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Auteur J. E. Cousens |
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The status of the pedunculate and sessile oaks in britain / J. E. Cousens in Watsonia, vol. 6, n°3 (Année 1965)
[article]
Titre : The status of the pedunculate and sessile oaks in britain Type de document : texte imprimé Auteurs : J. E. Cousens, Auteur Année de publication : 1965 Article en page(s) : pp. 161-176 Langues : Anglais (eng) Catégories : [ZG] Royaume-Uni
[Espèces (in biblio)] Quercus petraea
[Espèces (in biblio)] Quercus roburMots-clés : comparaison d'espèce description Résumé : "Introgression in the pedunculate oak: (Quereus robur L.) and sessile oak : (Q. petraea (Matt.) Liebl.) in Scotland was known to be so extensive that neither could be defined satisfactorily. Population studies were therefore carried out in Eire to clarify the status of the sessile oak: and in south-east England and in the flood plain oak: forests of Yugoslavia in an attempt to find good pedunculate oak:. Each of these collections revealed some evidence for introgression. A method of analysis has been devised to distinguish between currently active introgression and a condition due either to incomplete evolutionary divergence or to old introgression now largely assimilated into the gene pool. Q. petraea is a relatively good species in Eire and possibly in southern England too. Q. robur is diagnosed as a species, possibly as homogeneous as Q. petraea at one time, but, if so, introgressed by a number of related species during the last glaciations or earlier; it arrived in post-glacial Britain already a very variable species and was subjected to a little secondary introgression by Q. petraea. Introgression of both species increases northwards into Scotland. The much greater introgression of Q. petraea in Scotland has been made possible by the practice of planting Q. robur to maintain the stocking of petraea coppice woods. The observed variation in the selected diagnostic characters in the Yugoslavian and Irish collections is outlined to provide a provisional definition of Q. robur and Q. petraea in Britain. " (source : auteur) Type de publication : périodique Référence biblio : Cousens J.-E., 1965 - The status of the pedunculate and sessile oaks in britain. Watsonia, 6 (3) : 161-176. ID PMB : 71611 En ligne : https://archive.bsbi.org.uk/Wats6p161.pdf Format de la ressource électronique : document Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=71611
in Watsonia > vol. 6, n°3 (Année 1965) . - pp. 161-176[article]Exemplaires(1)
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