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Linked fire activity and climate whiplash in California during the early Holocene. Nat Commun 2022; 13:7175. [PMID: 36418893 PMCID: PMC9684419 DOI: 10.1038/s41467-022-34950-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 11/11/2022] [Indexed: 11/24/2022] Open
Abstract
Recent wildfire activity in semi-arid regions like western North America exceeds the range of historical records. High-resolution paleoclimate archives such as stalagmites could illuminate the link between hydroclimate, vegetation change, and fire activity in pre-anthropogenic climate states beyond the timescale of existing tree-ring records. Here we present an analysis of levoglucosan, a combustion-sensitive anhydrosugar, and lignin oxidation products (LOPs) in a stalagmite, reconstructing fire activity and vegetation composition in the California Coast Range across the 8.2 kyr event. Elevated levoglucosan concentrations suggest increased fire activity while altered LOP compositions indicate a shift toward more woody vegetation during the event. These changes are concurrent with increased hydroclimate volatility as shown by carbon and calcium isotope proxies. Together, these records suggest that climate whiplash (oscillations between extreme wetness and aridity) and fire activity in California, both projected to increase with anthropogenic climate change, were tightly coupled during the early Holocene.
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Li H, Sinha A, Anquetil André A, Spötl C, Vonhof HB, Meunier A, Kathayat G, Duan P, Voarintsoa NRG, Ning Y, Biswas J, Hu P, Li X, Sha L, Zhao J, Edwards RL, Cheng H. A multimillennial climatic context for the megafaunal extinctions in Madagascar and Mascarene Islands. SCIENCE ADVANCES 2020; 6:6/42/eabb2459. [PMID: 33067226 PMCID: PMC7567594 DOI: 10.1126/sciadv.abb2459] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 08/12/2020] [Indexed: 06/02/2023]
Abstract
Madagascar and the Mascarene Islands of Mauritius and Rodrigues underwent catastrophic ecological and landscape transformations, which virtually eliminated their entire endemic vertebrate megafauna during the past millennium. These ecosystem changes have been alternately attributed to either human activities, climate change, or both, but parsing their relative importance, particularly in the case of Madagascar, has proven difficult. Here, we present a multimillennial (approximately the past 8000 years) reconstruction of the southwest Indian Ocean hydroclimate variability using speleothems from the island of Rodrigues, located ∼1600 km east of Madagascar. The record shows a recurring pattern of hydroclimate variability characterized by submillennial-scale drying trends, which were punctuated by decadal-to-multidecadal megadroughts, including during the late Holocene. Our data imply that the megafauna of the Mascarenes and Madagascar were resilient, enduring repeated past episodes of severe climate stress, but collapsed when a major increase in human activity occurred in the context of a prominent drying trend.
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Affiliation(s)
- Hanying Li
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - Ashish Sinha
- Department of Earth Science, California State University, Dominguez Hills, Carson, CA, USA.
| | - Aurèle Anquetil André
- François Leguat Giant Tortoise and Cave Reserve, Anse Quitor, Rodrigues Island, Mauritius
| | - Christoph Spötl
- Institute of Geology, University of Innsbruck, 6020 Innsbruck, Austria
| | - Hubert B Vonhof
- Max Planck Institute of Chemistry, Hahn-Meitnerweg 1, Mainz, Germany
| | - Arnaud Meunier
- François Leguat Giant Tortoise and Cave Reserve, Anse Quitor, Rodrigues Island, Mauritius
| | - Gayatri Kathayat
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - Pengzhen Duan
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - Ny Riavo G Voarintsoa
- Department of Earth and Environmental Sciences, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Youfeng Ning
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - Jayant Biswas
- National Cave Research and Protection Organization, Raipur, India
| | - Peng Hu
- Center for Monsoon System Research, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xianglei Li
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Lijuan Sha
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - Jingyao Zhao
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China
| | - R Lawrence Edwards
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
| | - Hai Cheng
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China.
- Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
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Miller AZ, De la Rosa JM, Jiménez-Morillo NT, Pereira MFC, Gonzalez-Perez JA, Knicker H, Saiz-Jimenez C. Impact of wildfires on subsurface volcanic environments: New insights into speleothem chemistry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 698:134321. [PMID: 31783462 DOI: 10.1016/j.scitotenv.2019.134321] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 09/04/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
Siliceous speleothems frequently reported in volcanic caves have been traditionally interpreted as resulting from basalt weathering combined with the activity of microbial communities. A characteristic feature in lava tubes from Hawaii, Azores and Canary Islands is the occurrence of black jelly-like speleothems. Here we describe the formation process of siliceous black speleothems found in a lava tube from La Palma, Canary Islands, Spain, based on mineralogy, microscopy, light stable isotopes, analytical pyrolysis, NMR spectroscopy and chemometric analyses. The data indicate that the black speleothems are composed of a hydrated gel matrix of amorphous aluminum silicate materials containing charred vegetation and thermally degraded resins from pines or triterpenoids from Erica arborea, characteristic of the overlying laurel forest. This is the first observation of a connection between fire and speleothem chemistry from volcanic caves. We conclude that wildfires and organic matter from the surface area overlying caves may play an important role in the formation of speleothems found in La Palma and demonstrate that siliceous speleothems are potential archives for past fires.
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Affiliation(s)
- Ana Z Miller
- Laboratório HERCULES, Universidade de Évora, Largo Marquês de Marialva 8, 7000-676 Évora, Portugal; Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas (IRNAS-CSIC), Av. Reina Mercedes 10, 41012 Sevilla, Spain.
| | - José M De la Rosa
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas (IRNAS-CSIC), Av. Reina Mercedes 10, 41012 Sevilla, Spain
| | | | - Manuel F C Pereira
- CERENA, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - José A Gonzalez-Perez
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas (IRNAS-CSIC), Av. Reina Mercedes 10, 41012 Sevilla, Spain
| | - Heike Knicker
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas (IRNAS-CSIC), Av. Reina Mercedes 10, 41012 Sevilla, Spain
| | - Cesareo Saiz-Jimenez
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas (IRNAS-CSIC), Av. Reina Mercedes 10, 41012 Sevilla, Spain
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