Autoécologie des chênaies de Quercus robur L. en Galice (Espagne)

Abstract

Résumé -Une caractérisation paramétrique des biotopes occupés actuellement par des formations de « carballo » (Quercus robur L.) est présentée pour la Galice (Espagne). Pour ceci, on a inventorié un total de 39 parcelles et on a élaboré 28 paramètres écologiques caractéristiques du biotope, avec 14 autres paramètres qui caractérisent de façon dendrométrique et sylvicole les chênaies inventoriées. Cette information a permis de définir l'habitat physiographique, climatique et édaphique, central et marginal, de Quercus robur en Galice, ainsi que d'établir la caractérisation de la situation actuelle de ses massifs d'un point de vue dendrométrique et sylvicole. Les chênaies galiciennes présentent une hétérogénéité élevée aussi bien dans les biotopes où elles se situent que dans l'utilisation et la gestion auxquelles elles ont été soumises. La variation altitudinale est supérieure à 1200 m, ceci se traduit par une différence de température moyenne de 7,3°C. Les précipitations moyennes annuelles sont de 1371,9 mm, la moyenne estivale atteint 164 mm, en conséquence, l'aridité estivale est très faible. Les sols, en majorité des cambisols, sont fortement acides, avec une composition texturale à dominante sableuse, ceci est dû à la nature des matériaux géologiques (granites et schistes) desquels ils proviennent. Quercus robur / autoécologie / biotope / limite écologique / Galice Abstract -Autoecology of oaks (Quercus robur L.) in Galicia (Spain).A parametric characterization of the biotypes currently in stands of "carballo" (Quercus robur L) in Galicia (Spain) is presented. For this, an inventory of a total of 39 plots has been made. Twenty-eight ecological parameters characteristic of each biotype as well as 14 more to characterize forest mensuration and silviculture of studied oaklands were elaborated. This information has permitted the determination of the fisiographic, climatic and edaphic habitat of Quercus robur in central and marginal area in Galicia, as well as the characterisation of the actual situation from a silvicultural stands point of view. Galician oakwoods are highly heterogeneous, as well in biotype location as their use and management they had been subjected. Their altitudinal difference is near to 1200 m and this signify a mean temperature difference of 7.3 ºC. The annual precipitation average is 1371.9 mm ; with 164 mm in summer rains, in consequence summer dryness is very scarce. The soils, mainly cambisols, are strongly acidic, with a dominant sandy textural composition due to the nature of their geological origin, which are by and large granite and schist rocks.Quercus robur / autoecology / site / ecologic limit / Galicia

Carbon and nutrient stocks in matureQuercus roburL. stands in NW Spain

“…III) were similar to those of most pedunculate oak stands in the region [16]. They are humic Umbrisols of total depths ranging from 60 to 110 cm.…”

“…However, in recent decades, abandonment of rural areas has reduced the intensity of the harvesting. Furthermore, in recognition of the importance of the environmental issues associated with oak forests (biodiversity, C accumulation, [6,16,27,43,45]), they are currently protected by different regional and national regulations. Less intensive management, along with the implementation of conservation measures can contribute to restoring forest structure and therefore, C stocks and nutrient cycling.…”

Variation des composés volatils du bois dans un peuplement mixte de chênes: forte différenciation interspécifique et forte structuration spatiale de la quantité de whisky-lactone

“…Several research groups have investigated the botanical species (Quercus robur L. and Quercus petraea Liebl.) in relation to climate, topography, soil and dendrology [4,13,20,32,33]. These species are known to differ in the concentration of some volatile substances, especially the β-methyl-γ-octolactone (whisky-lactone), which was consistently found to be more abundant in Q. petraea than in Q. robur [8,14,18,[26][27][28].…”

Un modèle pour l’estimation du volume commercialisable de chêne pédonculé dans le Nord-Ouest de l’Espagne

“…This oak is also the dominant tree species in native forest in areas of Galicia (northwest Spain) with a wet oceanic climate, where currently 187 000 ha of pure oak stands are found [62]. Because of its importance and wide occurrence, studies related to the autoecology [20], site quality [4], and carbon and nutrient stocks [2] of pedunculate oak in the area have been carried out recently; nevertheless, none of them was related to merchantable volume estimation. The objective of the present study was therefore to develop a merchantable volume system for this species in Galicia.…”