Treesearch

Statistical analysis of African wood-owl (Strix woodfordii) song spectrograms suggest a significantly different song type in Democratic Republic of Congo (DRC), central Africa, than elsewhere in eastern or southern Africa. Songs of DRC owls tend to be consistently shorter in duration and more monotone in overall frequency range. The first note is either absent or is very soft and slightly lower in frequency than the second note in DRC owls, compared with owls found elsewhere whose first note was prominent, loud, and much higher in frequency than the second note. Also, male owls in DRC sing...

We studied seasonal courses of soil water utilization in a 450-year-old Pseudotsuga menziesii/Tsuga heterophylla forest. Mean root area in the upper 60 cm of soil was significantly greater in the vicinity of T. heterophylla trees. However, seasonal water extraction on a root area basis was significantly greater near P. menziesii trees at all depths between 20 and 60 cm, leading to significantly lower water storage in the upper 60 cm of soil near P. menziesii trees at the end of the summer dry season. The results provide information on functional traits relevant for understanding the...

An increase in land dominated by young second-growth Douglas-fir forests in the Pacific Northwest has coincided with heightened concerns over loss of old-growth habitat. In search of options for managing young forests to provide late-successional forest structures, the Young Stand Thinning and Diversity Study was designed to test the effectiveness of modified thinning in acceleration of late-successional structural characteristics. Thinning treatments included: a control, a light thin (typical of standard commercial thins), a heavy thin (densities lower than typically prescribed), and a...

This Special Section includes 8 peer-reviewed papers on the wolverine (Gulo gulo) in southern North America. These papers provide new information on current and historical distribution, habitat relations at multiple spatial scales, and interaction with humans. In aggregate, these papers substantially increase our knowledge of wolverine ecology and population dynamics in North America, in many cases replacing previous speculation and informed judgments with empirical information. North American wolverines occur primarily in tundra, taiga, and subalpine environments. These environments...

We examine both the variation and the changing proportions of different wood products obtained from trees and logs in the Douglas-fir region of the Northwestern United States. Analyses are based on a large product recovery database covering over 40 years of recovery studies; 13 studies are available for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Visual lumber grades were combined into four broad value classes. We used the multinomial logistic model to estimate the yield proportion of each value class as a function of age, diameter, and their interaction. We also examined changes...

With increasing opportunity costs of keeping land in forests because of increasing values for other land uses, such as for developed uses, forest ownership may become less attractive for some landowners and the return on investment less viable for both private and public landowners. This raises the question of what will become of the forests and the resources the forest supports, such as water and wildlife, if owners of the forests find it too costly to manage the forest. Land markets provide evidence on revealed behavior about what people are willing to actually pay for a bundle of rights...

We conducted a preliminary examination of the responses of stream amphibians and instream habitat conditions to alternative riparian buffer zones with forest thinning upslope. Pre- and posttreatment surveys were carried out on 68 headwater stream reaches (including 23 unthinned reference reaches) at 11 sites in western Oregon. Streams were in managed conifer stands 40 to 80 years old where the thinning treatment reduced stands from 600 trees per hectare (tph) to 200 tph. Treatments consisted of four widths of riparian buffers approximately 6, 15, 70, and 145 m on each side of streams. Over...

This conference was attended by nearly 450 Forest Service earth scientists representing hydrology, soil science, geology, and air. In addition to active members of the earth science professions, many retired scientists also attended and participated. These 60 peer-reviewed papers represent a wide spectrum of earth science investigation, experience, research, and innovation in the Forest Service.

Definitive results from the Starkey Project’s first decade (1989–99) have given managers defensible options for managing roads, timber production, and range allotments in relation to elk, deer, and cattle. Study results have prompted changes in policies, management standards and guidelines, hunting regulations, and timber sale planning throughout western North America.In the 1970s and 1980s, wildlife managers, hunters, and forest managers had intense debates about how elk, mule deer, and cattle should be managed on public lands. In response, scientists from the Pacific Northwest (PNW)...

Geospatial data describing wildland fuel and current as well as historical vegetation conditions are essential for planning, implementing, and monitoring projects supported by the National Fire Plan and the Healthy Forests Restoration Act. Scientifically credible, consistent, and standardized spatial data allow fire and land managers to accurately identify the amount and locations of lands or communities with hazardous fuel build-up or extreme departure from historical conditions. These data also facilitate the prioritization of ecosystem restoration and hazardous fuel reduction treatments...