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Schiferl J, Kingston M, Åkesson CM, Valencia BG, Rozas-Davila A, McGee D, Woods A, Chen CY, Hatfield RG, Rodbell DT, Abbott MB, Bush MB. A neotropical perspective on the uniqueness of the Holocene among interglacials. Nat Commun 2023; 14:7404. [PMID: 37973878 PMCID: PMC10654573 DOI: 10.1038/s41467-023-43231-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
Understanding how tropical systems have responded to large-scale climate change, such as glacial-interglacial oscillations, and how human impacts have altered those responses is key to current and future ecology. A sedimentary record recovered from Lake Junín, in the Peruvian Andes (4085 m elevation) spans the last 670,000 years and represents the longest continuous and empirically-dated record of tropical vegetation change to date. Spanning seven glacial-interglacial oscillations, fossil pollen and charcoal recovered from the core showed the general dominance of grasslands, although during the warmest times some Andean forest trees grew above their modern limits near the lake. Fire was very rare until the last 12,000 years, when humans were in the landscape. Here we show that, due to human activity, our present interglacial, the Holocene, has a distinctive vegetation composition and ecological trajectory compared with six previous interglacials. Our data reinforce the view that modern vegetation assemblages of high Andean grasslands and the presence of a defined tree line are aspects of a human-modified landscape.
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Affiliation(s)
- J Schiferl
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - M Kingston
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - C M Åkesson
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - B G Valencia
- Facultad de Ciencias de La Tierra y Agua, Universidad Regional Amazónica Ikiam, Tena, Ecuador
| | - A Rozas-Davila
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA
| | - D McGee
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - A Woods
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA
| | - C Y Chen
- Chemical and Isotopic Signatures Group, Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - R G Hatfield
- Department of Geological Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - D T Rodbell
- Geoscience Department, Union College, Schenectady, NY, 12308, USA
| | - M B Abbott
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA
| | - M B Bush
- Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, 32901, USA.
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Seltzer GO, Rodbell DT, Baker PA, Fritz SC, Tapia PM, Rowe HD, Dunbar RB. Early warming of tropical South America at the last glacial-interglacial transition. Science 2002; 296:1685-6. [PMID: 12040193 DOI: 10.1126/science.1070136] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Glaciation in the humid tropical Andes is a sensitive indicator of mean annual temperature. Here, we present sedimentological data from lakes beyond the glacial limit in the tropical Andes indicating that deglaciation from the Last Glacial Maximum led substantial warming at high northern latitudes. Deglaciation from glacial maximum positions at Lake Titicaca, Peru/Bolivia (16 degrees S), and Lake Junin, Peru (11 degrees S), occurred 22,000 to 19,500 calendar years before the present, several thousand years before the Bølling-Allerød warming of the Northern Hemisphere and deglaciation of the Sierra Nevada, United States (36.5 degrees to 38 degrees N). The tropical Andes deglaciated while climatic conditions remained regionally wet, which reflects the dominant control of mean annual temperature on tropical glaciation.
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Affiliation(s)
- G O Seltzer
- Department of Earth Sciences, Syracuse University, 204 Heroy Geology Laboratory, Syracuse, NY 13244, USA.
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Abstract
The transition from the last ice age to the current warm period was interupted by a ~1000-year return to glacial conditions. Most of the evidence for this Younger Dryas (YD) event comes from in and around the North Atlantic, and the geographical extent of the event remains uncertain. In his Perspective, Rodbell reviews the evidence for and against a YD event in the Southern Hemisphere and highlights the study by Bennett et al., who have found no evidence for a YD event in four lake records from southern Chile.
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Rodbell DT, Seltzer GO, Anderson DM, Abbott MB, Enfield DB, Newman JH. An approximately 15,000-year record of El Nino-driven alluviation in southwestern ecuador. Science 1999; 283:516-20. [PMID: 9915694 DOI: 10.1126/science.283.5401.516] [Citation(s) in RCA: 572] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Debris flows have deposited inorganic laminae in an alpine lake that is 75 kilometers east of the Pacific Ocean, in Ecuador. These storm-induced events were dated by radiocarbon, and the age of laminae that are less than 200 years old matches the historic record of El Nino events. From about 15,000 to about 7000 calendar years before the present, the periodicity of clastic deposition is greater than or equal to 15 years; thereafter, there is a progressive increase in frequency to periodicities of 2 to 8.5 years. This is the modern El Nino periodicity, which was established about 5000 calendar years before the present. This may reflect the onset of a steeper zonal sea surface temperature gradient, which was driven by enhanced trade winds.
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Affiliation(s)
- DT Rodbell
- D. T. Rodbell and J. H. Newman, Department of Geology, Union College, Schenectady, NY 12308-2311, USA. G. O. Seltzer, Department of Earth Sciences, Syracuse University, Syracuse, NY 13244-1070, USA. D. M. Anderson, National Oceanic and Atmospheric Adm
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