Héctor Francisco Del Valle

• Doctor in Agronomy
• Principal Investigator at Universidad Autónoma de Entre Ríos (UADER), Oro Verde, Entre Ríos, Argentina

In the past few decades, attempts have been made to map and monitor disturbances affecting white-sand ecosystems in the Amazonian lowlands. Status and dynamics of the plant communities of these ecosystems are related to a variety of factors (soil type, flooding, nutrient availability, and wildfire), and full characterization of these unique ecosyst...

The study region encompasses the lowlands lying between the Orinoco and the Rio Negro rivers to the west and the borders of the Guayana highlands to the east, approximately between 5°N and 2°N. The study region was divided into six eco-chorological study areas showing the presence of meadow islands in the forest matrix, based on criteria such as be...

This chapter proposes a conceptual framework for integrating geopedology in the preliminary assessments required to establish the baseline for land degradation neutrality (LDN) at national or sub-national levels and to monitor outcomes of interventions targeting the LDN hierarchy of avoid, reduce, reverse land degradation. Specifically, it proposes...

This second version of Geopedology contains 27 chapters covering many subjects, including the basics of geopedology, implementation methods and techniques, and applications in land degradation and land use planning. Issues addressed by the contributing authors are diverse and complementary. This shows that geopedology is a far-reaching discipline t...

The synergistic use of optical and radar data is already a well-known alternative in the literature for land cover characterization. The objective of this chapter is to quantify the added value of combining radar imagery from Sentinel-1 and multispectral imagery from Sentinel-2 (both at 10 m resolution) to provide information on land use and land c...

In the past decades, important research has been carried out to map the natural disturbances in the Paraná River Delta. The benefits of the combined use optical and radar data are also known. The main objective of this paper is to assess the wetland fire cartography through a synergetic use of radar and optical data. We focus on integrating radar (...

Resumen | En la presente contribución se da a conocer la génesis de las acumulaciones de carbonatos ampliamente distribuidas en los suelos del centro-este y noreste del Chubut a través del análisis de las propiedades morfológicas, físicas, químicas, geoquímicas (isótopos estables) y mineralógicas. Los suelos estudiados se asocian a terrazas marinas...

Se presenta el primer mapa de zonificaciónde susceptibilidad a procesos erosivos según exposición de laderas, considerando valores de pendiente, orientación y estado de cobertura del suelo para un sector de la estepa fueguina localizado en el norte de la provincia de Tierra del Fuego. Se identifcaron dos sitios de observa-ción de procesos de remoci...

In semiarid rangelands where the anthropogenic impact is currently increasing, as occurs in the rangelands of the Península Valdés, the detrimental impacts of soil degradation on land resources became really dramatic. This chapter presents a review on the current knowledge of soil degradation in the Península Valdés rangelands. Section 1 introduces...

The present landscape of the Península Valdés is the result of a complex interrelation between climatic (aeolian deposition, windblown processes, glacial and interglacial cycles, pluvial and fluvial processes), tectonic, and eustatic controls that had work in the Andean foreland during the late Cenozoic. Based on a geomorphological approach, which...

Our aim was to describe vegetation heterogeneity at a regional scale in northeastern Patagonia and to identify the environmental variables associated to it. The study area encompasses 13 144 km² and is characterized by a mixture of species typical of Patagonian steppes and Monte Desert. We performed 48 vegetation relevés, which were randomly assign...

The Japan Aerospace Agency (JAXA) recently released multi-temporal global SAR mosaics derived from a 4-year data acquisition project (2007–2010) of the Advanced Land Observing Satellite (ALOS) PALSAR, L-band at 25 m spatial resolution. These open access data sets could assist traditional soil surveys and/or digital soil mapping programs undertaken...

The book contains a preface and 33 chapters that cover a large array of subjects including the basics of geopedology, implementation methods and techniques, and applications in land degradation and land use planning. Subjects addressed by the contributing authors are diverse but complementary. This shows that geopedology can be seen as a far-reachi...

Geopedology aims at integrating geomorphology and pedology to analyze soil-landscape relationships and map soils as they occur on the landscape. This book on geopedology fi lls a knowledge gap, presenting a proven approach for reliable mapping of soil-landscape relationships to derive value-added information for policy making, planning, and managem...

The book contains a preface and 33 chapters that cover a large array of subjects including the basics of geopedology, implementation methods and techniques , and applications in land degradation and land use planning. Subjects addressed by the contributing authors are diverse but complementary. This shows that geopedology can be seen as a far-reach...

The Japan Aerospace Agency (JAXA) recently released multi-temporal global SAR mosaics derived from a 4-year data acquisition project (2007-2010) of the Advanced Land Observing Satellite (ALOS) PALSAR, L-band at 25 m spatial resolution. These open access data sets could assist traditional soil surveys and/or digital soil mapping programs undertaken...

The hydrogen isotopic composition (δ2H) of leaf waxes, especially of n-alkanes (δ2Hn-alkanes), is increasingly used for paleohydrological and paleoclimate reconstructions. However, it is challenging to disentangle past changes in the isotopic composition of precipitation and changes in evapotranspirative enrichment of leaf water, which are both rec...

Understanding spatial and temporal patterns of burned areas at regional scales, provides a long-term perspective of fire processes and its effects on ecosystems and vegetation recovery patterns, and it is a key factor to design prevention and post-fire restoration plans and strategies. Standard satellite burned area and active fire products derived...

Wildlife is part of the Patagonian rangelands sheep farming environment, with the potential of providing extra revenue to livestock owners. As sheep farming became less profitable, farmers and ranchers could focus on sustainable wildlife harvesting. It has been argued that sustainable wildlife harvesting is ecologically one of the most rational for...

This paper presents EROSAR, a model for soil erosion hazard assessment in rangelands at a regional scale. The use of remote sensing as input for EROSAR model parameters proved valuable both for ecological sites mapping as well as to assess vegetation distribution and connectivity of runoff to source areas. Largest values for soil loss are predicted...

Drylands land degradation is a major environmental issue of the 21st century because of its impact on food security and environmental quality (MEA, 2005). Remote sensing provides meaningful spatial data for mapping and monitoring drylands land degradation in. Synthetic Aperture Radars (SAR) offer a considerable potential to identify and map wind de...

The δ2H isotopic composition of leaf waxes is used increasingly for paleohydrological and -climate reconstructions. However, it is challenging to disentangle past changes in the isotopic composition of precipitation and changes in evapotranspirative enrichment of leaf water. We analyzed δ2H on n-alkanes and fatty acids in topsoils along a climate t...

The quantitative contribution of shoot and root organic matter (OM) to the soil carbon (C) stock is still unknown, mainly because of methodological restrictions. The novel measurement of the nonexchangeable hydrogen (H) stable isotope ratio (δ2Hn) in bulk OM provides new opportunities to investigate the sources of soil C and its climate-dependent t...

International Journal of Applied Earth Observation and Geoinformation j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / j a g: Bushfires Burned area Time series Image segmentation MODIS Normalized burn ratio Rangelands a b s t r a c t Understanding spatial and temporal patterns of burned areas at regional scales, provi...

Los algoritmos de segmentación que se han desarrollado han sido específicos principalmente para imágenes satelitales ópticas y/o de radar, pero muy pocos de estos pueden usarse sin sufrir alteraciones por tener dependencias específicas de las imágenes para las que fueron creados. En este trabajo, se analiza la literatura pasada y reciente sobre los...

En general, la información necesaria para el análisis de las imágenes de satélite no se encuentra en los píxeles de la imagen, sino en los objetos significativos de la misma y en sus relaciones mutuas. Pese a ello, aún la mayoría de las aplicaciones basadas en datos procedentes de teledetección utiliza los conceptos básicos de procesamiento de las...

La fotografía hemisférica es profusamente utilizada en climatología y ciencias forestales en vinculación con tecnología geomática. Permite obtener un registro detallado de los claros del dosel y estimar, tanto la estructura del mismo, como la transmisión de luz al sotobosque, ambas variables de gran importancia para el inventario forestal y el mane...

El objetivo del Atlas es apoyar el uso sostenible del suelo, proporcionando una herramienta útil para conocer su estado y llamar la atención sobre su importancia. Estos aspectos constituyen el punto de partida para fomentar la conservación de este valioso recurso natural. Es por ello que, con el fin de mejorar la comunicación y concienciar a la soc...

The oxygen isotopic composition of precipitation (δ18Oprec) is well known to be a valuable (paleo-)climate proxy. Paleosols and sediments and hemicelluloses therein have the potential to serve as archives recording the isotopic composition of paleoprecipitation. In a companion paper (Zech et al., 2014) we investigated δ18Ohemicellulose values of pl...

Hemispherical photography is profusely used in climatology and forest sciences in association with geomatics technology. It is possible to get a detailed record of the canopy and estimate, both of the same structure and understory light transmission, both variables important for forest inventory and management of natural regeneration. Hemispherical...

We evaluated the effects of soil properties and climate on concentrations of parent and oxygenated polycyclic aromatic compounds (PAHs and OPAHs) and azaarenes (AZAs) in topsoil and subsoil at 20 sites along a 2100-km north (N)-south (S) transect in Argentina. The concentrations of Σ29PAHs, Σ15OPAHs and Σ4AZAs ranged 2.4-38ngg(-1), 0.05-124ngg(-1)...

Se ha estudiado la ocurrencia de incendios en el Complejo Litoral del Río Paraná, Argentina (período 2004-2008), mediante el análisis de focos de calor (FC). Se evaluó información espacial de diferentes sensores remotos (MODIS, ERS, Goes, NOAA) descargados de diferentes fuentes de consulta (CONAE, ESA, INPE). Los datos del sensor MODIS Aqua (descar...

Fire occurrences at the of Parana River Coastal Complex during the 2004-2008 period were studied through hotspot data analysis. Spatial information from different remote sensors (MODIS, ERS, Goes, NOAA) and sources (CONAE, ESA, INPE) was evaluated. The MODIS Aqua sensor (downloaded and processed by CONAE), showed a high hotspot detection performanc...

We focus on Shannon Entropy (SE) for the characterization of polarimetric Synthetic Aperture Radar (PolSAR) images. This approach analyzes the information contribution made by individual pixels to the whole image for assessment of land degradation in the information content of ALOS PALSAR images. Additionally, the performance of other polarization...

Land cover maps at different resolutions and mapping extents contribute to modeling and support decision making processes. Because land cover affects and is affected by climate change, it is listed among the 13 terrestrial essential climate variables. This paper describes the generation of a land cover map for Latin America and the Caribbean (LAC)...

Introducción Durante los últimos 40 años, Latinoamérica ha experimentado un proceso de cambios am-bientales sin precedentes en la historia. La de-forestación, los incendios, la expansión de la agricultura, el cambio climático y la globali-zación de la economía mundial son algunas de las principales causas. Para el estudio del cambio global, se requ...

Pressure on land resources has increased during recent years despite international goals to improve their management. The fourth Global Environment Outlook (UNEP) highlighted the unprecedented land-use changes created by a burgeoning population, economic development and global markets. The outcome of those drivers continues to cause resource deplet...

Nonexchangeable H isotope ratios of soil organic matter across different ecoregions in Argentina

This work was developed in the framework of the Latin American Network of Monitoring and Study of Natural Resources (SERENA) in response to the need for accurate and reliable information on landcover, with a medium spatial resolution in the region of Latin America and the Caribbean (LAC). This article describes the methodology and presents the resu...

Lenga forests (Nothofagus pumilio) are the most important forest resource of the Argentinean Andean Patagonia, however, more information about their structure is needed to implement forest management policies and practices in order to prevent their degradation and revert it. One option to obtain this kind of information is to relate satellite data...

Lenga forests (Nothofagus pumilio) are the most important forest resource of the Argentinean Andean Patagonia, however, more information about their structure is needed to implement forest management policies and practices in order to prevent their degradation and revert it. One option to obtain this kind of information is to relate satellite data...

In many rangeland ecosystems, the role of wildfires has been the object of detailed studies. However, in Argentina and especially in the Monte biome this knowledge is limited. This region is prone to wildfires during late spring and summer, when high winds and temperatures are coupled with low relative humidity. In addition, this region also presen...

The synergistic use of multispectral and hyperspectral data is evaluated for discrimination and mapping of ecological sites in the Patagonian rangelands. The method proposed encompasses two steps. First, mixture tuned matched filtering and logistic regression analyses are used for Hyperion data processing to obtain ecological site probability image...

Land degradation caused by deforestation, overgrazing, and inappropriate irrigation practices affects about 16% of Latin America and the Caribbean (LAC). This paper addresses issues related to the application of remote sensing technologies for the identification and mapping of land degradation features, with special attention to the LAC region. The...

Wind-driven land degradation negatively impacts on rangeland production and infrastructure in the Valdes Peninsula, northeastern Patagonia. The Valdes Peninsula has the most noticeable dunefields of the Patagonian drylands. Wind erosion has been assessed at different scales in this region, but often with limited data. In general, terrain features c...

Soil erosion is a key factor in land degradation processes in the sandy rangelands of the Peninsula Valdes of Patagonia, Argentina. Mapping landform and vegetation patterns is important for improving prediction, monitoring and planning of areas threatened by sand and shrub encroachment. This paper investigates the contribution of optical sensors, s...

The compilation of published results on the geography of the Monte Desert biome of Argentina that we present here offers a review of its boundaries and ecotones, and of its biophysical and socio-economic characteristics. In relation to socio-ecological issues, the focus is on a case study in the province of Mendoza. An analysis is presented about t...

The complex interactions between human activity and natural processes determine non-linear dynamics in ecosystems that can difficult their management. Human settlements in arid lands contribute to the modification of disturbance regimes, including the introduction of new disturbances and the elimination of others. In consequence, they can alter the...

In arid and semiarid ecosystems, primary productivity and nutrient cycling are directly related to the amount and seasonal distribution of precipitation. However, depending on morphological, phenological, physiological, and biochemical traits, plants may influence the quality and quantity of organic matter inputs to the soil and thus the biomass an...

Evaluamos la distribución y el tamaño de las colonias de Spheniscus magellanicus (Pingüino de Magallanes o Patagónico) en el Norte del Golfo San Jorge, Argentina. Caracterizamos el hábitat de nidificación en 14 islas con colonias (IC) y 28 islas sin pingüinos anidando (INC). Empleamos análisis digital de una imágen satelital Landsat TM y datos de c...

Recent studies have emphasized the impact of dust emissions from southern South American (SSA) deserts (in particular the Patagonian desert) on past and present climate, as well as possible links to marine biology and carbon uptake in the high-latitude southern oceans. However, understanding is hindered by the lack of observations about dust activi...

The Valdes Peninsula has the most noticeable aeolian landforms of the Patagonian drylands. The southern sector of the peninsula is affected by the advance of several fronts of active sand dunes grouped in discrete megapatches. The objectives of the study were to: (1) analyse the morphology of sand dunes, and (2) measure the migration rates and orie...

This study deals with the changes induced by grazing on soil erosion processes in vegetated dune fields of Peninsula Valdes, in the Patagonia region of Argentina. We performed a spatial analysis to assess erosion features' patterns. Blowouts, used as main indicators of aeolian erosion processes, as well as dune crests, which are susceptible to eros...

This paper presents results of the AQL2004 project, which has been develope within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLatif). The project intended to obtain monthly burned-land maps of the entire region, from Mexico to Patagonia, using MODIS (moderate-resolution imaging spectroradiometer) reflectance data. T...

Recent studies of soil–landscape relationships in northeastern Patagonia identified fibrous-clay minerals in calcic and petrocalcic horizons developed on old fluvio-glacial plains called “Rodados Patagónicos” (RP). The objectives of this study were: i) to evaluate the occurrence of fibrous-clay minerals in the arid soil environment, and ii) to esta...

RESUMEN Areas como Península Valdés (SE Argentina), Patrimonio de la Humanidad desde 1999, están sujetas a degradación del suelo por acción eólica y sobrepastoreo. La cartografía de indicadores de degradación del paisaje, como dunas activas activas y estabilizadas, es crucial para mejorar la predicción, monitoreo y manejo de suelos afectados. Este...

In many rangeland ecosystems, the role of fire on vegetation dynamics has been the object of detailed studies. In Argentina, and especially in Patagonia, the knowledge of how fire changes vegetation is scarce. In 3 areas affected by wildfires on different dates (in 1988, 1994, and 1998), we determined the structure of the vegetation (plant cover, d...

Introducción La Teledetección y los Sistemas de Información Geográfica (SIG) han resultado una herramienta crucial para la obtención de indicadores espectrales y paisajísticos de desertificación (Collado et al., 2002). Sin embargo, son escasos los trabajos en el país sobre el uso de los datos radar, principalmente en esta temática (del Valle, 2000)...

In many rangeland ecosystems, the role of fire on vegetation dynamics has been the object of detailed studies. In Argentina, and especially in Patagonia, the knowledge of how fire changes vegetation is scarce. In 3 areas affected by wildfires on different dates (in 1988, 1994, and 1998), we determined the structure of the vegetation (plant cover, d...

Arid and semiarid shrublands occupy extensive land areas over the world, are susceptible to desertification by anthropic use and can contribute to regional climate change. These prompt the interest to monitor and evaluate these lands adequately in order to detect early stages of degradation. Evaluation topics must refer to biology relevant characte...

Great part of Patagonia is covered by Jurassic to lowermost Cretaceous intermediate to acid volcanic rocks, considered as a “Silicic Large Igneous Province” by Pankhurst et al. (1998), and formed in connection with the opening of the South Atlantic Ocean. These volcanic rocks have got various formation names in Argentina and Chile. At the eastern b...

We evaluated distribution and size of Magellanic Penguin (Spheniscus magellanicus) colonies in northern San Jorge Gulf, Argentina, characterizing nesting habitat at 14 islands with colonies (IC) and 28 islands without nesting penguins (INC). Digital analysis of a Landsat TM satellite image and field measurements were used to assess vegetation and s...

The atmospheric and fuel conditions that led to the case of extreme fire behaviour registered in Puerto Madryn in north-eastern Patagonia, Argentina, on 21 January 1994 were analysed in this study. The analyses included surface and upper-air meteorological conditions, fuel composition and load, and morphometry of the burnt area. When the fire occur...

Ecology may benefit from long term, large scale experiments on low intensity farming to test theoretical principles and convert them into practical lessons. One century of land conversion in the Argentine pampas, and its effect on critical ecological properties, were analysed and discussed. Land transformation has resulted in significant changes of...

There is increasing interest in developing criteria to evaluate the environmental implications of intensive agricultural land use. This implies discriminating between nature and man-made effects upon structural and functional attributes of agroecosystems. Adequate indicators of these combined effects should be cost efficient yet compatible with the...

This study was conducted to (1) quantify the mineral composition of litter, new leaves, and stems of two plant species (Atriplex lampa and Prosopis alpataco) in shrub patches, occurring with common abundance in the northeastern Patagonian region, and (2) determine the spatial and temporal variabilities of the mineral elements. There were 240 vegeta...

Soil loss and runoff were assessed in five land units (LUs) of a closed basin by means of 18 experimental plots within a 42 month period . Temporal distribution of runoff and erosion was unequal . Among 120 rainfall events recorded during the study period , only 15 events caused runoff . Maximum percent of runoff (79 . 9 % ) and maximum specific ru...

The objective of this research was to determine the degree of decomposition and alteration of lignin in soils of two types of shrub patches , featured by the dominant species (Prosopis alpataco and Atriplex lampa) in the northeastern Patagonian region . These species have been widely utilized in land reclamation programs mainly in west and south -...

The objective of this study was to assess the formation, distribution, and physicochemical properties of litter in two types of shrub patches, featured by the dominant species (Atriplex lampa and Prosopis alpataco). These species are important components of the Monte Phytogeographic Province . The surface layers of the shrub-steppe have been classi...

Desertification advance in the Patagonian region is the main socioecological problem. However, in this region the precise location, extent, severity, and characteristics of desertification are often unknown. The objectives of this research were (1) to evaluate, classify, and interpret the status of desertification, based on biological and physical...

The objective of this article was to summarize and review critically the available information on soil heterogeneity at the regional scale. The result of this effort is a map at the suborder level and at an approximate scale of 1:10,000,000 were I pointed out the main inconsistencies between the local studies and the regional maps. I also provide a...

The objectives of this paper were: 1) to establish a classification system of crusts and layers, based on micromorphology and genesis, and 2) to determine the pedological modifications in the presence of the progressive soil degradation processes. The study site is located in a shrubby steppe of northeastern Chubut (Argentina). The microtopographic...

A study was conduced in a burnt area of rangelands (01.21.1994), located 10 km west of the city of Puerto Madryn (42° 46′ S, 65° 03′ W), in the northeast of Central Patagonia (Argentina). The objective of this study was to relate certain parameters of the surface affected by the fire to the features of different ERS-1/SAR images. The gathering of f...

Radar image (ERS-1/SAR) and SPOT composites have been analyzed with the purpose of identifying and describing surface features with better results than those to be obtained by single-sensor images. The objective of this study was to provide an apparent increase in resolution, classification and to portray better relief by adding radar images to Spo...

Radar images present diverse types of textures in direct and/or indirect relationships with geophysical and biophysical information. Space resolution and sign-noise relationship characteristics, make these images useful for the analysis of human impact and natural disturbances. According to this, the applications of ERS-1/SAR images make it necessa...

The objectives of this study were to determine the factors and processes of desert pavement formation in relation to superficial soil properties and morphological features. The study site is located in a shrubby steppe of northeastern Chubut, where the microtopography consists of mounds beneath shrub clumps, and areas of desert pavements. Surface l...

The guanaco (Lama guanicoe) is the largest mammal inhabiting the Argentine Patagonia. The distribution of this species is strongly based on its sociobiological characteristics. Family and non-reproductive groups tend to be associated with environments with food resources, water availability and escape corridors in areas of slopes and rough terrain....

Degradation processes and their association with spatial and lithological discontinuities in argillic horizons of nine profiles in northeastern Chubut province were examined. Twelve test pits were used as stratigraphic controls. The reconstruction of the upper limit of the argillic horizons and its position in relation to the soil surface was perfo...

Calcretes closely linked with fossil ice-wedge pseudomorphs in Pleistocene alluvial deposits are widespread in Patagonia from Rio Negro (Lat. 40°S) to Rio Gallegos (Lat. 53°S). As carbonate rocks are absent in the region, the questions to be asked are: where did the calcium carbonate come from, how did it accumulate, what does this relationship bet...

Calcretes closely linked with fossil ice-wedge pseudomorphs in Pleistocene alluvial deposits are wide-spread in Patagonia from Rio Negro (Lat. 40°S) to Rio Gallegos (Lat. 53°S). As carbonate rocks are absent in the region, the questions to be asked are: where did the calcium carbonate come from, how did it accumulate, what does this relationship be...