Treesearch

A computer simulation of the burning oflarge woody natural fuels has been created. The model simulates flaming combustion of large woody surface fuels but includes the influence of smoldering duff on this burning. This paper describes calibration of empirical constants in the model using data from laboratory crib burns and from prescribed burns in harvest debris and in natural fuel accumulations. The calibrated model reproduced laboratory crib burning rates and natural fuel loading reductions with acceptable accuracy.

Western larch (Larix occidentalis Nutt.) regenerates and grows adequately on a variety of soils and sites. Mineral soil and burned-over surfaces are excellent for natural regeneration, but organic surfaces also provide adequate seedbeds. Planted western larch are aggressive root producers especially in moist soils. Best development occurs in soils with high organic matter content. Competing vegetation often reduces performance. Site preparation can significantly impact growth and development of this species.

Western larch (Larix occidentalis Nutt.) is a sporadic cone and seed producer. Because the species is such an important component of the -Northern Rocky Mountain forests, methods of increasing seed production are needed. Girdling, fertilizing, and a combination of the two were used on 75-year-old western larch in northern Idaho. Girdling at the base of the live crown was effective in stimulating cone production, while the combination of fertilizing with ammonium nitrate and girdling did not increase seed yield. Fertilizer alone appeared to decrease the number of seeds per cone. Cones from...

ECO-News is an annual Rocky Mountain Research Station (RMRS) publication which contains a set of articles showcasing the Bitterroot Ecosystem Management Research Project (BEMRP) research projects and activities. The articles are concise, user-friendly, and designed to inform a broad range of audiences interested in ecosystem management. Articles featured in this issue: BEMRP - a first of its kind within the Forest Service; A team approach to resource planning; Project goals reflect ecosystem-based principles; Ecosystem management a different approach to land management; The Bitterroot...

Northern goshawks (Accipiter gentilis) feed on a wide variety of birds and mammals (R. T. Reynolds, et al. 1992, USDA For. Ser. Gen. Tech. Rep. RM-217. Fort Collins, CO U.S.A.), but few accounts describe goshawks feeding on carrion. J.H. Schnell (1958, Condor 60:377-403) stated that, "It seems highly unlikely that the goshawk would forage for carrion under normal circumstances." However, G.M. Sutton (1925, Wilson Bull. 37:193-199) reported a goshawk shot while feeding on a black bear (Ursus american us) carcass in Pennsylvania. Carrion use has also been reported for two species of Australia...

Winter movements of four adult northern goshawks (Accipiter gentilis) that nest in southcentral Wyoming were monitored during the winter of 1992-93. Goshawks initiated fall migrations in early fall (primarily mid-September) while weather conditions are moderate. Female 1 migrated 185 km south of her nest. She wintered in a mountainous area in Colorado at a higher elevation (277 4 m) than her nest site (2500 m elevation). Male 1 migrated approximately 65 km west southwest of his nest before he was killed by a hard blow from a blunt object. This strike may have been caused by another raptor...

We documented the winter, spring and summer food habits of trumpeter swans (Cygnus buccinator) in the greater Yellowstone area (the intersection of Idaho, Montana and Wyoming) and studied the diet preference of nesting swans. Although 23 foods were detected in trumpeter swan diets during the winter, spring and summer, only 8 contributed at least 3% to the diet during any one season (Table 1). Dominant foods (over 10% of the diet in at least one season) included Chara spp. (21.7%, 4.1%, mean, SE), Elodea canadensis (11.4%, 3.1), Potamogeton spp. (32.3%, 4.2), and Potamogeton pectinatus...

Erosion rates of recently graded nongravel forest roads were measured under rainfall simulation on five different soils. The erosion rates observed on 24 forest road erosion plots were compared with values predicted by the Water Erosion Prediction Project (WEPP) Model, Version 93.1. Hydraulic conductivity and soil erodibility values were predicted from methods developed for rangeland and cropland soils. It was found that on four of the five soils, runoff values were closely predicted and that the predicted erosion was not significantly different from the observed erosion when using...

There are two experimental forests in Montana established by the U.S. Department of Agriculture, Forest Service, Intermountain Research Station (INT). Both experimental forests are administered by INT's Research work Unit, RWU-4151, Silviculture of Subalpine Forest Ecosystems. Tenderfoot Creek Experimental Forest (TCEF) is east of the continental Divide and is located 24 miles north of White Sulphur Springs and 9 miles northwest of Highway 89 at Kings Hill in central Montana. All of the 8,874 acre (area obtained from Lewis and Clark National Forest Geographic Information System) experimenta...

Field surveys of stream channels in forested mountain drainage basins in southeast Alaska and Washington reveal that pool spacing depends on large woody debris (LWD) loading and channel type, slope, and width. Mean pool spacing in pool-riffle, plane-bed, and forced pool-riffle channels systematically decreases from greater than 13 channel widths per pool to less than 1 channel width with increasing LWD loading, whereas pool spacing in generally steeper, step-pool channels is independent of LWD loading. Although plane-bed and pool-riffle channels occur at similar low LWD loading, they...