Ricardo Villalba

Ricardo Villalba
National Scientific and Technical Research Council | conicet · Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (IANIGLA-CONICET), Mendoza

Doctor of Philosophy

About

364
Publications
119,622
Reads
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15,818
Citations
Citations since 2017
105 Research Items
7040 Citations
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201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
201720182019202020212022202302004006008001,0001,2001,400
Additional affiliations
January 1996 - March 1998
Lamont - Doherty Earth Observatory Columbia University
Position
  • PostDoc Position
August 1989 - March 1993
University of Colorado Boulder
Position
  • PhD Student

Publications

Publications (364)
Poster
Full-text available
Poster titulado "Reconstrucción de la altitud de la isoterma 0°C en Patagonia norte durante los últimos 900 años utilizando anillos de árboles". Parte de mi tesis de pregrado para optar al título de Geofísico de la Universidad de Concepción. Esta investigación cuenta con apoyo y financiamiento de FONDECYT 1201411, FONDAP 15110009, FONDECYT 1201429...
Article
Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this exceptional cold phase are, however, still under debate because of the limited resolution and geographical distribution of the availabl...
Article
The high sensitivity of Nothofagus pumilio growth to climate variations at upper treelines provides a unique opportunity to document changes in tree responses to a warmer climate in the Patagonian Andes. In the context of significant recent temperature and precipitation changes across Patagonia, we conducted a study along the precipitation gradient...
Article
Full-text available
We present geodetic mass-balance estimates for ten glaciers (22.6 ± 1.1 km2) around Volcán Domuyo between 1962 and 2020 (and 46 glaciers covering 29 ± 1.5 km2 between 1984 and 2020), derived from airborne, ASTER and Pléiades imagery. Overall, we find a slightly negative mass balance (−0.15 ± 0.09 m w.e. a–1) for the entire 1962–2020 time span. A cl...
Article
Full-text available
Aim: Climate change is expected to impact mountain biodiversity by shifting species ranges and the biomes they shape. The extent and regional variation in these impacts are still poorly understood, particularly in the highly biodiverse Andes. Regional syntheses of climate change impacts on vegetation are pivotal to identify and guide research prio...
Article
Tree-ring width (TRW) chronologies have been widely and long-time used to reconstruct past climate variations in the Andes in South America. The use of tree-ring isotopic chronologies is still not widespread in this region although they have proved to be very efficient climate proxies. Araucaria araucana (Molina) K. Koch is a conifer tree species w...
Article
Dendrochronological methods have been widely used to determine the date of construction and provenance of shipwrecks. Despite a large number of shipwrecks, the application of dendroarchaeological techniques is relatively incipient in the coasts of South America. This paper presents the results of a dendroarchaeological study conducted at the shipwr...
Article
Full-text available
Recent climatic trends, such as warming temperatures, decrease in rainfall, and extreme weather events (e.g., heatwaves), are negatively affecting the performance of forests. In northern Patagonia, such conditions have caused tree growth reduction, crown dieback, and massive die-back events. However, studies looking at these consequences in the sou...
Article
Full-text available
The Desert Andes contain >4500 ice masses, but only a handful are currently being monitored. We present the mass changes of the small mountain glacier Agua Negra (1 km ² ) and of the rest of glaciers in the Jáchal river basin. Remote-sensing data show Agua Negra glacier lost 23% of its area during 1959–2019. Glaciological measurements during 2014–2...
Preprint
Full-text available
Given the short span of instrumental precipitation records in the South American Altiplano, long-term hydroclimatic records are needed to understand the nature of climate variability and to improve the predictability of 25 precipitation, a key natural resource for the socioeconomic development in the Altiplano and adjacent arid lowlands. In this re...
Article
Full-text available
Predicted warmer temperatures and more frequent extreme climatic events in the southern Andes may affect the dynamics of the Patagonian forests. These environmental changes may differentially alter the probability of Nothofagus pumilio establishment across its altitudinal range of distribution. We monitored fruit fall, seedling emergence and surviv...
Article
Full-text available
Interannual variability in the global land carbon sink is strongly related to variations in tropical temperature and rainfall. This association suggests an important role for moisture-driven fluctuations in tropical vegetation productivity, but empirical evidence to quantify the responsible ecological processes is missing. Such evidence can be obta...
Article
Full-text available
Plain Language Summary Understanding past climatic changes in the Central Andes in tropical South America is of great importance to contextualize current hydroclimatic conditions. Here, we present the first P. tarapacana tree‐ring stable oxygen isotope (δ¹⁸OTR) chronologies and analyze their value as environmental records for this region. Locally k...
Article
Numerous ring-width chronologies from different species have recently been developed in diverse tropical forests across South America. However, the temporal and spatial climate signals in these tropical chronologies is less well known. In this work, annual growth rings of Amburana cearensis, a widely distributed tropical tree species, were employed...
Article
Full-text available
Southwestern South America (SWSA) has undergone frequent and persistent droughts in recent decades with severe impacts on water resources, and consequently, on socio-economic activities at a sub-continental scale. The local drying trend in this region has been associated with the expansion of the subtropical drylands over the last decades. It has b...
Method
Full-text available
El Observatorio de Nieve fue desarrollado para analizar la evolución de la cubierta nival en las principales hídricas de Argentina y Chile en los Andes subtropicales (27°-37°S). La información de nieve es obtenida dos veces por día por el sensor MODIS a bordo de los satélites Terra y Aqua de la NASA (Hall y Riggs 2016). Los datos de base están disp...
Article
Full-text available
Over the past 40 years, the HBV (Hydrologiska Byråns Vattenbalansavdelning) hydrological model has been one of the most used worldwide due to its robustness, simplicity and reliable results. Despite these advantages, the available versions impose some limitations for research studies in mountain watersheds dominated by ice-snow melt runoff (i.e.: n...
Preprint
Full-text available
Predicted warmer temperatures and more frequent extreme climatic events in the southern Andes will affect the dynamics of the Patagonian forests. These environmental changes may differentially alter the probability of Nothofagus pumilio establishment across its altitudinal range of distribution. We monitored fruit rain, seedling emergence and survi...
Article
Full-text available
A number of glaciological observations on debris-covered glaciers around the globe have shown a delayed length and mass adjustment in relation to climate variability, a behavior normally attributed to the ice insulation effect of thick debris layers. Dynamic interactions between debris cover, geometry and surface topography of debris-covered glacie...
Article
Extreme weather events are increasing in frequency and magnitude due to climate change. In this context, the impacts of droughts on forest mortality will increase making it more relevant to determine the resilience of native forests to drought. Austrocedrus chilensis is an endemic conifer adapted to dry-mesic environmental conditions in the Patagon...
Article
In many tree species, trunk forking plays a major role in crown construction, and stands out as an indicator of the architectural transition between juvenile and adult trees. We aimed to evaluate the effects of trunk forking on height and diameter growth of Nothofagus pumilio trees in an even-aged monospecific stand in northern Patagonia, Argentina...
Article
Zooarchaeologists have relied upon various approaches to study the impacts of harvest pressure and environmental change on ungulate populations, such as analysis of prey mortality patterns and morphometrics. Analysis of ancient DNA from ungulate bones and bone fragments from archaeological sites provides an additional means for studying prey popula...
Article
Background : Despite extensive efforts to understand how biotic interactions and their effects on community dynamics respond to changes in environmental conditions many gaps in knowledge remain. Assessing the responses of biotic interactions involving little studied organisms, such as the biological soil crust (BSC), can widen our understanding of...
Article
Full-text available
Tree growth is generally considered to be temperature-limited at upper elevation treelines. Yet, climate factors controlling tree growth at semiarid treelines are poorly understood. We explored the influence of climate on stem growth and stable isotopes for Polyepis tarapacana, the world's highest elevation tree-species found only in the South Amer...
Preprint
En el presente capítulo se comparan desde el punto de vista hidroclimático, político y social, tres de las mayores sequías producidas en Mendoza en los últimos 120 años (1924/25; 1968/69 y 2010/15; 2017/19). De esta manera, se exploran los procesos a través de los cuales, la escasez y la carencia son construidas discursiva y políticamente a lo larg...
Article
Full-text available
Based on the recently released National Glacier Inventory (NGI), we analyzed the characteristics and the mass balance rates of ice masses in the Argentinean Central Andes (ca. 30°–37° S). The NGI provides unprecedented information on area, number and distribution of different ice masses, including debris-covered glaciers and rock glaciers. In the C...
Article
Key message The precise demarcation and cross-dating of tree rings in Aspidosperma tomentosum Mart., a valuable timber species in the tropical dry forests of South America, were used to develop the first well-replicated chronology covering the period 1843–2015. A. tomentosum Mart. tree growth is strongly regulated by soil water availability prior t...
Article
Full-text available
En muchas regiones del planeta las montañas son las principales generadoras de agua, elemento que constituye el componente esencial para la conservación de diversos ecosistemas y el desarrollo socioeconómico de las poblaciones aledañas (Mariano H. Masiokas et al., 2006; Viviroli & Weingartner, 2004). En el oeste argentino, resulta indispensable par...
Article
Full-text available
Rainfall and river levels in the Amazon are associated with significant precipitation anomalies of opposite sign in temperate North and South America, which is the dominant mode of precipitation variability in the Americas that often arises during extremes of the El Niño/Southern Oscillation (ENSO). This co-variability of precipitation extremes acr...
Article
Full-text available
Resumen La presente contribución considera a Machaerium acutifolium (Fabaceae) como una especie potencialmente apta para estudios dendrocronológicos en los bosques secos tropicales de la Chiquitania. En la comunidad Palmarito de la Frontera (Departamento de Santa Cruz, este de Bolivia) se analizaron 69 radios provenientes de 21 árboles para determi...
Article
Full-text available
Glaciers and the periglacial environment in Argentina have been protected by the Law since 2010. This legislation required the development of the first National Glacier Inventory (NGI), which was officially presented in May 2018 and based on satellite images spanning between 2004 and 2016. Here, we present the methods and results of the NGI, summar...
Article
Full-text available
Land vegetation is currently taking up large amounts of atmospheric CO 2 , possibly due to tree growth stimulation. Extant models predict that this growth stimulation will continue to cause a net carbon uptake this century. However, there are indications that increased growth rates may shorten trees′ lifespan and thus recent increases in forest car...
Article
Full-text available
Glacier ice thickness is crucial to quantifying water resources in mountain regions, and is an essential input for ice-flow models. Using a surface velocity inversion method, we combine ice thickness measurements with detailed surface elevation and velocity data, and derive ice thickness and volume estimates for the Monte Tronador glaciers, North P...
Article
Full-text available
Significance The SADA is an annually-resolved hydroclimate atlas in South America that spans the continent south of 12°S from 1400 to 2000 CE. Based on 286 tree ring records and instrumentally-based estimates of soil moisture, the SADA complements six drought atlases worldwide filling a geographical gap in the Southern Hemisphere. Independently val...
Article
Full-text available
In this paper we explore how changes in human strategies are differentially modulated by climate in a border area between hunter-gatherers and farmers. We analyze multiple proxies: radiocarbon summed probability distributions (SPDs), stable C and N isotopes, and zooarchaeological data from northwestern Patagonia. Based on these proxies, we discuss...
Article
Full-text available
The Andes is the most biodiverse region across the globe. In addition, some of the largest urban areas in South America are located within this region. Therefore, ecosystems and human population are affected by hydroclimate changes reported at global, regional and local scales. This paper summarizes progress of knowledge about long-term trends obse...
Chapter
Full-text available
Isolated forest patches of Nothofagus antarctica (ñire) are frequent in the Patagonian forest-steppe ecotone. These remnants, also called relicts (R), are separate from the continuous forests (C). Over the past century, these ecotonal forests have been impacted by anthropogenic activities, including fires, logging, and cattle ranching. In order to...
Chapter
Full-text available
The study of forest dynamics over large temporal and spatial scales has widely benefited from dendrochronological techniques. Patagonia is home to several long-lived tree species (Austrocedrus chilensis, Araucaria araucana, Fitzroya cupressoides, Nothofagus dombeyi and N. pumilio) with well-defined tree rings suitable for reconstructing tree establ...
Chapter
Whereas tree establishment after large-scale disturbances such as fires, avalanches, and landslides have been documented for Patagonian forests, information on forest recovery following floods is scarce. Glaciar Perito Moreno has remained stable throughout the twentieth century, reaching the Peninsula de Magallanes several times and embalming parts...
Article
Full-text available
Modeling work of the isotopic composition of tree ring cellulose (δ¹⁸Ocell) relies on the isotopic equilibrium assumption between atmospheric water vapor and tree source water, frequently assimilated to integrated precipitation. Here, we explore the veracity of this assumption based on observations collected during a field campaign in Río Negro pro...
Article
Full-text available
To place recent hydroclimate changes, including drought occurrences, in a long-term historical context, tree-ring records serve as an important natural archive. Here, we evaluate 46 millennium-long tree-ring based hydroclimate reconstructions for their Data Homogeneity, Sample Replication, Growth Coherence, Chronology Development, and Climate Signa...
Article
Full-text available
Severe droughts have the potential to reduce forest productivity and trigger tree mortality. Most trees face several drought events during their life and therefore resilience to dry conditions may be crucial to long-term survival. We assessed how growth resilience to severe droughts, including its components resistance and recovery, is related to t...
Article
Full-text available
In this study, we identify the main modes of variability of the Normalized Difference Vegetation Index (NDVI) and their relationships with precipitation and temperature variations across northern Patagonia (36°–45° S). In this approach, we combined a recently developed high-resolution gridded dataset (20 × 20 km) for temperature and precipitation w...
Presentation
Record rainfall totals have recently been recorded over the Amazon Basin and may be part of an amplified cycle of wet to dry season precipitation and streamflow. Just how unprecedented these recent hydroclimatic changes might be in the context of natural climate variability over the Amazon is difficult to determine from the short, sparse, and often...
Article
Full-text available
A full understanding of glacier changes in the Patagonian Andes over decadal to century timescales is presently limited by a lack of detailed and appropriate long-term observations. Here, we present geodetic mass and area changes of three valley glaciers from Monte San Lorenzo derived from stereo aerial photos, the Shuttle Radar Topography Mission...
Article
Full-text available
It is widely documented that the Earth's surface temperatures have increased in recent decades. However , temperature increment patterns are not uniform around the globe, showing different or even contrasting trends. Here we present a mean maximum summer temperature record, based on tree-ring widths, over the past 5682 years (3672BC e 2009AD) for s...
Article
Full-text available
The rivers originating in the southern Andes (18°–55°S) support numerous ecosystems and a large number of human populations and socio-economic activities in the adjacent lowlands of Chile, Argentina and Bolivia. Here we show that ca. 75% of the total variance in the streamflow records from this extensive region can be explained by only eight spatia...
Article
Premise: Fire scars on trees are created by excessive heat from a fire that kills the vascular cambium. Although, fires are one of the most important forest disturbances in Patagonia, the effects of fire on tree physiology and wood anatomy are still unknown. In this study, we hypothesized that abnormal functioning of the cambium after a fire will...
Chapter
Full-text available
Las respuestas de los cuerpos de hielo al cambio climático involucran una compleja cadena de procesos físicos que interactúan con las características locales de cada glaciar. Los cambios en la temperatura, la radiación solar, la precipitación, el viento y la nubosidad, influyen en el balance de masa y energía de los glaciares. La temperatura tiene...
Chapter
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Geographical variations in tree-growth responses to climate were examined in the southern Andes from c. 32 to 44 S.
Conference Paper
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Proxy tree-ring data are often well correlated with meteorological variables such as precipitation and temperature and can therefore be useful for developing long-term estimates of specific meteorological variables. In this paper, we used a network of temperature sensitive pehuén (Araucaria araucana) chronologies located in Argentina and Chile betw...
Article
Full-text available
Extreme climatic events, such as late frosts in spring during leaf flush, have considerable impacts on the radial growth of temperate broadleaf trees. Albeit, all broadleaved species are potentially vulnerable, damage depends on the particularities of the local climate, the species, and its phenology. The impact of late spring frosts has been widel...
Article
Full-text available
Earthquakes with magnitudes M > 7 can trigger large landslides and rockfalls at epicenter distances of up to 400 km, whereas moderate shaking (M = 5–7) is generally thought to result in abundant co-seismic mass movements in the vicinity of the epicenter. Although one might anticipate that large magnitude earthquakes off the Chilean coast would resu...
Article
Widely documented for temperate and cold forests in both hemispheres, variations in tree growth responses to climate along environmental gradients have rarely been investigated in the tropics. Seven tree‐ring chronologies of Centrolobium microchaete (Fabaceae) in the Cerrado tropical forests of Bolivia are used to determine the growth responses to...
Article
Full-text available
Recent studies documenting climate variability in South America have provided valuable information for understanding current and past dynamics of the climate system. Long meteorological records represent an essential tool to properly characterize climate fluctuations from decadal to multi-decadal scales. Unfortunately, the scarcity of continuous an...