Villa Martinez, Rodrigo Patricio

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Villa Martinez, Rodrigo Patricio

Afiliación principal

Centro de Investigación Gaia Antártica

rodrigo.villa@umag.cl

ORCID

0000-0001-6041-4393

Jerarquía académica

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Ciencia Antartica y Subantartica

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DOI 10.1016/j.quascirev.2022.107899
Fires and rates of change in the temperate rainforests of northwestern Patagonia since-18 ka
2023-01-15
Moreno, Patricio
;
Mendez, Cesar
;
Henriquez, Carla A.
;
Fercovic, Emilia
;
Videla, Javiera
;
Reyes, Omar
;
Villacis, Leonardo A.
;
Villa Martinez, Rodrigo Patricio
;
Alloway, Brent
We examine the temporal and spatial structure of wildfires and rates of vegetation change in the Pacific sector of northwestern Patagonia (40 degrees-44 degrees S) over the last-18,000 years. Macroscopic Charcoal Accu-mulation Rates (CHAR), a proxy of past local fires, shows a geographic variation that mirrors the modern north-to-south and low-to-high elevation increase in annual precipitation and decrease in precipitation seasonality, and the frequency of explosive volcanic events. Variability in past fires is evident at multiple timescales, with a significant multi-millennial low between-18-13.1 ka, an abrupt rise between-13.1 -12.5 ka, and heightened fire activity between-11.4-8.2 ka with significant high values between-10 -9.4 ka. A subsequent decline led to the lowest Holocene values between-6-5.4 ka, which rose and led to significant high values between-3.1 ka and the present. Andean and Western Upwind Environments share a multi-millennial structure of fire activity since-18 ka, overprinted by millennial and centennial -scale divergences. These differences underscore the role of explosive volcanism as a trigger or modulator of fire activity in the vicinity of Andean eruptive centers. We posit that fire activity in Western Upwind Environments was driven primarily by hydroclimate variations, namely changes in the intensity of the Southern Westerly Winds. Compilations of CHAR and the Rates of Change (ROC) parameter, a measure of the magnitude and rapidity of changes in the pollen records, covary during the onset of the interglacial fire regime at-13.1 ka and the last-4000 years, suggesting that fires catalyzed vegetation changes during specific intervals since the last glaciation. Highly mobile human occupations deployed along the coasts started at-6.2 ka, increased in pulses, and spread widely during the last two millennia. Covariation with CHAR and ROC since-4 ka suggests that hunter-gatherer -fishers contributed to enhanced fire activity and abrupt vegetation changes at regional scale. The ubiquitous fire maximum over the last four cen-turies relates to widespread settlement and associated large-scale land clearance conducted by Euro-pean/Chilean settlers.(c) 2022 Elsevier Ltd. All rights reserved.
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DOI 10.1016/j.quascirev.2022.107899
Fires and rates of change in the temperate rainforests of northwestern Patagonia since-18 ka
2023-01-15
Moreno, Patricio
;
Mendez, Cesar
;
Henriquez, Carla A.
;
Fercovic, Emilia
;
Videla, Javiera
;
Reyes, Omar
;
Villacis, Leonardo A.
;
Villa Martinez, Rodrigo Patricio
;
Alloway, Brent
We examine the temporal and spatial structure of wildfires and rates of vegetation change in the Pacific sector of northwestern Patagonia (40 degrees-44 degrees S) over the last-18,000 years. Macroscopic Charcoal Accu-mulation Rates (CHAR), a proxy of past local fires, shows a geographic variation that mirrors the modern north-to-south and low-to-high elevation increase in annual precipitation and decrease in precipitation seasonality, and the frequency of explosive volcanic events. Variability in past fires is evident at multiple timescales, with a significant multi-millennial low between-18-13.1 ka, an abrupt rise between-13.1 -12.5 ka, and heightened fire activity between-11.4-8.2 ka with significant high values between-10 -9.4 ka. A subsequent decline led to the lowest Holocene values between-6-5.4 ka, which rose and led to significant high values between-3.1 ka and the present. Andean and Western Upwind Environments share a multi-millennial structure of fire activity since-18 ka, overprinted by millennial and centennial -scale divergences. These differences underscore the role of explosive volcanism as a trigger or modulator of fire activity in the vicinity of Andean eruptive centers. We posit that fire activity in Western Upwind Environments was driven primarily by hydroclimate variations, namely changes in the intensity of the Southern Westerly Winds. Compilations of CHAR and the Rates of Change (ROC) parameter, a measure of the magnitude and rapidity of changes in the pollen records, covary during the onset of the interglacial fire regime at-13.1 ka and the last-4000 years, suggesting that fires catalyzed vegetation changes during specific intervals since the last glaciation. Highly mobile human occupations deployed along the coasts started at-6.2 ka, increased in pulses, and spread widely during the last two millennia. Covariation with CHAR and ROC since-4 ka suggests that hunter-gatherer -fishers contributed to enhanced fire activity and abrupt vegetation changes at regional scale. The ubiquitous fire maximum over the last four cen-turies relates to widespread settlement and associated large-scale land clearance conducted by Euro-pean/Chilean settlers.(c) 2022 Elsevier Ltd. All rights reserved.
Scopus© Citations 19 5
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DOI 10.1016/j.earscirev.2022.104240
Glacier and terrestrial ecosystem evolution in the Chilotan archipelago sector of northwestern Patagonia since the Last Glacial Termination
2022-12
Moreno, P.
;
Fercovic, E.
;
Soteres, R. L.
;
Ugalde, P.
;
Sagredo, E. A.
;
Villa Martinez, Rodrigo Patricio
We examine the glacier, terrestrial ecosystem, and climate evolution since the Last Glacial Termination (T1) based on glacial sediments/landform assemblages and palynological data from the Chilotan archipelago (41 degrees 30 ' S-43 degrees 30 ' S), northwestern Patagonia. Deglacial warming drove recession of the Golfo Corcovado glacier lobe from the Last Glacial Maximum moraines in the interior of Isla Grande de Chiloe ' (IGC) before-17.8 ka, along with a rapid and irreversible trend toward arboreal dominance. Subsequent glacier stabilization led to deposition of the innermost moraines in eastern IGC and adjacent islands sometime between-17.5-16.9 ka, followed by an acceleration in glacial retreat that vacated the Chilotan Interior Sea in-200 years or less. Early successional cold-tolerant shade-intolerant trees prevailed during the initial stages of T1, followed by temperate rainforests dominated by thermophilous shade-tolerant species between-15-14.5 ka. A mixed forest with cold -tolerant hygrophilous conifers established between-14.5-12.6 ka, implying cooler climate and stronger Southern Westerly Wind (SWW) influence during the Antarctic Cold Reversal. Stand-replacing fires favored early successional shade-intolerant trees, shrubs, and herbs between-12.6-10.8 ka in response to milder temperatures and weaker SWW during Younger Dryas time. The early Holocene (-10.8-7.5 ka) features a maximum in shade -intolerant thermophilous trees, absence of conifers, and peak fire activity, signaling a warm/dry interval with minimum SWW influence. Cooler/wetter conditions have prevailed over the last-7500 years driven by strong SWW influence. We conclude that Patagonian glaciers and terrestrial ecosystems responded simultaneously to climate changes at regional, hemispheric, and global scales multiple times since T1. We adhere to the concept that millennial-scale variations in the SWW linked the response of the hydro-bio and cryosphere across the southern mid-and high southern latitudes, and were teleconnected with northern hemisphere events through the atmospheric concentration of greenhouse gases, latitudinal shifts in the Intertropical convergence zone, and deep ocean circulation.
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DOI 10.1016/j.earscirev.2022.104240
Glacier and terrestrial ecosystem evolution in the Chilotan archipelago sector of northwestern Patagonia since the Last Glacial Termination
2022-12
Moreno, P.
;
Fercovic, E.
;
Soteres, R. L.
;
Ugalde, P.
;
Sagredo, E. A.
;
Villa Martinez, Rodrigo Patricio
We examine the glacier, terrestrial ecosystem, and climate evolution since the Last Glacial Termination (T1) based on glacial sediments/landform assemblages and palynological data from the Chilotan archipelago (41 degrees 30 ' S-43 degrees 30 ' S), northwestern Patagonia. Deglacial warming drove recession of the Golfo Corcovado glacier lobe from the Last Glacial Maximum moraines in the interior of Isla Grande de Chiloe ' (IGC) before-17.8 ka, along with a rapid and irreversible trend toward arboreal dominance. Subsequent glacier stabilization led to deposition of the innermost moraines in eastern IGC and adjacent islands sometime between-17.5-16.9 ka, followed by an acceleration in glacial retreat that vacated the Chilotan Interior Sea in-200 years or less. Early successional cold-tolerant shade-intolerant trees prevailed during the initial stages of T1, followed by temperate rainforests dominated by thermophilous shade-tolerant species between-15-14.5 ka. A mixed forest with cold -tolerant hygrophilous conifers established between-14.5-12.6 ka, implying cooler climate and stronger Southern Westerly Wind (SWW) influence during the Antarctic Cold Reversal. Stand-replacing fires favored early successional shade-intolerant trees, shrubs, and herbs between-12.6-10.8 ka in response to milder temperatures and weaker SWW during Younger Dryas time. The early Holocene (-10.8-7.5 ka) features a maximum in shade -intolerant thermophilous trees, absence of conifers, and peak fire activity, signaling a warm/dry interval with minimum SWW influence. Cooler/wetter conditions have prevailed over the last-7500 years driven by strong SWW influence. We conclude that Patagonian glaciers and terrestrial ecosystems responded simultaneously to climate changes at regional, hemispheric, and global scales multiple times since T1. We adhere to the concept that millennial-scale variations in the SWW linked the response of the hydro-bio and cryosphere across the southern mid-and high southern latitudes, and were teleconnected with northern hemisphere events through the atmospheric concentration of greenhouse gases, latitudinal shifts in the Intertropical convergence zone, and deep ocean circulation.
Scopus© Citations 15 3
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DOI 10.1016/j.quascirev.2020.106730
An early Holocene westerly minimum in the southern mid-latitudes
2021-01-01
Moreno, P.
;
Henriquez, W.
;
Pesce, O. H.
;
Henriquez, C. A.
;
Fletcher, M. S.
;
Garreaud, R. D.
;
Villa Martinez, Rodrigo Patricio
An important coupled ocean-atmospheric system in the mid- and high latitudes involves the Southern Westerly Winds (SWW) and the Southern Ocean (SO), which controls climate in the southernmost third of the world, deep water formation, and ventilation of CO2 from the deep ocean. Most studies have examined its role as a driver of atmospheric CO2 concentrations during glacial terminations, but very few have investigated its influence during the Holocene, i.e. the current interglacial. A fundamental problem, however, is resolving whether the SWW strength increased or declined during the early Holocene (similar to 11.5-7.5 ka, ka = 1000 cal yr BP) in sectors adjacent to the Drake Passage. Here we assess past changes in SWW influence over the last similar to 17,000 years using terrestrial paleoclimate records from southwestern Patagonia (similar to 52 degrees S). We detect a zonally symmetric Early Holocene Westerly Minimum which diminished wind stress and upwelling on the SO, contributing to a contemporary decline in atmospheric CO2 concentrations and enrichment in the stable carbon isotope ratio of atmospheric CO2 (delta C-13(atm)). Our midlatitude data also indicate a shift to strong SWW influence at similar to 7.5 ka which correlates with a sustained increase in atmospheric CO2 and halt in the delta C-13(atm) rise, suggesting enhancement of high-latitude ocean ventilation by an invigorated SWW-SO coupled system. (C) 2020 Elsevier Ltd. All rights reserved.
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DOI 10.1016/j.quascirev.2020.106730
An early Holocene westerly minimum in the southern mid-latitudes
2021-01-01
Moreno, P.
;
Henriquez, W.
;
Pesce, O. H.
;
Henriquez, C. A.
;
Fletcher, M. S.
;
Garreaud, R. D.
;
Villa Martinez, Rodrigo Patricio
An important coupled ocean-atmospheric system in the mid- and high latitudes involves the Southern Westerly Winds (SWW) and the Southern Ocean (SO), which controls climate in the southernmost third of the world, deep water formation, and ventilation of CO2 from the deep ocean. Most studies have examined its role as a driver of atmospheric CO2 concentrations during glacial terminations, but very few have investigated its influence during the Holocene, i.e. the current interglacial. A fundamental problem, however, is resolving whether the SWW strength increased or declined during the early Holocene (similar to 11.5-7.5 ka, ka = 1000 cal yr BP) in sectors adjacent to the Drake Passage. Here we assess past changes in SWW influence over the last similar to 17,000 years using terrestrial paleoclimate records from southwestern Patagonia (similar to 52 degrees S). We detect a zonally symmetric Early Holocene Westerly Minimum which diminished wind stress and upwelling on the SO, contributing to a contemporary decline in atmospheric CO2 concentrations and enrichment in the stable carbon isotope ratio of atmospheric CO2 (delta C-13(atm)). Our midlatitude data also indicate a shift to strong SWW influence at similar to 7.5 ka which correlates with a sustained increase in atmospheric CO2 and halt in the delta C-13(atm) rise, suggesting enhancement of high-latitude ocean ventilation by an invigorated SWW-SO coupled system. (C) 2020 Elsevier Ltd. All rights reserved.
Scopus© Citations 52 3
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DOI 10.1016/j.quascirev.2019.105976
The last glacial termination in the Coyhaique sector of central Patagonia
2019-11-15
Vilanova, I.
;
Moreno, P. I.
;
Miranda, C. G.
;
Villa Martinez, Rodrigo Patricio
Southern South America is the only continental landmass that intersects the core of the Southern Westerly Winds (SWW), and thus is important for studying their role as a driver/conduit for the initiation/propagation of climate signals since the last glaciation. Their interaction with the Southern Ocean (SO) affects global climate through its influence on high-latitude upwelling and biological productivity, deep-water convection sites and, consequently, ventilation of CO2 from the deep ocean. Variations in the SWW-SO coupled system have been postulated as fundamental drivers of climate change during glacial terminations and the current interglacial. Hence, deciphering the evolution of the SWW from sensitive locations in the southern middle latitudes is essential for understanding important climatic transitions during and since the Last Glacial Termination (T1). Terrestrial records from the central Patagonian Andes (CPA) (44 degrees-49 degrees S), however, show heterogeneities in the timing, rates, and direction of climate change during T1, impeding detailed assessment of its drivers at regional, hemispheric, and global scales. Here we present new data on glacier, vegetation, and fire-regime changes in the Coyhaique sector (45 degrees 34'S) of CPA to improve our understanding on the timing and structure of the T1, including the behavior of the SWW. Our results indicate glacial recession from the youngest Last Glacial Maximum moraines just before similar to 17.9 ka and development of an ice-dammed proglacial lake during the early stages of T1. Drainage of the ice-dammed lake, triggered by renewed glacial recession, was near-synchronous with the onset of a gradual multi-millennial trend toward arboreal dominance that started at similar to 16 ka east and west of the Andes at that latitude. We detect increased influence of the SWW at similar to 45 degrees S starting at similar to 16.6 ka, relative to the first millennium of T1, that led to positive anomalies in precipitation between similar to 16-14.4 and similar to 12.8-11.5 ka, followed by negative anomalies between similar to 11.5-9 ka. The synchronous spread of arboreal vegetation east and west of the CPA divide during T1, despite the trans-Andean precipitation contrasts, suggests an upward shift in the temperature-controlled Andean tree line, underscoring the role of deglacial warming as the critical driver for afforestation at regional scale. (C) 2019 Elsevier Ltd. All rights reserved.
Scopus© Citations 25 3
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DOI 10.1016/j.quascirev.2019.06.004
Early arboreal colonization, postglacial resilience of deciduous Nothofagus forests, and the Southern Westerly Wind influence in central-east Andean Patagonia
2019-8-15
Moreno, P.
;
Simi, E.
;
Villa Martinez, Rodrigo Patricio
;
Vilanova, I
The history and dynamics of deciduous Nothofagus forests along the eastern slopes of the central Patagonian Andes (44 degrees-49 degrees S) remain insufficiently studied and understood, particularly at timescales ranging from centuries to millennia. Available fossil pollen records point to time-transgressive responses of the arboreal vegetation to climatic changes during the Last Glacial Termination (T1) and early Holocene, and spatial heterogeneity since then along north-south, east-west, and elevation transects. The degree to which these results represent biogeographic and climatic trends, varying environmental gradients, or site-specific phenomena has not been assessed in detail. Here we present a fossil pollen and macroscopic charcoal record from Lago Churrasco (45 degrees 41'S, 71 degrees 49'W), a small closed-basin lake located in the deciduous Nothofagus forest zone of the central-east Andes of Chilean Patagonia. Our results suggest that Nothofagus trees colonized newly deglaciated terrains at similar to 16,000 cal yr BP and formed scrublands/woodlands several millennia earlier than reported by previous studies east of the Andes. This suggests expansion and local densification of tree populations sourced from the eastern margin of the Patagonian Ice Sheet during the Last Glacial Maximum, with the additional implication that temperature and precipitation conditions favorable for tree survival and reproduction developed early during T1. We posit that the amount of moisture delivered by the Southern Westerly Winds was not a limiting factor for arboreal expansion during T1 in this sector of the central Patagonian Andes. Closed-canopy Nothofagus forests established at similar to 10,000 cal yr BP and have remained essentially invariant despite climate change and natural disturbance regimes. This resilience was challenged and exceeded by human disturbance during the 20th century through the use of fire, leading to deforestation and spread of invasive exotic species in an extraordinarily rapid event. Our record suggests a permanent influence of the Southern Westerly Winds over the last 10,000 years, with relatively modest variations at centennial and millennial timescales. (C) 2019 Elsevier Ltd. All rights reserved.
Scopus© Citations 29 1
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DOI 10.1016/j.palaeo.2021.110459
Development and resilience of deciduous Nothofagus forests since the Last Glacial Termination and deglaciation of the central Patagonian Andes
2021-7-15
Villa Martinez, Rodrigo Patricio
;
Moreno, Patricio
Resolving the history of vegetation, fire, and glaciation on the eastern slope of the central Patagonian Andes (44 degrees-49 degrees S) since the Last Glacial Termination (T1) has proved difficult. This is due to the steep environmental gradients, vegetation heterogeneity, and scarcity of dated glacial deposits and geomorphic features. Unsurprisingly, published records show important heterogeneities which limit our understanding of the timing and magnitude of climate and vegetation changes, and their driving mechanisms since T1. In this paper, we describe sediment cores from small closed-basin lakes located in the deciduous Nothofagus forest zone near Coyhaique, Chile. Our results indicate that the Coyhaique glacier lobe abandoned its final Last Glacial Maximum position just before similar to 17.9 cal kyr BP and underwent a step-wise recession that included a halt/readvance that culminated at similar to 16.8 cal kyr BP, contemporaneous with the formation of an ice-dammed proglacial lake in the Coyhaique/Balmaceda sector. This glacial lake stood at its highest level between similar to 17.9-17.2 cal kyr BP (<726 and > 650 m.a.s.l.), lowered between similar to 17.2-16.2 cal kyr BP (<650 and > 570 m.a.s.l.), and disappeared thereafter. Herbs and shrubs, currently dominant in high Andean and Patagonian steppe environments, colonized the ice-free terrains distal to the glacier margins and proglacial lakes under cold and dry conditions. This was followed by a steady increase in Nothofagus between similar to 16.6-14.8 cal kyr BP that led to the establishment of forests starting at similar to 14.8 cal kyr BP. The Holocene started with a sudden increase in Nothofagus and disappearance of conifers in the context of increase fire activity between similar to 11.7-9.4 cal kyr BP. Closed-canopy Nothofagus forests persisted virtually unaltered from similar to 9.4 cal kyr BP to the present day, despite frequent explosive volcanism and millennial-scale variations in fire regimes, attesting to their extraordinary postglacial resilience which contrasts with their behavior during T1. Recent large-scale deforestation by fire, livestock grazing, and the spread of non-native invasive plant species drove the fastest and largest-magnitude shifts seen during the last similar to 16,500 years.
Scopus© Citations 14 1
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DOI 10.3389/fevo.2018.00034
Modulation of Fire Regimes by Vegetation and Site Type in Southwestern Patagonia Since 13 ka
2018-4-9
Moreno, Patricio I.
;
Vilanova, Isabel
;
Villa Martinez, Rodrigo Patricio
;
Francois, Jean P.
The degree to which vegetation and site type have influenced fire regimes through the Holocene has not been investigated in detail in the temperate ecosystems of southern Patagonia. Here we present a first attempt using a paired-basin approach to study the evolution of fire regimes in sectors dominated by humid Nothofagus forests and the xeric Patagonian steppe in the Magallanes region of Chilean Patagonia (51 degrees S). We analyzed sediment cores from two small lakes and a bog located within the same climate zone on opposite sides of the forest-steppe ecotone, similar to 28 km apart. The position of this biological boundary east of the Andes is controlled by the strength and position of the southern westerly winds, which constitute the sole source of precipitation throughout western Patagonia. Our results indicate that fires have occurred in the study region repeated times over the last similar to 13,000 years at bi- and tridecadal timescales. Sectors currently dominated by Patagonian steppe feature high frequency and low magnitude of local fires, and vice versa in humid forests. Climate-driven expansion of Nothofagus scrubland/woodland into steppe environments over the last similar to 4,200 years increased the magnitude and lowered the frequency of fire events, culminating with peak Nothofagus abundance, fire magnitude and frequency during the last millennium. We also detect divergences between lake-based vs. bog-based paleofire histories among paired sites located within the Patagonian steppe, similar to 12 km apart, which we attribute to local burning of the bog at times of lowered water table. This divergence suggests to us that bog-based vegetation and fire histories exacerbate a local, azonal, signal blurring extra-local or regional regimes, thus accounting for some discrepancies in the Quaternary paleovegetation/paleoclimate literature of southern Patagonia.
Scopus© Citations 18 2

Villa Martinez, Rodrigo Patricio

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