Treesearch

The Middle Fork Clearwater Wild and Scenic River was established under the 1968 Wild and Scenic Rivers Act. Forest Service managers gradually became concerned with the increasing loss of the large, old ponderosa pine and Douglas-fir that characterize much of the river corridor and adjacent uplands. The perceived dilemma was how to maintain both high esthetic values and a seral forest that was resilient in the face of wildfire, insect attacks, and disease presence. The Lochsa District on the Clearwater Forest developed guidelines for management within the corridor. Prescriptions included...

The 38 papers in this proceedings are divided into six sections; the first includes an overview paper and documentation of the first Shrub Research Consortium Distinguished Service Award. The next four sections cluster papers on restoration and revegetation, soil and microsite requirements, germination and establishment of desired species, and community ecology of shrubland systems. The final section contains descriptions of the field trips to the High Plains Grassland Research Station and to the Snowy Range and Medicine Bow Peak. The proceedings unites many papers on germination of native...

Pinus ponderosa Laws. (ponderosa pine) forests have changed considerably during the past century, partly because recurrent fires have been absent for a century or more. A number of studies have explored the influence of timber harvest or burning on understory production in ponderosa pine forests, but study designs incorporating cutting and prescribed burning in an experimental framework are needed to identify mechanisms responsible for the observed changes. In this study, we first characterized the disturbance history and the soil seed bank of a ponderosa pine stand in the northern Black...

The USDA Forest Service established the Beaver Creek Experimental Watershed Pilot Project in north-central Arizona in 1957 and operated it until 1982. After the Forest Service discontinued the project in 1982, Northern Arizona University's School of Forestry continued to monitor and do research in two of the largest watersheds, known as Woods Canyon and Bar M. From 1982 to 1995 only streamflow data are available for these watersheds. A weak correlation between streamflow and precipitation for both watersheds was determined by analyzing the USDA data from 1961 to 1982, using spatial...

Snags provide an important resource for a rich assemblage of cavity-nesting birds in the southwestern United States. To expand our knowledge of snag use by cavity-nesting birds in this region, we documented characteristics of snags with and without excavated cavities in mixed-conifer and ponderosa pine (Pinus ponderosa Dougl. ex Laws) forest in north-central Arizona. Snags were sampled in 113 square plots (1 ha each) randomly located within a study area covering approximately 73,000 ha across two National Forests. Density of snags was three times greater in mixed-conifer forest (n ¼ 53...

To evaluate the hypothesis that spotted owls (Strix occidentalis) select habitats with cool microclimates to avoid high daytime temperatures, I sampled thermal regimes in nest areas used by Mexican spotted owls (S. o. lucida) in northern Arizona. I sampled air temperature at 30-min intervals in 30 pairs of nest and random sites from May through August and used the resulting thermal profiles to estimate a suite of diurnal temperature parameters. I estimated diurnal energy use and evaporative water loss, and compared these estimates and temperature parameters between nest and random areas....

Many ponderosa pine (Pinus ponderosa) forests in the western US are dense and contain excessive accumulations of ground and ladder fuels, resulting in forests at high risk of catastrophic fire. Prescribed fire and thinning are two potential tools used in the reduction of forest fuels, although the ecological and economic consequences of applying these tools are not well understood. The national Fire and Fire Surrogates (FFS) Program seeks to quantify the effects of prescribed fire and thinning on a set of response variables, including wildlife. We measured the pre-treatment characteristics...

Riparian buffers can improve surface water quality by filtering contaminants from runoff before they enter streams. Infiltration is an important process in riparian buffers. Computer models are often used to assess the performance of riparian buffers. Accurate prediction of infiltration by these models is dependent upon accurate estimates of infiltration parameters. Of particular interest here are Green-Ampt infiltraiton parameters, satiated hydraulic conductivity (Ko) and wetting front suction (hf). The objectives of this research were to (i) modify the Smith sorptivity procedure so that...

Conservation buffers are designed to reduce sediment and agrichemical runoff to surface water. Much is known about plot and field scale effectiveness of buffers; but little is known about their - watershed scale impact. Our objective was to estimate the watershed scale impact of grass buffers by comparing sediment and agrichemical losses from two adjacent 141 - 165 hectare watersheds, one with conservation buffers and one without. Rainfall derived runoff events from 2002-2003 were monitored for water runoff, TSS, phosphorous and atrazine loss. A conservation-watershed included 0.8 km of...

Intentional introductions of nonnative trout into headwater lakes and streams can have numerous effects on the receiving ecosystems, potentially threatening native species and disrupting key ecological processes. In this perspective, we focus on seven key issues for assessing the biological and economic consequences of nonnative trout in headwater ecosystems: (1) effects of nonnative trout can span multiple biological domains, (2) effects of nonnative trout can extend beyond waters where they are introduced, (3) nonnative trout do not travel alone, (4) not all habitats are equal, (5)...