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Carmichael MJ, Martinez M, Bräuer SL, Ardón M. Microbial Communities in Standing Dead Trees in Ghost Forests are Largely Aerobic, Saprophytic, and Methanotrophic. Curr Microbiol 2024; 81:229. [PMID: 38896154 PMCID: PMC11186919 DOI: 10.1007/s00284-024-03767-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024]
Abstract
Standing dead trees (snags) are recognized for their influence on methane (CH4) cycling in coastal wetlands, yet the biogeochemical processes that control the magnitude and direction of fluxes across the snag-atmosphere interface are not fully elucidated. Herein, we analyzed microbial communities and fluxes at one height from ten snags in a ghost forest wetland. Snag-atmosphere CH4 fluxes were highly variable (- 0.11-0.51 mg CH4 m-2 h-1). CH4 production was measured in three out of ten snags; whereas, CH4 consumption was measured in two out of ten snags. Potential CH4 production and oxidation in one core from each snag was assayed in vitro. A single core produced CH4 under anoxic and oxic conditions, at measured rates of 0.7 and 0.6 ng CH4 g-1 h-1, respectively. Four cores oxidized CH4 under oxic conditions, with an average rate of - 1.13 ± 0.31 ng CH4 g-1 h-1. Illumina sequencing of the V3/V4 region of the 16S rRNA gene sequence revealed diverse microbial communities and indicated oxidative decomposition of deadwood. Methanogens were present in 20% of the snags, with a mean relative abundance of < 0.0001%. Methanotrophs were identified in all snags, with a mean relative abundance of 2% and represented the sole CH4-cycling communities in 80% of the snags. These data indicate potential for microbial attenuation of CH4 emissions across the snag-atmosphere interface in ghost forests. A better understanding of the environmental drivers of snag-associated microbial communities is necessary to forecast the response of CH4 cycling in coastal ghost forest wetlands to a shifting coastal landscape.
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Affiliation(s)
- Mary Jane Carmichael
- Departments of Biology and Environmental Studies, Hollins University, Roanoke, VA, 24020, USA.
| | - Melinda Martinez
- U.S. Geological Survey, Eastern Ecological Science Center, Laurel, MD, 20708, USA
| | - Suzanna L Bräuer
- Department of Biology, Appalachian State University, Boone, NC, 28608, USA
| | - Marcelo Ardón
- Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, 27695, USA
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Cunha J, Cabecinha E, Villasante S, Gonçalves JA, Balbi S, Elliott M, Ramos S. Quantifying the role of saltmarsh as a vulnerable carbon sink: A case study from Northern Portugal. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171443. [PMID: 38447727 DOI: 10.1016/j.scitotenv.2024.171443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 03/08/2024]
Abstract
Saltmarshes play a crucial role in carbon sequestration and storage, although they are increasingly threatened by climate change-induced sea level rise (SLR). This study assessed the potential variation in Blue Carbon stocks across regional and local scales, and estimated their economic value and potential habitat loss due to SLR based on the IPCC AR6 scenarios for 2050 and 2100 in three estuarine saltmarshes in northern Portugal, the saltmarshes of the Minho, Lima and Cávado estuaries. The combined carbon stock of these saltmarshes was 38,798 ± 2880 t of organic carbon, valued at 3.96 ± 0.38 M€. Local and regional differences in carbon stocks were observed between common species, with the cordgrass Spartina patens and the reed Phragmites australis consistently showing higher values in the Lima saltmarsh in some of the parameters. Overall, the Lima saltmarsh had the highest total carbon per species cover, with S. patens showing the highest values among common species. Bolboschoenus maritimus had the highest values in the Minho saltmarsh, while the other species presented a similar carbon storage capacity. Potential habitat loss due to SLR was most evident in the Cávado saltmarsh over shorter timescales, with a significant risk of inundation even for median values of SLR, while the Lima saltmarsh was shown to be more resistant and resilient. If habitat loss directly equates to carbon loss within these saltmarshes, projected CO2 emissions may range from 22,000 to 43,449 t by 2050 and 33,000 to 130,000 t by 2100 (under the IPCC SSP5-8.5 scenario). The study shows the importance of Blue Carbon site-specific estimates, acknowledging the potential future repercussions from habitat loss due to SLR. It emphasizes the need to consider local and regional variability in Blue Carbon stocks assessments and highlights the critical importance of preserving and rehabilitating these ecosystems to ensure their continued efficacy as vital carbon sinks, thereby contributing to climate change mitigation efforts.
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Affiliation(s)
- Jacinto Cunha
- CIIMAR/CIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Matosinhos, Portugal; CITAB/Inov4Agro - Centre for Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
| | - Edna Cabecinha
- CITAB/Inov4Agro - Centre for Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal
| | - Sebastian Villasante
- EqualSea Lab - CRETUS, Department of Applied Economics, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - José A Gonçalves
- CIIMAR/CIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Matosinhos, Portugal; Department of Geosciences Environment and Spatial Planning, Faculty of Sciences, University of Porto, Porto, Portugal
| | - Stefano Balbi
- Basque Centre for Climate Change (BC3), Sede Building, Campus EHU/UPV, Leioa, Bizkaia, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao, Bizkaia, Spain
| | - Michael Elliott
- School of Environmental Sciences, University of Hull, HU6 7RX, UK; International Estuarine & Coastal Specialists (IECS) Ltd, Leven HU17 5LQ, UK
| | - Sandra Ramos
- CIIMAR/CIMAR - Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Matosinhos, Portugal
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3
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Adame MF, Kelleway J, Krauss KW, Lovelock CE, Adams JB, Trevathan-Tackett SM, Noe G, Jeffrey L, Ronan M, Zann M, Carnell PE, Iram N, Maher DT, Murdiyarso D, Sasmito S, Tran DB, Dargusch P, Kauffman JB, Brophy L. All tidal wetlands are blue carbon ecosystems. Bioscience 2024; 74:253-268. [PMID: 38720908 PMCID: PMC11075650 DOI: 10.1093/biosci/biae007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 01/14/2024] [Accepted: 02/06/2024] [Indexed: 05/12/2024] Open
Abstract
Managing coastal wetlands is one of the most promising activities to reduce atmospheric greenhouse gases, and it also contributes to meeting the United Nations Sustainable Development Goals. One of the options is through blue carbon projects, in which mangroves, saltmarshes, and seagrass are managed to increase carbon sequestration and reduce greenhouse gas emissions. However, other tidal wetlands align with the characteristics of blue carbon. These wetlands are called tidal freshwater wetlands in the United States, supratidal wetlands in Australia, transitional forests in Southeast Asia, and estuarine forests in South Africa. They have similar or larger potential for atmospheric carbon sequestration and emission reductions than the currently considered blue carbon ecosystems and have been highly exploited. In the present article, we suggest that all wetlands directly or indirectly influenced by tides should be considered blue carbon. Their protection and restoration through carbon offsets could reduce emissions while providing multiple cobenefits, including biodiversity.
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Affiliation(s)
- Maria Fernanda Adame
- Australian Rivers Institute, Griffith University, Brisbane, Queensland, Australia
| | - Jeff Kelleway
- University of Wollongong, School of Earth, Atmospheric, and Life Sciences, Wollongong, New South Wales, Australia
| | - Ken W Krauss
- US Geological Survey, Wetland and Aquatic Research Center, Lafayette, Louisiana, United States
| | - Catherine E Lovelock
- School of the Environment The University of Queensland, St Lucia, Queensland, Australia
| | - Janine B Adams
- Nelson Mandela University, Institute for Coastal & Marine Research and Department of Botany, Gqeberha, South Africa
| | - Stacey M Trevathan-Tackett
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences at Deakin University, Melboourne, Victoria, Australia
| | - Greg Noe
- U.S. Geological Survey, Florence Bascom Geoscience Center, Reston, Virginia, United States
| | - Luke Jeffrey
- Faculty of Science and Engineering at Southern Cross University, Lismore, New South Wales, Australia
| | - Mike Ronan
- Department of Environment, Science, and Innovation, Wetlands Team, Queensland Government, Brisbane, Queensland, Australia
| | - Maria Zann
- Department of Environment, Science, and Innovation, Wetlands Team, Queensland Government, Brisbane, Queensland, Australia
| | - Paul E Carnell
- Deakin Marine Research and Innovation Centre, School of Life and Environmental Sciences at Deakin University, Melboourne, Victoria, Australia
| | - Naima Iram
- Australian Rivers Institute, Griffith University, Brisbane, Queensland, Australia
- Centre for Nature-Based Climate Solutions, Faculty of Science at the National University of Singapore, Singapore
| | - Damien T Maher
- Faculty of Science and Engineering at Southern Cross University, Lismore, New South Wales, Australia
| | - Daniel Murdiyarso
- Centre for International Forestry Research, Word Agroforestry, Department of Geophysics and Meteorology at IPB University, Bogor, Indonesia
| | - Sigit Sasmito
- NUS Environmental Research Institute, National University of Singapore, Singapore
| | - Da B Tran
- Vietnam National University of Agriculture, Hanoi, Vietnam
| | - Paul Dargusch
- School of the Environment The University of Queensland, St Lucia, Queensland, Australia
| | - J Boone Kauffman
- Ilahee Sciences International and with the Department of Fisheries, Wildlife, Corvallis, Oregon, United States
- Conservation Sciences at Oregon State University, Corvallis, Oregon, United States
| | - Laura Brophy
- Institute for Applied Ecology and the College of Earth, Ocean, Corvallis Oregon, United States
- Atmospheric Sciences at Oregon State University, Corvallis Oregon, United States
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Abstract
Marine transgression associated with rising sea levels causes coastal erosion, landscape transitions, and displacement of human populations globally. This process takes two general forms. Along open-ocean coasts, active transgression occurs when sediment-delivery rates are unable to keep pace with accommodation creation, leading to wave-driven erosion and/or landward translation of coastal landforms. It is highly visible, rapid, and limited to narrow portions of the coast. In contrast, passive transgression is subtler and slower, and impacts broader areas. It occurs along low-energy, inland marine margins; follows existing upland contours; and is characterized predominantly by the landward translation of coastal ecosystems. The nature and relative rates of transgression along these competing margins lead to expansion and/or contraction of the coastal zone and-particularly under the influence of anthropogenic interventions-will dictate future coastal-ecosystem response to sea-level rise, as well as attendant, often inequitable, impacts on human populations.
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Affiliation(s)
- Christopher J Hein
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, Virginia, USA; ,
| | - Matthew L Kirwan
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, Virginia, USA; ,
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Abernathy VE, Good A, Blanchard A, Bongiovanni M, Bonds E, Warner H, Chaknis E, Pulsifer G, Huntley F. The Effects of Climate Change on the Nesting Phenology of Three Shorebird Species in the United States. Animals (Basel) 2023; 13:2459. [PMID: 37570268 PMCID: PMC10416824 DOI: 10.3390/ani13152459] [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: 06/19/2023] [Revised: 07/20/2023] [Accepted: 07/27/2023] [Indexed: 08/13/2023] Open
Abstract
Previous research suggests that a frequent response of organisms to the ongoing climate crisis is the adjustment of their reproductive timing or breeding phenology. Shorebirds may be especially vulnerable to increasing temperatures and precipitation, as many are migratory and depend on coastal habitats for wintering and breeding. These particular habitats could be at risk due to changes in climate, and nesting times often depend on food availability, which is often directly influenced by temperature. We investigated if clutch initiation dates (CID) for three shorebird species in the United States have become earlier over time with increasing temperatures and precipitation. We used nest records from Cornell's NestWatch program and various museum databases and weather station data from the National Oceanic and Atmospheric Administration. We found evidence that CIDs have become earlier over time, though this was only a significant factor for one species. While temperature in our study areas has increased significantly over time, precipitation changes were more variable and not always significantly predicted by time. We found evidence that one species may be responding to increasing temperatures by nesting earlier, but there was no support for our hypothesis that CID has changed due to changes in precipitation for any species. Results varied for each species, indicating the importance of further studies on shorebirds as the effects of climate change on their nesting phenology may not be fully realized and will likely depend on the species' biology and distribution.
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Affiliation(s)
- Virginia E. Abernathy
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
| | - Abby Good
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
- GAI Consultants, Homestead, PA 15120, USA
| | - Autum Blanchard
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
- Department of Geology and Environmental Geosciences, University of Charleston, SC at the College of Charleston, Charleston, SC 29424, USA
| | - Marlisa Bongiovanni
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
- Graduate School of Education & Human Development, George Washington University; Washington, DC 20052, USA
| | - Emily Bonds
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
| | - Hampton Warner
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
- School of Medicine Greenville, University of South Carolina, Greenville, SC 29605, USA
| | - Eleni Chaknis
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
- East Cooper OB/GYN, Mount Pleasant, SC 29464, USA
| | - Gabriella Pulsifer
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
| | - Faith Huntley
- Department of Biological Sciences, Clemson University, Clemson, SC 29631, USA; (A.G.); (A.B.); (M.B.); (E.B.); (H.W.); (E.C.); (G.P.); (F.H.)
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6
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Ohenhen LO, Shirzaei M, Ojha C, Kirwan ML. Hidden vulnerability of US Atlantic coast to sea-level rise due to vertical land motion. Nat Commun 2023; 14:2038. [PMID: 37041168 PMCID: PMC10090057 DOI: 10.1038/s41467-023-37853-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 03/28/2023] [Indexed: 04/13/2023] Open
Abstract
The vulnerability of coastal environments to sea-level rise varies spatially, particularly due to local land subsidence. However, high-resolution observations and models of coastal subsidence are scarce, hindering an accurate vulnerability assessment. We use satellite data from 2007 to 2020 to create high-resolution map of subsidence rate at mm-level accuracy for different land covers along the ~3,500 km long US Atlantic coast. Here, we show that subsidence rate exceeding 3 mm per year affects most coastal areas, including wetlands, forests, agricultural areas, and developed regions. Coastal marshes represent the dominant land cover type along the US Atlantic coast and are particularly vulnerable to subsidence. We estimate that 58 to 100% of coastal marshes are losing elevation relative to sea level and show that previous studies substantially underestimate marsh vulnerability by not fully accounting for subsidence.
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Affiliation(s)
- Leonard O Ohenhen
- Department of Geosciences, Virginia Tech, Blacksburg, VA, USA.
- Virginia Tech National Security Institute, Blacksburg, VA, USA.
| | - Manoochehr Shirzaei
- Department of Geosciences, Virginia Tech, Blacksburg, VA, USA
- Virginia Tech National Security Institute, Blacksburg, VA, USA
| | - Chandrakanta Ojha
- Department of Earth and Environmental Science, IISER Mohali, Punjab, India
| | - Matthew L Kirwan
- Virginia Institute of Marine Science, College of William and Mary, Gloucester Point, Virginia, USA
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Let M, Pal S. Socio-ecological well-being perspectives of wetland loss scenario: A review. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 326:116692. [PMID: 36435140 DOI: 10.1016/j.jenvman.2022.116692] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/26/2022] [Accepted: 11/01/2022] [Indexed: 06/16/2023]
Abstract
Previous original research focused on wetland loss and finding out its drivers across different regional units of the world. A few reports also tried to account world's condition on wetland loss. A couple of review articles articulated the causes of wetland loss and services. The present study intended to explore the linkage between wetland loss rate and processes concerning socio-ecological well-being parameters to highlight alternative ways to adopt wetland conservation policies. A total of 132 pieces of Scopus index literature were taken analysing loss rate and drivers of loss from 22 sample countries where publication frequency is relatively high. Meta-analysis was done to explain the publication trend and spatial change in publication polarity. Results distinctly revealed that the rate of wetland loss varies from 0.06% to 4.81% annually, with substantially low in developed countries (DC) than in developing (DeV) and least developed countries (LDC). Six drivers, such as agricultural land expansion, the built-up area, the conversion to grassland area, construction of the dam, climate change and tourism, were the primary drivers. But all these are not equally active across the DC, DeV and LDC. Climate change, tourism development in DC, agriculture and built-up expansions in the Dev and LDC appeared as the major causes behind wetland loss. Socio-ecological well-being parameters like human development, environmental performance, social progression, and economic status were found to be significantly negatively (-0.48 to -0.57), and the poverty rate was positively (0.27) associated with the rates of wetland loss. Drivers also varied with respect to the socio-ecological conditions. These findings are not merely added knowledge to the state-of-arts but are also helpful in re-directing global policies toward wetland conservation.
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Affiliation(s)
- Manabendra Let
- Junior Research Fellow, Department of Geography, University of Gour Banga, Malda, India.
| | - Swades Pal
- Professor, Department of Geography, University of Gour Banga, Malda, India.
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8
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Campbell AD, Fatoyinbo L, Goldberg L, Lagomasino D. Global hotspots of salt marsh change and carbon emissions. Nature 2022; 612:701-706. [PMID: 36450979 PMCID: PMC9771810 DOI: 10.1038/s41586-022-05355-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 09/15/2022] [Indexed: 12/02/2022]
Abstract
Salt marshes provide ecosystem services such as carbon sequestration1, coastal protection2, sea-level-rise (SLR) adaptation3 and recreation4. SLR5, storm events6, drainage7 and mangrove encroachment8 are known drivers of salt marsh loss. However, the global magnitude and location of changes in salt marsh extent remains uncertain. Here we conduct a global and systematic change analysis of Landsat satellite imagery from the years 2000-2019 to quantify the loss, gain and recovery of salt marsh ecosystems and then estimate the impact of these changes on blue carbon stocks. We show a net salt marsh loss globally, equivalent to an area double the size of Singapore (719 km2), with a loss rate of 0.28% year-1 from 2000 to 2019. Net global losses resulted in 16.3 (0.4-33.2, 90% confidence interval) Tg CO2e year-1 emissions from 2000 to 2019 and a 0.045 (-0.14-0.115) Tg CO2e year-1 reduction of carbon burial. Russia and the USA accounted for 64% of salt marsh losses, driven by hurricanes and coastal erosion. Our findings highlight the vulnerability of salt marsh systems to climatic changes such as SLR and intensification of storms and cyclones.
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Affiliation(s)
- Anthony D Campbell
- Biospheric Sciences Laboratory, National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, Greenbelt, MD, USA.
- NASA Postdoctoral Program, Oak Ridge Associated Universities, Oak Ridge, TN, USA.
- GESTAR II, University of Maryland, Baltimore County, Baltimore, MD, USA.
| | - Lola Fatoyinbo
- Biospheric Sciences Laboratory, National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, Greenbelt, MD, USA
| | - Liza Goldberg
- Biospheric Sciences Laboratory, National Aeronautics and Space Administration (NASA) Goddard Space Flight Center, Greenbelt, MD, USA
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, USA
| | - David Lagomasino
- Integrated Coastal Programs, East Carolina University, Wanchese, NC, USA
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Bernhardt E. Coastal freshwater wetlands squeezed between migrating salt marshes and working lands. SCIENCE ADVANCES 2022; 8:eadd1628. [PMID: 35767608 PMCID: PMC11094673 DOI: 10.1126/sciadv.add1628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
Creative solutions are needed to sustain the diversity of coastal wetland ecosystems as sea levels rise.
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Affiliation(s)
- Emily Bernhardt
- Department of Biology, Duke University, Durham, NC 27708, USA
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10
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Coastal Wetland Responses to Sea Level Rise: The Losers and Winners Based on Hydro-Geomorphological Settings. REMOTE SENSING 2022. [DOI: 10.3390/rs14081888] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Many coastal wetlands are under pressure due to climate change and the associated sea level rise (SLR). Many previous studies suggest that upslope lateral migration is the key adaptive mechanism for saline wetlands, such as mangroves and saltmarshes. However, few studies have explored the long-term fate of other wetland types, such as brackish swamps and freshwater forests. Using the current wetland map of a micro-tidal estuary, the Manning River in New South Wales, Australia, this study built a machine learning model based on the hydro-geomorphological settings of four broad wetland types. The model was then used to predict the future wetland distribution under three sea level rise scenarios. The predictions were compared to compute the persistence, net, swap, and total changes in the wetlands to investigate the loss and gain potential of different wetland classes. Our results for the study area show extensive gains by mangroves under low (0.5 m), moderate (1.0 m), and high (1.5 m) sea level rise scenarios, whereas the other wetland classes could suffer substantial losses. Our findings suggest that the accommodation spaces might only be beneficial to mangroves, and their availability to saltmarshes might be limited by coastal squeeze at saline–freshwater ecotones. Furthermore, the accommodation spaces for freshwater wetlands were also restrained by coastal squeeze at the wetland-upland ecotones. As sea level rises, coastal wetlands other than mangroves could be lost due to barriers at the transitional ecotones. In our study, these are largely manifested by slope impacts on hydrology at a higher sea level. Our approach provides a framework to systematically assess the vulnerability of all coastal wetland types.
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