Sundarban mangroves: diversity, ecosystem services and climate change impacts

Abstract

Abstract:The Bengal delta coast harboring the famous Sundarban mangroves is extremely vulnerable to climate change. Already, salinity intrusion, increasing cyclones and anomalies in rainfall, and temperature, are causing many social and livelihood problems. However, our knowledge on the diversified climate change impacts on Sundarban ecosystems services, providing immense benefits, including foods, shelters, livelihood, and health amenities, is very limited. Therefore, this article has systematically reviewed the major functional aspects, and highlights on biodiversity, ecosystem dynamics, and services of the Sunderban mangroves, with respect to variations in climatic factors. The mangrove ecosystems are highly productive in terms of forest biomass, and nutrient contribution, especially through detritus-based food webs, to support rich biodiversity in the wetlands and adjacent estuaries. Sundarban mangroves also play vital role in atmospheric CO 2 sequestration, sediment trapping and nutrient recycling. Sea level rise will engulf a huge portion of the mangroves, while the associated salinity increase is posing immense threats to biodiversity and economic losses. Climate-mediated changes in riverine discharge, tides, temperature, rainfall and evaporation will determine the wetland nutrient variations, influencing the physiological and ecological processes, thus biodiversity and productivity of Sundarban mangroves. Hydrological changes in wetland ecosystems through increased salinity and cyclones will lower the food security, and also induce human vulnerabilities to waterborne diseases. Scientific investigations producing high resolution data to identify Sundarban"s multidimensional vulnerabilities to various climatic regimes are essential. Sustainable plans and actions are required integrating conservation and climate change adaptation strategies, including promotion of alternative livelihoods. Thus, interdisciplinary approaches are required to address the future climatic disasters, and better protection of invaluable ecosystem services of the Sunderban mangroves.

Low CO<sub>2</sub> evasion rate from the mangrove surrounding waters of Sundarban

“…Denitrification has also been reported in the mangrove sediment of the Indian (Das et al, 2013;Ray et al, 2014) and Bangladesh (Neogi et al, 2016) parts of the Sundarbans, and from the mangrove environment of Goa (India), where it accounts for <0% to 72% of the pore-water nitrate reduction (Fernandes et al, 2010(Fernandes et al, , 2012. As the present study is the first of its kind in Sundarbans, our results can be considered baseline data; no comparison with other parts of the Sundarbans is possible, but this might be an avenue of future research.…”

Sundarbans mangrove forest of Bangladesh: causes of degradation and sustainable management options

“…Stable sea levels are needed for long-term existence of mangroves. But, due to the global climate change rise in sea level and increased intensity and frequency of cyclones, storms, coastal floods and erosion (Islam and Uddin 2015), are disrupting the mangroves ecosystem (Neogi et al 2016). Recent cyclones Sidr, Reshmi and Aila had devastating impacts on Sundarbans as reported by many authors (Islam 2013; Borrell et al (2016) 2015; Dutta et al 2015;Deb and Ferreira 2017).…”

“…Owing to the concept of sustainable development and coastal environmental conservation in Southeast Asian countries, it is of great importance to understand the Sundarbans mangrove ecosystem, which is under threat due to natural and anthropogenic causes (Kumar and Ramanathan 2015;Neogi et al 2016). To manage mangrove ecosystems sustainably within an integrated approach, it is essential to identify the information gaps and constraints.…”

Evaluating the Effectiveness of Climate Change Adaptations in the World’s Largest Mangrove Ecosystem

“…All of this has been causing a sizeable male population to emigrate from the villages. Phenomena like global and regional climatic changes coupled with anthropogenic pressures including poaching, human encroachment for agriculture and fishing, and overexploitation of both timber and non-timber forest produce have led to multiple alterations in the mangrove flora, fauna, and ecosystem dynamics and functions posing, as a consequence, severe threats to the Sundarbans' ecosystem [9]. They also introduce many changes in the ecosystem services vital for human health, wellbeing, and livelihoods [1,9,20].…”

“…The coastal regions of the Bay of Bengal, especially the Sundarbans delta, are among the most vulnerable areas of the world in terms of experiencing the rapid sea-level rise, seawater intrusion, and other climate change impacts [7,8]. The Sundarbans landscape is highly fragile and particularly vulnerable to global and regional climate change impacts because of its complex geomorphology and environmental settings attributable to continuing global warming, rising sea-levels, seawater intrusion, land erosion, gradual subsidence, and cyclones [1,9,10]. The Sundarbans' mangroves, which protect more than 10 million people from cyclonic storms, today stand threatened by cyclonic damage.…”