Filters: Types: Citation (X) > Types: Journal Citation (X)3,186 results (117ms)
Trends in snowpack chemistry and comparison to National Atmospheric Deposition Program results for the Rocky Mountains, US, 1993?2004
Seasonal snowpack chemistry data from the Rocky Mountain region of the US was examined to identify long-term trends in concentration and chemical deposition in snow and in snow-water equivalent. For the period 1993?2004, comparisons of trends were made between 54 Rocky Mountain Snowpack sites and 16 National Atmospheric Deposition Program wetfall sites located nearby in the region. The region was divided into three subregions: Northern, Central, and Southern. A non-parametric correlation method known as the Regional Kendall Test was used. This technique collectively computed the slope, direction, and probability of trend for several sites at once in each of the Northern, Central, and Southern Rockies subregions....
Categories: Publication; Types: Citation, Journal Citation; Tags: Atmospheric Environment, Rocky mountains, atmospheric deposition, chemical trends, nitrogen,
The Status, Habitat, and Response to Grazing of Water Vole Populations in the Big Horn Mountains of Wyoming, U.S.A.
Microtus richardsoni, the water vole, was listed as a sensitive species in Region 2 of the USDA Forest Service in 1994. Historical records indicate water voles were found in the Big Horn Mountains, but little was known about their current status. The purpose of this study was to locate water voles in the Big Horn Mountains of Wyoming, develop a habitat profile, and evaluate the extent to which livestock grazing affects them. Accessible creeks with habitat requirements for water voles were surveyed. Water voles were not captured below 2440 m. Grazed and ungrazed sites occupied by water voles were matched and analyzed for percent plant cover, dry weight biomass, riparian classification, mean stream depth, channel...
Categories: Publication; Types: Citation, Journal Citation; Tags: Arctic, Antarctic, and Alpine Research, WLCI Related Publication
Black-footed ferrets (Mustela nigripes) excavate subsoil from black-tailed prairie dog (Cynomys ludovicianus) burrows and deposit it in unique piles. Black-tailed prairie dogs tend to fill in or "plug" burrows visited or occupied by ferrets (Hillman 1968, Henderson et al. 1969, Fortenbery 1972). In this paper, we describe the configuration, rate of production, persistence, and seasonality of ferret diggings and rate of burrow plugging by prairie dogs within white-tailed prairie dog (C. leucurus) colonies. Published in Journal of Wildlife Management, volume 48, issue 4, on pages 1441 - 1444, in 1984.
Categories: Publication; Types: Citation, Journal Citation; Tags: JSTOR, Journal of Wildlife Management
Sedimentology, stratigraphy, and depositional environment of the crystal geyser dinosaur quarry, East-Central Utah
The Crystal Geyser Dinosaur Quarry, near Green River, Utah, is located at the base of the Lower Cretaceous (Barremian) Yellow Cat Member of the Cedar Mountain Formation. The quarry preserves a nearly monospecific accumulation of a new basal therizinosauroid, Falcarius utahensis. We used field descriptions and petrographic analysis to determine the depositional environment and development of the quarry strata. Results of these analyses suggest that the quarry represents multiple episodes of bone accumulation buried by spring and overbank flood deposits. Evidence for these previously undescribed spring deposits includes calcite macroscopic structures within the quarry strataâ€”such as pisolites and travertine fragmentsâ€”and...
Categories: Publication; Types: Citation, Journal Citation; Tags: PALAIOS
The pollen of three Ephedra taxa, Ephedra torreyana, E. trifurca and E. funerealeft right double arrowE. torreyana, showed a marked pollen dimorphism when examined using scanning electron microscopy. Typical pollen grains in all of these taxa have straight ridges, but the variant forms exhibit a highly folded ectexine. In addition, previously used characters such as the presence or absence of bifurcating valley structure do not appear to be uniform, even within a single microsporangium, suggesting that their value to taxonomic study should be reassessed. Published in Review of Palaeobotany and Palynology, volume 124, issue 3-4, on pages 325 - 334, in 2003.
Categories: Publication; Types: Citation, Journal Citation; Tags: Ephedra, Review of Palaeobotany and Palynology, pollen dimorphism, section Alatae
Increased Lesser Earless Lizard (Holbrookia maculata) Abundance on Gunnison's Prairie Dog Colonies and Short Term Responses to Artificial Prairie Dog Burrows
Our studies of the association between the lesser earless lizard (Holbrookia maculata) and Gunnison's prairie dogs (Cynomys gunnisoni) revealed: (1) the lesser earless lizard was more abundant on prairie dog colonies than off, (2) lesser earless lizard abundance was positively correlated with prairie dog burrow abundance; (3) lesser carless lizards responded positively to artificial burrows created on noncolonized areas; and (4) lesser earless lizards used prairie dog burrows as refuges from predators; however, the relative use of burrows was greatest at high and low temperature extremes. Although prairie dogs alter habitat in many ways, our study suggests that burrows are an important mechanism involved in the...
Categories: Publication; Types: Citation, Journal Citation; Tags: American Midland Naturalist, The University of Notre Dame
The synthesis of glycosaminoglycans (GAG) in a freshwater mussel was studied in organ culture using labeled precursors. The major GAGs synthesized were determined and characterized by chemical and enzymatic methods. They were shown to be heparin and an unusual type of heparan sulfate. Gills produced about 50% of each polymer; mantles synthesized little heparin and mostly the heparan-sulfate-like compound, which is similar to a GAG isolated previously from lobsters. No significant amounts of chondroitin sulfates were present. Histological data showed that the sulfate-labeled GAGs were present mainly in exterior pericellular and basement membrane locations of gills and mantle. That is, they would be in contact with...
Categories: Publication; Types: Citation, Journal Citation; Tags: The Biological Bulletin
The length of gestation is the number of days between fertilization and parturition, and the length of lactation is the number of days between parturition and weaning. Determination of these lengths is difficult for ground-dwelling squirrels such as prairie dogs, marmots, and ground squirrels that usually copulate, give birth, and nurse offspring underground. For Gunnison's prairie dogs (Cynomys gunnisoni), the mean +1 SD length of gestation is 29.3 ? 0.53 days (n = 124). The approximate length of lactation, estimated from the mean +1 SD duration between parturition and the first emergence of juveniles from the natal burrow, is 38.6 ? 2.08 days (n = 112). Published in Journal of Mammalogy, volume 78, issue 1, on...
Categories: Publication; Types: Citation, Journal Citation; Tags: Cynomys gunnisoni, Gunnison's prairie dog, Journal of Mammalogy, gestation, lactation,
Theoverthrust belt of western North America extends from British Columbiato southern Nevada. Large anticlines lie on thrust sheets alongthe length of this overthrust trend. Many oil and gasfields have been discovered on these structures in Canada, butsignificant hydrocarbon production in the United States has been primarilylimited to a productive salient in southwestern Wyoming and northeasternUtah (Figure 1). On 23 December 2003, Wolverine Gas andOil-Kings Meadow Ranches well 17-1 drilled into a 487-ft oilcolumn in the Navajo Sandstone in Sevier County, Utah. Thisnew significant oil reservoir is 146 miles southwest of thenearest thrust belt production at Pineview Field in Summit County,Utah. The discovery of what...
Categories: Publication; Types: Citation, Journal Citation; Tags: SEG, The Leading Edge
Sage-grouse (Centrocercus spp.) were abundant in all of Utah's 29 counties at the time of European settlement wherever sagebrush (Artemisia spp.) occurred. Greater Sage-Grouse (G. urophasianus) inhabited areas north and west of the Colorado River, and Gunnison Sage-Grouse (G. minimus) occupied suitable habitat south and east of the Colorado River. The largest Greater Sage-Grouse populations in Utah are currently restricted to suitable habitats in Box Elder, Garfield, Rich, Uintah, and Wayne Counties. A remnant breeding population of Gunnison Sage-Grouse occurs in eastern San Juan County. We stratified Greater Sage-Grouse populations (1971-2000) by counties where the 1996 to 2000 moving average for estimated spring...
Categories: Publication; Types: Citation, Journal Citation; Tags: Artemisia tridentata, Centrocercus minimus, Centrocercus urophasianus, DemoAtomFeed, Gunnison sage-grouse,
An accounting procedure is developed which determines a flow regime that is capable of transporting an amount of bedload sediment necessary to ensure channel stability downstream. The method allows for sediment buildup in the channel within geomorphic threshold limits during low flow periods. During periods of high runoff, enough water is bypassed to transport the stored sediment. The procedure utilizes only those flows of sufficient magnitude to maintain channel stability over the long run (25â€“50+ years). An example is presented which determines the volume of water and frequency of release for channel maintenance purposes downstream from a hypothetical water diversion project. Of some 1,200,000 acre feet generated...
As an estimate of species-level differences in the capacity to take up different forms of N, we measured plant uptake of 15N-NH4+, 15N-NO3- and 15N, -13C glycine within a set of herbaceous species collected from three alpine community types. Plants grown from cuttings in the greenhouse showed similar growth responses to the three forms of N but varied in the capacity to take up NH4+, NO3- and glycine. Glycine uptake ranged from approximately 42% to greater than 100% of NH4+ uptake; however, four out of nine species showed significantly greater uptake of either NH4+ or NO3- than of glycine. Relative concentrations of exchangeable N at the sites of plant collection did not correspond with patterns of N uptake among...
Categories: Publication; Types: Citation, Journal Citation; Tags: Plant and Soil, Springer Netherlands, ammonium, glycine, nitrate
Acidobacteria phylum sequences in uranium-contaminated subsurface sediments greatly expand the known diversity within the phylum
The abundance and composition of bacteria of the phylum Acidobacteria were surveyed in subsurface sediments from uranium-contaminated sites using amplification of 16S rRNA genes followed by clone/sequence analysis. Analysis of sequences from this study and public databases produced a revised and greatly expanded phylogeny of the Acidobacteria phylum consisting of 26 subgroups. Published in Applied and Environmental Microbiology, volume 73, issue 9, on pages 3113 - 6, in 2007.
Categories: Publication; Types: Citation, Journal Citation; Tags: Applied and Environmental Microbiology
A 40,000-year woodrat-midden record of vegetational and biogeographical dynamics in north-eastern Utah, USA
Aim: A conspicuous climatic and biogeographical transition occurs at 40?45� N in western North America. This pivot point marks a north?south opposition of wet and dry conditions at interannual and decadal time-scales, as well as the northern and southern limits of many dominant western plant species. Palaeoecologists have yet to focus on past climatic and biotic shifts along this transition, in part because it requires comparisons across dissimilar records [i.e. pollen from lacustrine sediments to the north and plant macrofossils from woodrat (Neotoma) middens to the south]. To overcome these limitations, we are extending the woodrat-midden record northward into the lowlands of the central Rocky Mountains. Published...
Categories: Publication; Types: Citation, Journal Citation; Tags: Holocene, Journal of Biogeography, extinction, glacial, invasions,
The ecology and phytosociology of a virgin grassland community (Virginia Park, Canyonlands National Park, Utah) have been investigated. Based on the use of C Ã— F index, Hilaria jamesii and Stipa comata are the most abundant of the four major perennial grasses. Oryzopsis hymenoides and Sporobolus cryptandrus are less abundant in decreasing order. The sites dominated by Hilaria are characterized by soils with finer texture, slightly warmer average temperature and higher surface K+ and organic matter compared to sites dominated by Stipa comata. In addition, frequency of both vascular and cryptogamic species is greater on sites dominated by Hilaria. Published in Journal of Range Management, volume 30, issue 4, on pages...
Categories: Publication; Types: Citation, Journal Citation; Tags: Journal of Range Management
Male boreal toads (Bufo boreas) are thought to return to the breeding site every year but, if absent in a particular year, will be more likely to return the following year. Using Pollock's robust design we estimated temporary emigration (the probability a male toad is absent from a breeding site in a given year) at three locations in Colorado, USA: two in Rocky Mountain National Park and one in Chaffee County. We present data that suggest that not all male toads return to the breeding site every year. Our analyses indicate that temporary emigration varies by site and time (for example, from 1992 to 1998, the probability of temporary emigration ranged from 10% to 29% and from 3% to 95% at Lost Lake and Kettle Tarn,...
Categories: Publication; Types: Citation, Journal Citation; Tags: Bufo boreas, Colorado, Ecology, USA, amphibians,
Double fertilization in Ephedra, a nonflowering seed plant: its bearing on the origin of angiosperms
Double fertilization and the associated formation of endosperm have long been considered unique and defining characters (autapomorphies) of the angiosperms. During normal fertilization in Ephedra nevadensis, a nonflowering seed plant, fusion of a second sperm nucleus with the ventral canal nucleus occurs regularly within the egg cytoplasm. The occurrence of double fertilization in Ephedra assumes added significance in light of its critical phylogenetic position as a basal member of the most closely related extant group of seed plants (Gnetales) to angiosperms. Thus, double fertilization in angiosperms and Ephedra may represent an evolutionary homology. Published in Science, volume 547, issue 4945, on pages 951 -...
Categories: Publication; Types: Citation, Journal Citation; Tags: Science
First paragraph of introduction: On 20 July 2004 a single Asian tapeworm (Bothriocephalus acheilognathi) was collected from the intestine of a roundtail chub (Gila robusta) in the Yampa River in Dinosaur National Monument in northwestern Colorado. This fish (274 mm TL) was collected at river mile 24 and dissected in the field. A single tapeworm was removed from the intestine and preserved in ethanol. The tapeworm was later identified in the laboratory as B. acheilognathi by its characteristic arrow-shaped scolex (Poole et al. 1984). This is the 1st recorded incidence of Asian tapeworm infecting fish in the Yampa River drainage. Published in Western North American Naturalist, volume 65, issue 3, on pages 403 - 404,...
Categories: Publication; Types: Citation, Journal Citation; Tags: Bothriocephalus acheilognathi, Colorado pikeminnow, Western North American Naturalist, asian tapeworm, bonytail chub,
Change in alpine meadow greenness and wetness over a 25-year period in the Sierra Nevada (In preparation)
Change in alpine meadow greenness and wetness over a 25-year period in the Sierra Nevada (In preparation), credited to Soulard, Chris, published in 2011.
Categories: Publication; Types: Citation, Journal Citation
Sediment Production and Infiltration Rates as Affected by Grazing and Debris Burning on Chained and Seeded Pinyon-Juniper
Sediment production and infiltration rates were measured in conjunction with an analysis of burning and grazing treatments in a chained pinyon-juniper study in southeastern Utah. While high natural variability was present among sites, no significant changes in sediment production were detected following our prescribed burning or grazing treatments. Following treatment, however, both the burned and grazed sites exhibited significantly depressed infiltration rates during certain time intervals in comparison to the ?undisturbed, natural? woodland control location. Published in Journal of Range Management, volume 29, issue 1, on pages 83 - 85, in 1976.
Categories: Publication; Types: Citation, Journal Citation; Tags: Allen Press and Society for Range Management, Journal of Range Management