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Growing international concern about the greenhouse effect has led to increased interest in the regional implications of changes in temperature and precipitation patterns for a wide range of societal and natural systems, including agriculture, seal level, biodiversity, and water resources. The accumulation of greenhouse gases in the atmosphere due to human activities are likely to have siginificant, though still poorly understood, impacts on water quality and availability. One method developed over the last several years for determining how regional water resources might be affected by climatic change is to develop scienarios of changes in temperature and precipitation and to use hydrologic simulation models to study...
Desert iguanas (Dipsosaurus dorsalis) were maintained at 10, 20, 30 or 40°C for one week. Animals were autopsied at zero time, and 30 and 90 minutes after a single injection of ACTH. Basal plasma corticosterone (B) level was similar in all lizards regardless of environmental temperature. Both blood glucose and liver glycogen levels showed highly significant correlations with environmental temperature. Injection of ACTH increased plasma B level in all temperature groups but the rate and magnitude of the response were temperature dependent. Liver glycogen was increased after ACTH injection at 20°C and plasma glucose response to ACTH was significantly correlated with temperature. Published in Journal of Comparative...
The Colorado River Extensional Corridor (CREC) of southeastern California, southern Nevada, and western Arizona experienced up to 100% extension between ~23 and 12 Ma. Extension was accommodated by low-angle normal faulting in the upper and middle crust, subvertical brittle failure of the lower crust, emplacement of mantle-derived magma in a crustal-scale fracture, and, later, crustal flow. Evidence for brittle, whole-crustal failure includes geophysical observations, structural analysis, geochronology, thermochronology, geobarometry, and paleomagnetic studies of surface exposures of syntectonic, mantle-derived mafic plutonic sheets emplaced as subvertical, crustal-scale intrusions tracking the zone of maximum extension....
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Summers on the Colorado Plateau (USA) are typified by harsh conditions such as high temperatures, brief soil hydration periods, and high UV and visible radiation. We investigated whether community composition, physiological status, and pigmentation might vary in biological soil crusts as a result of such conditions. Representative surface cores were sampled at the ENE, WSW, and top microaspects of 20 individual soil crust pedicels at a single site in Canyonlands National Park, Utah, in spring and fall of 1999. Frequency of cyanobacterial taxa, pigment concentrations, and dark adapted quantum yield [F(v)/F(m)] were measured for each core. The frequency of major cyanobacterial taxa was lower in the fall compared to...
We capitalized on a regional-scale, anthropogenic experiment?the reduction of black-tailed prairie dog (Cynomys ludovicianus) towns across the Great Plains of North America?to test the hypothesis that decline of this species has led to declines in diversity of native grassland vertebrates of this region. We compared species richness and species composition of non-volant mammals, reptiles and amphibians at 36 prairie dog towns and 36 paired sites in the Panhandle Region of Oklahoma during the summers and falls of 1997, 1998 and 1999. We detected 30 species of mammals, 18 species of reptiles and seven species of amphibians. Comparisons between communities at prairie dog towns and paired sites in the adjacent landscape...
Floodplains are presumed to be important rearing habitat for the endangered razorback sucker (Xyrauchen texanus). To help recover this endemic Colorado River Basin species, the Upper Colorado River Endangered Fish Recovery Program implemented a floodplain acquisition and enhancement program. Levee removal was initiated in 1996 as one component of this floodplain restoration program. The goal of the Levee Removal Study was to evaluate the system responses to levee removal and make specific recommendations concerning the value of floodplain/river reconnecting for endangered species (specifically razorback sucker) recovery.
Continental successions of the North American Western Interior retroarc foreland basin provide an excellent opportunity to evaluate the tectonic controls on nonmarine sequence stratigraphy. The transition between the Upper Jurassic Brushy Basin Member anastomosed fluvial system of the Morrison Formation and the gravelly braided-river deposits of the Buckhorn Conglomerate has been studied to assess the dispersal of coarse clastics and the development of associated basin-wide unconformities in a sequence stratigraphic framework. The sharp contact between the two members is interpreted to be conformable based on stratigraphic, sedimentologic, and petrologic data collected at and near Cedar Mountain in central Utah,...
Native fishes of the Upper Colorado River Basin have experienced substantial declines in abundance and distribution, and are extirpated from most of Wyoming. Muddy Creek, in south-central Wyoming (Little Snake River watershed), contains sympatric populations of native roundtail chub (Gila robusta), bluehead sucker, (Catostomus discobolus), and flannelmouth sucker (C. latipinnis), and represents an area of high conservation concern because it is the only area known to have sympatric populations of all 3 species in Wyoming. However, introduced creek chub (Semotilus atromaculatus) are abundant and might have a negative influence on native fishes. We assessed summer food habits of roundtail chub and creek chub to provide...
Southern Utah comprises 4 major physiographic divisions: the Great Basin, Colorado Plateau, Central Rocky Mountains, and Southern Rocky Mountains, which have been partitioned into faunal regions. We discuss the uniqueness of southern Utah and the amount of land set aside for recreation and preservation, and we encourage the study and preservation of its water resources. The stonefly (Plecoptera) fauna of 13 counties in southern Utah was surveyed. We found 58 species representing 34 genera and 8 families. Three new state records for Utah and many new county records for southern Utah are presented, along with a discussion of distribution patterns and faunal affinities of each species. Distribution patterns indicate...
The Canyonlands grabens in southeast Utah form an active extensional fault array covering 200 km2 southeast of the Colorado River. The fault array formed as a result of gravity gliding above a thick layer of salt. Growth of this fault array within the last 0.5 m.y. (possibly last 0.1 m.y.) has resulted in major changes in the stream drainages across the area through processes of stream capture and diversion. During growth of the fault array, relay ramps between overlapping fault segments form topographic lows along the graben margins. These commonly act as access points for captured streams to enter a graben system. As fault segments continue to propagate laterally, linkage leads to breaching of the relay ramp structures....
ABSTRACT-Spawninagn d movementso f the razorbacks ucker,X yrauchent exanus,w ere evaluated by radiotelemetry( n = 17 fish) and captureo f 230 adults (105 recaptures)i n the Green and Yampa rivers, 1987 to 1989. Ripe fish (n = 194) were captured in riffles with cobble, gravel, and sand substratesf romm id-Aprilt o early June. Recapturedm alesw ere ripe from2 to 28 days and recaptured females from 2 to 15 days. Razorback suckers spawned during ascending and highest spring flows at water temperatureso f about 14'C (range of 9 to 17?C).S pawning migrationso f 30 to 106 km were detectedi n 17 razorbacks uckers,b ut movementsw ere more limitedo r undetectedi n other individuals. Floodedl owlandsa nd lower portionso f...
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This survey was made to provide information about the soils and miscellaneous areas in the Ute Mountain Soil Survey area. The information includes a description of the soils and miscellaneous areas and their location and a discussion of their suitability, limitations, and management for specified uses. Soil scientists observed the steepness, length, and shape of the slopes; the general pattern of drainage; native plants; and the kinds of bedrock. Soil scientists working in the Ute Mountain Area dug many holes, using shovels, hydraulic probes, and backhoes to study the soil profile, which is the sequence of natural layers, or horizons, in a soil.
Categories: Publication; Types: Citation
A written survey of 200 Moab residents was used to measure residents' attitudes toward tourism. Three regression models were developed using variables identified in the tourism literature to measure the relative importance of interpersonal contacts with tourists, negative impacts to outdoor-recreation experiences, and community experience in predicting attitudes toward tourism. Interpersonal contacts and recreation impacts both had fairly high predictive capabilities. It was concluded that interactions between recreation visitors/tourists and local residents should be a focus of further research. Data from the Moab resident survey were also used in conjunction with a survey of mountain bikers visiting or living...
This research investigates the interannual variability of soil moisture as related to large-scale climate variability and also evaluates the spatial and temporal variability of modeled deep layer (40?140 cm) soil moisture in the Upper Colorado River Basin (UCRB). A three layers hydrological model VIC-3L (Variable Infiltration Capacity Model ? 3 layers) was used to generate soil moisture in the UCRB over a 50-year period. By using wavelet analysis, deep layer soil moisture was compared to the Palmer Drought Severity Index (PDSI), precipitation, and streamflow to determine whether deep soil moisture is an indicator of climate extremes. Wavelet and coherency analysis for the UCRB indicated a strong relationship between...
This study was undertaken to determine any differences in the soil-moisture percentage at various soil depths between controlled and uncontrolled sagebrush areas, and to determine the effect of sagebrush control on the snow-holding capacity, of the areas. Published in Weeds, volume 9, issue 1, on pages 27 - 35, in 1961.
Categories: Publication; Types: Citation, Journal Citation; Tags: Weeds
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A comparative study was made of the soils of a virgin grassland and an adjacent grazed area in Canyonlands National Park. Soils from the virgin site were finer textured than those of the grazed area, and the surface 5 cm contains a significantly lower amount of calcium. In addition, the surface 5 cm of the virgin site contains significantly greater amounts of phosphorus, potassium, and organic matter. Subsurface soils in the two parks are less dissimilar. Cryptogams on the virgin grassland appear to have an important influence on chemical characteristics of the surface 5 cm of soil. The difference in surface soils between the parks may be related to the presence of these species. Data point strongly to light winter...
The Grand Staircase—Escalante National Monument (GSENM) contains a rich diversity of native plant communities. However, many exotic plant species have become established, potentially threatening native plant diversity. We sought to quantify patterns of native and exotic plant species and cryptobiotic crusts (mats of lichens, algae, and mosses on the soil surface), and to examine soil characteristics that may indicate or predict exotic species establishment and success. We established 97 modified-Whittaker vegetation plots in 11 vegetation types over a 29,000 ha area in the Monument. Canonical correspondence analysis (CCA) and multiple linear regressions were used to quantify relationships between soil characteristics...
We explore the potential for applying broad ecological theories to interactions between soil animals and micro-organisms to generate a predictive framework within which more hypothesis led research can be undertaken. The paper stems from discussions during a workshop at the XIVth International Symposium on Soil Zoology. The possible linkage between biodiversity and ecosystem functions forms a good example of how soil zoology research can be productively stimulated by addressing a broader ecological concept but also how the concept can be tested below ground at fundamentally different scales to those commonly used above ground. Other areas of theory rapidly developing above ground, which are yet to be fully tested...
In this study we identify the physiographic and snowpack conditions currently represented by snowpack telemetry (SNOTEL) stations in the Rio Grande headwaters. Based on 8 years of advanced very high-resolution radiometer data (1995–2002) a snow cover persistence index was derived. Snow cover persistence values at the seven SNOTEL sites ranged from 3·9 to 4·75, with an average 14% greater than the mean persistence of the watershed. Using elevation, western barrier distance, and vegetation density, a 32-node binary classification tree model explained 75% of the variability in average snow cover persistence. Terrain classes encompassing the Lily Pond, Middle Creek, and Slumgullion SNOTEL sites represented 4·1%,...
Wind erosion and associated dust emissions play a fundamental role in many ecological processes and provide important biogeochemical connectivity at scales ranging from individual plants up to the entire globe. Yet, most ecological studies do not explicitly consider dust-driven processes, perhaps because most relevant research on aeolian (wind-driven) processes has been presented in a geosciences rather than an ecological context. To bridge this disciplinary gap, we provide a general overview of the ecological importance of dust, examine complex interactions between wind erosion and ecosystem dynamics from the scale of plants and surrounding space to regional and global scales, and highlight specific examples of...
map background search result map search result map Soil Properties in Relation to Cryptogamic Groundcover in Canyonlands National Park Soil Survey of Ute Mountain Area, Colorado and New Mexico Temporal variation in community composition, pigmentation, and F(v)/F(m) of desert cyanobacterial soil crusts. Soil Properties in Relation to Cryptogamic Groundcover in Canyonlands National Park Temporal variation in community composition, pigmentation, and F(v)/F(m) of desert cyanobacterial soil crusts. Soil Survey of Ute Mountain Area, Colorado and New Mexico