Treesearch

We developed a density management diagram (DMD) for longleaf pine (Pinus palustris P. Mill.) using data from Forest Inventory and Analysis plots. Selection criteria were for purity, defined as longleaf pine basal area (BA) that is 90% or more of plot BA, and even-agedness, as defined by a ratio between two calculations of stand density index. The diagram predicts stand top height (mean of tallest 40 trees/ac) and volume (ft3/ac) as a function of quadratic mean diameter and stem density (trees/ac). In this DMD we introduce a "mature stand boundary" that, as a model of stand dynamics,...

We tested predictions of the spatially explicit ArcHSI habitat model for elk. The distribution of elk relative to proximity of forage and cover differed from that predicted. Elk used areas near primary roads similar to that predicted by the model, but elk were farther from secondary roads. Elk used areas categorized as good (> 0.7), fair (> 0.42 to 0.7), and poor (< 0.42) HSI (habitat suitability index) from the model proportional to the distribution of the landscape during summer, but not winter. Evaluation of the cover component of the model showed elk used areas disproportional to the...

A limited erosion potential analysis was carried out on the 50,000 acre School Fire. Three WEPP interfaces were used for the analysis, a GIS wizard, an online interface and a windows interface. Ten watersheds within the fire area were modeled with the GeoWEPP tool (a geo-spatial interface for WEPP, Water Erosion Predication Project). The watersheds covered 18,823 acres, or about 38 percent of the total burned area. Hillslopes were specified high, moderate or low burn severity by examining the BAER (Burned Area Emergency Response) severity map.

A computer interface has been developed to assist with analyzing soil erosion rates associated with fuel management activities. This interface uses the Water Erosion Prediction Project (WEPP) model to predict sediment yields from hillslopes and road segments to the stream network. The simple interface has a large database of climates, vegetation files and forest soil properties to support this and other interfaces, including Disturbed WEPP for forests and WEPP:Road for road segment analyses. The soil databases for roads and disturbed forested hillslopes are based on rainfall simulation and...

Silvicultural cutting treatments may be needed to restore whitebark pine (Pinus albicaulis) forests, but little is known of the response of this species to removal of competition through prescribed burning or silvicultural cuttings. We analyzed stem cross-sections from 48 whitebark pine trees in Montana around which most of the competing vegetation was removed by timber harvest treatments. We compared tree ring growth rates before and after the harvest treatment using intervention analysis to determine 1) the potential of release for this littlestudied tree species and 2) whether the...

Volcanic ash distribution and thickness were determined for a forested region of north-central Idaho. Mean ash thickness and multiple linear regression analyses were used to model the effect of environmental variables on ash thickness. Slope and slope curvature relationships with volcanic ash thickness varied on a local spatial scale across the study area. Ash distribution and aspect showed weak correlation. Elevation and ecologically based plant associations accounted for about 54 percent of the observed variation in volcanic ash thickness. Climax plant associations moister than grand...

Fire managers need better estimates of fuel loading so they can more accurately predict the potential fire behavior and effects of alternative fuel and ecosystem restoration treatments. This report presents a new fuel sampling method, called the photoload sampling technique, to quickly and accurately estimate loadings for six common surface fuel components (1 hr, 10 hr, 100 hr, and 1000 hr downed dead woody, shrub, and herbaceous fuels). This technique involves visually comparing fuel conditions in the field with photoload sequences to estimate fuel loadings. Photoload sequences are a...

Sustainability protocols recognize forest soil disturbance as an important issue at national and international levels. At regional levels continual monitoring and testing of standards, practices, and effects are necessary for successful implementation of sustainable soil management. Volcanic ash-cap soils are affected by soil disturbance and changes to soil properties influence ecosystem responses such as productivity and hydrologic function. Soil disturbance from timber harvesting, reforestation, or stand tending is mainly a result of moving equipment and trees. Compaction and organic...

Volcanic ash from the eruption of Mt. Mazama ~7,700 years ago has a strong influence on many forested landscapes of the Pacific Northwest and Intermountain regions of the USA and Canada. Because of the unique biological, physical and chemical properties of the ash, it is closely tied to plant communities and forest productivity, and should therefore be considered as a resource to protect when harvesting, burning, or site preparation activities occur on it. How did this symposium get started? There has been a steady stream of questions, problems, and research on volcanic ash-cap soils for...

Currently, laboratory measurements are definitive for identifying andic soil properties in both the USDA Soil Taxonomy (Soil Survey Staff 1999) and the World Reference Base for Soil Resources (FAO/ISRIC/ISSS 1998). Andic soil properties, as described in Soil Taxonomy, result mainly from the presence of significant amounts of allophone, imogolite, ferrihydrite or aluminum- humus complexes in soils. The required properties are high acid-oxalate extractable aluminum and iron percentages, low bulk density, and high phosphate retention. In addition, glass is a common component of andic soils of...