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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...
Arbuscular mycorrhizal fungi (AMF) are important root symbionts that can provide benefits to plant hosts, yet we understand little about how neighboring hosts in a plant community contribute to the composition of the AMF community. We hypothesized that the composition of the plant neighborhood, including the identities of both host and neighbor, would alter AMF community composition. We tested this in a glasshouse experiment in which a native perennial grass (Nassella pulchra) and three annual grasses (Avena barbata, Bromus hordeaceaous and Vulpia microstachys) were grown in two neighborhoods: conspecific monocultures and heterospecific perennial-annual mixtures. To identify AMF taxa colonizing plant roots, we used...
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From 2011-2018 USGS biologists recorded vegetation and biological soil crust (BSC) cover by species and tracked survival of tagged individual plants (388 in total) across 40 locations where paired experimental plots had been installed in 2010. Plant cover was visually estimated using four 75 x 100 cm survey frames. Each site contained a two plots measuring 1.5 by 2.0 meteres: a control plot and a plot covered by a shelter that excluded 35% of incoming precipitation. Plots were selected to represent shallow vs. deep soils, sandstone vs. shale parent material, and dominant plant species on the Colorado Plateau around Moab, Utah. We used an information theoretic approach using generalized linear models to determine...
Fire risk in deserts is increased by high production of annual forbs and invasive grasses that create a continuous fine fuel bed in the interspaces between shrubs. Interspace production is influenced by water, nitrogen (N) availability, and soil texture, and in some areas N availability is increasing due to anthropogenic N deposition. The DayCent model was used to investigate how production of herbaceous annuals changes along gradients of precipitation, N availability, and soil texture, and to develop risk-based critical N loads. DayCent was parameterized for two vegetation types within Joshua Tree National Park, California, USA: creosote bush (CB) and pi�on?juniper (PJ). The model was successfully calibrated in...
The spatial distribution of roots of two alien grasses, Bromus tectorum and Poa pratensis, grown singly and in a mixture, was examined using a double-labelling radioisotope technique. Interactions between the root systems of these plants led to a restricted B. tectorum rooting volume in P. pratensis neighborhoods @?30-d-old. The roots of B. tectorum failed to develop laterally. The altered B. tectorum root systems may contribute to its inability to persist in established P. pratensis swards. Published in Ecology, volume 63, issue 3, on pages 640 - 646, in 1982.
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Maps of invasive annual grasses were created using multi-season Landsat imagery over a 12 years period (2009-2020), and validated using an extensive network of plot data. Annual maps were used to identify persistent and productive populations of invasive annual grass, called hot spots, across entire Mojave Desert ecoregion. The data provided include a 12 band raster geospatial data file (.tiff) that represents classified early season invasive (ESI) grasses for each year from 2009-2020, and a single .tiff file of ESI hot spots made using the Getis-Ord Gi* Hot Spot classification method.


    map background search result map search result map Revegetation Methods for High-Elevation Roadsides at Bryce Canyon National Park, Utah Long-term precipitation reduction experiment in the Colorado Plateau - Survival and mortality data from 2010 to 2018 Maps of early season invasive grasses and hot spots in the Mojave Ecoregion from 2009-2020 Revegetation Methods for High-Elevation Roadsides at Bryce Canyon National Park, Utah Long-term precipitation reduction experiment in the Colorado Plateau - Survival and mortality data from 2010 to 2018 Maps of early season invasive grasses and hot spots in the Mojave Ecoregion from 2009-2020