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Five alcoves (rock shelters) in the Forty-Mile Canyon—Willow Gulch area of the Escalante River Basin in southeastern Utah yielded rich deposits of late Quaternary macrobotanical remains. The deposits were sampled and the contents identified in order to construct a chronology of vegetational change. Fourteen radiocarbon dates indicate that the fossils were deposited between 12,690 and 7510 yr B.P. (years before present). Ninety-one plant taxa were identified, 62 to species. Six species were common to all alcoves: Gambel oak (Quercus gambelii), box-elder (Acer negundo), prickly pear (Opuntia subgenus Platyopuntia), skunkbush (Rhus aromatica var. trilobata), serviceberry (Amelanchier utahensis), and Indian ricegrass...
Carbon and nitrogen are supplied by a variety of sources in the desert food web; both vascular and non-vascular plants and cyanobacteria supply carbon, and cyanobacteria and plant-associated rhizosphere bacteria are sources of biological nitrogen fixation. The objective of this study was to compare the relative influence of vascular plants and biological soil crusts on desert soil nematode and protozoan abundance and community composition. In the first experiment, biological soil crusts were removed by physical trampling. Treatments with crust removed had fewer nematodes and a greater relative ratio of bacterivores to microphytophages than treatments with intact crust. However, protozoa composition was similar with...
We examined the biogeography of aquatic and semiaquatic Heteroptera (ASH) in the Grand Canyon (GC) ecoregion (GCE) on and adjacent to the southern Colorado Plateau. We report 89 ASH taxa in 86 species, 37 genera, and 14 families in the GCE, including 54 ASH taxa detected within or on the rims of GC and its major tributaries, a fauna 3.8-fold greater than previously reported. We tested 2 groups of biogeographic hypotheses to account for this high level of diversity, demonstrating an underlying pattern of mixed biogeographic affinity and strong landform-climate effects. Equal numbers of ASH taxa were derived from allochthonous (neotropical and nearctic) sources and autochthonous (range-centered) sources. A negative...
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These plant and soil data were collected by Timothy M. Wertin and Sasha C. Reed in the spring, summer, and fall of 2011 at a climate manipulation experiment site near Moab, UT (38.521411, -109.470567). These data were collected to assess how warming affects leaf photosynthesis, soil CO 2 efflux, and soil chemistry in plots of ambient and warming treatments.
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This dataset consists of 102 magnetotelluric (MT) stations collected in 2012-2014 in the Rio Grande Rift and southern Rocky Mountains. The U.S. Geological Survey acquired these data to improve regional conductivity models of the western United States. This work is in support of studies of the effect of lithospheric modification on electrical resistivity structure and tectonic evolution of the western United States.
Categories: Data; Types: Citation, Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Carson National Forest, Colfax County, Colorado, Colorado Plateau, Dona Ana County, All tags...
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The dataset describes rangeland monitoring results from the Hanksville, UT (USA) area. Monitoring results consist of canopy cover of plant species and functional types according to ecological site group from 1967 to 2013. The study area is bordered on the north by the Wayne-Emery County line, on the west by Capitol Reef National Park, and on the south and east by the Colorado River, Glen Canyon National Recreation Area, and Canyonlands National Park. Cover was estimated every 1 to 5 years (except the last measurement that had a 12 year interval) from 1967 to 2013 at 36 permanently marked sites in 15 livestock grazing allotments/pastures. Canopy cover of perennial plant species was estimated to the nearest tenth...
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In this study, we examined N gas loss as nitric oxide (NO) from N-fixing biologically crusted soils in Canyonlands National Park, Utah. We hypothesized that NO gas loss would increase with increasing N fixation potential of the biologically crusted soil. NO fluxes were measured from biologically crusted soils with three levels of N fixation potential (Scytonema-Nostoc-Collema spp. (dark)>Scytonema-Nostoc-Microcoleus spp. (medium)>Microcoleus spp. (light)) from soil cores and field chambers. In both cores and field chambers there was a significant effect of crust type on NO fluxes, but this was highly dependent on season. NO fluxes from field chambers increased with increasing N fixation potential of the biologically...
Holocene debris flows do not occur uniformly on the Colorado Plateau province of North America. Debris flows occur in specific areas of the plateau, resulting in general from the combination of steep topography, intense convective precipitation, abundant poorly sorted material not stabilized by vegetation, and the exposure of certain fine-grained bedrock units in cliffs or in colluvium beneath those cliffs. In Grand and Cataract Canyons, fine-grained bedrock that produces debris flows contains primarily single-layer clays—notably illite and kaolinite—and has low multilayer clay content. This clay-mineral suite also occurs in the colluvium that produces debris flows as well as in debris-flow deposits, although unconsolidated...
Hanging garden plant communities form at seeps on cliffs. A given community may include common riparian species, disjunct populations, and species endemic to hanging gardens. What structures hanging harden communities, and how they respond to disturbance are poorly understood. In 1989, fireworks ignited a hanging garden in Knowles Cañon, destroying aboveground vegetation. Permanent plots were established in July 1993 to monitor changes in vegetation and soil biota. Revegetation of the garden has been limited to grasses, forbs, and ferns where water was present at the soil surface, and shrubs and trees sprouting from surviving rootstocks. Water drips from the overhanging cliff in the central area, where plant cover...
Hanging garden plant communities form at seeps on cliffs. A given community may include common riparian species, disjunct populations, and species endemic to hanging gardens. What structures hanging harden communities, and how they respond to disturbance are poorly understood. In 1989, fireworks ignited a hanging garden in Knowles Cañon, destroying aboveground vegetation. Permanent plots were established in July 1993 to monitor changes in vegetation and soil biota. Revegetation of the garden has been limited to grasses, forbs, and ferns where water was present at the soil surface, and shrubs and trees sprouting from surviving rootstocks. Water drips from the overhanging cliff in the central area, where plant cover...
The Colorado Plateau was one of the last areas in the United States to be developed economically. Before the 1880s it was virtually empty except for Indians. Today the vast scenic and energy resources of the area are under development, and projections for future development are frightening. Problems of land use management are directly related to the fragmented nature of landholdings. Present methods of consolidation are inadequate, and new approaches to the organization of space must be devised if further degradation of the environment is to be prevented. Published in Annals of the Association of American Geographers, volume 62, issue 2, on pages 211 - 236, in 1972.
Newly discovered olivine phlogopite lamproite dikes intrude Jurassic siliciclastic strata in the Green River Desert subregion of the western Colorado Plateau tectonic province in southeastern Utah. The dikes yield an age of 22 Ma both from 40Ar/39Ar step-heating of phlogopite and from isochron modeling of laser-fused sanidine. This age is similar to those of mica-rich minettes and melanephelinites of the Wasatch Plateau about 125 km northwest and within the age range of the Navajo potassic volcanic field about 150 km to the southeast. The dikes intruded a pre-existing, northwest-oriented fracture system containing previously introduced bitumen, indicating that some regional lineaments of this trend are Early Miocene...
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These data provide the locational coordinates, soil texture characteristics, plant species occurrence and cover, and vegetation summary characteristics for the Tsezhin bii region in the south-central area of the Navajo Nation. They were collected in the fall of 2004 and their subsequent analysis reported in the paper titled 'Vegetation of semi-stable rangeland dunes of the Navajo Nation, Southwestern USA' in the journal Arid Lands Research and Management in 2016.
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Two unique datasets were gathered to document whether flow management for hydropower affects the abundance and diversity of aquatic insect assemblages. The first dataset was collected in Grand Canyon from 2012-2014 by citizen scientists rafting the Colorado River. Simple light traps were set out each night in camp and used to capture the adult life stages of aquatic insects that emerged from the Colorado River. Three aquatic insect taxa were captured in sufficient abundance to analyze statistically including midges (order Diptera, family Chironomidae), micro-caddisflies (order Trichoptera, family Hydroptilidae), and blackflies (order Diptera, family Simuliidae, principally Simulium arcticum). These data were used...
Types: Citation; Tags: Adult aquatic insects, Arizona, Biodiversity, Biological traits, California, All tags...
The Colorado Plateau is a distinct physiographic province in western North America, which presently straddles the transition between summer-wet and summer-dry climatic regimes to the south and northwest, respectively. In addition to climate, the diversity of environments and plant communities on the Colorado Plateau has resulted from extreme topographic diversity. Desert lowlands as low as 360 m elevation are surrounded by forested plateaus, and even higher peaks greater than 3800 m elevation. This environmental diversity provides a unique opportunity to study the history of biotic communities in an arid region of North America. Although the Colorado Plateau harbours numerous potential sites, the paleoecological...
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In this study, we conducted rainfall simulation experiments in a cool desert ecosystem to examine the role of biological soil crust disturbance and composition on dissolved and sediment C and N losses. We compared runoff and sediment C and N losses from intact late-successional dark cyanolichen crusts (intact) to both trampled dark crusts (trampled) and dark crusts where the top 1 cm of the soil surface was removed (scraped). In a second experiment, we compared C and N losses in runoff and sediments in early-successional light cyanobacterial crusts (light) to that of intact late-successional dark cyanolichen crusts (dark). A relatively high rainfall intensity of approximately 38 mm per 10-min period was used to...
Long-lived desert shrubs exhibit infrequent, episodic recruitment from seed. In spite of this long time scale, selection on life history attributes that affect seedling recruitment should be strong. We studied factors affecting germination phenology and seedling establishment for Coleogyne ramosissima, a dominant shrub species in the ecotone between warm and cold deserts in western North America. We also examined ecotypic differentiation in establishment strategy in response to selection regimes in two contrasting habitats. We followed patterns of dormancy loss, germination, emergence, and survival in reciprocal field experiments at warm winter Mojave Desert and cold winter Colorado Plateau study sites. Seed germination...
Molecular methodologies were used to characterize fungal communities associated with lichen-dominated biological soil crusts (BSCs) at two sites on the Colorado Plateau (USA) in order to investigate their diversity and abundance, in relation to that of bacteria, as well as how these parameters corresponded to overall soil crust cover and the presence of anthropogenic disturbance. Fungal community diversity and composition were assessed with denaturing gradient gel electrophoresis (DGGE) fingerprinting of PCR amplified ribosomal genes and by sequencing. Quantitative PCR, specific for fungi as well as bacteria, was used to evaluate relative microbial densities. Two sites with similar soil characteristics, both of...
In this study, we examined N gas loss as nitric oxide (NO) from N-fixing biologically crusted soils in Canyonlands National Park, Utah. We hypothesized that NO gas loss would increase with increasing N fixation potential of the biologically crusted soil. NO fluxes were measured from biologically crusted soils with three levels of N fixation potential (Scytonema-Nostoc-Collema spp. (dark)>Scytonema-Nostoc-Microcoleus spp. (medium)>Microcoleus spp. (light)) from soil cores and field chambers. In both cores and field chambers there was a significant effect of crust type on NO fluxes, but this was highly dependent on season. NO fluxes from field chambers increased with increasing N fixation potential of the biologically...
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Great thicknesses of eolian dune deposits of early Oligocene age crop out in the Chuska Mountains of northwestern New Mexico-Arizona (as much as 535 m thick) and in the Mogollon-Datil volcanic field of western New Mexico-Arizona (as much as 300 m thick). 40Ar/39Ar ages of intercalated volcanic rocks indicate eolian deposition in these areas was approximately synchronous, with eolian accumulation beginning regionally at ca. 33.5 Ma and ending at ca. 27 Ma. Probable eolian sandstone of Oligocene age 483 m thick is also present in the subsurface of the Albuquerque Basin of the Rio Grande rift. The beginning of eolian deposition on the Colorado Plateau corresponds closely to the beginning of eolian (loessic) deposition...
map background search result map search result map The Chuska erg: Paleogeomorphic and paleoclimatic implications of an Oligocene sand sea on the Colorado Plateau The Knowles Cañon Hanging Garden, Glen Canyon National Recreation Area, Five Years after Burning: Vegetation and Soil Biota Patterns Impacts of Biological Soil Crust Disturbance and Composition on C and N Loss from Water Erosion NO gas loss from biologically crusted soils in Canyonlands National Park, Utah Rangeland Ecology Monitoring Data, Utah, 1967-2013 Flow management, aquatic insects and river food webs - Data Experimental Design Plant and Soil Measurement Data for Achnatherum hymenoides from a warming experiment, Colorado Plateau, 2011 - Data Tsézhin Bii’ Field and Summary Data 2004 - Data Regional scale magnetotelluric data from the Rio Grande Rift and southern Rocky Mountains Experimental Design Plant and Soil Measurement Data for Achnatherum hymenoides from a warming experiment, Colorado Plateau, 2011 - Data Tsézhin Bii’ Field and Summary Data 2004 - Data Impacts of Biological Soil Crust Disturbance and Composition on C and N Loss from Water Erosion NO gas loss from biologically crusted soils in Canyonlands National Park, Utah Rangeland Ecology Monitoring Data, Utah, 1967-2013 The Chuska erg: Paleogeomorphic and paleoclimatic implications of an Oligocene sand sea on the Colorado Plateau Regional scale magnetotelluric data from the Rio Grande Rift and southern Rocky Mountains Flow management, aquatic insects and river food webs - Data