Treesearch

We discuss ecological theory and population models pertinent to the population biology of southern lynx. Fragmented forest cover types, high vagility of lynx, and linkages in population dynamics suggest that lynx in the contiguous United States are arranged as metapopulations. Metapopulation stability depends on not only habitat quality but also dispersal rates between habitat islands. Models indicate that dispersal rates between habitat islands should sharply decrease as the islands become smaller and more distant and the risks associated with crossing between islands increase. Southern...

Prevention and estimation of soil erosion from forest roads requires an understanding of how road design and maintenance affect sediment production. Seventy-four plots were installed on forest roads in the Oregon Coast Range to examine the relationship between sediment production and road attributes such as distance between culverts, road slope, soil texture, and cutslope height. An additional comparison was made between road segments with cutslopes and ditches freshly cleared of vegetation and segments with established vegetation on cutslopes and in ditches. All road segments were 5 m...

Lynx occur across a large geographic area, but have only been studied in a few locations, and this has led to extrapolation of understandings into areas with very divergent ecologies. We discuss ecological differences across the range of lynx, contrasting the patterns of climate, vegetation, disturbance dynamics and succession, and predator/prey relationships. In all these particulars, areas where lynx occur within the contiguous United States diverge from the well-studied areas of the taiga. We caution against uncritical application of ecological understandings derived from the North to...

We investigated winter activity patterns of American Martens, Martes americana, Snowshoe Hares, Lepus americanus, and Red Squirrels, Tamiasciurus hudsonicus, in westcentral Montana between November 1994 and March 1995 using dual-sensor remote cameras. One hundred percent of Snowshoe Hare (n = 25) observations occurred at night while Martens (n = 85) exhibited random activity during diel and nocturnal hours and Red Squirrels (n = 22) were diurnal. Marten activity coincided with the nocturnal and diurnal rnicrotines and diurnal Red Squirrels though they could take advantage of the strictly...

Five second order tributaries to Tenderfoot Creek were investigated: Upper Tenderfoot Creek, Sun Creek, Spring Park Creek, Bubbling Creek, and Stringer Creek. Second order reaches were initially located on 7.5 minute topographic maps using techniques first applied by Strahler (1952). Reach breaks were determined in the field through visual inspection. Vegetation type (forested vs. non forested), channel slope, sinuosity, entrenchment ratio, and channel materials were used in the classification of stream reaches, using channel classification techniques developed by Rosgen (1995).

The objectives of this Research Joint Venture Agreement (RJVA) were to install and calibrate three flumes on Tenderfoot Creek Experimental Forest (TCEF) in central Montana; check calibration of the existing seven flumes on TCEF; estimate the influence of fire on water yields over the 400-year fire history period; and estimate back records of monthly temperature, monthly snow water equivalent, monthly precipitation for TCEF, and monthly streamflow for the lower Tenderfoot Creek flume (Tenderfoot Creek below Stringer Creek). Because of the potential for high streamflows in 1997, and the...

Scientists either directly or indirectly associated with previous Bitterroot Ecosystem Research Management Project (BEMRP) vegetation studies continue to pursue both fundamental and applied vegetation research projects in the interior West. Most of the "recent happenings" in vegetation research relate to restoration of forested ecosystems, including activities in whitebark pine, lodgepole pine, old growth ponderosa pine, mixed conifer canyons, and fir-dominated riparian areas.

Age structure and distribution of leaf area index (LAI) of even and multiaged lodgepole pine (Pinus contorta var. latifolia Engelm.) stands were examined on three study areas in western and central Montana. Projected leaf area was determined based on a relationship with sapwood cross-sectional area at breast height. Stand structure and LAI varied considerably between individual plots. LAI and stand stem volume increment were significantly higher in multiaged than even-aged stands with the exception of one study area, which had higher volume increment in even-aged stands. Older cohorts and...

Textural patches (i.e., grain-size facies) are commonly observed in gravel-bed channels and are of significance for both physical and biological processes at subreach scales. We present a general framework for classifying textural patches that allows modification for particular study goals, while maintaining a basic degree of standardization. Textures are classified using a two-tier system of ternary diagrams that identifies the relative abundance of major size classes and subcategories of the dominant size. An iterative procedure of visual identification and quantitative grain-size...

Field studies of forest gravel-bed rivers in northwestern Washington and southeastern Alaska demonstrate that bed-surface grain size is responsive to hydraulic roughness caused by bank irregularities, bars, and wood debris. We evaluate textural response by comparing reach-average median grain size (D50) to that predicted from the total bank-full boundary shear stress (T0bf), representing a hypothetical reference condition of low hydraulic roughness. For a given T0bf, channels with progressively greater hydraulic roughness have systematically finer bed surfaces presumably due to reduced bed...