Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires
While it is well known that wildfires can greatly contribute to soil water repellency by changing soil chemical composition, the mechanisms of these changes are still poorly understood. In the past decade, the number, size, and intensity of wildfires have greatly increased in the western USA. Recent...
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MDPI AG
2023-05-01
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| Series: | Fire |
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| Online Access: | https://www.mdpi.com/2571-6255/6/5/186 |
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| author | Vera Samburova Eric Schneider Christopher P. Rüger Shelby Inouye Brad Sion Kevin Axelrod Palina Bahdanovich Lukas Friederici Yasaman Raeofy Markus Berli Alexandra Lutz Ralf Zimmermann Hans Moosmüller |
| author_facet | Vera Samburova Eric Schneider Christopher P. Rüger Shelby Inouye Brad Sion Kevin Axelrod Palina Bahdanovich Lukas Friederici Yasaman Raeofy Markus Berli Alexandra Lutz Ralf Zimmermann Hans Moosmüller |
| author_sort | Vera Samburova |
| collection | DOAJ |
| description | While it is well known that wildfires can greatly contribute to soil water repellency by changing soil chemical composition, the mechanisms of these changes are still poorly understood. In the past decade, the number, size, and intensity of wildfires have greatly increased in the western USA. Recent megafires in California (i.e., the Dixie, Beckwourth Complex, Caldor, and Mosquito fires) provided us with an opportunity to characterize pre- and post-fire soils and to study the effects of fires on soil water repellency, soil organic constituents, and connections between the two. Water drop penetration time (WDPT) tests performed in the field showed a significant increase (from <1 s up to >600 s) in WDPT from pre- to post-fire soils. This increase in soil water repellency after fires was confirmed by increases in apparent contact angle (ACA) between 1.1 and 9 times from unburned to burned soils. The chemical characterization of burned soils with high resolution mass spectrometry showed the increased abundance of hydrophobic organics (e.g., PAH-like compounds and organic molecules with a low number of oxygen atoms) as well as the correlation of the average H/C ratio and aromaticity index (AI) with ACA. Most likely, these compounds contribute to post-fire soil water repellency that triggers hydrological effects such as landslides, flooding, and debris flows. |
| first_indexed | 2024-03-11T03:44:23Z |
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| id | doaj.art-1a1d115dd3b24f338f1225fa813c44a1 |
| institution | Directory Open Access Journal |
| issn | 2571-6255 |
| language | English |
| last_indexed | 2024-03-11T03:44:23Z |
| publishDate | 2023-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fire |
| spelling | doaj.art-1a1d115dd3b24f338f1225fa813c44a12023-11-18T01:18:59ZengMDPI AGFire2571-62552023-05-016518610.3390/fire6050186Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA MegafiresVera Samburova0Eric Schneider1Christopher P. Rüger2Shelby Inouye3Brad Sion4Kevin Axelrod5Palina Bahdanovich6Lukas Friederici7Yasaman Raeofy8Markus Berli9Alexandra Lutz10Ralf Zimmermann11Hans Moosmüller12Division of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USAJoint Mass Spectrometry Centre, University of Rostock, 18059 Rostock, GermanyJoint Mass Spectrometry Centre, University of Rostock, 18059 Rostock, GermanyDivision of Hydrologic Sciences, Desert Research Institute, Las Vegas, NV 89119, USADivision of Earth and Ecosystem Sciences, Desert Research Institute, Reno, NV 89512, USADivision of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USADivision of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USAJoint Mass Spectrometry Centre, University of Rostock, 18059 Rostock, GermanyDivision of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USADivision of Hydrologic Sciences, Desert Research Institute, Las Vegas, NV 89119, USADivision of Hydrologic Sciences, Desert Research Institute, Reno, NV 89512, USAJoint Mass Spectrometry Centre, University of Rostock, 18059 Rostock, GermanyDivision of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, USAWhile it is well known that wildfires can greatly contribute to soil water repellency by changing soil chemical composition, the mechanisms of these changes are still poorly understood. In the past decade, the number, size, and intensity of wildfires have greatly increased in the western USA. Recent megafires in California (i.e., the Dixie, Beckwourth Complex, Caldor, and Mosquito fires) provided us with an opportunity to characterize pre- and post-fire soils and to study the effects of fires on soil water repellency, soil organic constituents, and connections between the two. Water drop penetration time (WDPT) tests performed in the field showed a significant increase (from <1 s up to >600 s) in WDPT from pre- to post-fire soils. This increase in soil water repellency after fires was confirmed by increases in apparent contact angle (ACA) between 1.1 and 9 times from unburned to burned soils. The chemical characterization of burned soils with high resolution mass spectrometry showed the increased abundance of hydrophobic organics (e.g., PAH-like compounds and organic molecules with a low number of oxygen atoms) as well as the correlation of the average H/C ratio and aromaticity index (AI) with ACA. Most likely, these compounds contribute to post-fire soil water repellency that triggers hydrological effects such as landslides, flooding, and debris flows.https://www.mdpi.com/2571-6255/6/5/186soil water repellencypost-fire soilsoil organic matterwater drop penetration timeapparent contact anglegoniometer |
| spellingShingle | Vera Samburova Eric Schneider Christopher P. Rüger Shelby Inouye Brad Sion Kevin Axelrod Palina Bahdanovich Lukas Friederici Yasaman Raeofy Markus Berli Alexandra Lutz Ralf Zimmermann Hans Moosmüller Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires Fire soil water repellency post-fire soil soil organic matter water drop penetration time apparent contact angle goniometer |
| title | Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires |
| title_full | Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires |
| title_fullStr | Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires |
| title_full_unstemmed | Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires |
| title_short | Modification of Soil Hydroscopic and Chemical Properties Caused by Four Recent California, USA Megafires |
| title_sort | modification of soil hydroscopic and chemical properties caused by four recent california usa megafires |
| topic | soil water repellency post-fire soil soil organic matter water drop penetration time apparent contact angle goniometer |
| url | https://www.mdpi.com/2571-6255/6/5/186 |
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