Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern Everglades
Abstract Saltwater intrusion is a significant threat to the structure and ecology of inland and coastal freshwater wetlands, altering biogeochemical cycling and disrupting important ecosystem services. As sea level rises along the Florida coast, the saltwater interface progressively moves further in...
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| Format: | Article |
| Language: | English |
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Wiley
2023-01-01
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| Series: | Water Resources Research |
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| Online Access: | https://doi.org/10.1029/2021WR029683 |
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| author | Matthew J. Sirianni Xavier Comas Gregory J. Mount Shelley Pierce Carlos Coronado‐Molina David Rudnick |
| author_facet | Matthew J. Sirianni Xavier Comas Gregory J. Mount Shelley Pierce Carlos Coronado‐Molina David Rudnick |
| author_sort | Matthew J. Sirianni |
| collection | DOAJ |
| description | Abstract Saltwater intrusion is a significant threat to the structure and ecology of inland and coastal freshwater wetlands, altering biogeochemical cycling and disrupting important ecosystem services. As sea level rises along the Florida coast, the saltwater interface progressively moves further inland reaching freshwater soils previously unexposed to saltwater. One result of this soil salinization is a phenomenon called peat collapse which is currently observable along the South Florida coastline. While previous studies have proposed conceptual models to explain peat collapse many uncertainties still exist regarding the physical mechanisms that trigger this phenomenon. In this study we use a unique combination of laboratory and field‐based measurements using geophysical methods, deformation rods, gas traps, time‐lapse photography, and hydraulic conductivity measurements to investigate the effects of salinization on the physical properties of peat soils across a salinity gradient in the southwestern Everglades. Our results show that freshwater peat soils have about three times greater degree of pore dilation when compared to peat soils previously exposed to saltwater conditions. Differences in soil surface deformation were also observed and related to differences in the soil matrix physical integrity across the salinity gradient. This work also uses electrical resistivity imaging surveys to image areas of peat collapse and demonstrates: (a) the role of salinity in the development of collapse features; and (b) the apparent lack of evidence to suggest subsurface lithological controls on the development of collapse features. A simplified conceptual framework for better understanding peat collapse and pock formation is presented. |
| format | Article |
| id | doaj-art-225d75bb3b16428fbda89ddaf59c1b9a |
| institution | Kabale University |
| issn | 0043-1397 1944-7973 |
| language | English |
| publishDate | 2023-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Water Resources Research |
| spelling | doaj-art-225d75bb3b16428fbda89ddaf59c1b9a2025-08-20T03:27:52ZengWileyWater Resources Research0043-13971944-79732023-01-01591n/an/a10.1029/2021WR029683Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern EvergladesMatthew J. Sirianni0Xavier Comas1Gregory J. Mount2Shelley Pierce3Carlos Coronado‐Molina4David Rudnick5Department of Geosciences Florida Atlantic University FL Boca Raton USADepartment of Geosciences Florida Atlantic University FL Boca Raton USABroward County Resilient Environment Department FL Fort Lauderdale USADepartment of Geosciences Florida Atlantic University FL Boca Raton USASouth Florida Water Management District FL West Palm Beach USASouth Florida Natural Resources Center Everglades National Park FL Homestead USAAbstract Saltwater intrusion is a significant threat to the structure and ecology of inland and coastal freshwater wetlands, altering biogeochemical cycling and disrupting important ecosystem services. As sea level rises along the Florida coast, the saltwater interface progressively moves further inland reaching freshwater soils previously unexposed to saltwater. One result of this soil salinization is a phenomenon called peat collapse which is currently observable along the South Florida coastline. While previous studies have proposed conceptual models to explain peat collapse many uncertainties still exist regarding the physical mechanisms that trigger this phenomenon. In this study we use a unique combination of laboratory and field‐based measurements using geophysical methods, deformation rods, gas traps, time‐lapse photography, and hydraulic conductivity measurements to investigate the effects of salinization on the physical properties of peat soils across a salinity gradient in the southwestern Everglades. Our results show that freshwater peat soils have about three times greater degree of pore dilation when compared to peat soils previously exposed to saltwater conditions. Differences in soil surface deformation were also observed and related to differences in the soil matrix physical integrity across the salinity gradient. This work also uses electrical resistivity imaging surveys to image areas of peat collapse and demonstrates: (a) the role of salinity in the development of collapse features; and (b) the apparent lack of evidence to suggest subsurface lithological controls on the development of collapse features. A simplified conceptual framework for better understanding peat collapse and pock formation is presented.https://doi.org/10.1029/2021WR029683peat collapsepeat deformationEvergladeselectrical resistivity imagingground‐penetrating radarhydraulic conductivity |
| spellingShingle | Matthew J. Sirianni Xavier Comas Gregory J. Mount Shelley Pierce Carlos Coronado‐Molina David Rudnick Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern Everglades Water Resources Research peat collapse peat deformation Everglades electrical resistivity imaging ground‐penetrating radar hydraulic conductivity |
| title | Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern Everglades |
| title_full | Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern Everglades |
| title_fullStr | Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern Everglades |
| title_full_unstemmed | Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern Everglades |
| title_short | Understanding Peat Soil Deformation and Mechanisms of Peat Collapse Across a Salinity Gradient in the Southwestern Everglades |
| title_sort | understanding peat soil deformation and mechanisms of peat collapse across a salinity gradient in the southwestern everglades |
| topic | peat collapse peat deformation Everglades electrical resistivity imaging ground‐penetrating radar hydraulic conductivity |
| url | https://doi.org/10.1029/2021WR029683 |
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