Treesearch

The Grand Fir Mosaic (GFM) ecosystem is found on ash-cap soils in some mid-elevation forests of northern Idaho and northeastern Oregon. Harvesting on GFM sites results in successional plant communities that are dominated by bracken fern (Pteridium aquilinum) and western coneflower (Rudbeckia occidentalis), and have large populations of pocket gophers (Thomomys talpoides). Succession to trees and shrubs is very slow on disturbed GFM sites. Four factors contribute to the protracted stages of bracken fern plant communities and the slow rate of succession to woody plants: (1) competition among...

Economic implications of soil disturbance are discussed in four categories: planning and layout, selection of harvesting systems and equipment, long-term site productivity loss, and rehabilitation treatments. Preventive measures are more effective in minimizing impacts on soils than rehabilitation treatments because of the remedial expenses, loss of productivity until mitigation occurs, and the possibility that original soil conditions may not be restored. Alternative harvesting practices that are designed to minimize impacts on soils, such as use of designated skid trails and wide...

Soil restoration (sometimes termed enhancement) is an important strategy for sustaining the productivity of managed forest landscapes. Tephra-derived soils have unique physical and chemical characteristics that affect their response to disturbance and restoration. A variety of factors reduce forest productivity on degraded soils. Site-specific information on soil physical conditions, organic matter, and nutrient status is required for efficient soil restoration, but only limited research is available to help interpret such information and guide efforts to restore tephra-derived soils....

With pressure and vibration on a soil, air spaces between soil particles can be reduced by displaced soil particles. Activity associated with heavy machine traffic increases the density of the soil and can also increase the resistance of the soil to penetration. This paper reviews research related to disturbance of forest soils with a primary focus on compaction in ash-cap soils. The general process of compaction is described along with physical properties of ash-cap soils that relate to compaction. Ash-cap soils have physical soil properties most closely aligned to silt-loam soils....

Holocene ash from the cataclysmic eruption of Mount Mazama (now Crater Lake) in southeastern Oregon is a major component of many forest soils that lie to the east of Cascade Mountains in the Pacific Northwest region. The relatively high productivity of the region’s ecosystems is closely linked to this volcanic ash component. This paper reports on the ecologically important properties of these ash-influenced soils by examining soil characterization data from over 500 soil horizons of the region contained in the National Soil Survey database. Volcanic ash-cap textures are generally silty in...

This handbook presents information and photographs obtained from forest lands along the breaks of the Missouri River in eastern Montana. Forest characteristics summarized in tables with accompanying photographs can be used to provide quick estimates of species composition and densities within similar landscape features. These estimates may be useful to foresters, wildlife biologists, range ecologists, and fire and fuel specialists. The book is organized by six physiographic positions: 1) waterways (ravines or gullies), 2) south aspects < 25 percent slope angle, 3) south aspect > 25 percent...

We assessed the effectiveness of planting techniques (seeding and transplanting) and restoration treatments designed to improve the physical, biological, and chemical properties of soils and ameliorate microclimatic conditions on six closed campsites in subalpine forests. Restoration treatments included scarification, soil amendment with organic matter, compost and soil inoculum, and application of a mulch blanket. Campsite closure, scarification, planting, and soil amendments were successful in increasing recovery rates. The mulch blanket had no effect on recovery. 10 years after campsite...

At the time of this study Fossil Creek was being considered as a site for the restoration of a native fish assemblage, however there was concern amongst fisheries managers about the stream being food limited due to calcium carbonate (travertine) deposition. To evaluate the effects of travertine deposition on the aquatic food base we used leaf litterbags to compare decomposition rates and nutrient diffusing artificial substrates to compare algal accrual rates and nutrient limitation between two distinct reaches in Fossil creek: a travertine dam forming reach and a reach without travertine...

Temperate and boreal forest ecosystems contain a large part of the carbon stored on land, in the form of both biomass and soil organic matter. Increasing atmospheric [CO2], increasing temperature, elevated nitrogen deposition and intensified management will change this C store. Well documented single-factor responses of net primary production are: higher photosynthetic rate (the main [CO2] response); increasing length of growing season (the main temperature response); and higher leaf-area index (the main N deposition and partly [CO2] response). Soil organic matter will increase with...

We report the first laboratory simulations of hyporheic exchange in gravel pool-riffle channels, which are characterized by coarse sediment, steep slopes, and three-dimensional bed forms that strongly influence surface flow. These channels are particularly important habitat for salmonids, many of which are currently at risk worldwide and which incubate their offspring within the hyporheic zone. Here we perform a set of laboratory experiments examining the effects of discharge and bed form amplitude on hyporheic exchange, with surface-subsurface mixing measured directly from the concentratio...