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Chanda A, Akhand A. Challenges towards the Sustainability and Enhancement of the Indian Sundarban Mangrove's Blue Carbon Stock. Life (Basel) 2023; 13:1787. [PMID: 37629645 PMCID: PMC10455859 DOI: 10.3390/life13081787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 08/11/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
The Sundarban is the world's largest contiguous mangrove forest and stores around 26.62 Tg of blue carbon. The present study reviewed the factors causing a decline in its blue carbon content and poses a challenge in enhancing the carbon stock of this region. This review emphasized that recurrent tropical cyclones, soil erosion, freshwater scarcity, reduced sediment load into the delta, nutrient deficiency, salt-stress-induced changes in species composition, mangrove clearing, and anthropogenic pollution are the fundamental drivers which can potentially reduce the total blue carbon stock of this region. The southern end of the Ganges-Brahmaputra-Meghna Delta that shelters this forest has stopped its natural progradation due to inadequate sediment flow from the upper reaches. Growing population pressure from the north of the Sundarban Biosphere Reserve and severe erosion in the southern end accentuated by regional sea-level rise has left minimal options to enhance the blue carbon stock by extending the forest premises. This study collated the scholarly observations of the past decades from this region, indicating a carbon sequestration potential deterioration. By collecting the existing knowledge base, this review indicated the aspects that require immediate attention to stop this ecosystem's draining of the valuable carbon sequestered and, at the same time, enhance the carbon stock, if possible. This review provided some key recommendations that can help sustain the blue carbon stock of the Indian Sundarban. This review stressed that characterizing the spatial variability of blue carbon with more sampling points, catering to the damaged trees after tropical cyclones, estuarine rejuvenation in the upper reaches, maintaining species diversity through afforestation programs, arresting coastal erosion through increasing sediment flow, and combating marine pollution have become urgent needs of the hour. The observations synthesized in this study can be helpful for academics, policy managers, and decision makers willing to uphold the sustainability of the blue carbon stock of this crucial ecosystem.
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Affiliation(s)
- Abhra Chanda
- School of Oceanographic Studies, Jadavpur University, Kolkata 700032, West Bengal, India
| | - Anirban Akhand
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
- Coastal and Estuarine Environment Research Group, Port and Airport Research Institute, Nagase, Yokosuka 239-0826, Kanagawa, Japan
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Temmerman S, Horstman EM, Krauss KW, Mullarney JC, Pelckmans I, Schoutens K. Marshes and Mangroves as Nature-Based Coastal Storm Buffers. ANNUAL REVIEW OF MARINE SCIENCE 2023; 15:95-118. [PMID: 35850492 DOI: 10.1146/annurev-marine-040422-092951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Tidal marshes and mangroves are increasingly valued for nature-based mitigation of coastal storm impacts, such as flooding and shoreline erosion hazards, which are growing due to global change. As this review highlights, however, hazard mitigation by tidal wetlands is limited to certain conditions, and not all hazards are equally reduced. Tidal wetlands are effective in attenuating short-period storm-induced waves, but long-period storm surges, which elevate sea levels up to several meters for up to more than a day, are attenuated less effectively, or in some cases not at all, depending on storm conditions, wetland properties, and larger-scale coastal landscape geometry. Wetlands often limit erosion, but storm damage to vegetation (especially mangrove trees) can be substantial, and recovery may take several years. Longer-term wetland persistence can be compromised when combined with other stressors, such as climate change and human disturbances. Due to these uncertainties, nature-based coastal defense projects need to adopt adaptive management strategies.
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Affiliation(s)
- Stijn Temmerman
- Ecosphere Research Group, University of Antwerp, Antwerp, Belgium; , ,
| | - Erik M Horstman
- Water Engineering and Management, University of Twente, Enschede, The Netherlands;
| | - Ken W Krauss
- Wetland and Aquatic Research Center, US Geological Survey, Lafayette, Louisiana, USA;
| | - Julia C Mullarney
- Coastal Marine Group, School of Science, University of Waikato, Hamilton, New Zealand;
| | - Ignace Pelckmans
- Ecosphere Research Group, University of Antwerp, Antwerp, Belgium; , ,
| | - Ken Schoutens
- Ecosphere Research Group, University of Antwerp, Antwerp, Belgium; , ,
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Osland MJ, Hughes AR, Armitage AR, Scyphers SB, Cebrian J, Swinea SH, Shepard CC, Allen MS, Feher LC, Nelson JA, O'Brien CL, Sanspree CR, Smee DL, Snyder CM, Stetter AP, Stevens PW, Swanson KM, Williams LH, Brush JM, Marchionno J, Bardou R. The impacts of mangrove range expansion on wetland ecosystem services in the southeastern United States: Current understanding, knowledge gaps, and emerging research needs. GLOBAL CHANGE BIOLOGY 2022; 28:3163-3187. [PMID: 35100489 DOI: 10.1111/gcb.16111] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Climate change is transforming ecosystems and affecting ecosystem goods and services. Along the Gulf of Mexico and Atlantic coasts of the southeastern United States, the frequency and intensity of extreme freeze events greatly influence whether coastal wetlands are dominated by freeze-sensitive woody plants (mangrove forests) or freeze-tolerant grass-like plants (salt marshes). In response to warming winters, mangroves have been expanding and displacing salt marshes at varying degrees of severity in parts of north Florida, Louisiana, and Texas. As winter warming accelerates, mangrove range expansion is expected to increasingly modify wetland ecosystem structure and function. Because there are differences in the ecological and societal benefits that salt marshes and mangroves provide, coastal environmental managers are challenged to anticipate the effects of mangrove expansion on critical wetland ecosystem services, including those related to carbon sequestration, wildlife habitat, storm protection, erosion reduction, water purification, fisheries support, and recreation. Mangrove range expansion may also affect wetland stability in the face of extreme climatic events and rising sea levels. Here, we review the current understanding of the effects of mangrove range expansion and displacement of salt marshes on wetland ecosystem services in the southeastern United States. We also identify critical knowledge gaps and emerging research needs regarding the ecological and societal implications of salt marsh displacement by expanding mangrove forests. One consistent theme throughout our review is that there are ecological trade-offs for consideration by coastal managers. Mangrove expansion and marsh displacement can produce beneficial changes in some ecosystem services, while simultaneously producing detrimental changes in other services. Thus, there can be local-scale differences in perceptions of the impacts of mangrove expansion into salt marshes. For very specific local reasons, some individuals may see mangrove expansion as a positive change to be embraced, while others may see mangrove expansion as a negative change to be constrained.
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Affiliation(s)
- Michael J Osland
- Wetland and Aquatic Research Center, U.S. Geological Survey, Lafayette, Louisiana, USA
| | - A Randall Hughes
- Northeastern University Marine Science Center, Nahant, Massachusetts, USA
| | - Anna R Armitage
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, USA
| | - Steven B Scyphers
- Northeastern University Marine Science Center, Nahant, Massachusetts, USA
| | - Just Cebrian
- Northern Gulf Institute, Mississippi State University, Stennis Space Center, Mississippi, USA
| | - Savannah H Swinea
- Northeastern University Marine Science Center, Nahant, Massachusetts, USA
| | | | | | - Laura C Feher
- Wetland and Aquatic Research Center, U.S. Geological Survey, Lafayette, Louisiana, USA
| | - James A Nelson
- University of Louisiana at Lafayette, Lafayette, Louisiana, USA
| | | | | | | | - Caitlin M Snyder
- Apalachicola National Estuarine Research Reserve, Eastpoint, Florida, USA
| | | | - Philip W Stevens
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, Florida, USA
| | - Kathleen M Swanson
- Mission-Aransas National Estuarine Research Reserve, Port Aransas, Texas, USA
| | | | - Janell M Brush
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, Gainesville, Florida, USA
| | - Joseph Marchionno
- Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, Gainesville, Florida, USA
| | - Rémi Bardou
- Northeastern University Marine Science Center, Nahant, Massachusetts, USA
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Kominoski JS, Weaver CA, Armitage AR, Pennings SC. Coastal carbon processing rates increase with mangrove cover following a hurricane in Texas,
USA. Ecosphere 2022. [DOI: 10.1002/ecs2.4007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- John S. Kominoski
- Department of Biological Sciences Florida International University Miami Florida USA
| | - Carolyn A. Weaver
- Department of Life Sciences Texas A&M University‐Corpus Christi Corpus Christi Texas USA
- Department of Biology Millersville University Millersville Pennsylvania USA
| | - Anna R. Armitage
- Department of Marine Biology Texas A&M University at Galveston Galveston Texas USA
| | - Steven C. Pennings
- Department of Biology and Biochemistry University of Houston Houston Texas USA
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Peng D, Montelongo DC, Wu L, Armitage AR, Kominoski JS, Pennings SC. A hurricane alters the relationship between mangrove cover and marine subsidies. Ecology 2022; 103:e3662. [PMID: 35157321 DOI: 10.1002/ecy.3662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/19/2021] [Accepted: 12/09/2021] [Indexed: 11/11/2022]
Abstract
As global change alters the composition and productivity of ecosystems, the importance of subsidies from one habitat to another may change. We experimentally manipulated black mangrove (Avicennia germinans) cover in ten large plots and over five years (2014-2019) quantifying the effects of mangrove cover on subsidies of floating organic material (wrack) into coastal wetlands. As mangrove cover increased from zero to 100%, wrack cover and thickness decreased by ~60%, the distance that wrack penetrated into the plots decreased by ~70%, and the percentage of the wrack trapped in the first six m of the plot tripled. These patterns observed during four "normal" years disappeared in a fifth year following Hurricane Harvey (2017), when large quantities of wrack were pushed far into the interior of all the plots, regardless of mangrove cover. Prior to the storm, the abundance of animals collected in grab samples increased with wrack biomass. Wrack composition did not affect animal abundance or composition. Experimental outplants of two types of wrack (red algae and seagrass) revealed that animal abundance and species composition varied between the fringe and interior of the plots, and between microhabitats dominated by salt marsh versus mangrove vegetation. The importance of wrack to overall carbon stocks varied as a function of autochthonous productivity: wrack inputs (per m2 ) based on survey data were greater than aboveground plant biomass in the plots (42 × 24 m) dominated by salt marsh vegetation, but decreased to 5% of total aboveground biomass in plots dominated by mangroves. Our results illustrate that increasing mangrove cover decreases the relative importance of marine subsidies into the intertidal at the plot level, but concentrates subsidies at the front edge of the mangrove stand. Storms, however, may temporarily override mangrove attenuation of wrack inputs. Our results highlight the importance of understanding how changes in plant species composition due to global change will impact marine subsidies and exchanges among ecosystems, and foster a broader understanding of the functional interdependence of adjacent habitats within coastal ecosystems.
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Affiliation(s)
- Dan Peng
- Department of Biology and Biochemistry, University of Houston, Texas, USA.,Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, China
| | - Denise C Montelongo
- Department of Biology and Biochemistry, University of Houston, Texas, USA.,Current address: Department of Entomology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Leslie Wu
- Department of Biology and Biochemistry, University of Houston, Texas, USA
| | - Anna R Armitage
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, USA
| | - John S Kominoski
- Department of Biological Sciences, Florida International University, Miami, Florida, United States
| | - Steven C Pennings
- Department of Biology and Biochemistry, University of Houston, Texas, USA
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GIS Models for Vulnerability of Coastal Erosion Assessment in a Tropical Protected Area. ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION 2021. [DOI: 10.3390/ijgi10090598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coastal erosion is considered a major worldwide challenge. The vulnerability assessment of coastal areas, in relation to climate change, is a key topic of worldwide increasing interest. The integration of methodologies supported by Remote Sensing, Geographical Information Systems (GIS) and in situ monitoring has allowed a viable identification of vulnerable areas to erosion. In the present study, a model was proposed to the assessment of the estuarine system of Cananéia-Iguape (Brazil), by applying the evaluation and prediction of vulnerability models for the conservation and preservation of mangroves. Approximately 1221 Km2 were classified, with 16% of the total presenting high and very high vulnerability to erosion. Other relevant aspects, were the identification and georeferencing sites that showed strong evidence of erosion and, thus, having a huge influence on the final vulnerability scores. The obtained results led to the development of a multidisciplinary approach through the application of a prediction and description model that resulted from the adaptation of the study system from a set of implemented models for coastal regions, in order to contribute to the erosion vulnerability assessment in the mangroves ecosystems (and associated localities, municipalities and communities).
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Kuhn AL, Kominoski JS, Armitage AR, Charles SP, Pennings SC, Weaver CA, Maddox TR. Buried hurricane legacies: increased nutrient limitation and decreased root biomass in coastal wetlands. Ecosphere 2021. [DOI: 10.1002/ecs2.3674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Amanda L. Kuhn
- Department of Biological Sciences Florida International University Miami Florida 33199 USA
| | - John S. Kominoski
- Department of Biological Sciences Florida International University Miami Florida 33199 USA
| | - Anna R. Armitage
- Department of Marine Biology Texas A&M University at Galveston P.O. Box 1675 Galveston Texas 77553 USA
| | - Sean P. Charles
- Department of Biological Sciences Florida International University Miami Florida 33199 USA
| | - Steven C. Pennings
- Department of Biology and Biochemistry University of Houston Houston Texas 77204 USA
| | - Carolyn A. Weaver
- Department of Life Sciences Texas A&M University – Corpus Christi Corpus Christi Texas 78412 USA
| | - Tom R. Maddox
- Stable Isotope Ecology Laboratory Center for Applied Isotope Studies University of Georgia Athens Georgia 30602 USA
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Pennings SC, Glazner RM, Hughes ZJ, Kominoski JS, Armitage AR. Effects of mangrove cover on coastal erosion during a hurricane in Texas, USA. Ecology 2021; 102:e03309. [PMID: 33576002 DOI: 10.1002/ecy.3309] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/24/2020] [Accepted: 02/05/2021] [Indexed: 11/07/2022]
Abstract
We tested the hypothesis that mangroves provide better coastal protection than salt marsh vegetation using 10 1,008-m2 plots in which we manipulated mangrove cover from 0 to 100%. Hurricane Harvey passed over the plots in 2017. Data from erosion stakes indicated up to 26 cm of vertical and 970 cm of horizontal erosion over 70 months in the plot with 0% mangrove cover, but relatively little erosion in other plots. The hurricane did not increase erosion, and erosion decreased after the hurricane passed. Data from drone images indicated 196 m2 of erosion in the 0% mangrove plot, relatively little erosion in other plots, and little ongoing erosion after the hurricane. Transects through the plots indicated that the levee (near the front of the plot) and the bank (the front edge of the plot) retreated up to 9 m as a continuous function of decreasing mangrove cover. Soil strength was greater in areas vegetated with mangroves than in areas vegetated by marsh plants, or nonvegetated areas, and increased as a function of plot-level mangrove cover. Mangroves prevented erosion better than marsh plants did, but this service was nonlinear, with low mangrove cover providing most of the benefits.
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Affiliation(s)
- Steven C Pennings
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, 77204, USA
| | - Rachael M Glazner
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, 77553, USA
| | - Zoe J Hughes
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, 77204, USA
- Department of Earth Sciences, Boston University, Boston, Massachusetts, 02215, USA
| | - John S Kominoski
- Department of Biological Sciences, Florida International University, Miami, Florida, 33199, USA
| | - Anna R Armitage
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, 77553, USA
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