Treesearch

We reconstructed the stand structure and composition for two western Washington old-growth forest stands harvested around 1930 (named Fresca and Rail) from field and historical data. Both old-growth stands had a codominant or dominant 250-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) overstory with a few scattered older Douglas-fir. Western hemlock (Tsuga heterophylla (Raf.) Sarg.) was codominant at Rail but was predominantly in the mid-story and understory at Fresca. The Fresca site is now dominated by Sitka spruce (Picea sitchensis (Bong.) Carr.) and western hemlock,...

Studies of resource selection form the basis for much of our understanding of wildlife habitat requirements, and resource selection functions (RSFs), which predict relative probability of use, have been proposed as a unifying concept for analysis and interpretation of wildlife habitat data. Logistic regression that contrasts used and available or unused resource units is one of the most common analyses for developing RSFs. Recently, resource utilization functions (RUFs) have been developed, which also predict probability of use. Unlike RSFs, however, RUFs are based on a continuous metric...

Can management of 40- to 80-year- old forests on the Olympic Peninsula accelerate the development of stand structures and plant and animal communities associated with much older forests? The Olympic Habitat Development Study, a cooperative project between the Pacific Northwest Research Station and the Olympic National Forest, began in 1994 to examine this question. It uses a novel type of variable-density thinning called thinning with skips and gaps. Ten percent of the study area was left unthinned, while 15 percent was cleared to create openings in the forest canopy. These gaps also...

The pileated woodpecker is a species of conservation concern and a keystone species in mature and old forests of the Pacific Northwest. In the Blue Mountains of northeast Oregon, researchers from the PNW Research Station in La Grande, Oregon, studied the effects of natural and human-caused disturbance on pileated populations and their habitat over a period spanning from 1973 to 2005. During this time, several pervasive insect outbreaks transformed the forest characterized by predominantly live conifers with dense canopy cover (prime pileated habitat) to one with increasing numbers of snags...

How should old-growth forests be managed? Should they be managed? Stakeholders with differing values and agendas have debated these questions for years. Over time, the debate has evolved: now there is greater awareness about the complexity of old-growth ecosystems and different ways humans value them. A scientist at the Pacific Northwest Research Station has co-edited a book to provide a comprehensive, multidisciplinary overview and synthesis to further this discussion. Written for a lay audience, Old Growth in a New World: A Pacific Northwest Icon Reexamined is meant to help deepen...

Oregon’s land use planning program has protected an estimated 1.2 million acres of forest and agricultural land from development since its inception in 1973. As a result, these resource lands continue to provide forest products and food as well as another unexpected benefit: carbon storage. By keeping forests as forests, land use planning capitalizes on the natural landscape’s ability to sequester atmospheric carbon, a key contributor to climate change. Nationwide, however, forest land is the land type most frequently converted to more developed uses. When this happens, carbon storage...

Excess nitrogen stemming from human activities is a common water pollutant. Fertilizer runoff, sewage, and fossil fuel emission all contain nitrogen that often ends in streams, rivers, and ultimately the ocean. Research has found that more nitrogen enters a river system than can be accounted for at its mouth, indicating that instream processing is occurring. A team of scientists conducted several experiments on streams across the country to better understand the fate of waterborne nitrogen.

Can we expedite the development of late-successional forest conditions by applying thinning treatments to young forest stands? What effect will these thinning treatments have on headwater ecosystems? These broad questions lie at the foundation of the Density Management and Riparian Buffer Study (DMS) of western Oregon.

Forests significantly influence the global carbon budget: they store massive amounts of carbon in their wood and soil, they sequester atmospheric carbon as they grow, and they emit carbon as a greenhouse gas when harvested or converted to another use. These factors make forest conservation and management important components of most strategies for adapting to and lessening the impacts of climate change. Developing these strategies is complicated by the constant interplay between forest ecosystems and climate, which impacts the costs and effectiveness of mitigation. based on science by...

Soil organisms play essential roles in forest health, and truffle fungi are one of the more fascinating groups of these important organisms. After 40 years of specimen collection and study, scientists with Pacific Northwest Research Station have published a report documenting how truffle fungi affect tree survival and growth, perform valuable functions in nutrient cycling and retention, and serve as a major food source for many forest animals. Based on science by Randy Molina, and Jane Smith