Search results for "soil"

Relaciones suelo-vegetación en una toposecuencia del Escudo Guayanés, Venezuela

2014

El Escudo Guayanés es uno de los territorios más antiguos del planeta; tiene millones de años sometido a procesos de lixiviación y erosión que dejan suelos oligotróficos. El objetivo de este trabajo fue hacer la caracterización de los parámetros físicos y químicos de los suelos, en diferentes comunidades boscosas de la Reserva Forestal Imataca, e identificar ciertas relaciones entre los componentes edáficos y las especies que allí se presentan. Se realizó un inventario de todos los individuos mayores a 10cm dap (diámetro a la altura del pecho) en 15 parcelas (1ha); en cada una de esas parcelas se evaluaron cuatro sub-parcelas de sotobosque (100m²) para contabilizar todas las espermatofitas;…

Assessing the performance of different model-based techniques to estimate water content in the upper soil layer

2016

he knowledge of soil water content (SWC) of the upper soil layer is important for most hydrological processes occurring over vegetated areas and under dry climate. Because direct field measurements of SWC are difficult, the use of different type of sensors and model-based approaches have been proposed and extensively used during the last decade. The main objective of this work is to assess the performance of two models estimating SWC of the upper soil layer: the transient line heat source method and the physically based Hydrus-1D model. The models' performance is assessed using field measurements acquired through a Time Domain Reflectometer (TDR). The experiment was carried out on an olive …

Regional Soil Moisture Retrieval Using Remotely Sensed Crop Water Stress Indicators

2011

Spatial distribution of soil water repellency in a grassland located in Lithuania

2014

Soil water repellency (SWR) it is recognized to be very heterogeneous in time in space and depends on soil type, climate, land use, vegetation and season (Doerr et al., 2002). It prevents or reduces water infiltration, with important impacts on soil hydrology, influencing the mobilization and transport of substances into the soil profile. The reduced infiltration increases surface runoff and soil erosion. SWR reduce also the seed emergency and plant growth due the reduced amount of water in the root zone. Positive aspects of SWR are the increase of soil aggregate stability, organic carbon sequestration and reduction of water evaporation (Mataix-Solera and Doerr, 2004; Diehl, 2013). SWR depe…

Caratterizzazione della componente volatile rilasciata da sostanza organica naturale di suoli vulcanici

2008

Il suolo è una matrice caratterizzata da notevole complessità chimico-fisica. Tra le varie componenti, la sostanza organica naturale (NOM) gioca un ruolo fondamentale nelle interazioni con contaminanti di natura organica ed inorganica. La NOM è attualmente considerata una associazione supramolecolare di sistemi organici con un peso molecolare non superiore a 1000-2000 Da. La sua caratterizzazione è tradizionalmente effettuata mediante l’ausilio di tecniche cromatografiche e spettroscopiche. La verifica dell’allontanamento di molecole a basso peso molecolare all’aumento della temperatura, nell’intervallo 40-100 °C, è stata condotta con tecniche di microestrazione in fase solida in spazio di …

Soil forming factors

2007

The Russian geologist Vasily Dokuchaev (1846–1903), considered the father of soil science, was the first to identify and discuss, at the end of 19th century, what we know today as the “factors of soil formation”. He introduced the idea that soil is not something inert and stable, but it develops and evolves under the influence of climatic agents and vegetation that operate over time on a given geological substrate

THE STRUCTURE OF SOIL CADASTRE. A MODEL OF SOIL INVENTORY FOR ENVIRONMENTAL, SOCIAL, ECONOMIC AND TAXATION PURPOSES IN A GLOBALISED MARKET

2018

The author shows the development of a structure, derived from the processing and integration of Ground Cadastre, where all soil characteristics are described. The soil is considered as divided according to the updated concept of cadastral parcel (soil and topographic uniformity of ownership and municipality). The land use is also assessed with reference to sustainability, taxation and environmental risk prevention. The structure of Soil Cadastre can contribute to the bureaucratic simplification of agricultural policies and environmental emergencies, as well as product presentation and traceability. Through the updating of some characteristics by professionals, the cadastre can become eviden…

Assessing the quality of dissolved organic matter in forest soils using ultraviolet absorption spectrophotometry

2007

Abbreviations: DOC, dissolved organic carbon; SUVA, specifi c ultraviolet absorbance; UV, ultraviolet. Ultraviolet spectrophotometry was used to investigate the effects, 30 yr after planting, of tree species substitution on the aromatic C content and related properties of dissolved organic carbon (DOC). Precautions were taken to correct measurements for the absorbance of NO 3 and dissolved Fe. In litter leachates, a signifi cant reduction in the aromatic content of DOC was found in the Douglas-fi r [Pseudotsuga menziesii (Mirb.) Franco] plantation but not in the beech (Fagus sylvatica L.) plantation. The disturbance of short-term C dynamics thus revealed agreed well with fi eld observations…

Mapping soil water content under sparse vegetation and changeable sky conditions: comparison of two thermal inertia approaches

2013

A critical analysis of a thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data is reported. The study area is an experimental field located in Barrax, Spain. In situ data were acquired within the Barrax 2011 research project. An advanced hyperspectral scanner airborne imager provides images in the visible/near-infrared and thermal infrared bands. Images were acquired both in day and night times by the Instituto Nacional de Técnica Aeroespacial between 12th and 13th of June 2011. The scene covers a corn irrigation pivot surrounded by bare soil, where a set of in situ data have been collected both previously and simult…

In situ measurements of background aerosol and subvisible cirrus in the tropical tropopause region

2002

[1] In situ aerosol measurements were performed in the Indian Ocean Intertropical Convergence Zone (ITCZ) region during the Airborne Polar Experiment-Third European Stratospheric Experiment on Ozone (APE-THESEO) field campaign based in Mahe, Seychelles between 24 February and 6 March 1999. These are measurements of particle size distributions with a laser optical particle counter of the Forward Scattering Spectrometer Probe (FSSP)-300 type operated on the Russian M-55 high-altitude research aircraft Geophysica in the tropical upper troposphere and lower stratosphere up to altitudes of 21 km. On 24 and 27 February 1999, ultrathin layers of cirrus clouds were penetrated by Geophysica directly…