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Báo cáo khoa học: "Sampling for wood properties in trial plots of 4 Eucalyptus species at Ruvu, Tanzania"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Sampling for wood properties in trial plots of 4 Eucalyptus species at Ruvu, Tanzania. | 233 Ann Sci For 1994 51 233-240 Elsevier INRA Original article Sampling for wood properties in trial plots of 4 Eucalyptus species at Ruvu Tanzania KFS Hamza s Lewark Institut fur Forstbenutzung und Forstliche Arbeitswissenschaft Werderring 6 D-79085 Freiburg Germany Received 1st September 1992 accepted 1st February 1993 Summary The objective of this study was to develop an effective sampling design for a planned investigation of basic density fibre length fibre-wall thickness vessel number and vessel proportion in trial plots of 16- and 17-year-old Eucalyptus tereticornis and 17-year-old E camaldulensis E paniculata and E citriodora grown in Ruvu Tanzania. The idea was to conduct the investigation stepwise starting with a higher number of samples per tree in one stand in order to get information about the variation within trees and between trees and later including more stands with a lower number of trees per stand and a lower number of samples per tree depending on the results of the first phase and calculations of the minimum number of measurements required. Calculations indicate that at a required precision of 5 of the mean it is possible to reduce the number of samples considerably. This will result in a substantial saving of time manpower and other costs needed for such studies. eucalyptus I sampling basic density fibre dimensions vessel number vessel proportion Resume Échantillonnage pour quelques propriétés du bois dans des parcelles experimentales de 4 espèces d eucalyptus installées à Ruvu Tanzanie . L objectif de I etude est de proposer un plan d echantillonnage efficace pour une recherche prévue sur I infradensite du bois la longueur et répaisseur des parols des fibres le nombre et la proportion de vaisseaux dans des parcelles experimentales d Eucalyptus tereticornis âgées de 16 et 17 ans et ƠE camaldulensis E paniculata et E citriodora âgées de 17 ans instances à Ruvu Tanzanie. L idee directrice de I etude est de conduire la recherche de manière .