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Xylem and soil CO2 fluxes in a Quercus pyrenaica Willd. coppice: root respiration increases with clonal size / Roberto Salomón in Annals of Forest Science, vol 72 n° 8 (December 2015)  

Public [article]  inAnnals of Forest Science > vol 72 n° 8 (December 2015) . - pp 1065-1078 Titre : Xylem and soil CO2 fluxes in a Quercus pyrenaica Willd. coppice: root respiration increases with clonal size Type de document : Article/Communication Auteurs : Roberto Salomón, Auteur ; María Valbuena-Carabaña, Auteur ; Jesús Rodríguez-Calcerrada, Auteur ; et al., Auteur Année de publication : 2015 Article en page(s) : pp 1065-1078 Note générale : biblographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes IGN] dioxyde de carbone [Termes IGN] Pyrénées (montagne) [Termes IGN] Quercus (genre) [Termes IGN] système radiculaire [Termes IGN] taillis Résumé : (auteur) : Key message: Xylem and soil CO 2 fluxes in coppiced oak forests increase with clonal size, suggesting larger expenditures of energy for root respiration. An imbalance between root demand and shoot production of carbohydrates may contribute to the degradation of abandoned coppices. Context: Our understanding of root respiration is limited, particularly in root-resprouting species with many stems and a large system of interconnected roots resulting from long-term coppicing. Aims: We tested the hypothesis that clone size influences the internal flux of CO2 dissolved in xylem sap (F T) from roots into the stem and soil CO2 efflux (F S) as indicators of root respiration. We predicted that large clones would exhibit higher F T per stem and F S than small clones due to larger root system per stem in large clones. Methods: Genetic analyses were performed to elucidate clonal grouping. F T was measured continuously for 100 days in 16 similar-sized stems of Quercus pyrenaica belonging to two large and two small clones. F S was measured in 20 clones of varying size. Results: F T per stem and F S were higher in large clones. F T was 2 % of the root-respired CO2 that diffused through soil to the atmosphere. Conclusions: Relative to other studies, the contribution of F T to root respiration was very low, pointing to large differences depending on species or site. Higher stem F T and F S in large clones compared with small clones suggest greater carbon consumption by roots in large clones, pointing to a root/shoot biomass and physiological imbalance resulting from long-term coppicing that would partially explain the degradation of currently abandoned stands of Q. pyrenaica. Numéro de notice : A2015-898 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s13595-015-0504-7 Date de publication en ligne : 08/08/2015 En ligne : https://doi.org/10.1007/s13595-015-0504-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79455 [article]