Treesearch

Much information is available on the specific gravity of wood on a dry weight over green volume and dry weight over dry volume basis. This paper presents the conventional specific gravity on a green weight over green volume basis. The relative specific gravities of bark and wood chips may be helpful in finding way to remove bark particles from chips.

The third forest survey of Wisconsin showed timber volume reaching 11 billion cubic feet of growing stock in 1968, and increase of about one-third since 1956. The growing stock included 22 million board feet of sawtimber.

This is the third in a series of papers dealing with the residential and commercial hardwood flooring industry. The first two paper are: PHYSICAL DISTRIBUTIOONF OAK STRIP FLOORING IN 1969 (U.S.D.A. Forest Serv. Res. Paper NE-207) and DISTRIBUTION OF MAPLE STRIP FLOORING IN 1969. (U.S.D.A. Forest Serv. Res. Paper NE-215).

Under the authority of the McSweeney-McNary Forest Research Act of May 22, 1928, and subsequent amendments, the Forest Service, U. S. Department of Agriculture, conducts a series of continuing forest surveys of all states to provide up-to-date information about the forest resources of the Nation. The first forest survey of Maine was made in 1954-58 by the Northeastern Forest Experiment Station, with cooperation from many individuals, forest industries, and state agencies. A resurvey of the timber resources of Maine was made in 1968-70, again with the cooperation of many persons and...

Two computational strategies are exhibited in hand-computing the solution of an elementary system identification problem.

Isolations and water flow-rate measurements made on short stem sections of young red oak seedlings inoculated with the oak wilt pathogen, Ceratocystis fagacearum, about 1 to 2 inches above the soil line, revealed that the oak wilt pathogen was isolable first near the inoculation site. As time after inoculation increased, the pathogen was isolated progressively farther up the stem until, when leaf symptoms became visible, it was present throughout the stem. At the onset of leaf symptoms, many but not all petioles contained the pathogen. The pathogen was never isolated from leaf blade...

During 1961-1969, the insects found damaging acorns of bur oak, Quercus macrocarpa Michauxii, in their order of importance were the weevils: Curculio pardalis (Chittenden), C. strictus (Casey), C. sulcatulus (Casey), C. iowensis (Casey), C. proboscideus F., C. confusor (Hamilton), Conotrachelus naso LeConte, and C. posticatus Boheman; and the moth: Melissopus latiferreanus (Walsingham).

Many log or pulpwood transporting machines have hinged or articulated frames for steering. The articulated frame offers advantages for these machines, but the design introduces some problems in stability. We formulated and analyzed a mathematical model simulating stability of a 4-wheel-drive, articulated frame logging tractor (wheeled skidder) at static or low constant velocity. The model was designed to be versatile so that the model data might be used for stability determinations of various machines.

A study was undertaken to elucidate the impact of the various components of disease on natural populations of the gypsy moth, Porthetria dispar. Diseased larvae from both sparse and dense populations were examined and categorized on the basis of etiologic and nonetiologic mortality factors. Results indicated a significantly higher incidence of parasitoid involvement—but virtual nonexistence of polyhedral viroses—in the relatively stable sparse populations. Nuclear polyhedrosis probably represented the primary mortality factor in the dense populations. Many insects examined from both...