Le Canigou : caractéristiques, aménagement forestier, enjeux d'un Grand Site

Les deux jours consacrés à la visite du Massif du Canigou lors de la tournée forestière annuelle de l'association Forêt Méditerranéenne a permis aux participants de traverser les différents étages de végétation : chênaie verte, pineraie sylvestre, sapinière ancienne, pineraie à crochet, hêtraie sapinière, jusqu'aux tourbières d'altitude près du refuge des Cortalets. Dans ce massif aux multiples fonctions, l'aménagement forestier doit pouvoir concilier l'ensemble des enjeux (forestiers, environnementaux, sociaux économiques...). Un défi à relever pour ce site exceptionnel

Gestion du chêne vert en Corse, quelques éléments de sylviculture

Le chêne vert est, en Corse, placé dans des conditions naturelles différentes de celles qui existent sur le continent : pluviosité généralement supérieure, relief accusé. Les peuplements peuvent être classés selon les types différents : le taillis, le maquis à chêne vert, la futaie et le taillis sous futaie. Outre la pérennité de l'état boisé, le gestionnaire recherche dans chaque peuplement à obtenir l'équilibre entre divers objectifs : produire du bois, obtenir des glands, préserver l'environnement pour rester une forêt accueillante aux promeneurs. Une gestion forestière peut être envisagée par le traitement en taillis et en futaie

Biological Flora of the British Isles: Sorbus torminalis

1.This account presents information on all aspects of the biology of Sorbus torminalis (L.) Crantz (Wild Service-tree) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation.2.Sorbus torminalis is an uncommon, mostly small tree (but can reach 33 m) native to lowland England and Wales, and temperate and Mediterranean regions of mainland Europe. It is the most shade-tolerant member of the genus in the British Isles and as a result it is more closely associated with woodland than any other British species. Like other British Sorbus species, however, it grows best where competition for space and sunlight is limited. Seedlings are shade tolerant but adults are only moderately so. This, combined with its low competitive ability, restricts the best growth to open areas. In shade, saplings and young adults form a sapling bank, showing reproduction and extensive growth only when released. Sorbus torminalis tolerates a wide range of soil reaction (pH 3.5-8.0) but grows best on calcareous clays and thin soils over limestone.3.Sorbus torminalis is a sexual, diploid, non-apomictic species that has hybridised with a number of other Sorbus species to form microspecies. The hermaphrodite flowers are primarily insect pollinated. Seed production is reliable only in warm years, especially at the edge of its range, although even then seed viability is low. The fruits are primarily dispersed by carnivorous mammals. Seeds display embryo dormancy but most will germinate the first spring after falling.4.This tree is very tolerant of short droughts but only moderately tolerant of frost, hence its southerly and lowland distribution. It faces no particular individual threats although the small size of most populations makes it susceptible to habitat loss and fragmentation, particularly through the loss of open coppiced areas. As a consequence it appears to be declining throughout Britain and Europe despite its wide range of historical uses and the high value of its timber. The extent to which these losses will be offset by increases due to climate change is unknown.This article is protected by copyright. All rights reserved

Le forêt domaniale de Valbonne (Gard) Aménagement 1987-2006.

Décrit la forêt domaniale de Valbonne (Gard), l'historique des aménagements, le bilan et les perpectives

Relating microstructure to shear strength of thin calcium phosphate coatings

The changes in shear strength and crystallinity along with microscopy of the thin calcium phosphate coating surface and sample fracture surfaces were analyzed. Samples of stainless steel were made the cathode in the reaction while platinum was made the anode. Coated samples and fractured surfaces from lapshear tests were carbon coated and viewed in a Jeol 840F FEG SEM at accelerating shear strength. It was found that increase in maturation time led to an increase in coating thickness and a reduction in surface porosity