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Pinaya JLD, Pitman NCA, Cruz FW, Akabane TK, Lopez MDCS, Pereira-Filho AJ, Grohman CH, Reis LS, Rodrigues ESF, Ceccantini GCT, De Oliveira PE. Humid and cold forest connections in South America between the eastern Andes and the southern Atlantic coast during the LGM. Sci Rep 2024; 14:2080. [PMID: 38267489 PMCID: PMC10808232 DOI: 10.1038/s41598-024-51763-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 01/09/2024] [Indexed: 01/26/2024] Open
Abstract
The presence of Andean plant genera in moist forests of the Brazilian Atlantic Coast has been historically hypothesized as the result of cross-continental migrations starting at the eastern Andean flanks. Here we test hypotheses of former connections between the Atlantic and Andean forests by examining distribution patterns of selected cool and moist-adapted plant arboreal taxa present in 54 South American pollen records of the Last Glacial Maximum (LGM), ca. 19-23 cal ka, known to occur in both plant domains. Pollen taxa studied include Araucaria, Drimys, Hedyosmum, Ilex, Myrsine, Podocarpus, Symplocos, Weinmannia, Myrtaceae, Ericaceae and Arecaceae. Past connectivity patterns between these two neotropical regions as well as individual ecological niches during the LGM were explored by cluster analysis of fossil assemblages and modern plant distributions. Additionally, we examined the ecological niche of 137 plant species with shared distributions between the Andes and coastal Brazil. Our results revealed five complex connectivity patterns for South American vegetation linking Andean, Amazonian and Atlantic Forests and one disjunction distribution in southern Chile. This study also provides a better understanding of vegetation cover on the large and shallow South American continental shelf that was exposed due to a global sea level drop.
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Affiliation(s)
- Jorge Luiz Diaz Pinaya
- Institute of Geosciences, University of São Paulo, São Paulo, Brazil.
- Polytechnic School, University of São Paulo, São Paulo, Brazil.
| | - Nigel C A Pitman
- Science Action, The Field Museum of Natural History, Chicago, IL, USA
| | | | - Thomas K Akabane
- Institute of Geosciences, University of São Paulo, São Paulo, Brazil
| | | | - Augusto José Pereira-Filho
- Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, São Paulo, Brazil
| | - Carlos H Grohman
- Institute of Energy and Environment, University of São Paulo, São Paulo, Brazil
| | - Luiza Santos Reis
- Institute of Geosciences, University of São Paulo, São Paulo, Brazil
| | | | | | - Paulo Eduardo De Oliveira
- Institute of Geosciences, University of São Paulo, São Paulo, Brazil.
- Science Action, The Field Museum of Natural History, Chicago, IL, USA.
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2
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Liu Z, Bao Y, Thompson LG, Mosley-Thompson E, Tabor C, Zhang GJ, Yan M, Lofverstrom M, Montanez I, Oster J. Tropical mountain ice core δ 18O: A Goldilocks indicator for global temperature change. SCIENCE ADVANCES 2023; 9:eadi6725. [PMID: 37939192 PMCID: PMC10631737 DOI: 10.1126/sciadv.adi6725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 10/12/2023] [Indexed: 11/10/2023]
Abstract
Very high tropical alpine ice cores provide a distinct paleoclimate record for climate changes in the middle and upper troposphere. However, the climatic interpretation of a key proxy, the stable water oxygen isotopic ratio in ice cores (δ18Oice), remains an outstanding problem. Here, combining proxy records with climate models, modern satellite measurements, and radiative-convective equilibrium theory, we show that the tropical δ18Oice is an indicator of the temperature of the middle and upper troposphere, with a glacial cooling of -7.35° ± 1.1°C (66% CI). Moreover, it severs as a "Goldilocks-type" indicator of global mean surface temperature change, providing the first estimate of glacial stage cooling that is independent of marine proxies as -5.9° ± 1.2°C. Combined with all estimations available gives the maximum likelihood estimate of glacial cooling as -5.85° ± 0.51°C.
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Affiliation(s)
- Zhengyu Liu
- Department of Geography, Ohio State University, Columbus, OH, USA
- School of Geography Science, Nanjing Normal University, Nanjing, China
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
| | - Yuntao Bao
- Department of Geography, Ohio State University, Columbus, OH, USA
| | - Lonnie G. Thompson
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
- School of Earth Sciences, Ohio State University, Columbus, OH, USA
| | - Ellen Mosley-Thompson
- Department of Geography, Ohio State University, Columbus, OH, USA
- Byrd Polar and Climate Research Center, Ohio State University, Columbus, OH, USA
| | - Clay Tabor
- Department of Earth Sciences, University of Connecticut, Storrs, CT, USA
| | - Guang J. Zhang
- Scripps Institute of Oceanography, University of California, San Diego, San Diego, CA, USA
| | - Mi Yan
- School of Geography Science, Nanjing Normal University, Nanjing, China
| | | | - Isabel Montanez
- Department of Earth and Planetary Sciences, University of California–Davis, Davis, CA, USA
| | - Jessica Oster
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA
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3
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Jaramillo C. The evolution of extant South American tropical biomes. THE NEW PHYTOLOGIST 2023; 239:477-493. [PMID: 37103892 DOI: 10.1111/nph.18931] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/26/2023] [Indexed: 06/15/2023]
Abstract
This review explores the evolution of extant South American tropical biomes, focusing on when and why they developed. Tropical vegetation experienced a radical transformation from being dominated by non-angiosperms at the onset of the Cretaceous to full angiosperm dominance nowadays. Cretaceous tropical biomes do not have extant equivalents; lowland forests, dominated mainly by gymnosperms and ferns, lacked a closed canopy. This condition was radically transformed following the massive extinction event at the Cretaceous-Paleogene boundary. The extant lowland tropical rainforests first developed at the onset of the Cenozoic with a multistratified forest, an angiosperm-dominated closed canopy, and the dominance of the main families of the tropics including legumes. Cenozoic rainforest diversity has increased during global warming and decreased during global cooling. Tropical dry forests emerged at least by the late Eocene, whereas other Neotropical biomes including tropical savannas, montane forests, páramo/puna, and xerophytic forest are much younger, greatly expanding during the late Neogene, probably at the onset of the Quaternary, at the expense of the rainforest.
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Affiliation(s)
- Carlos Jaramillo
- Smithsonian Tropical Research Institute, Apartado 0843-03092, Balboa, Ancón, Panama City, Panama
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4
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Abstract
Our understanding of the climatic teleconnections that drove ice-age cycles has been limited by a paucity of well-dated tropical records of glaciation that span several glacial–interglacial intervals. Glacial deposits offer discrete snapshots of glacier extent but cannot provide the continuous records required for detailed interhemispheric comparisons. By contrast, lakes located within glaciated catchments can provide continuous archives of upstream glacial activity, but few such records extend beyond the last glacial cycle. Here a piston core from Lake Junín in the uppermost Amazon basin provides the first, to our knowledge, continuous, independently dated archive of tropical glaciation spanning 700,000 years. We find that tropical glaciers tracked changes in global ice volume and followed a clear approximately 100,000-year periodicity. An enhancement in the extent of tropical Andean glaciers relative to global ice volume occurred between 200,000 and 400,000 years ago, during sustained intervals of regionally elevated hydrologic balance that modified the regular approximately 23,000-year pacing of monsoon-driven precipitation. Millennial-scale variations in the extent of tropical Andean glaciers during the last glacial cycle were driven by variations in regional monsoon strength that were linked to temperature perturbations in Greenland ice cores1; these interhemispheric connections may have existed during previous glacial cycles. Analysis of a continuous and independently dated record of glaciation in the tropical Andes spanning 700,000 years shows that Andean glaciation follows patterns of global ice volume change, with a periodicity of approximately 100,000 years.
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5
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González-Pinilla FJ, Latorre C, Rojas M, Houston J, Rocuant MI, Maldonado A, Santoro CM, Quade J, Betancourt JL. High- and low-latitude forcings drive Atacama Desert rainfall variations over the past 16,000 years. SCIENCE ADVANCES 2021; 7:eabg1333. [PMID: 34533988 PMCID: PMC8448445 DOI: 10.1126/sciadv.abg1333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Accepted: 07/27/2021] [Indexed: 06/13/2023]
Abstract
Late Quaternary precipitation dynamics in the central Andes have been linked to both high- and low-latitude atmospheric teleconnections. We use present-day relationships between fecal pellet diameters from ashy chinchilla rats (Abrocoma cinerea) and mean annual rainfall to reconstruct the timing and magnitude of pluvials (wet episodes) spanning the past 16,000 years in the Atacama Desert based on 81 14C-dated A. cinerea paleomiddens. A transient climate simulation shows that pluvials identified at 15.9 to 14.8, 13.0 to 8.6, and 8.1 to 7.6 ka B.P. can be linked to North Atlantic (high-latitude) forcing (e.g., Heinrich Stadial 1, Younger Dryas, and Bond cold events). Holocene pluvials at 5.0 to 4.6, 3.2 to 2.1, and 1.4 to 0.7 ka B.P. are not simulated, implying low-latitude internal variability forcing (i.e., ENSO regime shifts). These results help constrain future central Andean hydroclimatic variability and hold promise for reconstructing past climates from rodent middens in desert ecosystems worldwide.
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Affiliation(s)
- Francisco J. González-Pinilla
- Centro UC Desierto de Atacama and Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute of Ecology and Biodiversity (IEB), Santiago, Chile
| | - Claudio Latorre
- Centro UC Desierto de Atacama and Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute of Ecology and Biodiversity (IEB), Santiago, Chile
| | - Maisa Rojas
- Center for Climate and Resilience Research (CR) and Departamento de Geofísica, Universidad de Chile, Santiago, Chile
| | | | - M. Ignacia Rocuant
- Centro UC Desierto de Atacama and Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Antonio Maldonado
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Universidad de La Serena, La Serena, Chile
- Departamento de Biología Marina, Universidad Católica del Norte, Coquimbo, Chile
| | - Calogero M. Santoro
- Instituto de Alta Investigación (IAI), Universidad de Tarapacá, Arica, Chile
| | - Jay Quade
- Department of Geosciences, The University of Arizona, Tucson, AZ, USA
| | - Julio L. Betancourt
- Scientist Emeritus, U.S. Geological Survey, Science and Decisions Center, Reston, VA, USA
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Hippe K, Jansen JD, Skov DS, Lupker M, Ivy-Ochs S, Kober F, Zeilinger G, Capriles JM, Christl M, Maden C, Vockenhuber C, Egholm DL. Cosmogenic in situ 14C- 10Be reveals abrupt Late Holocene soil loss in the Andean Altiplano. Nat Commun 2021; 12:2546. [PMID: 33953195 PMCID: PMC8099901 DOI: 10.1038/s41467-021-22825-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 03/29/2021] [Indexed: 02/03/2023] Open
Abstract
Soil sustainability is reflected in a long-term balance between soil production and erosion for a given climate and geology. Here we evaluate soil sustainability in the Andean Altiplano where accelerated erosion has been linked to wetter climate from 4.5 ka and the rise of Neolithic agropastoralism in the millennium that followed. We measure in situ cosmogenic 14C directly on cultivated hilltops to quantify late Holocene soil loss, which we compare with background soil production rates determined from cosmogenic 26Al and 10Be. Our Monte Carlo-based inversion method identifies two scenarios to account for our data: an increase in erosion rate by 1-2 orders of magnitude between ~2.6 and 1.1 ka, or a discrete event stripping ~1-2 m of soil between ~1.9 and 1.1 ka. Coupled environmental and cultural factors in the Late Holocene signaled the onset of the pervasive human imprint in the Andean Altiplano seen today.
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Affiliation(s)
- Kristina Hippe
- grid.5801.c0000 0001 2156 2780Laboratory of Ion Beam Physics, ETH Zürich, Zürich, Switzerland ,grid.14095.390000 0000 9116 4836Institute of Geological Sciences, Freie Universität Berlin, Berlin, Germany
| | - John D. Jansen
- grid.418095.10000 0001 1015 3316GFÚ Institute of Geophysics, Czech Academy of Sciences, Prague, Czechia
| | | | - Maarten Lupker
- grid.5801.c0000 0001 2156 2780Geological Institute, ETH Zürich, Zürich, Switzerland
| | - Susan Ivy-Ochs
- grid.5801.c0000 0001 2156 2780Laboratory of Ion Beam Physics, ETH Zürich, Zürich, Switzerland
| | - Florian Kober
- grid.425451.30000 0004 0449 1417National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen, Switzerland
| | - Gerold Zeilinger
- grid.11348.3f0000 0001 0942 1117Institute of Geosciences, University of Potsdam, Potsdam, Germany
| | - José Mariano Capriles
- grid.29857.310000 0001 2097 4281Department of Anthropology, Pennsylvania State University, State College, USA
| | - Marcus Christl
- grid.5801.c0000 0001 2156 2780Laboratory of Ion Beam Physics, ETH Zürich, Zürich, Switzerland
| | - Colin Maden
- grid.5801.c0000 0001 2156 2780Institute of Geochemistry and Petrology, ETH Zürich, Zürich, Switzerland
| | - Christof Vockenhuber
- grid.5801.c0000 0001 2156 2780Laboratory of Ion Beam Physics, ETH Zürich, Zürich, Switzerland
| | - David Lundbek Egholm
- grid.7048.b0000 0001 1956 2722Department of Geoscience, Aarhus University, Aarhus, Denmark
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7
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Woods A, Rodbell DT, Abbott MB, Hatfield RG, Chen CY, Lehmann SB, McGee D, Weidhaas NC, Tapia PM, Valero-Garcés BL, Bush MB, Stoner JS. Andean drought and glacial retreat tied to Greenland warming during the last glacial period. Nat Commun 2020; 11:5135. [PMID: 33046707 PMCID: PMC7552390 DOI: 10.1038/s41467-020-19000-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 09/25/2020] [Indexed: 11/25/2022] Open
Abstract
Abrupt warming events recorded in Greenland ice cores known as Dansgaard-Oeschger (DO) interstadials are linked to changes in tropical circulation during the last glacial cycle. Corresponding variations in South American summer monsoon (SASM) strength are documented, most commonly, in isotopic records from speleothems, but less is known about how these changes affected precipitation and Andean glacier mass balance. Here we present a sediment record spanning the last ~50 ka from Lake Junín (Peru) in the tropical Andes that has sufficient chronologic precision to document abrupt climatic events on a centennial-millennial time scale. DO events involved the near-complete disappearance of glaciers below 4700 masl in the eastern Andean cordillera and major reductions in the level of Peru’s second largest lake. Our results reveal the magnitude of the hydroclimatic disruptions in the highest reaches of the Amazon Basin that were caused by a weakening of the SASM during abrupt arctic warming. Accentuated warming in the Arctic could lead to significant reductions in the precipitation-evaporation balance of the southern tropical Andes with deleterious effects on this densely populated region of South America. How the abrupt warming events recorded in Greenland ice cores during the last glacial cycle have influenced the tropical climate is not well known. Here the authors present new lake sediment data from the Peruvian Andes that shows that these events resulted in rapid glacier retreat and large reductions in lake level.
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Affiliation(s)
- Arielle Woods
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Mark B Abbott
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Robert G Hatfield
- College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR, USA.,Department of Geological Sciences, University of Florida, Gainesville, FL, USA
| | - Christine Y Chen
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Sophie B Lehmann
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA
| | - David McGee
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nicholas C Weidhaas
- Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, USA
| | - Pedro M Tapia
- Instituto Nacional de Investigación en Glaciares y Ecosistemas de Montaña, Ancash, Peru
| | - Blas L Valero-Garcés
- Pyrenean Institute of Ecology, Spanish National Research Council, Zaragoza, Spain
| | - Mark B Bush
- Florida Institute of Technology, Melbourne, FL, USA
| | - Joseph S Stoner
- College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR, USA
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8
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Abstract
Results of five climate model simulation studies on the Younger Dryas cold event (YD) are compared with a focus on temperature and precipitation. Relative to the Bølling-Allerød interstadial (BA), the simulations show consistent annual cooling in Europe, Greenland, Alaska, North Africa and over the North Atlantic Ocean and Nordic Seas with maximum reduction of temperatures being simulated over the oceans, ranging from −25 °C to −6 °C. Warmer conditions were simulated in the interior of North America. In two experiments, the mid-to-high latitudes of the Southern Hemisphere were also warmer, associated with a strong bi-polar seesaw mechanism in response to a collapse of the Atlantic meridional overturning circulation (AMOC). The modelled YD-BA temperature response was in general agreement with proxy-based evidence. The simulations reveal reduced YD-BA precipitation (up to 150 mm yr−1) over all regions with major cooling, and over the northern equatorial region. South of the equator, modelled precipitation seemed to increase due to a southward shift of the InterTropical Convergence Zone (ITCZ). The largest uncertainty in the YD is the high-latitude response, where the models show diverging results. This disagreement is partly related to uncertainties in the freshwater forcing. Most model studies assume an AMOC shutdown, but this is incompatible with proxy evidence.
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9
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Beyond Refugia: New Insights on Quaternary Climate Variation and the Evolution of Biotic Diversity in Tropical South America. NEOTROPICAL DIVERSIFICATION: PATTERNS AND PROCESSES 2020. [DOI: 10.1007/978-3-030-31167-4_3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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10
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UAV Imaging of a Martian Brine Analogue Environment in a Fluvio-Aeolian Setting. REMOTE SENSING 2019. [DOI: 10.3390/rs11182104] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Understanding extraterrestrial environments and landforms through remote sensing and terrestrial analogy has gained momentum in recent years due to advances in remote sensing platforms, sensors, and computing efficiency. The seasonal brines of the largest salt plateau on Earth in Salar de Uyuni (Bolivian Altiplano) have been inadequately studied for their localized hydrodynamics and the regolith volume transport across the freshwater-brine mixing zones. These brines have recently been projected as a new analogue site for the proposed Martian brines, such as recurring slope lineae (RSL) and slope streaks. The Martian brines have been postulated to be the result of ongoing deliquescence-based salt-hydrology processes on contemporary Mars, similar to the studied Salar de Uyuni brines. As part of a field-site campaign during the cold and dry season in the latter half of August 2017, we deployed an unmanned aerial vehicle (UAV) at two sites of the Salar de Uyuni to perform detailed terrain mapping and geomorphometry. We generated high-resolution (2 cm/pixel) photogrammetric digital elevation models (DEMs) for observing and quantifying short-term terrain changes within the brines and their surroundings. The achieved co-registration for the temporal DEMs was considerably high, from which precise inferences regarding the terrain dynamics were derived. The observed average rate of bottom surface elevation change for brines was ~1.02 mm/day, with localized signs of erosion and deposition. Additionally, we observed short-term changes in the adjacent geomorphology and salt cracks. We conclude that the transferred regolith volume via such brines can be extremely low, well within the resolution limits of the remote sensors that are currently orbiting Mars, thereby making it difficult to resolve the topographic relief and terrain perturbations that are produced by such flows on Mars. Thus, the absence of observable erosion and deposition features within or around most of the proposed Martian RSL and slope streaks cannot be used to dismiss the possibility of fluidized flow within these features.
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12
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"Climatic fluctuations in the hyperarid core of the Atacama Desert during the past 215 ka". Sci Rep 2019; 9:5270. [PMID: 30918294 PMCID: PMC6437205 DOI: 10.1038/s41598-019-41743-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 03/08/2019] [Indexed: 11/08/2022] Open
Abstract
Paleoclimate records from the Atacama Desert are rare and mostly discontinuous, mainly recording runoff from the Precordillera to the east, rather than local precipitation. Until now, paleoclimate records have not been reported from the hyperarid core of the Atacama Desert (<2 mm/yr). Here we report the results from multi-disciplinary investigation of a 6.2 m drill core retrieved from an endorheic basin within the Coastal Cordillera. The record spans the last 215 ka and indicates that the long-term hyperarid climate in the Central Atacama witnessed small but significant changes in precipitation since the penultimate interglacial. Somewhat ‘wetter’ climate with enhanced erosion and transport of material into the investigated basin, commenced during interglacial times (MIS 7, MIS 5), whereas during glacial times (MIS 6, MIS 4–1) sediment transport into the catchment was reduced or even absent. Pelagic diatom assemblages even suggest the existence of ephemeral lakes in the basin. The reconstructed wetter phases are asynchronous with wet phases in the Altiplano but synchronous with increased sea-surface temperatures off the coasts of Chile and Peru, i.e. resembling modern El Niño-like conditions.
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13
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Maezumi SY, Robinson M, de Souza J, Urrego DH, Schaan D, Alves D, Iriarte J. New Insights From Pre-Columbian Land Use and Fire Management in Amazonian Dark Earth Forests. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00111] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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14
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Martin LCP, Blard PH, Lavé J, Condom T, Prémaillon M, Jomelli V, Brunstein D, Lupker M, Charreau J, Mariotti V, Tibari B, Davy E. Lake Tauca highstand (Heinrich Stadial 1a) driven by a southward shift of the Bolivian High. SCIENCE ADVANCES 2018; 4:eaar2514. [PMID: 30167458 PMCID: PMC6114991 DOI: 10.1126/sciadv.aar2514] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 07/20/2018] [Indexed: 06/08/2023]
Abstract
Heinrich events are characterized by worldwide climate modifications. Over the Altiplano endorheic basin (high tropical Andes), the second half of Heinrich Stadial 1 (HS1a) was coeval with the highstand of the giant paleolake Tauca. However, the atmospheric mechanisms underlying this wet event are still unknown at the regional to global scale. We use cosmic-ray exposure ages of glacial landforms to reconstruct the spatial variability in the equilibrium line altitude of the HS1a Altiplano glaciers. By combining glacier and lake modeling, we reconstruct a precipitation map for the HS1a period. Our results show that paleoprecipitation mainly increased along the Eastern Cordillera, whereas the southwestern region of the basin remained relatively dry. This pattern indicates a southward expansion of the easterlies, which is interpreted as being a consequence of a southward shift of the Bolivian High. The results provide a new understanding of atmospheric teleconnections during HS1 and of rainfall redistribution in a changing climate.
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Affiliation(s)
- Léo C. P. Martin
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
- Department of Geosciences, University of Oslo, P.O. Box 1047, Blindern, 0316 Oslo, Norway
| | - Pierre-Henri Blard
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
- Laboratoire de Glaciologie, Département Géosciences, Environnement et Société–Institut des Géosciences, Université Libre de Bruxelles, 1050 Brussels, Belgium
| | - Jérôme Lavé
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
| | - Thomas Condom
- Université de Grenoble Alpes, Institut de Recherche pour le Développement (IRD), CNRS, Institut des Géosciences de l’Environnement, F-38000 Grenoble, France
| | - Mélody Prémaillon
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
| | - Vincent Jomelli
- Université Paris 1 Panthéon-Sorbonne, CNRS Laboratoire de Géographie Physique, 92195 Meudon, France
| | - Daniel Brunstein
- Université Paris 1 Panthéon-Sorbonne, CNRS Laboratoire de Géographie Physique, 92195 Meudon, France
| | - Maarten Lupker
- ETH, Geological Institute, Sonneggstrasse 5, 8092 Zurich, Switzerland
| | - Julien Charreau
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
| | - Véronique Mariotti
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
| | - Bouchaïb Tibari
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
| | | | - Emmanuel Davy
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS–Université de Lorraine, 54500 Vandœuvre-lès-Nancy, France
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15
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dC Rubin SS, Marín I, Gómez MJ, Morales EA, Zekker I, San Martín-Uriz P, Rodríguez N, Amils R. Prokaryotic diversity and community composition in the Salar de Uyuni, a large scale, chaotropic salt flat. Environ Microbiol 2017; 19:3745-3754. [DOI: 10.1111/1462-2920.13876] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 07/16/2017] [Accepted: 07/24/2017] [Indexed: 12/29/2022]
Affiliation(s)
- Sergio S. dC Rubin
- Centro Nacional de Investigaciones Biotecnológicas; CNIB; Bolivia
- Departamento de Biología Molecular; Universidad Autónoma de Madrid, Cantoblanco; Madrid 28049 Spain
| | - Irma Marín
- Departamento de Biología Molecular; Universidad Autónoma de Madrid, Cantoblanco; Madrid 28049 Spain
| | - Manuel J. Gómez
- Centro Nacional de Investigaciones Cardiovasculares, Melchor Fernández Almagro 3; Madrid 28029 Spain
| | - Eduardo A. Morales
- Centro Nacional de Investigaciones Biotecnológicas; CNIB; Bolivia
- Herbario Criptogámico; Universidad Católica Boliviana; Cochabamba Bolivia
| | - Ivar Zekker
- Institute of Chemistry; University of Tartu; Tartu Estonia
| | | | - Nuria Rodríguez
- Centro de Astrobiología (INTA-CSIC), Torrejón de Ardoz; Madrid 28055 Spain
| | - Ricardo Amils
- Centro Nacional de Investigaciones Biotecnológicas; CNIB; Bolivia
- Centro de Astrobiología (INTA-CSIC), Torrejón de Ardoz; Madrid 28055 Spain
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM); Universidad Autónoma de Madrid; Madrid 28049 Spain
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16
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Novello VF, Cruz FW, Vuille M, Stríkis NM, Edwards RL, Cheng H, Emerick S, de Paula MS, Li X, Barreto EDS, Karmann I, Santos RV. A high-resolution history of the South American Monsoon from Last Glacial Maximum to the Holocene. Sci Rep 2017; 7:44267. [PMID: 28281650 PMCID: PMC5345026 DOI: 10.1038/srep44267] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 02/07/2017] [Indexed: 11/22/2022] Open
Abstract
The exact extent, by which the hydrologic cycle in the Neotropics was affected by external forcing during the last deglaciation, remains poorly understood. Here we present a new paleo-rainfall reconstruction based on high-resolution speleothem δ18O records from the core region of the South American Monsoon System (SAMS), documenting the changing hydrological conditions over tropical South America (SA), in particular during abrupt millennial-scale events. This new record provides the best-resolved and most accurately constrained geochronology of any proxy from South America for this time period, spanning from the Last Glacial Maximum (LGM) to the mid-Holocene.
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Affiliation(s)
- Valdir F Novello
- Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Francisco W Cruz
- Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Mathias Vuille
- Department of Atmospheric and Environmental Sciences, University at Albany, Albany, New York 12222, USA
| | - Nicolás M Stríkis
- Departamento de Geoquímica,Universidade Federal Fluminense, Niterói, Rio de Janeiro 24220-900, Brazil
| | - R Lawrence Edwards
- Department of Earth Sciences, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Hai Cheng
- Department of Earth Sciences, University of Minnesota, Minneapolis, Minnesota 55455, USA.,Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Suellyn Emerick
- Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Marcos S de Paula
- Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Xianglei Li
- Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an 710049, China
| | - Eline de S Barreto
- Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Ivo Karmann
- Instituto de Geociências, Universidade de São Paulo, São Paulo 05508-090, Brazil
| | - Roberto V Santos
- Instituto de Geociências, Universidade de Brasília, Brasília, Brazil
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17
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Haferburg G, Gröning JAD, Schmidt N, Kummer NA, Erquicia JC, Schlömann M. Microbial diversity of the hypersaline and lithium-rich Salar de Uyuni, Bolivia. Microbiol Res 2017; 199:19-28. [PMID: 28454706 DOI: 10.1016/j.micres.2017.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 02/25/2017] [Indexed: 10/20/2022]
Abstract
Salar de Uyuni, situated in the Southwest of the Bolivian Altiplano, is the largest salt flat on Earth. Brines of this athalassohaline hypersaline environment are rich in lithium and boron. Due to the ever- increasing commodity demand, the industrial exploitation of brines for metal recovery from the world's biggest lithium reservoir is likely to increase substantially in the near future. Studies on the composition of halophilic microbial communities in brines of the salar have not been published yet. Here we report for the first time on the prokaryotic diversity of four brine habitats across the salar. The brine is characterized by salinity values between 132 and 177 PSU, slightly acidic to near-neutral pH and lithium and boron concentrations of up to 2.0 and 1.4g/L, respectively. Community analysis was performed after sequencing the V3-V4 region of the 16S rRNA genes employing the Illumina MiSeq technology. The mothur software package was used for sequence processing and data analysis. Metagenomic analysis revealed the occurrence of an exclusively archaeal community comprising 26 halobacterial genera including only recently identified genera like Halapricum, Halorubellus and Salinarchaeum. Despite the high diversity of the halobacteria-dominated community in sample P3 (Shannon-Weaver index H'=3.12 at 3% OTU cutoff) almost 40% of the Halobacteriaceae-assigned sequences could not be classified on the genus level under stringent filtering conditions. Even if the limited taxonomic resolution of the V3-V4 region for halobacteria is considered, it seems likely to discover new, hitherto undescribed genera of the family halobacteriaceae in this particular habitat of Salar de Uyuni in future.
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Affiliation(s)
- Götz Haferburg
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany.
| | | | - Nadja Schmidt
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | - Nicolai-Alexeji Kummer
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | | | - Michael Schlömann
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany
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18
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Glacial refugia and the prediction of future habitat coverage of the South American lichen species Ochrolechia austroamericana. Sci Rep 2016; 6:38779. [PMID: 27929090 PMCID: PMC5144090 DOI: 10.1038/srep38779] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 11/14/2016] [Indexed: 11/24/2022] Open
Abstract
The biogeographic history of lichenized fungi remains unrevealed because those organisms rarely fossilize due to their delicate, often tiny and quickly rotting thalli. Also the ecology and factors limiting occurrence of numerous taxa, especially those restricted in their distribution to tropical areas are poorly recognized. The aim of this study was to determine localization of glacial refugia of South American Ochrolechia austroamericana and to estimate the future changes in the coverage of its habitats using ecological niche modeling tools. The general glacial potential range of the studied species was wider than it is nowadays and its niches coverage decreased by almost 25% since last glacial maximum. The refugial areas were covered by cool and dry grasslands and scrubs and suitable niches in South America were located near the glacier limit. According to our analyses the further climate changes will not significantly influence the distribution of the suitable niches of O. austroamericana.
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19
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Solar Output Controls Periodicity in Lake Productivity and Wetness at Southernmost South America. Sci Rep 2016; 6:37521. [PMID: 27869191 PMCID: PMC5116613 DOI: 10.1038/srep37521] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 10/31/2016] [Indexed: 11/08/2022] Open
Abstract
Cyclic changes in total solar irradiance (TSI) during the Holocene are known to affect global climatic conditions and cause cyclic climatic oscillations, e.g., Bond events and related changes of environmental conditions. However, the processes how changes in TSI affect climate and environment of the Southern Hemisphere, especially in southernmost South America, a key area for the global climate, are still poorly resolved. Here we show that highly sensitive proxies for aquatic productivity derived from sediments of a lake near the Chilean South Atlantic coast (53 °S) strongly match the cyclic changes in TSI throughout the Holocene. Intra-lake productivity variations show a periodicity of ~200-240 years coherent with the time series of TSI-controlled cosmogenic nuclide 10Be production. In addition TSI dependent periodicity of Bond events (~1500 years) appear to control wetness at the LH site indicated by mineral matter erosion from the catchment to the lake assumingly through shifts of the position of the southern westerly wind belt. Thus, both intra-lake productivity and wetness at the southernmost South America are directly or indirectly controlled by TSI.
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20
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21
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Effects of large-scale deforestation on precipitation in the monsoon regions: remote versus local effects. Proc Natl Acad Sci U S A 2015; 112:3257-62. [PMID: 25733889 DOI: 10.1073/pnas.1423439112] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this paper, using idealized climate model simulations, we investigate the biogeophysical effects of large-scale deforestation on monsoon regions. We find that the remote forcing from large-scale deforestation in the northern middle and high latitudes shifts the Intertropical Convergence Zone southward. This results in a significant decrease in precipitation in the Northern Hemisphere monsoon regions (East Asia, North America, North Africa, and South Asia) and moderate precipitation increases in the Southern Hemisphere monsoon regions (South Africa, South America, and Australia). The magnitude of the monsoonal precipitation changes depends on the location of deforestation, with remote effects showing a larger influence than local effects. The South Asian Monsoon region is affected the most, with 18% decline in precipitation over India. Our results indicate that any comprehensive assessment of afforestation/reforestation as climate change mitigation strategies should carefully evaluate the remote effects on monsoonal precipitation alongside the large local impacts on temperatures.
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22
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Rademaker K, Hodgins G, Moore K, Zarrillo S, Miller C, Bromley GRM, Leach P, Reid DA, Álvarez WY, Sandweiss DH. Paleoindian settlement of the high-altitude Peruvian Andes. Science 2014; 346:466-9. [PMID: 25342802 DOI: 10.1126/science.1258260] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Study of human adaptation to extreme environments is important for understanding our cultural and genetic capacity for survival. The Pucuncho Basin in the southern Peruvian Andes contains the highest-altitude Pleistocene archaeological sites yet identified in the world, about 900 meters above confidently dated contemporary sites. The Pucuncho workshop site [4355 meters above sea level (masl)] includes two fishtail projectile points, which date to about 12.8 to 11.5 thousand years ago (ka). Cuncaicha rock shelter (4480 masl) has a robust, well-preserved, and well-dated occupation sequence spanning the past 12.4 thousand years (ky), with 21 dates older than 11.5 ka. Our results demonstrate that despite cold temperatures and low-oxygen conditions, hunter-gatherers colonized extreme high-altitude Andean environments in the Terminal Pleistocene, within about 2 ky of the initial entry of humans to South America.
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Affiliation(s)
- Kurt Rademaker
- Department of Anthropology, South Stevens Hall, University of Maine, Orono, ME 04469-5773, USA. Department of Early Prehistory and Quaternary Ecology, Schloß Hohentübingen, Burgsteige 11, 72070 Tübingen, Germany. Climate Change Institute, Bryand Global Sciences Center, University of Maine, Orono, ME 04469, USA.
| | - Gregory Hodgins
- Accelerator Mass Spectrometry Laboratory, Department of Physics and School of Anthropology, University of Arizona, Tucson, AZ 85721, USA
| | - Katherine Moore
- University of Pennsylvania Museum, 3260 South Street, Philadelphia, PA 19104, USA
| | - Sonia Zarrillo
- Department of Anthropology and Archaeology, Earth Sciences Building, Room 806, 844 Campus Place Northwest, Calgary, British Columbia, Canada
| | - Christopher Miller
- Institute for Archaeological Sciences, University of Tübingen, Rümelinstrasse 23, 72070 Tübingen, Germany. Senckenberg Centre for Human Evolution and Paleoenvironment, University of Tübingen, Rümelinstrasse 23, 72070 Tübingen, Germany
| | - Gordon R M Bromley
- Climate Change Institute, Bryand Global Sciences Center, University of Maine, Orono, ME 04469, USA
| | - Peter Leach
- Department of Anthropology, 354 Mansfield Road, University of Connecticut, Storrs, CT 06269-1176, USA
| | - David A Reid
- Department of Anthropology, University of Illinois at Chicago, Behavioral Sciences Building, 1007 West Harrison Street, Chicago, IL 60607-7139, USA
| | | | - Daniel H Sandweiss
- Department of Anthropology, South Stevens Hall, University of Maine, Orono, ME 04469-5773, USA. Climate Change Institute, Bryand Global Sciences Center, University of Maine, Orono, ME 04469, USA
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23
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Migrations and dynamics of the intertropical convergence zone. Nature 2014; 513:45-53. [PMID: 25186899 DOI: 10.1038/nature13636] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 07/01/2014] [Indexed: 11/08/2022]
Abstract
Rainfall on Earth is most intense in the intertropical convergence zone (ITCZ), a narrow belt of clouds centred on average around six degrees north of the Equator. The mean position of the ITCZ north of the Equator arises primarily because the Atlantic Ocean transports energy northward across the Equator, rendering the Northern Hemisphere warmer than the Southern Hemisphere. On seasonal and longer timescales, the ITCZ migrates, typically towards a warming hemisphere but with exceptions, such as during El Niño events. An emerging framework links the ITCZ to the atmospheric energy balance and may account for ITCZ variations on timescales from years to geological epochs.
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24
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Zhang X, Lohmann G, Knorr G, Purcell C. Abrupt glacial climate shifts controlled by ice sheet changes. Nature 2014; 512:290-4. [DOI: 10.1038/nature13592] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 06/10/2014] [Indexed: 11/09/2022]
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25
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Orbital pacing and ocean circulation-induced collapses of the Mesoamerican monsoon over the past 22,000 y. Proc Natl Acad Sci U S A 2013; 110:9255-60. [PMID: 23690596 DOI: 10.1073/pnas.1222804110] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dominant controls on global paleomonsoon strength include summer insolation driven by precession cycles, ocean circulation through its influence on atmospheric circulation, and sea-surface temperatures. However, few records from the summer North American Monsoon system are available to test for a synchronous response with other global monsoons to shared forcings. In particular, the monsoon response to widespread atmospheric reorganizations associated with disruptions of the Atlantic Meridional Overturning Circulation (AMOC) during the deglacial period remains unconstrained. Here, we present a high-resolution and radiometrically dated monsoon rainfall reconstruction over the past 22,000 y from speleothems of tropical southwestern Mexico. The data document an active Last Glacial Maximum (18-24 cal ka B.P.) monsoon with similar δ(18)O values to the modern, and that the monsoon collapsed during periods of weakened AMOC during Heinrich stadial 1 (ca. 17 ka) and the Younger Dryas (12.9-11.5 ka). The Holocene was marked by a trend to a weaker monsoon that was paced by orbital insolation. We conclude that the Mesoamerican monsoon responded in concert with other global monsoon regions, and that monsoon strength was driven by variations in the strength and latitudinal position of the Intertropical Convergence Zone, which was forced by AMOC variations in the North Atlantic Ocean. The surprising observation of an active Last Glacial Maximum monsoon is attributed to an active but shallow AMOC and proximity to the Intertropical Convergence Zone. The emergence of agriculture in southwestern Mexico was likely only possible after monsoon strengthening in the Early Holocene at ca. 11 ka.
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26
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Salazar-Bravo J, Pardiñas UFJ, D'Elía G. A phylogenetic appraisal of Sigmodontinae (Rodentia, Cricetidae) with emphasis on phyllotine genera: systematics and biogeography. ZOOL SCR 2013. [DOI: 10.1111/zsc.12008] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jorge Salazar-Bravo
- Department of Biological Sciences; Texas Tech University; Lubbock; TX; 79409; USA
| | - Ulyses F. J. Pardiñas
- Unidad de Investigación Diversidad; Sistemática y Evolución; Centro Nacional Patagónico; Puerto Madryn; Argentina
| | - Guillermo D'Elía
- Instituto de Ciencias Ambientales y Evolutivas; Universidad Austral de Chile; Valdivia; Chile
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27
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Ramírez-Barahona S, Eguiarte LE. The role of glacial cycles in promoting genetic diversity in the Neotropics: the case of cloud forests during the Last Glacial Maximum. Ecol Evol 2013; 3:725-38. [PMID: 23531632 PMCID: PMC3605859 DOI: 10.1002/ece3.483] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 12/06/2012] [Accepted: 12/11/2012] [Indexed: 11/30/2022] Open
Abstract
The increasing aridity during the Last Glacial Maximum (LGM) has been proposed as a major factor affecting Neotropical species. The character and intensity of this change, however, remains the subject of ongoing debate. This review proposes an approach to test contrasting paleoecological hypotheses by way of their expected demographic and genetic effects on Neotropical cloud forest species. We reviewed 48 paleoecological records encompassing the LGM in the Neotropics. The records show contrasting evidence regarding the changes in precipitation during this period. Some regions remained fairly moist and others had a significantly reduced precipitation. Many paleoecological records within the same region show apparently conflicting evidence on precipitation and forest stability. From these data, we propose and outline two demographic/genetic scenarios for cloud forests species based on opposite precipitation regimes: the dry refugia and the moist forests hypotheses. We searched for studies dealing with the population genetic structure of cloud forest and other montane taxa and compared their results with the proposed models. To date, the few available molecular studies show insufficient genetic evidence on the predominance of glacial aridity in the Neotropics. In order to disentangle the climatic history of the Neotropics, the present study calls for a general multi-disciplinary approach to conduct future phylogeographic studies. Given the contradictory paleoecological information, population genetic data on Neotropical cloud forest species should be used to explicitly test the genetic consequences of competing paleoecological models.
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Affiliation(s)
- Santiago Ramírez-Barahona
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México Mexico City, Mexico
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28
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Clark PU, Shakun JD, Baker PA, Bartlein PJ, Brewer S, Brook E, Carlson AE, Cheng H, Kaufman DS, Liu Z, Marchitto TM, Mix AC, Morrill C, Otto-Bliesner BL, Pahnke K, Russell JM, Whitlock C, Adkins JF, Blois JL, Clark J, Colman SM, Curry WB, Flower BP, He F, Johnson TC, Lynch-Stieglitz J, Markgraf V, McManus J, Mitrovica JX, Moreno PI, Williams JW. Global climate evolution during the last deglaciation. Proc Natl Acad Sci U S A 2012; 109:E1134-42. [PMID: 22331892 PMCID: PMC3358890 DOI: 10.1073/pnas.1116619109] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Deciphering the evolution of global climate from the end of the Last Glacial Maximum approximately 19 ka to the early Holocene 11 ka presents an outstanding opportunity for understanding the transient response of Earth's climate system to external and internal forcings. During this interval of global warming, the decay of ice sheets caused global mean sea level to rise by approximately 80 m; terrestrial and marine ecosystems experienced large disturbances and range shifts; perturbations to the carbon cycle resulted in a net release of the greenhouse gases CO(2) and CH(4) to the atmosphere; and changes in atmosphere and ocean circulation affected the global distribution and fluxes of water and heat. Here we summarize a major effort by the paleoclimate research community to characterize these changes through the development of well-dated, high-resolution records of the deep and intermediate ocean as well as surface climate. Our synthesis indicates that the superposition of two modes explains much of the variability in regional and global climate during the last deglaciation, with a strong association between the first mode and variations in greenhouse gases, and between the second mode and variations in the Atlantic meridional overturning circulation.
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Affiliation(s)
- Peter U. Clark
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331
| | - Jeremy D. Shakun
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138
| | - Paul A. Baker
- Division of Earth and Ocean Sciences, Duke University, Durham, NC 27708
| | | | - Simon Brewer
- Department of Geography, University of Utah, Salt Lake City, UT 84112
| | - Ed Brook
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331
| | - Anders E. Carlson
- Department of Geoscience, University of Wisconsin, Madison, WI 53706
- Center for Climatic Research, University of Wisconsin, Madison, WI 53706
| | - Hai Cheng
- Institute of Global Environmental Change, Xi’an Jiaotong University, Xi’an 710049, China
- Department of Geology and Geophysics, University of Minnesota, Minneapolis, MN 55455
| | - Darrell S. Kaufman
- School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff, AZ 86011
| | - Zhengyu Liu
- Center for Climatic Research, University of Wisconsin, Madison, WI 53706
- Laboratory for Ocean-Atmosphere Studies, School of Physics, Peking University, Beijing 100871, China
| | - Thomas M. Marchitto
- Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309
| | - Alan C. Mix
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331
| | - Carrie Morrill
- National Oceanic and Atmospheric Administration National Climatic Data Center, Boulder, CO 80305
| | - Bette L. Otto-Bliesner
- Climate and Global Dynamics Division, National Center for Atmospheric Research, Boulder, CO 80307
| | - Katharina Pahnke
- Department of Geology and Geophysics, University of Hawaii, Honolulu, HI 96822
| | - James M. Russell
- Department of Geological Sciences, Brown University, Providence, RI 02912
| | - Cathy Whitlock
- Department of Earth Sciences, Montana State University, Bozeman, MT 97403
| | - Jess F. Adkins
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - Jessica L. Blois
- Center for Climatic Research, University of Wisconsin, Madison, WI 53706
- Department of Geography, University of Wisconsin, Madison, WI 53706
| | - Jorie Clark
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331
| | - Steven M. Colman
- Large Lakes Observatory and Department Geological Sciences, University of Minnesota, Duluth, MN 55812
| | - William B. Curry
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543
| | - Ben P. Flower
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701
| | - Feng He
- Center for Climatic Research, University of Wisconsin, Madison, WI 53706
| | - Thomas C. Johnson
- Large Lakes Observatory and Department Geological Sciences, University of Minnesota, Duluth, MN 55812
| | - Jean Lynch-Stieglitz
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Vera Markgraf
- School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff, AZ 86011
| | - Jerry McManus
- Lamont-Doherty Earth Observatory, Palisades, NY 10964; and
| | - Jerry X. Mitrovica
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138
| | - Patricio I. Moreno
- Institute of Ecology and Biodiversity and Department of Ecological Sciences, Universidad de Chile, Santiago 1058, Chile
| | - John W. Williams
- Department of Geography, University of Wisconsin, Madison, WI 53706
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Rodbell DT. Marching in Near Lock-Step. Science 2012; 335:548-9. [DOI: 10.1126/science.1218365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A cave record from Peru closely matches climate patterns seen in cores from Greenland and the North Atlantic Ocean.
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A 2,300-year-long annually resolved record of the South American summer monsoon from the Peruvian Andes. Proc Natl Acad Sci U S A 2011; 108:8583-8. [PMID: 21555548 DOI: 10.1073/pnas.1003719108] [Citation(s) in RCA: 194] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Decadal and centennial mean state changes in South American summer monsoon (SASM) precipitation during the last 2,300 years are detailed using an annually resolved authigenic calcite record of precipitation δ(18)O from a varved lake in the Central Peruvian Andes. This unique sediment record shows that δ(18)O peaked during the Medieval Climate Anomaly (MCA) from A.D. 900 to 1100, providing evidence that the SASM weakened considerably during this period. Minimum δ(18)O values occurred during the Little Ice Age (LIA) between A.D. 1400 and 1820, reflecting a prolonged intensification of the SASM that was regionally synchronous. After the LIA, δ(18)O increased rapidly, particularly during the current warm period (CWP; A.D. 1900 to present), indicating a return to reduced SASM precipitation that was more abrupt and sustained than the onset of the MCA. Diminished SASM precipitation during the MCA and CWP tracks reconstructed Northern Hemisphere and North Atlantic warming and a northward displacement of the Intertropical Convergence Zone (ITCZ) over the Atlantic, and likely the Pacific. Intensified SASM precipitation during the LIA follows reconstructed Northern Hemisphere and North Atlantic cooling, El Niño-like warming in the Pacific, and a southward displacement of the ITCZ over both oceans. These results suggest that SASM mean state changes are sensitive to ITCZ variability as mediated by Western Hemisphere tropical sea surface temperatures, particularly in the Atlantic. Continued Northern Hemisphere and North Atlantic warming may therefore help perpetuate the recent reductions in SASM precipitation that characterize the last 100 years, which would negatively impact Andean water resources.
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31
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De la Riva I, García-París M, Parra-Olea G. Systematics of Bolivian frogs of the genusTelmatobius(Anura, Ceratophryidae) based on mtDNA sequences. SYST BIODIVERS 2010. [DOI: 10.1080/14772000903526454] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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South American Climate Variability and Change: Remote and Regional Forcing Processes. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/978-90-481-2672-9_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Sylvestre F. Moisture Pattern During the Last Glacial Maximum in South America. PAST CLIMATE VARIABILITY IN SOUTH AMERICA AND SURROUNDING REGIONS 2009. [DOI: 10.1007/978-90-481-2672-9_1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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34
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Silva Dias PL, Turcq B, Silva Dias MAF, Braconnot P, Jorgetti T. Mid-Holocene Climate of Tropical South America: A Model-Data Approach. PAST CLIMATE VARIABILITY IN SOUTH AMERICA AND SURROUNDING REGIONS 2009. [DOI: 10.1007/978-90-481-2672-9_11] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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35
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Baker PA, Fritz SC, Burns SJ, Ekdahl E, Rigsby CA. The Nature and Origin of Decadal to Millennial Scale Climate Variability in the Southern Tropics of South America: The Holocene Record of Lago Umayo, Peru. PAST CLIMATE VARIABILITY IN SOUTH AMERICA AND SURROUNDING REGIONS 2009. [DOI: 10.1007/978-90-481-2672-9_13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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36
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Manners RB, Magilligan FJ, Goldstein PS. Floodplain Development, El Niño, and Cultural Consequences in a Hyperarid Andean Environment. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1467-8306.2007.00533.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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37
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Cook KH, Vizy EK. South American climate during the Last Glacial Maximum: Delayed onset of the South American monsoon. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jd005980] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Bush MB, Oliveira PED. The rise and fall of the Refugial Hypothesis of Amazonian speciation: a paleoecological perspective. BIOTA NEOTROPICA 2006. [DOI: 10.1590/s1676-06032006000100002] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The refugial hypothesis is treated as the definitive history of Amazonian forests in many texts. Surprisingly, this important theoretical framework has not been based on paleoecological data. Consequently, a model of Amazonian aridity during the northern hemispheric glaciation has been accepted uncritically. Ironically, the Refuge Hypothesis has not been tested by paleobotanical data. We present a revision of the concept of Neotropical Pleistocene Forest Refuges and test it in the light of paleocological studies derived from pollen analysis of Amazonian lake sediments deposited during the last 20,000 years. Our analysis is based primarily on paleoenvironmental data obtained from sites in Brazil and Ecuador. These data are contrasted with those that favor the hypothesis of fragmented tropical forests in a landscape dominated mainly by tropical savannas under an arid climate. The Ecuadorian data set strongly suggests a 5ºC cooling and presence of humid forests at the foot of the Andes, during the last Ice Age. The same climatic and vegetational scenario was found in the western Brazilian Amazon. On the other hand, somewhat drier conditions were observed in the central Amazon, but the landscape remained a forested landscape during the supposedly arid phases of the Late Quaternary. Data obtained from the Amazon Fan sediments containing pollen derived from extensive sections of the Amazon Basin, were fundamental to the conclusion that the predominance of savannas in this region is not supported by botanical data. Our revision of the assumptions derived from the Refuge Hypothesis indicates that it has succumbed to the test now permitted by a larger paleocological data set, which were not available during the golden age of this paradigm, when indirect evidence was considered satisfactory to support it.
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Smith JA, Seltzer GO, Farber DL, Rodbell DT, Finkel RC. Early Local Last Glacial Maximum in the Tropical Andes. Science 2005; 308:678-81. [PMID: 15860623 DOI: 10.1126/science.1107075] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The local last glacial maximum in the tropical Andes was earlier and less extensive than previously thought, based on 106 cosmogenic ages (from beryllium-10 dating) from moraines in Peru and Bolivia. Glaciers reached their greatest extent in the last glacial cycle approximately 34,000 years before the present and were retreating by approximately 21,000 years before the present, implying that tropical controls on ice volumes were asynchronous with those in the Northern Hemisphere. Our estimates of snowline depression reflect about half the temperature change indicated by previous widely cited figures, which helps resolve the discrepancy between estimates of terrestrial and marine temperature depression during the last glacial cycle.
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Affiliation(s)
- Jacqueline A Smith
- 204 Heroy Geology Laboratory, Department of Earth Sciences, Syracuse University, Syracuse, NY 13244-1070, USA.
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40
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Wang X, Auler AS, Edwards RL, Cheng H, Cristalli PS, Smart PL, Richards DA, Shen CC. Wet periods in northeastern Brazil over the past 210 kyr linked to distant climate anomalies. Nature 2005; 432:740-3. [PMID: 15592409 DOI: 10.1038/nature03067] [Citation(s) in RCA: 585] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Accepted: 09/28/2004] [Indexed: 11/08/2022]
Abstract
The tropics are the main source of the atmosphere's sensible and latent heat, and water vapour, and are therefore important for reconstructions of past climate. But long, accurately dated records of southern tropical palaeoclimate, which would allow the establishment of climatic connections to distant regions, have not been available. Here we present a 210,000-year (210-kyr) record of wet periods in tropical northeastern Brazil--a region that is currently semi-arid. The record is obtained from speleothems and travertine deposits that are accurately dated using the U/Th method. We find wet periods that are synchronous with periods of weak East Asian summer monsoons, cold periods in Greenland, Heinrich events in the North Atlantic and periods of decreased river runoff to the Cariaco basin. We infer that the wet periods may be explained with a southward displacement of the Intertropical Convergence Zone. This widespread synchroneity of climate anomalies suggests a relatively rapid global reorganization of the ocean-atmosphere system. We conclude that the wet periods probably affected rainforest distribution, as plant fossils show that forest expansion occurred during these intermittent wet intervals, and opened a forest corridor between the Amazonian and Atlantic rainforests.
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Affiliation(s)
- Xianfeng Wang
- Department of Geology & Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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41
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Vizy EK. Evaluation of Last Glacial Maximum sea surface temperature reconstructions through their influence on South American climate. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jd005415] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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42
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Water Resources in the Arid Mountains of the Atacama Desert (Northern Chile): Past Climate Changes and Modern Conflicts. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/1-4020-3508-x_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Jennerjahn TC, Ittekkot V, Arz HW, Behling H, Pätzold J, Wefer G. Asynchronous terrestrial and marine signals of climate change during Heinrich events. Science 2004; 306:2236-9. [PMID: 15576572 DOI: 10.1126/science.1102490] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Tropical regions have been reported to play a key role in climate dynamics. To date, however, there are uncertainties in the timing and the amplitude of the response of tropical ecosystems to millennial-scale climate change. We present evidence of an asynchrony between terrestrial and marine signals of climate change during Heinrich events preserved in marine sediment cores from the Brazilian continental margin. The inferred time lag of about 1000 to 2000 years is much larger than the ecological response to recent climate change and appears to be related to the nature of hydrological changes.
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Affiliation(s)
- Tim C Jennerjahn
- Zentrum für Marine Tropenökologie, Fahrenheitstrasse 6, D-28359 Bremen, Germany.
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44
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Cowling SA, Betts RA, Cox PM, Ettwein VJ, Jones CD, Maslin MA, Spall SA. Contrasting simulated past and future responses of the Amazonian forest to atmospheric change. Philos Trans R Soc Lond B Biol Sci 2004; 359:539-47. [PMID: 15212101 PMCID: PMC1693338 DOI: 10.1098/rstb.2003.1427] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Modelling simulations of palaeoclimate and past vegetation form and function can contribute to global change research by constraining predictions of potential earth system responses to future warming, and by providing useful insights into the ecophysiological tolerances and threshold responses of plants to varying degrees of atmospheric change. We contrasted HadCM3LC simulations of Amazonian forest at the last glacial maximum (LGM; 21 kyr ago) and a Younger Dryas-like period (13-12 kyr ago) with predicted responses of future warming to provide estimates of the climatic limits under which the Amazon forest remains relatively stable. Our simulations indicate that despite lower atmospheric CO2 concentrations and increased aridity during the LGM, Amazonia remains mostly forested, and that the cooling climate of the Younger Dryas-like period in fact causes a trend toward increased above-ground carbon balance relative to today. The vegetation feedbacks responsible for maintaining forest integrity in past climates (i.e. decreased evapotranspiration and reduced plant respiration) cannot be maintained into the future. Although elevated atmospheric CO2 contributes to a positive enhancement of plant carbon and water balance, decreased stomatal conductance and increased plant and soil respiration cause a positive feedback that amplifies localized drying and climate warming. We speculate that the Amazonian forest is currently near its critical resiliency threshold, and that even minor climate warming may be sufficient to promote deleterious feedbacks on forest integrity.
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Affiliation(s)
- Sharon A Cowling
- Department of Geography, University College London, 26 Bedford Way, London WC1H 0AP, UK.
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45
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Mayle FE, Beerling DJ, Gosling WD, Bush MB. Responses of Amazonian ecosystems to climatic and atmospheric carbon dioxide changes since the last glacial maximum. Philos Trans R Soc Lond B Biol Sci 2004; 359:499-514. [PMID: 15212099 PMCID: PMC1693334 DOI: 10.1098/rstb.2003.1434] [Citation(s) in RCA: 181] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aims of this paper are to review previously published palaeovegetation and independent palaeoclimatic datasets together with new results we present from dynamic vegetation model simulations and modern pollen rain studies to: (i) determine the responses of Amazonian ecosystems to changes in temperature, precipitation and atmospheric CO2 concentrations that occurred since the last glacial maximum (LGM), ca. 21 000 years ago; and (ii) use this long-term perspective to predict the likely vegetation responses to future climate change. Amazonia remained predominantly forested at the LGM, although the combination of reduced temperatures, precipitation and atmospheric CO2 concentrations resulted in forests structurally and floristically quite different from those of today. Cold-adapted Andean taxa mixed with rainforest taxa in central areas, while dry forest species and lianas probably became important in the more seasonal southern Amazon forests and savannahs expanded at forest-savannah ecotones. Net primary productivity (NPP) and canopy density were significantly lower than today. Evergreen rainforest distribution and NPP increased during the glacial-Holocene transition owing to ameliorating climatic and CO2 conditions. However, reduced precipitation in the Early-Mid-Holocene (ca. 8000-3600 years ago) caused widespread, frequent fires in seasonal southern Amazonia, causing increased abundance of drought-tolerant dry forest taxa and savannahs in ecotonal areas. Rainforests expanded once more in the Late Holocene owing to increased precipitation caused by greater austral summer insolation, although some of this forest expansion (e.g. in parts of the Bolivian Beni) is clearly caused by palaeo Indian landscape modification. The plant communities that existed during the Early-Mid-Holocene may provide insights into the kinds of vegetation response expected from similar increases in temperature and aridity predicted for the twenty-first century. We infer that ecotonal areas near the margins of the Amazon Basin are liable to be most sensitive to future environmental change and should therefore be targeted with conservation strategies that allow 'natural' species movements and plant community re-assortments to occur.
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Affiliation(s)
- Francis E Mayle
- Department of Geography, University of Leicester, Leicester LE1 7RH, UK.
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Abstract
A continuous 48,000-year-long paleoecological record from Neotropical lower montane forest reveals a consistent forest presence and an ice-age cooling of approximately 5 degrees to 9 degrees C. After 30,000 years of compositional stability, a steady turnover of species marks the 8000-year-long transition from ice-age to Holocene conditions. Although the changes were directional, the rates of community change were no different during this transitional period than in the preceding 30,000-year period of community stability. The warming rate of about 1 degrees C per millennium during the Pleistocene-Holocene transition was an order of magnitude less than the projected changes for the 21st century.
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Affiliation(s)
- Mark B Bush
- Florida Institute of Technology, 150 West University Boulevard, Melbourne, FL 32901-6975, USA.
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47
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Hardy DR, Vuille M, Bradley RS. Variability of snow accumulation and isotopic composition on Nevado Sajama, Bolivia. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2003jd003623] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- D. R. Hardy
- Climate System Research Center, Department of GeosciencesUniversity of Massachusetts Amherst Massachusetts USA
| | - M. Vuille
- Climate System Research Center, Department of GeosciencesUniversity of Massachusetts Amherst Massachusetts USA
| | - R. S. Bradley
- Climate System Research Center, Department of GeosciencesUniversity of Massachusetts Amherst Massachusetts USA
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48
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Vuille M, Bradley RS, Healy R, Werner M, Hardy DR, Thompson LG, Keimig F. Modeling δ
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O in precipitation over the tropical Americas: 2. Simulation of the stable isotope signal in Andean ice cores. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2001jd002039] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- M. Vuille
- Climate System Research Center, Department of Geosciences University of Massachusetts Amherst Massachusetts USA
| | - R. S. Bradley
- Climate System Research Center, Department of Geosciences University of Massachusetts Amherst Massachusetts USA
| | - R. Healy
- Woods Hole Oceanographic Institution Woods Hole Massachusetts USA
| | - M. Werner
- Max Planck Institute for Biogeochemistry Jena Germany
| | - D. R. Hardy
- Climate System Research Center, Department of Geosciences University of Massachusetts Amherst Massachusetts USA
| | - L. G. Thompson
- Byrd Polar Research Center Ohio State University Columbus Ohio USA
| | - F. Keimig
- Climate System Research Center, Department of Geosciences University of Massachusetts Amherst Massachusetts USA
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49
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Thompson LG, Mosley-Thompson E, Davis ME, Lin PN, Henderson K, Mashiotta TA. Tropical Glacier and Ice Core Evidence of Climate Change on Annual to Millennial Time Scales. ADVANCES IN GLOBAL CHANGE RESEARCH 2003. [DOI: 10.1007/978-94-015-1252-7_8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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50
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Cumming BF, Laird KR, Bennett JR, Smol JP, Salomon AK. Persistent millennial-scale shifts in moisture regimes in western Canada during the past six millennia. Proc Natl Acad Sci U S A 2002; 99:16117-21. [PMID: 12461174 PMCID: PMC138574 DOI: 10.1073/pnas.252603099] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inferences of past climatic conditions from a sedimentary record from Big Lake, British Columbia, Canada, over the past 5,500 years show strong millennial-scale patterns, which oscillate between periods of wet and drier climatic conditions. Higher frequency decadal- to centennial-scale fluctuations also occur within the dominant millennial-scale patterns. These changes in climatic conditions are based on estimates of changes in lake depth and salinity inferred from diatom assemblages in a well dated sediment core. After periods of relative stability, abrupt shifts in diatom assemblages and inferred climatic conditions occur approximately every 1,220 years. The correspondence of these shifts to millennial-scale variations in records of glacial expansionrecession and ice-rafting events in the Atlantic suggest that abrupt millennial-scale shifts are important to understanding climatic variability in North America during the mid- to late Holocene. Unfortunately, the spatial patterns and mechanisms behind these large and abrupt swings are poorly understood. Similar abrupt and prolonged changes in climatic conditions today could pose major societal challenges for many regions.
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Affiliation(s)
- Brian F Cumming
- Paleoecological Environmental Assessment and Research Laboratory, Department of Biology, Queen's University, Kingston, ON, Canada K7L 3N6.
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