Skip to main content

Roundy, Bruce A

thumbnail
Establishment of native plant populations on disturbed roadsides was investigated at Bryce Canyon National Park (BCNP) in relation to several revegetation and seedbed preparation techniques. In 1994, the BCNP Rim Road (2,683?2,770 m elevation) was reconstructed resulting in a 23.8-ha roadside disturbance. Revegetation comparisons included the influence of fertilizer on plant establishment and development, the success of indigenous versus commercial seed, seedling response to microsites, methods of erosion control, and shrub transplant growth and survival. Plant density, cover, and biomass were measured 1, 2, and 4 years after revegetation implementation (1995?1998). Seeded native grass cover and density were the...
After wildfires in 1996 in the sagebrush (Artemisia spp.) and pinyon-juniper (Pinus spp.-Juniperus spp.) zones of west-central Utah, the USDI-BLM attempted to reduce soil erosion and cheatgrass proliferation (Bromus tectorum L.) through rehabilitation treatments. We compared the vegetation of aerially seeded, chained treatments with aerially seeded but non-chained treatments for 3 years following seeding. Vegetation cover increased significantly in both treatments between the first and second year, concurrent with above-average precipitation. By the second year, seeded grasses, primarily crested wheatgrass Agropyron cristatum (L.) Gaertn. and intermediate wheatgrass Elymus hispidus (Opiz) Meld. and Elymus elongatus...
Microbiotic soil crusts play several important roles in many arid and semiarid ecosystems around the world. Their effects on soil hydrology, however, are poorly understood. It has been speculated that crusts (1) improve soil water availability by "sealing" the soil surface to water loss, or (2) diminish soil water by increasing the latent heat of a soil profile thereby increasing evaporation. In order to distinguish between these two opposing hypotheses, we analyzed water loss and temperature of soil profiles covered by different types of microbiotic soil crust (cyanobacteria, Psora decipiens, Placidium squamulosum) and a bare soil. We conducted experiments under growth chamber and field conditions. After watering...
We investigated soil compaction and hydrologic responses from mechanically shredding Utah juniper (Juniperus ostesperma [Torr.] Little) to control fuels in a sagebrush/bunchgrass plant community (Artemisia nova A. Nelson, Artemisia tridentata Nutt. subsp. wyomingensis Beetle & Young/Pseudoroegneria spicata [Pursh] A. L�ve, Poa secunda J. Presl) on a gravelly loam soil with a 15% slope in the Onaqui Mountains of Utah. Rain simulations were applied on 0.5-m2 runoff plots at 64 mm � h?1 (dry run: soil initially dry) and 102 mm � h?1 (wet run: soil initially wet). Runoff and sediment were collected from runoff plots placed in five blocks, each containing four microsites (juniper mound, shrub mound, vegetation-free or...
Ecosystem susceptibility to invasion by nonnative species is poorly understood, but evidence is increasing that spatial and temporal variability in resources has large-scale effects. We conducted a study in Artemisia tridentata ecosystems at two Great Basin locations examining differences in resource availability and invasibility of Bromus tectorum over elevation gradients and in response to direct and interacting effects of removal of perennial herbaceous vegetation and fire. We monitored environmental conditions, soil variables, and B. tectorum establishment and reproduction over two years. Soil water (measured as the number of days soil matric potential was >?1.5 MPa) and nitrate availability (measured as micromoles...
ScienceBase brings together the best information it can find about USGS researchers and offices to show connections to publications, projects, and data. We are still working to improve this process and information is by no means complete. If you don't see everything you know is associated with you, a colleague, or your office, please be patient while we work to connect the dots. Feel free to contact sciencebase@usgs.gov.