Treesearch

Interim definitions of old-growth forests are provided to guide efforts in land-management planning until comprehensive definitions based on research that is currently underway can be formulated. The basic criteria for identifying old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and mixed-conifer forests in western Washington and Oregon and California are given.

Eight species of woodpeckers coexist in conifer forests in northeastern Oregon: northern flicker (Colaptes auratus); yellow-bellied (Sphyrapicus varius) and Williamson's (S. thyroideus) sapsuckers; and pileated (Dryocopus pileatus), hairy (Picoides villosus), white-headed (P. albolarvatus), three-toed (P. tridactylus), and black-backed (P. arcticus) woodpeckers. Tree diameter was the most important factor considered in selection of nest trees by northern flickers, Williamson's sapsuckers, and pileated and hairy woodpeckers. These species partitioned the nest habitat by occupying different...

Radial growth of white fir trees, Abies concolor (Gord. and Glend.) Lindl. ex Hildebr., defoliated almost 30 years ago by Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), in the central Sierra Nevada was compared with 22 years of growth prior to the outbreak. There was little difference in growth between the two periods indicating that enhanced growth of defoliated trees after the out-break did not occur as reported for two other California outbreaks. Increment cores also revealed for the first time an even older outbreak, which occurred on the same site in 1906-8.

Nitrogen-fixing bacteria in small mammal droppings are potentially important to forest productivity. As we study this phenomenon, however, we continually find unknowns, such as bacteria that we cannot isolate and purify because we do not know which techniques to use. For example, we have recently observed acetylene reduction in the droppings of the tundra vole (Microtus oeconomus) from St. Lawrence Island, Alaska, but we have failed three times to isolate the responsible bacterium. We hope this note will help stimulate parallel research on use of techniques under various circumstances.

An inventory of Orthoptera (grasshoppers and crickets) at the H.J. Andrews Experimental Forest, near Blue River, Oregon, was conducted to determine the species present and ecological relationships. A key for identification and an annotated list are presented. From qualitative assessments of successional habitat relationships, generalized species associations of forest Orthoptera are proposed, and their responses to forest succession are predicted.

Diameter growth of young trees as measured on Douglas-fir stumps of the previous stand was related to height of 5-year-old Douglas-fir seedlings on 16 cable-yarded, broadcast-burned progeny test plantations in southwestern Oregon. The resulting regression can be used to estimate the preharvest potential for seedling height growth on cutover land.

A pilot study was undertaken to determine drying rates for small diameter, unsplit paper birch firewood that was dried: (1) in a conventional top-covered pile; (2) in a simple, temporary solar kiln; and (3) in tree length. Drying rates were the same for firewood piles whether they were in the temporary solar kilns or only covered on top to keep rain or snow from entering the pile. Trees that were severed at the stump and left to dry in tree length form, complete with branches and leaves, however, dried slower than firewood cut to length, stacked, and top-covered or placed in the temporary...

Accurate estimation of the weight of each load of logs is necessary for safe and efficient aerial logging operations. The prediction of green density (lb/ft3) as a function of height is a critical element in the accurate estimation of tree bole and log weights. Two sampling methods, disk and increment core (Bergstrom xylodensimeter), were used to measure the density-moisture complex in wood. The relationship between wood density and height was best described by either quadratic or cubic polynomial functions. Prediction functions for green and dry wood density are presented for old-growth...

The eastern larch beetle (Dendroctonus simplex LeConte) exists throughout the range of tamarack (Larix laricina (Du Roi) K. Koch) in interior Alaska where it has a 1-year life cycle. Beetles overwinter as adults in the bark of the trunk below snowline in infested trees. Tamarack trees that are slow growing because of repeated defoliation by larch bud moth (Zeiraphera sp.) or that inhabit cold wet river bottom sites underlain with permafrost are usually susceptible to attack by eastern larch beetles.

The suitability of western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Sitka spruce (Picea sitchensis (Bong.) Carr.) beach logs in southeast Alaska for lumber, pulp, and energy was determined. Logs were sawn at a cant mill in southeast Alaska and at a dimension mill in northern Washington. Volume and value recovery was compared among samples of live, recent dead, and older dead classes of logs. The live and recent dead samples produced about the same quantity and quality of lumber. The older dead sample produced less volume and lower quality lumber. There were no difficulties in pulping...