Treesearch

Multiple discriminant analysis was used to identify biographic and employment history variables associated with job tenure in a lumber-plywood mill. Several variables-friends and relatives, type of housing, commuting distance, and prior work experience in the wood industry-were found to be significant.

Changing land use often results in removal of the existing forest cover. During a resurvey of Delaware's timber resources, a study was made to measure the losses of wood fiber that resulted from forest land clearing. It was estimated that nearly 33 million cubic feet of growing stock was destroyed on the 37,000 acres of commercial forest land that was cleared between 1954 and 1968.

In some areas of forestry and wood utilization research, use of automatic data recording equipment has become commonplace. This research note describes the basic electronic components needed to modify an existing intervalometer into a simplified pulsing device for controlling an automatic data recording camera. The pulsing device is easily assembled and inexpensive, when compared to similar proprietary units.

Reproduction tallies on 65 areas planned for clearcutting were compared with reproduction 2 to 4 years after cutting. As a result, we recommend that 70 percent of the area be stocked with at least 5,000 black cherry seedlings or 30,000 seedlings per acre of desirable species before cutting. If this requirement had been used on these 65 areas, the proportion of regeneration successes would have been raised from 54 to 92 percent.

Sixty yellow-poplar seedlings were divided into two groups. One group was defoliated twice, and the second group served as the control. Three months after the second defoliation there was no difference in carbohydrate content between the defoliated and undefoliated seedlings in either the stems or roots.

A two-celled chamber for measuring gas exchange in tree seedlings is described. Temperature is controlled within ± 0.5º C by means of a copper coil. The two cells are independent of one another, and one cell can be used as a preconditioning cell while gas exchange measurements are being made in the second cell.

The recently completed forest survey of New Jersey indicates that 54 percent of the land area has tree cover on it. Thirty-eight percent of the state is classified as commercial forest land. Total growing-stock volume has increased, although the softwood component of the resource has decreased in both cubic-foot volume and area occupied by the softwood types. Average annual growth for all species combined exceeded timber removals; however, softwood removals exceeded growth by 22 percent.

Several features of central importance to genetic improvement of white spruce have been demonstrated by tree breeders. First, white spruce is genetically a highly variable species and much of the existent variation can be readily incorporated in planting stock (Jeffers 1969, Holst and Teich 1969). Second, local seed often is not the best for rapid growth (Nienstaedt 1969). Third, certain stands in southeastern Ontario (Ottawa River Valley) have demonstrated genetic potential for relatively rapid growth over a wide geographic range, including the Lake States (Nienstaedt and Teich 1972)....

More than 20 years ago Scott Pauley (1949) designated the genus Populus as the "guinea pig of forest-tree breeding. This designation is still appropriate as evidenced by the steady, almost overwhelming, stream of publications related to the genetics and breeding of poplars. A good indication of the scope and depth of genetic work with poplars can be found in the recent review of poplar breeding by Muhle Larsen (1970) and discussions of cottonwood genetics and breeding by Sckreiner (1971) and Farmer and Mohn (1970). These reviews cover a variety of research and breeding activities at widely...

Jack pine (Pinus banksiana Lamb.) is the most common pine in the Lake States and is expected to play an increasingly important role in Lake States planting programs. This species is easy to plant successfully even on dry, sandy soils. Its rapid growth during the first 30 years makes it suitable for intensive-culture, short-rotation forestry. And it is suitable for kraft process pulping - particularly important because of the expanding kraft mill capacity in the Lake States.