Search results for "FOREST"

USING ROTATING SPRINKLER GUNS IN CENTRE‐PIVOT IRRIGATION SYSTEMS †

2019

The use of centre-pivot irrigation systems has significantly increased in the last few decades, since they are easier and less time-consuming to manage compared to other irrigation systems. Standard high-pressure impact sprinklers, low-pressure spray sprinklers or LEPA (Low Energy Precision Application) systems are usually combined with a centre-pivot irrigation system (CP-SYS). However, when applying waste water or with reclaimed effluents that are extremely dirty, small nozzle sizes that require CP-SYS could get plugged. As an alternative to common centre-pivot irrigation systems, this paper analyses the ‘geometry’ of areas irrigated by rotating sprinkler guns in a centre-pivot irrigation…

Centre-pivot irrigation system design for uniform water application rate

2020

<p>In the last few decades, the use of centre-pivot irrigation systems has significantly increased, since it makes farming easier, is more efficient and less time-consuming compared to the other irrigation systems. Several studies have been focused on the hydraulics of the centre-pivot systems. Standard high-pressure impact sprinklers or low-pressure spray sprinklers or Low Energy Precision Application (LEPA) systems are generally mounted on the pipeline.</p><p>To ensure the uniformity of water application, the centre-pivot design requires increasing the flow rates along the lateral, because the sprinklers farther from the pivot move faster, and th…

Experimental Study of Central Baffle Flume

2019

In this paper, the hydraulics of a central baffle flume (CBF) were experimentally studied. Extensive experimental runs were carried out to highlight the effects of different geometrical parameters such as baffle length, contraction ratio, and the length of upstream and downstream guide walls. Two different approaches, i.e., the Π theorem of dimensional analysis coupled with the incomplete self-similarity theory and the energy balance equation, were applied to deduce the stage–discharge formula of a CBF characterized by different geometrical parameters. The stage–discharge relationship deduced by the dimensional analysis approach was more accurate than that obtained by the energy approach. F…

Woodland key habitats in northern Europe: concepts, inventory and protection

2010

Abstract The woodland key habitat (WKH) concept has become an essential instrument in biodiversity-orientated forest management in northern Europe. The philosophy behind the concept is basically the same in all of the countries: to conserve the biodiversity of production landscapes by preserving small habitat patches that are supposed to be particularly valuable. This article reviews the definitions, inventories and implementation processes of WKHs in Sweden, Finland, Norway, Latvia, Estonia and Lithuania. Sweden and the Baltic countries have similar WKH models, while the models in Finland and Norway are clearly deviating. Depending on the country, the definitions emphasize different factor…

Les hêtraies du Châtillonnais (Côte-d'Or) face au changement climatique.

2013

15 pages; International audience; L'étude traite des hêtraies du Châtillonnais (Côte-d'Or, Bourgogne) face au changement climatique observé. Les données regroupent les séries bourguignonnes de température et de précipitation des stations de Météo France (1989-2009), la carte des hêtraies de l'Institut forestier national (IFN), un modèle numérique de terrain (MNT, SRTM) et quatre indices de vulnérabilité du hêtre identifiés dans la littérature. La méthode repose sur une interpolation fine (mailles de 100 m) de ces indices par régression-krigeage. Les résultats permettent de cartographier les risques actuels.

The vegetation of a historic road system in the suburban area of Monte Pellegrino (Palermo, Sicily)

2020

Knowledge of the processes by which plants colonize old structures is a key element for nature-based design both in urban and suburban contexts. This paper analyses the natural vegetation on walls and in other microhabitats of the roadway structures of Monte Pellegrino (606 m a.s.l.) near Palermo (Sicily), built in the first half of the 1900s. The historical road has particular construction and architectural features, and its characteristics have been maintained to this day. The route, approximately 16 kilometers long, is well integrated within a site of high naturalistic value which has been designated as a Special Area of Conservation (ITA020014) of the Natura 2000 network, and it is also…

Ring diameter effects on determination of field-saturated hydraulic conductivity of different loam soils

2017

Abstract Establishing ring diameter effects on the field-saturated soil hydraulic conductivity, Kfs, determined with ponding infiltrometer methods can help to find a compromise between the need to sample a large area with an individual measurement and the impracticality of using large rings in the field. Five ring sizes (diameter, D = 5.5, 10.9, 16.0, 27.8 and 31.8 cm) were used to determine Kfs by the simplified falling head (SFH) technique in four loamy soils with different salinity (electrical conductivity of saturated extract, ECe = 0.9–29.4 dS/m) and sodicity (exchangeable sodium percentage, ESP = 2.7–81.3%) levels. According to USDA classification, two soils were non-saline, non-sodic…

Die bedeutung von Eiwei� und Fett f�r die ern�hrung des Menschen.

1948

Biomasse, productivité et transferts de matière organique dans une séquence altitudinale de peuplements de Castanea sativa Mill de l'Etna

1996

Les differents compartiments et flux caracterisant la repartition de la matiere organique sont etudies dans quatre taillis de Castanea sativa Mill, etages le long d'un gradient altitudinal, dans le massif de l'Etna (Sicile). Les biomasses epigees sont respectivement de 22 et de 24 Mg ha -1 a 7 ans, 83 Mg ha -1 a 12 ans et 100 Mg ha -1 a 22 ans, avec de bonnes correlations : biomasse/âge et biomasse/facteurs climatiques. Le bois represente 95 % et les feuilles 5 % de ces biomasses. Les productions aeriennes perennes s'echelonnent entre 2,4 et 5,4 Mg ha -1 an -1 en relation a la fois avec l'âge des taillis et leur localisation geographique. Les retombees de litiere, observees durant 3 annees …

CPMAS 13C NMR Characterization of Leaves and Litters from the Reafforestated Area of Mustigarufi in Sicily (Italy)

2010

Reafforestation is generally based on the planting of exotic fast growing tree species suitable for adapting to even harsh environments. Once the introduced plants ameliorate soil conditions, they can be progressively replaced by au- tochthonous plant species. Reafforestation is applied worldwide. However, only few studies on the effect of reafforesta- tion on lands from Mediterranean regions are available. This paper reports the characterization by cross polarization 13C NMR spectroscopy of fresh leaves and superficial litters from a reafforestated area in central Sicily (Italy). NMR assign- ment is attempted. A differentiation among the molecular systems within leaves and litters is also …