Alvaro Gonzalez Reyes

Alvaro Gonzalez Reyes
Universidad Mayor · Hémera Centro de Observación de la Tierra

Doctor in Science, Geology

About

52
Publications
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Introduction
My main interests are related to the past, present, and future hydroclimatic variations across South America and their linkages with large scale climatic forcings such as ENSO, SAM, IPO, and others. My form to operate it combines observations, modeling, remote sensing, data Science, and climatic proxies such as tree rings. Also, I have more curiosity to understand climate extreme events and their present and future evolution in Chile, South America, and the Southern Hemisphere.

Publications

Publications (52)
Poster
Full-text available
Introduction Presently, much of the sub-tropical environments around are rapidly changing due to direct human influences and recurrent droughts. Among them, the Mediterranean region of Chile (MC; 30 ° -37 ° S) in western South America is considered as part of the hotspot of earth biologically richest and most endangered terrestrial ecosystems (Mit...
Article
Full-text available
The Mediterranean-type Ecosystems of Central Chile is one of the most threatened regions in South America by global change, particularly evidenced by the historical megadrought that has occurred in central Chile since 2010. The sclerophyllous forest stands out, whose history and relationship with drought conditions has been little studied. Cryptoca...
Poster
Full-text available
Introducción Los eventos Puelche, denominado así localmente al efecto Föhn, son masas de aire cálido con flujo Este-Oeste (de Argentina hacia Chile), que generan una disminución de la humedad relativa, y en la región de los Andes del Sur (36°-54°S), su ocurrencia se asocia también con una migración hacia el sur del Anticiclón Subtropical del Pacífi...
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
Highland ecosystems of western Andes foothills are currently poorly represented by dendrochronological information. The dendroclimatological potential of the Acerillo plant (Adesmia pinifolia), a shrub species well represented at these latitudes, was investigated. We reported the first ring width chronology of A. pinifolia growing at the central se...
Data
https://sada.cr2.cl / Este Explorador WEB se basa en los datos de la publicación de la reconstrucción de aridez de Sudamérica (scPDSI) utilizando anillos de árboles https://doi.org/10.1073/pnas.2002411117. A través de el es posible visualizar mapas anuales de aridez, calcular mapas promedio de grupos de años, mapas de correlación con otras variabl...
Article
State-of-the-art climate models project droughts of stronger intensity and longer persistence in many arid and semi-arid regions such as northern Patagonia, which constitutes a serious concern worldwide. Moisture availability has a significant influence on the dynamic, stability and function of terrestrial ecosystems. In this study, we used wood sa...
Conference Paper
Full-text available
Soil moisture (SM) is a key variable in the earth surface dynamics; however, long-term in situ measurements at the global scale are scarce. In the Mediterranean Chilean Andes (MA; 30°-37°S), Sclerophyllous Forest tree species such as Belloto del Norte (BN; Beilschmiedia miersii) can grow for more than two centuries in very scarce humid lowland geog...
Article
Full-text available
Prumnopitys andina is a South American podocarp with a restricted distribution in southern Andean temperate forests, and is severely threatened due to habitat loss. Despite much dendrochronological work on other temperate South American conifers, little is known about the dendrochronological potential of P. andina. Here, we examine the main feature...
Article
Full-text available
Almost half of the tributaries of the Amazon River originate in the tropical Andes and support large populations in mountain regions and downstream areas. However, it is difficult to assess hydroclimatic conditions or to evaluate future scenarios due to the scarcity of long, high‐quality instrumental records. Data from the Global Precipitation Clim...
Article
Full-text available
Spatio-temporal patterns of climatic variability have effects on the environmental conditions of a given land territory and consequently determine the evolution of its productive activities. One of the most direct ways to evaluate this relationship is to measure the condition of the vegetation cover and land-use information. In southernmost South A...
Article
Full-text available
South American (SA) societies are highly vulnerable to droughts and pluvials, but lack of long-term climate observations severely limits our understanding of the global processes driving climatic variability in the region. The number and quality of SA climate-sensitive tree ring chronologies have significantly increased in recent decades, now provi...
Article
Full-text available
We study a regional precipitation time series, built upon seven meteorological records from South-Central Chile (SCC; 37° - 42°S), which together cover the period 1900 - 2019. As a first objective, we investigated changes in the return period (RP) of dry (<P20) and wet (> P80) seasonal extreme events of precipitation (SEE), for each season. We obse...
Article
Full-text available
Since 2010, Chile has experienced one of the most severe droughts over the last century, the so-called mega-drought (MD). The MD conditions, combined with intensive agricultural activities and the current water management system, have led to water scarcity problems in Mediterranean and Semi-arid regions of Chile. An emblematic case is the Petorca b...
Article
Full-text available
Historical fire regimes are critical for understanding the potential effects of changing climate and human land-use on forest landscapes. Fire is a major disturbance process affecting the Andean Araucaria forest landscape in north-west Patagonia. The main goals of this study were to reconstruct the fire history of the Andean Araucaria–Nothofagus fo...
Poster
Full-text available
Heat waves have drawn major attention in southern South America due to their related socio-economic impacts, such as health emergencies, energy and water supply shortages, and wildfires, among others. Therefore, the understanding of the factors leading to these extreme events, along with any additional information on their predictability -beyond ty...
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
Trees’ growth responses to climate may depend on tree age and site conditions. In dioecious species, sex adds an extra level of complexity due to differential reproductive effort between the sexes and potentially sex-related dimorphic growth. Araucaria araucana is a long-lived dioecious conifer with outstanding morphological and functional adaptati...
Article
Full-text available
The "Little Ice Age" (LIA; 1500–1850 Common Era (CE)), has long been recognized as the last period when mountain glaciers in many regions of the Northern Hemisphere (NH) recorded extensive growth intervals in terms of their ice mass and frontal position. The knowledge about this relevant paleoclimatic interval is vast in mountainous regions such as...
Article
Full-text available
Recent evidence shows that most of Patagonian glaciers are receding rapidly. Due to the lack of in-situ long-term meteorological observations, the understanding of how glaciers are responding to changes in climate over this region is extremely limited and high uncertainties exist in the glacier surface mass balance model parameterizations. This pre...
Article
Full-text available
In January 2017, hundreds of fires in Mediterranean Chile burnt more than 5000 km2, an area nearly 14 times the 40-year mean. We contextualize these fires in terms of estimates of global fire intensity using MODIS satellite record, and provide an overview of the climatic factors and recent changes in land use that led to the active fire season and...
Data
Supplementary material caption Fig. S1. View of the four study sites with Austrocedrus chilensis populations in the upper Cachapoal Valley, central Chile. Fig. S2. Cross sections of Austrocedrus chilensis relict wood showing multiple fire scars. Fig. S3. Continuous wavelet power spectra of mean fire frequency and mean fire interval in the 1200–1...
Article
The long-term history of fire regimes in the Mediterranean Andes of Chile is almost unknown. Subalpine woodlands of Austrocedrus chilensis include long-lived trees resilient to low-intensity fires, which can provide valuable tree-ring-based information about fire history. In this work, we performed an annually resolved multicentury reconstruction o...
Article
Full-text available
Streamflow in south-central Chile (SCC, ∼ 37–42° S) is vital for agriculture, forestry production, hydroelectricity, and human consumption. Recent drought episodes have generated hydrological deficits with damaging effects on these activities. This region is projected to undergo major reductions in water availability, concomitant with projected inc...
Article
Full-text available
This paper evaluates the relationship between fire occurrence (number and burned area) and climate variability (precipitation and maximum temperatures) across central and south-central Chile (32°-43° S) during recent decades (1976-2013). This region sustains the largest proportion of the Chilean population, contains ecologically important remnants...
Conference Paper
Full-text available
The current deficit in water availability in south-central Chile (37-45S) has increased the necessity to understand the natural hydro-climate variability in long-term perspectives. This knowledge is a key to assess the current climate patterns with respect to the last centuries to provide a long-term perspective to the water management. Two of the...
Preprint
Streamflow in South-Central Chile (SCC, ∼35 o S-42 o S) is vital for agriculture, forestry production, hydroelectricity, and human consumption. Recent drought episodes have generated hydrological deficits with damaging effects on these activities. This region is projected to undergo major reductions in water availability, concomitant with projected...
Article
Full-text available
In the Mediterranean Andes (MA; 30°S–37°S), the main rivers are largely fed by melting snowpack and provide fresh water to around 10 million people on both sides of the Cordillera. Water resources in the MA are under pressure due to the extensive development of industrial agriculture and mining activities. This pressure is increasing as the region...
Article
Full-text available
The iconic conifer Araucaria araucana (Arau- caria), called Pehuén by native people, is an en- demic species of the Andes of northern Patago- nia in Chile and Argentina. Its range encompasses only three degrees of latitude (37 ◦ 20 � – 40 ◦ 20 � S) with a small outlying presence in the coastal moun- tains of Chile (Veblen et al. 1995). The species...
Article
Full-text available
Extended and continuous instrumental records of precipitation are scarce in South America, even more at high latitudes. These records are useful to validate past climatic reconstructions and calibrate regional climatic models. Few Chilean cities (e.g. Santiago, Concepción, and Valdivia) present long meteorological observations, since mid-19th centu...
Article
Full-text available
As rainfall in South-Central Chile has decreased in recent decades, local communities and industries have developed an understandable concern about their threatened water supply. Reconstructing streamflows from tree-ring data has been recognized as a useful paleoclimatic tool in providing long-term perspectives on the temporal characteristics of hy...
Article
Full-text available
High quality instrumental precipitation records are useful in evaluating extreme events suchs as droughts and their recurrence rate at different time scales. The city of Santiago de Chile has a historical rainfall record that started in 1867, making it one of the most complete and extensive in South America. In this work, April through October prec...
Article
Full-text available
Despite the great number and variety of glaciers in southern South America, in situ glacier mass-balance records are extremely scarce and glacier–climate relationships are still poorly understood in this region. Here we use the longest (> 35 years) and most complete in situ mass-balance record, available for the Echaurren Norte glacier (ECH) in the...
Conference Paper
Full-text available
The interest in understanding how streamflow variability and trends will behave under a global climate change scenario in the short and long term is an emergent topic. This concern arises in response to an increase in extreme climatic events such as recurrent and long droughts in several regions of the world. In the arid and semiarid regions a prog...
Article
Full-text available
Extensive records of rainfall are considered fundamental for analysing potential current climate change especially in zones where ecosystems are highly humidity dependent. Valdivia city has the longest instrumental record in the nation, starting in 1853, though including a lapse between 1880 and 1899. The present study had the main objective of eva...
Conference Paper
Full-text available
We developed a streamflow reconstruction of the Biobío River, located on the limit of influence of Mediterranean and wet-temperate climate. We compared it with previous reconstructions from the Temperate (Puelo-River) and Mediterranean (Maule-River) climates. The present trend of reduced flow in both Biobío and Puelo Rivers seems to be part of a lo...
Article
Full-text available
Araucaria araucana (Araucaria) is a long-lived conifer growing along a sharp west–east biophysical gradient in the Patagonian Andes. The patterns and climate drivers of Araucaria growth have typically been documented on the driest part of the gradient relying on correlations with meteorological records, but the lack of in situ soil moisture observa...
Article
Full-text available
Registros extensos de precipitación son fundamentales para analizar potenciales cambios en el clima, especialmente en zonas que albergan ecosistemas pluvio-dependientes. La ciudad de Valdivia posee el registro más extenso de Chile, comenzando en 1853, pero encontrándose incompleto entre 1880-1899. El presente estudio tuvo por objetivo central evalu...
Conference Paper
Full-text available
Chile Central es la zona más densamente poblada del país concentrando a más del 50 % de la población e inscrita dentro de las 25 áreas prioritarias de conservación a nivel mundial debido a la fuerte presión sobre sus ecosistemas. Las principales fuentes de abastecimiento de agua potable, generación hidroeléctrica, minería y actividades agro-foresta...
Conference Paper
Full-text available
Introduction Long climatic instrumental records in Chile are scarce, however in some cities (e.g. Santiago, La Serena, Valparaiso, Valdivia) is possible to find out precipitation measurement since XIX century. In Valdivia, rainfall register started in 1853 thanks to Carlos Anwandter, a german colon propulsory of industrial activity, where his beer...

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Projects

Projects (2)
Project
*Contrast several soil moisture products based on remote sensing and understand temporal variations *Reconstruct soil moisture variability using tree rings during the last half millennia *Understand soil moisture variability and dynamics in decadal to multi decadal time scales
Project
- Evaluate past Heat Waves and understand current variations in Chile and South America based on historical observations and reanalysis products. - Carry out attribution experiments using GCM, RCM and the weather@home model to explore human attribution to HW