返回Google圖書搜尋

Improvement in Butt-log Grade with Increase in Tree Size, for Six Hardwood Species

出版	Northeastern Forest Experiment Station, Forest Service, U.S. Department of Agriculture, 1965
URL	http://books.google.com.hk/books?id=Noc2DP3b3DAC&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋S2Work carried out by the Northeastern Forest Experiment Station in West Virginia in the past 12 years provides useful information about the relationships between tree d.b.h. and butt-log grade. The upper logs are not included in the relationships. Being smaller and containing more knots, these upper logs are generally of lower grade than the butt logs. Thus the average grade of all material in the sawlog portion of the tree is generally lower than the average grade of the butt log. In the West Virginia data, species differences in d.b.h.-grade relationship are readily apparent. This inherent tendency for species to have different proportions of the various grades in logs of the same size is a familiar phenomenon to grade-conscious foresters who work with hardwoods. The results in this paper provide a quantitative evaluation of this tendency for six of the local species.S3.