Treesearch

Forest managers need methods to evaluate the impacts of management at the watershed scale. The Water Erosion Prediction Project (WEPP) has the ability to model disturbed forested hillslopes, but has difficulty addressing some of the critical processes that are important at a watershed scale, including baseflow and water yield. In order to apply WEPP to forested watersheds, we developed and assessed new approaches for simulating streamflow and sediment transport from large watersheds using WEPP. We created specific algorithms to spatially distribute soil, climate, and management input files...

Post-fire forest management commonly requires accepting some negative ecological impacts from management activities in order to achieve management objectives. Managers need to know, however, whether ecological impacts from post-fire management activities are transient or cause long-term ecosystem degradation. We studied the long-term response of understory vegetation to two post-fire logging treatments - commercial salvage logging with and without additional fuel reduction logging - on a long-term post-fire logging experiment in northeastern Oregon, USA. We sampled understory plant cover...

Efforts to amend the Tongass National Forest Land Management Plan have necessitated the development of several management scenarios to assist with planning efforts. One scenario focuses on increasing the utilization of sawmill residues and low-grade material as feedstock for expanding biomass energy markets. The development of a biomass industry is viewed as a solution for a variety of problems in Alaska, from high heating fuel costs to a persistent lack of markets for mill and logging residue and low-grade logs since the last Alaska pulp mill closed in 1997. To support scenario development...

This report presents updated information on a 1981 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii ) plantation spacing trial at 33 years from planting. Stand statistics at the most recent measurement were compared for initial spacing of 1 through 6 meters and associated relative densities. There was no clear relationship of spacing to top height. Diameter, live crown ratio, and percent survival increased with spacing; basal area and relative density decreased with increase in spacing. Volume in trees ≥ 4 cm diameter was greatest at 2 m spacing, while utilizable volume...

We selected 66 sample trees from two thinning treatments, each of which was applied at three sites on the Siuslaw National Forest in Oregon. The first commercial thinnings, conducted in 1992 and 1993, had been designed to accelerate the development of large trees with large branches and other old-growth characteristics so as to improve habitat for bird species that depend on such characteristics. Our sample trees, removed in commercial thinnings from 2008 to 2010, were felled and bucked into long (woods-length) logs whose stems were measured in detail, with surface defects also measured...

Determining how the frequency, severity, and extent of forest fires are changing in response to changes in management and climate is a key concern in many regions where fire is an important natural disturbance. In the USA the only national-scale fire severity classification uses satellite image changedetection to produce maps for large (>400 ha) fires, and is generated by the Monitoring Trends in Burn Severity (MTBS) program. It is not clear how much forested area burns in smaller fires or whether ground-based fire severity estimates from a statistical sample of all forest lands might...

Backgrounds and aims Scotch broom is an N-fixing invasive species that has high potential to alter soil properties. We compared soil from areas of Scotch broom invasion with nearby areas that had no evidence of invasion to assess the influence of broom on soil P fractions and other chemical properties. Methods The study was conducted at two contrasting Douglas-fir sites in Oregon (OR) and Washington (WA), USA with broom invasion for 10 years. We used the Hedley sequential fractionation procedure to assess effects of Scotch broom invasion on P pools of varying bioavailability, and also...

This resource update is a brief look at some of the basic metrics that describe the status of and changes to forest resources in Arkansas. Estimates presented here are for the survey year 2015 with resource changes compared against the 2014 survey year. This information is based on field data collected using the Forest Inventory and Analysis (FIA) annualized sample design, and it is updated yearly. Arkansas has about 5,700 sample plots across the State; each year, 20 percent of these plots (one panel) are visited and measured by field crews, the data compiled, and new estimates produced.

This paper focuses on the use of models for increasing the precision of estimators in large-area forest surveys. It is motivated by the increasing availability of remotely sensed data, which facilitates the development of models predicting the variables of interest in forest surveys. We present, review and compare three different estimation frameworks where models play a core role: model-assisted, model-based, and hybrid estimation. The first two are well known, whereas the third has only recently been introduced in forest surveys. Hybrid inference mixes design-based and model-based...

A poorly placed or unsuitably designed road can result in landslides, flooding, gullies, stream damage, and wildlife habitat destruction. Particularly in natural areas, benefits of roads, such as accessibility and convenience, must be weighed against potential water quality degradation, scenic and wildlife habitat destruction, and hazardous driving conditions. Scientists at the Rocky Mountain Research Station helped create two free tools - GRAIP (Geomorphic Road Analysis and Inventory Package) and GRAIP-Lite - to help land managers make better decisions about road management in environmenta...