• Drolet, J.C.
  Canadian Forestry Service: Department of the Environment
  
• Newnham, R.M.
  Canadian Forestry Service: Department of the Environment
  
• Tsay, T.B.
  Canadian Forestry Service: Department of the Environment
  

A total of 541 trees of jack pine, black spruce and balsam fir were felled on 16 one-tenth-acre plots in Ontario and Quebec. For each live branch (of 0.5-inch diameter outside bark or greater, at one inch from the stem) below the top of the last pulpwood log, the height, diameter outside bark (dob), angle with the stem, and the quadrant in which it was attached to the tree, were recorded. Additional branch dob measurements, between 0.25 and four inches from the stem, were made on a ten per cent sub-sample of branches. Live crown weight was measured on a 20 percent sub-sample of trees. Summary statistics for tree variables are given. The maximum number of branches and maximum branch-stub area(BSA), in any three-inch and in any 12-inch section of stem, were calculated for each tree. Regression equations for the relationships between these variables and the plot and tree variables were calculated, but the resulting values of R^2 were generally low. Jack pine had the greatest average maximum BSA per tree and the largest branches but the smallest branch angle, indicating that it would be the most difficult species to delimb; black spruce would be the easiest with balsam fir intermediate Ninety-five per cent of all the trees could be completely delimbed by a machine capable of removing eight square inches of BSA from a three inch stem section or 12 square inches from a 12-inch section, the remaining  five percent could be only partially delimbed by such a machine. Branches were not evenly distributed around the stem, the quadrant with the most branches or BSA having two to three times more than the quadrant on the opposite side of the stent. By aspect, the SW stem quadrant contained the greatest number of branches and BSA. Balsam fir produces the greatest weight of live crown (slash) per tree and jack pine the least.