Treesearch

Black-light trap collections in mixed-coniferous forests in eastern Oregon resulted in the identification of one Arctiidae, six Noctuidae, and one Geometridae species not previously known to occur in Oregon. The ranges of 18 other species of Noctuidae, known previously in Oregon from only the Cascade and Coast Ranges, were extended to northeastern Oregon.

Covering stacks of spruce firewood with either clear or black polyethylene sheeting does not raise log temperatures high enough to kill spruce beetle brood in the logs. Based on the results of this study, we do not recommend the use of polyethylene sheeting as a remedial measure for the reduction of spruce beetle brood in infested firewood or log decks in south-central Alaska.

A mill recovery study of ponderosa pine in Arizona and New Mexico showed wide variation in quality within the resource. Lumber grade ranged widely by log grade and diameter, with a major difference within grade 5 logs between old growth and young growth. Old growth produced mostly Shop and Selects grades of lumber while young growth produced mostly Dimension grades of lumber; small-diameter young growth developed severe problems of warpage. Log grades separated logs into distinct value classes, and separating young-growth timber (as if an additional grade) allowed better segregation of...

Tree improvement has become an essential part of the management of forest lands for wood production, and predicting yields and realized gains from forests planted with genetically-improved trees will become increasingly important. This paper discusses concepts of tree improvement and genetic gain important to growth and yield modeling, and reviews previous studies of the growth and yield of genetically improved stands. Three types of studies that have been done include: (1) simulations in which assumptions have been made about key inputs into the models, (2) studies of genetic variation in...

Field tests on the efficacy of various scolytid bark beetle pheromones to attract Ipsperturbatus (Eichhoff) were conducted from 1977 through 1992 in stands of white spruce (Picea glauca (Moench) Voss) in interior Alaska. Several pheromones attracted high numbers of L. perturbatus and species of the predator Thanasimus to baited funnel traps. Test results also indicated that attacks by I. perturbatus may be deterred by certain semiochemicals.

Bareroot Douglas-fir seedlings inoculated with Rhizopogon sp. and processed by standard nursery and reforestation procedures performed equally well whether planted near Douglas-fir stumps previously fumigated with two dosages of chloropicrin to control Phellinus weirii infection or near stumps not fumigated. Before stump-fumigation can be generally recommended for Phellinus-rehabilitation sites, the fate of the chemical and its derivatives.

For as long as logs have been exported from the Pacific Northwest, they seem to have been worth more offshore than in the domestic market. Five reasons for the export premium are the inconvenience of trade, quality, extra "haul and hassle," continuity in export arrangements, and export embargoes. A large and increasing differential remains between export and domestic prices for comparable logs in high grades. Logs of lower quality do not seem to have a dual price structure, and there appears to be a declining premium for logs overall. Year-to-year fluctuations in the premium can be...

The involvement of porcupines, Erethizon dorsatum (L.), in the ecology of Colorado tick fever (CTF) virus in Rocky Mountain National Park was investigated from 1975 to 1977. Porcupine dens and feeding activity were found mostly on rocky knolls or on south-facing slopes within open stands of the montane coniferous forest, and 20 adult porcupines were trapped or captured by hand at those locations. An average of 24.6 ± 5.4 adult Dermacentor andersoni Stiles ticks were found per animal (annual range, 17.5-31.4 ticks). The minimum CTF virus infection rate of the ticks removed from porcupines...

Twelve species of bats occur in Douglas-fir forests of the Pacific Northwest, of which nine are known to roost in tree cavities, bark crevices, or foliage, and several are closely associated with old-growth forests. Thus bat populations may be detrimentally affected by forest management practices involving the removal of large, old trees and snags. We review the life history characteristics and habitat relations of bats in the Pacific Northwest and provide information useful in managing forests for the persistence of native bat populations.

Tree seedling studies, covering a wide range of experimental conditions in pollutant treatment, species, facilities, and exposure regimes, have become commonplace in forestry research for assessing the actual and potential environmental effects of air pollutants on forest ecosystems. While assuring a wide breadth of scientific information, sufficient consideration has not been given to either the comparability of such population studies or to their appropriate inference. Th e populations of seedlings for which seedling experiments have inference, including the limitations in national or...