• Krebs, Charles Fredric
  University of Michigan
  

Jack Pine, rarely utilized even as recently as 1920, is now a significant source of pulpwood in the Great Lakes region. It is surpassed only by aspen in total cords harvested. During the five year period 1965-1969 and average of 633.6 thousand cords were harvested annually in the three Lake States. Over one-third of that volume -- an average 215.8 thousand cords per year -- were grown in Michigan. This investigation was undertaken to facilitate the collection of some of that information in Michigan. The principal objective of the study was to develop a sampling procedure for estimating the percentage of trees infested by the white pine weevil in the state's young jack pine plantations.