Treesearch

Social and economic systems provide the context and rationale for rangeland management. Sustaining rangeland ecosystems requires attention to the social and economic conditions that accompany the functioning of those systems. We present and discuss economic and social indicators for rangeland sustainability. A brief conceptual basis for each indicator is offered, describing its potential relationship to rangelands.

Land managers have long identified a critical need for a practical and effective framework for designing restoration strategies, especially where invasive plants dominate. A holistic, ecologically based, invasive plant management (EBIPM) framework that integrates ecosystem health assessment, knowledge of ecological processes, and adaptive management into a successional management model has recently been proposed. However, well-defined principles that link ecological processes that need to be repaired to tools and strategies available to managers have been slow to emerge, thus greatly...

Seeding rangeland following wildfire is a central tool managers use to stabilize soils and inhibit the spread of invasive plants. Rates of successful seeding on arid rangeland, however, are low. The objective of this study was to determine the degree to which water availability, invasive plant abundance, and seeding technology influence postfire seedling establishment. Across four fire complexes, whole plots were either seeded using a rangeland drill, seeded by hand where seeds could be placed at an exact depth, or left as unseeded controls. Irrigation and weeding treatments were applied...

Native forb seed is needed to restore the rangelands of the Intermountain West. Studies were conducted to identify herbicides that can be used to control weeds in forb seed production with limited injury to the forbs. The forbs evaluated in this project include: basalt milkvetch (Astragalus filipes), Western prairie clover (Dalea ornata), and Searls' prairie clover (Dalea searlsiae). Field trials were conducted in 2009 in Logan, UT on established fields transplanted in 2005 from cone-tainers and treatments were applied with a shielded bicycle sprayer delivering 20 gpa at 30 psi.

Cheatgrass (Bromus tectorum, downy brome) is arguably the most common plant in the western United States, dominating literally millions of acres of degraded rangeland; yet it is a relative newcomer, having arrived on the scene only a little over a century ago. It first entered the West as an unknown but probably small number of seeds in contaminated grain or packing material, a few years before the turn of the twen tieth century. How did it progress so rapidly from these humble beginnings to become a scourge over such a vast area? Is it still in the process of expansion? The story of how...

Searls' prairie clover (Dalea searlsiae) is a forb native to Utah and the Great Basin. Recent rangeland restoration efforts have lead to an interest in commercial Dalea seed production. This trial was designed to evaluate prairie clover tolerance to herbicides that have potential for use in prairie clover seed production. Treatments were applied May 12, 2009 on an established stand at a site in North Logan, Utah.

The project goal is to understand how multiple disturbance events including fire, insect outbreaks, and climate variability interact in space and time, and how they combine to influence forest species composition, spatial structure, and tree population dynamics in high elevation forests of the Pinaleno Mountains. Information from each of these components is needed in order to understand the events and processes that resulted in contemporary forest conditions, and to guide management plans toward restoration of a sustainable healthy ecosystem during a period of potentially rapid climate...

Rill erosion can be a large portion of the total erosion in disturbed forests, but measurements of the runoff and erosion at the rill scale are uncommon. Simulated rill erosion experiments were conducted in two forested areas in the northwestern United States on slopes ranging from 18 to 79%. We compared runoff rates, runoff velocities, and sediment flux rates from natural (undisturbed) forests and in forests either burned at low soil burn severity (10 months or 2 weeks post?fire), high soil burn severity, or subject to skidding of felled logs.

As forest management scenarios become more complex, the ability to more accurately predict erosion from those scenarios becomes more important. In this second part of a two-part study we report model parameters based on 66 simulated runoff experiments in two disturbed forests in the northwestern U.S. The 5 disturbance classes were natural, 10-month old and 2-week old low soil burn severity, high soil burn severity, and logging skid trails. In these environments the erosion rates were clearly detachment limited, and the rill erodibility parameters calculated from four hydraulic variables...

Roost use by African bats is poorly known, particularly for those using cavities in trees. Two sympatric species of Scotophilus were fitted with transmitters and tracked to their respective roosts in a natural savanna site in Swaziland. Both species roosted exclusively in trees, apparently preferring Combretum imberbe trees with large girths. The conservation of such roosting trees may be critical to the continued persistence of cavity-nesting insectivorous bats in African savannas.