Search results for "FOREST"
showing 10 items of 3780 documents
Biomass, litterfall and nutrient content in Castanea sativa coppice stands of southern Europe
1996
Les biomasses et les mineralomasses, les retombees de litiere et la restitution au sol de bioelements par leur intermediaire ont ete etudiees dans des peuplements de Castanea sativa Mill en Espagne (province de Salamanque), en Italie (massif de l'Etna) et en France (Cevennes). Les meilleurs correlations et resultats ont ete trouves avec des regressions allometriques de type: Y (biomasse) = aX (diametre tronc a 1,30 m) b . Les parametres des differentes equations de regression sont semblables et tres proches pour les châtaigniers de France et d'Italie. La principale source de differences, au niveau stationnel, resulte de la repartition differente des arbres en fonction des classes de diametr…
New Business Models for innovating the cork sector and contrasting cork oak woodland abandonment
2021
The traditional agro-silvo-pastoral system is characterized by wooded grasslands derived from human-induced transformation of forests by tree clearing and tillage. One of the most common tree species of agro-silvo-pastoral systems in Sicily is cork oak (Quercus suber L.). According to the regional inventory these species cover 18830 ha (Camerano et al., 2011) from sea level up to 600 m a.s.l. in siliceous and volcanic substrates. Traditional management of cork oak forest is an example of integration of sustainable land use and biodiversity conservation. Cork oak woodlands are ecologically sensitive and maintained by active human management. Currently, this ecosystem in the Mediterranean Bas…
Dye-tracer technique for rill flows by velocity profile measurements
2020
Abstract Water flow on hillslope soil surface supplies energy which is required to detach soil particles, to transport and deposit sediments, therefore flow velocity is a key variable related to hillslope hydrodinamics of soil erosion processes. Among the different methods available for measuring velocity of shallow interrill and rill flow, the trace technique is widely used. Trace technique is applied by adding a material (salt, magnetic material, water isotope, floating object) and then measuring the speed of the material to travel a known distance from the injection point. When flow velocity is measured using a dye-tracing method, the mean velocity is calculated by multiplying the measur…
Flume experiments for assessing the dye-tracing technique in rill flows
2021
Abstract Flow velocity controls hillslope soil erosion and is a key hydrodynamic variable involved in sediment transport and deposition processes. The dye-tracer technique is one of the most applied methods for measuring velocity of shallow interrill and rill flow. The technique is based on the injection of a tracer in a specific point and the measurement of its speed to travel the known distance from the injection point to a given channel section. The dye-tracer technique requires that the measured surface flow velocity has to be corrected to obtain the mean flow velocity using a correction factor which is generally empirically deduced. The technique has two sources of uncertainties: i) th…
Uncertainty analysis of gross primary production upscaling using Random Forests, remote sensing and eddy covariance data
2015
Abstract The accurate quantification of carbon fluxes at continental spatial scale is important for future policy decisions in the context of global climate change. However, many elements contribute to the uncertainty of such estimate. In this study, the uncertainties of eight days gross primary production (GPP) predicted by Random Forest (RF) machine learning models were analysed at the site, ecosystem and European spatial scales. At the site level, the uncertainties caused by the missing of key drivers were evaluated. The most accurate predictions of eight days GPP were obtained when all available drivers were used (Pearson's correlation coefficient, ρ ~ 0.84; Root Mean Square Error (RMSE…
The Baryon Oscillation Spectroscopic Survey of SDSS-III
2012
The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large-scale structure. BOSS uses 1.5 million luminous galaxies as faint as i = 19.9 over 10,000 deg(2) to measure BAO to redshifts z < 0.7. Observations of neutral hydrogen in the Ly alpha forest in more than 150,000 quasar spectra (g < 22) will constrain BAO over the redshift range 2.15 < z < 3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Ly alpha forest and a strong detection from the Data R…
Where are we now with global forest regulation and governance? Insights from a 'Global Public Goods' Perspective
2016
Even if an encouraging tendency has recently been observed towards a reduction in the rates of global deforestation, the extent and quality of forests continue to decline in many regions of the world, with alarming consequences on the functioning of global hydrological cycles, the conservation of the world's biological diversity, and the fight against climate change. Against this background, the aim of the present article is to investigate the weaknesses of, and the areas for improvement in, the current framework of global forest governance, through an analysis conducted using the lens of the concept of «global public goods» as transposed into, and shaped by, two competing theoretical appro…
L’agroforesterie, le futur de la viticulture ?
2020
L’agroforesterie est l’association sur une même parcelle d’une végétation arborée et/ou arbustive, et d’une production végétale, animale ou mixte. Les espèces ligneuses peuvent être réparties uniformément, inégalement ou en bordure de parcelle. Les systèmes agroforestiers fournissent des services écosystémiques et des produits et ce à différentes échelles ; parcelle, exploitation agricole, unité paysagère » (RRAF, 2018). La productivité de ces systèmes dépend de la différence nette entre les avantages et les coûts, entre les utilisations et les composantes biophysiques de l’agroenvironnement. Dans les systèmes de cultures intercalaires, les avantages des arbres sont à la fois économiques et…
Are Cover Crops Affecting the Quality and Sustainability of Fruit Production?
2021
The study of the interaction between fruit trees and cover crops has been addressed in numerous works over the last 50 years or more, evidencing the need to evolve from a productive orchard to an orchard that plays different ecosystem roles in terms of environmental sustainability rather than just productivity. This review, through an analysis of the scientific literature since the 1950s, highlights the development of sustainable soil management models in fruit tree orchards, mostly considering the relationship with fruit quality traits and with the ecosystem services that result from the adoption of cover crops, aiming at identifying and formulating technical recommendations in perennial o…
No-till durum wheat yield success probability in semi arid climate: A methodological framework
2018
Abstract The aim of this study is to develop a framework for the evaluation of no-till (NT) yield success probability as a decision tool for farmers or decision makers. The effect of soil management on durum wheat yield has been tested on many long-term field experiments. Results of these researches were collected in a unique dataset to evaluate the success of NT management in comparison to conventional tillage (CT) as influenced by the aridity index, crop residue management and cropping system. A total of 519 observations of long-term experiments (>3years) regarding durum wheat in a number of areas with semi arid climate were included in the present study. The relative ratio of yield under…