Compound (VOC) levels, wind velocity and direction. Similarly methane is also an important greenhouse gas and plays ...
متن کاملApplication of Gis in Ecotourism Development:
GIS can be used in tourism as a decision supporting tool for sustainable tourism planning, impact assessment, visitor flow management, and tourism site selection. Therefore, the potential for GIS applications in tourism is significant. The purpose of the study was fixed to explore the potential of using GIS for planning resources pertinent to ecotourism development. The study investigated a cas...
متن کاملMapping and Change Analysis in Mangrove Forest by Using Landsat Imagery
Mangrove is located in the tropical and subtropical regions and brings good services for native people. Mangrove in the world has been lost with a rapid rate. Therefore, monitoring a spatiotemporal distribution of mangrove is thus critical for natural resource management. This research objectives were: (i) to map the current extent of mangrove in the West and Central Africa and in the Sundarban...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2017