Treesearch

In 1994, a large-tree harvest standard known as the “21-inch rule” was applied to land and resource management plans of national forests in eastern Oregon and Washington (hereafter, the “east side”) to halt the loss of large, old, live, and dead trees and old forest patches. These trees and forest patches have distinct ecological, economic, and social values, as reflected in widespread fish and wildlife use, public support for protecting them, and commercial interest in harvesting them, thus they have been the topic of much discussion and debate. At the request of regional Forest Service...

Considerable resources have been invested in ecological restoration projects across the globe to restore ecosystem integrity. Restoration strategies are often diverse and have been met with mixed success. In this article, we describe the Chinook salmon (Oncorhynchus tshawytscha) decision-support models developed by the Central Valley Project Improvement Act Science Integration Team as part of a larger structured decision-making effort aimed at maximizing natural adult production of Chinook salmon in California’s Central Valley, the United States. We then describe the decision-analytic...

In interior Alaska’s 115 million acres of boreal forest, white and black spruce are the dominant tree species. Climate models suggest that the region is becoming warmer and drier, resulting in declining growth of black and white spruce, according to some researchers. These drier conditions also may lead to greater risk of stand-replacing wildfires, resulting in forests dominated by birch and aspen, which are early-successional tree species. To compare long-term growth trends of the dominant coniferous and deciduous tree species, a team of researchers with the USDA Forest Service Pacific...

In recent years, many forest managers have become interested in managing forests for a wider range of objectives than previously. As an initial or intermediate treatment, variable-density thinning (VDT) can help meet objectives such as improving wildlife and plant habitats, increasing structural and compositional diversity, and enhancing aesthetic values in stands that are currently lacking spatial variability. The “skips and gaps” method of VDT is flexible, allowing for the preservation of existing desirable features. Areas that are not thinned (“skips”) will protect existing features...

Application of progeny test breeding values to forecast yield gains at rotation-age in genetically improved stands remains a very challenging yet crucial task for breeders of Douglas-fir and other long-rotation timber species such as western hemlock, white spruce, Norway spruce, and Scots pine. Evaluation of the economic returns on genetic improvement requires reliable estimates of yield gains at rotation age. Large-plot realized gain trials should provide more accurate estimates of yield gain than inferences from progeny tests, but are most dependable when they reach rotation age or at...

Conceptual and methodological tools from behavioral ecology can inform studies of habitat quality, and their potential for evaluating habitat restoration in conservation efforts is explored here. Such approaches provide mechanistic detail in understanding the relationship between organisms and their habitats and are thus more informative than correlations between density and habitat characteristics. Several Pacific salmon species have been the target of habitat restoration efforts for the past 2–3 decades, but most post-restoration effectiveness studies have been limited to correlative...

Individual growth data are useful in assessing relative habitat quality, but this approach is less common when evaluating the efficacy of habitat restoration. Furthermore, available models describing growth are infrequently combined with computational approaches capable of handling large data sets. We apply a mechanistic model to evaluate whether selection of restored habitat can affect individual growth. We used mark-recapture to collect size and growth data on sub-yearling Chinook salmon and steelhead in restored and unrestored habitat in five sampling years (2009, 2010, 2012, 2013,...

Beavers have become a source of inspiration for public and private land managers over the past decade. Beaver dams can help control flooding, raise groundwater levels, and improve surface water flows. Some land managers are now designing stream restoration projects that mimic the way beaver dams shape river ecosystems. Beaver-related restoration may even help the recovery of endangered species that depend on healthy aquatic and riparian areas.The approach also holds promise for ranchers who graze livestock on rangelands in the Western United States where drier conditions are expected in...

Smoke emissions from wildland fires contribute to concentrations of atmospheric particulate matter and greenhouse gases, influencing public health and climate. Prediction of emissions is critical for smoke management to mitigate the effects on visibility and air quality. Models that predict emissions require estimates of the amount of combustible biomass. When measurements are unavailable, fuel maps may be used to define the inputs for models. Mapped products are based on averages that poorly represent the inherent variability of wildland fuels, but that variability is an important source...