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Báo cáo lâm nghiệp: "Influence of individual tree and stand attributes in stem straightness in Pinus pinaster Ait. stands"
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Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Influence of individual tree and stand attributes in stem straightness in Pinus pinaster Ait. stands. | Ann. For. Sci. 61 2004 141-148 INRA EDP Sciences 2004 DOI 10.1051 forest 2004005 141 Original article Influence of individual tree and stand attributes in stem straightness in Pinus pinaster Ait. stands Miren DEL RÍO Felipe Bravo Valentín Pando Gemma Sanz Rosario Sierra de Grado Dept. Producción Vegetal y Recursos Forestales Universidad de Valladolid Avda. de Madrid 57 Palencia 34004 Spain Received 14 June 2002 accepted 2 January 2003 Abstract - The potential relationships between stem straightness and site and both individual and stand attributes were studied in Pinus pinaster Ait. stands. To this effect 32 plots encompassing different densities and sites of varying quality were laid out in mature stands. In a young stand a completely randomised design with 9 plots was set up in order to compare three regeneration densities. During the study numerous saplings were bent down by heavy snowfalls. Data analysis using multinomial logistic regression failed to show any relationship between stem straightness and the attributes under study in mature stands. In young stands however stem straightness appeared to be influenced by the height diameter ratio as well as by the total height and the density of the stand at the time of the snowfalls. High density plots were severely affected by snow and consistently contained the least satisfactory instances in terms of stem straightness. stem straightness Pinus pinaster regeneration density height-diameter ratio snowfall Résumé - Influence des caractéristiques des arbres individuels et des peuplements sur la rectitude du tronc dans les peuplements de Pinus pinaster Ait. Le rapport entre la rectitude du tronc et les caractéristiques du site des arbres individuels et des peuplements a été étudié dans des peuplements de Pinus pinaster Ait. On a mesuré 32 parcelles dans des peuplements matures couvrant des sites de différentes densités et qualités. On a établi tout à fait au hasard dans un jeune peuplement un modèle comprenant 9 .