Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo lâm nghiệp: "Stem profile equations for young trembling aspen in northern Ontario"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài: Stem profile equations for young trembling aspen in northern Ontario. | 109 Ann. For. Sci. 61 2004 109-115 INRA EDP Sciences 2004 DOI 10.1051 forest 2004001 Original article Stem profile equations for young trembling aspen in northern Ontario Michael T. TER-MIKAELIANa Wojciech T. ZAKRZEWSKIa G. Blake MACDONALDa David H. WEINGARTNERb a Ontario Forest Research Institute 1235 Queen Street East Sault Ste. Marie Ontario P6A 2E5 Canada b118 Country Club Place Sault Ste. Marie Ontario P6A 6A3 Canada Received 5 February 2002 accepted 18 February 2003 Abstract - Stem profile equations were developed for young trembling aspen Populus tremuloides Michx. growing on 6 different sites in northern Ontario. The objective was to develop a model using stem diameter at any height to predict stem diameter at other heights and then compare the model among sites. The 262 sample trees were split into calibration 180 and validation 82 sets. Four stem profile models having from 1 to 3 parameters were tested for parameter significance for each site and then compared among sites. Data analysis was performed using bootstrap methods. One of the 4 models was not significantly different P 0.278 among sites. Validation of this model produced mean prediction errors and mean relative prediction errors of less than 0.001 cm and 0.09 respectively standard deviations of these errors were 0.15 cm and 4.09 respectively. The presented method can be used to develop stem profile equations that are applicable to a broad range of growing conditions. Populus tremuloides stem profile models stem diameter bootstrap methods Résumé - Equations de profil de tige de jeunes trembles de l Ontario septentrional. On a mis au point des équations de profil de tige pour des trembles Populus tremuloides Michx. se développant dans 6 stations différentes du nord de l Ontario. L objectif était de créer un modèle utilisant le diamètre pris à n importe quelle hauteur pour prédire le diamètre à d autres hauteurs et ensuite pour comparer les modèles selon les sites. Les 262 arbres témoins ont été .