Treesearch

Grazing and how it impacts the landscape is a concern for public and private land managers. This issue of "Science Findings" examines the issue of cattle and grazing and provides some background, perspective, and research results on various grazing systems. Researchers Jim McIver, of the Forest Service's Blue Mountains Natural Resources Institute, and Mike McInnis, of Oregon State University, share their findings.Work by collaborators at the University of Idaho and Oregon State University show that the presence of water, salt, and upland forage can attract cattle away from riparian areas...

Twenty years after publication of a report on wildlife habitat in managed east-side forests, Pacific Northwest Research Station scientists Evelyn Bull, Catherine Parks, and Torolf Torgersen, are updating that report and discovering that the current direction for providing wildlife habitat on public forest lands does not reflect findings from research since 1979. More snags and dead wood structures are required for foraging, denning, nesting, and roosting that previously thought. In this issue of Science Findings, Bull, Parks, and Torgersen, share their latest findings, which include the...

Adaptive management. What is it and how can it help us learn? Bernard Bormann, a PNW Research Station scientist, is leading a study on the subject. He defines the term this way: the management of complex natural systems by building on common sense and learning from experience. Experience can often mean change. The challenge of implementing adaptive management is how to adapt to constant change--in society and in the ecosystem. The learning process is often not fast enough, however, to deal with quickly emerging land management issues. Bormann proposes that management produce knowledge...

This issue of "Science Findings" focuses on ecologist Mary Willson's research in Alaska that has revealed anadromous fish to be "cornerstone species." A cornerstone species provides a resource base to support much of an ecosystem. Anadromous fish, in this case, have been found support much of the Pacific coastal ecosystem. Key findings of Willson's team research are that the productivity of freshwater and riparian ecosystems is fueled by marine-derived nutrient subsidies from anadromous fishes. Many wildlife species depend seasonally on anadromous fish runs. In some cases predator species'...

Ecosystem function—the internal dynamics of a forest—is now recognized as a crucial component to forest health and biological diversity.Pacific Northwest Research Station scientist Andy Carey and others propose that the presence of small critters can be a measure of a forest's health. His research also shows that thinning, rather than legacy retention, produces higher quality trees for timber and plant diversity.Carey's findings suggest that concurrent management of decadence, stand structure, and plant species composition is required for ecosystem management. High-quality wood may result...

Variation in belowground traits of herbaceous species may influence their ability to persist and spread during and after the closed-canopy period of forest development. In 40- to 60-year-old closed-canopy, coniferous forests of the Olympic Peninsula, Washington, we excavated root and rhizome systems of 11 herbaceous species to compare morphology, vegetative spread, and proportion of biomass in belowground structures. All species were perennial and most were rhizomatous; four species were nonclonal. Of the seven clonal species, only two (Maianthemum dilatatum and Oxalis oregana) spread...

During early stand development, coniferous forests of the coastal Pacific Northwest commonly pass through a period of dense shade and intense competition during which the abundance and diversity of understory plants decline dramatically. In young, managed forests, silvicultural thinning has been proposed to enhance the structural and floristic diversity of the understory. Although germination of buried seeds is likely to be stimulated by thinning, we know little about the composition of the soil seed bank in these forests. We used the greenhouse emergence method to assess the potential...

Ponderosa pines (Pinus ponderosa Dougl. ex. Laws) 21 to 60 yr old were used to assess the relative importance of environmental stressors (O3, drought) versus an enhancer (N deposition) on foliar retention, components of aboveground growth, and whole tree biomass allocation. Sites were chosen across a well-described gradient in ozone exposure (40 to 80 ppb per h, 24 h basis, 6 month growing season) and nitrogen deposition (5 to 40 kg ha−1 yr−1) in the San Bernardino Mountains east of Los Angeles, California. A high level of chlorotic mottle indicated high 0, injury at sites closest to the...

Many species of Dendroctonus, particularly the so-called aggressive species, are notorious outbreak organisms with more or less predictable or characteristic, cyclic patterns of outbreak locally if not regionally. D. frontalis, for example, exhibits an approximately 7-10 year cycle with 2-3 year duration of outbreak. The last south-wide outbreak of D. frontalis began in 1992 and peaked in 1995, with an estimated timber resource loss of $350 million in that year alone (Price and others 1998). The previous peak occurred in 1986. The presumption is that at epidemic levels, beetle populations...

Private timberlands in the United States have the biological potential to provide larger quantities of timber on a sustainable basis than they do today. Most opportunities for increasing growth and harvest lie on nonindustrial private lands in the South. Past studies, based on fixed scenarios of future prices, also suggest that many of these opportunities for intensified management can be undertaken with positive economic returns. Translation of these physical and apparent economic potentials into projections of future management and harvest requires a model of private timber management...