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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...
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...
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...
Grasshopper sparrows produce unusually high-pitched vocalizations for birds, with fundamental frequencies of species typical songs in the range of 7-9 kHz. The characteristics of vocalizations produced early in life, however, are relatively understudied in this and related species. In this study, the development of vocal signal structure and vocal behavior in grasshopper sparrows was investigated in the field immediately after birds hatched. Acoustic characteristics of nestling begging calls were measured throughout the course of the 8-9-day nestling period. Starting at day 6 post-hatch, nestling calls changed qualitatively, incorporating frequency-modulated elements that resembled some parts of the adult vocalizations....
Activity times of pika along an elevation gradient in the Sierra Nevada (In preparation), credited to Perrine, John, published in 2011.
Categories: Publication; Types: Citation, Journal Citation
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We revised distribution maps of potential presettlement habitat and current populations for Greater Sage-Grouse (Centrocercus urophasianus) and Gunnison Sage-Grouse (C. minimus) in North America. The revised map of potential presettlement habitat included some areas omitted from previously published maps such as the San Luis Valley of Colorado and Jackson area of Wyoming. Areas excluded from the revised maps were those dominated by barren, alpine, and forest habitats. The resulting presettlement distribution of potential habitat for Greater Sage-Grouse encompassed 1 200 483 km(2), With the species' current range 668 412 km(2). The distribution of potential Gunnison Sage-Grouse habitat encompassed 46 521 km(2), with...
Microbial crusts are present on surfaces of soils throughout the world. A key feature of these crusts in arid zones is the abundance of filamentous sheath-forming and polysaccharide-excreting cyanobacteria. Several isolates of cyanobacteria were prepared from crust samples (Nizzana sand dunes, north-western Negev Desert, Israel). Optimal growth conditions for two such isolates of Microcoleus sp. were defined, and the role of the excreted polysaccharides in affecting the hydrological properties of crust-covered sand dunes was studied. Experiments with the native crust microbial population demonstrated the possibility of net primary productivity at both high relative air humidities and low moisture content. Published...
Geomechanical modeling of induced seismicity source parameters and implications for seismic hazard assessment, credited to Goertz-Allmann, BP, published in 2012. Published in Geophysics, volume 78, issue 1, in 2012.
Categories: Publication; Types: Citation, Journal Citation; Tags: Geophysics
The invasion of woody vegetation into deserts, grasslands and savannas is generally thought to lead to an increase in the amount of carbon stored in those ecosystems. For this reason, shrub and forest expansion (for example, into grasslands) is also suggested to be a substantial, if uncertain, component of the terrestrial carbon sink. Here we investigate woody plant invasion along a precipitation gradient (200 to 1,100 mm yr(-1)) by comparing carbon and nitrogen budgets and soil delta(13)C profiles between six pairs of adjacent grasslands, in which one of each pair was invaded by woody species 30 to 100 years ago. We found a clear negative relationship between precipitation and changes in soil organic carbon and...
Categories: Publication; Types: Citation, Journal Citation; Tags: Nature
Geographic variation in 17 cranial characters of 138 specimens of Idionycteris phyllotis was examined by use of univariate and multivariate techniques. Larger individuals occur in the central portion of the range (New Mexico and southern Arizona) Published in The Southwestern Naturalist, volume 19, issue 1, on pages 114 - 115, in 1974.
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We examined the content and isotopic composition of nitrogen within soils of a juniper woodland and found that a cryptobiotic crust composed of cyanobacteria, lichens, and mosses was the predominant source of nitrogen for this ecosystem. Disturbance of the crust has resulted in considerable spatial variability in soil nitrogen content and isotopic composition; intercanopy soils were significantly depleted in nitrogen and had greater abundance of 15N compared to intra-canopy soils. Variations in the 15N\14N ratio for inter- and intracanopy locations followed similar Rayleigh distillation curves, indicating that the greater 15N/14N ratios for inter-canopy soils were due to relatively greater net nitrogen loss. Coverage...
Genetic variation among 62 populations of ponderosa pine was studied by comparing seedlings from all populations according to (1) growth and development of 4-yr-old seedlings in three disparate common gardens and (2) patterns of shoot elongation of 2-yr-old seedlings in a greenhouse. Genetic variation was detected among populations for 19 of the variables, most of which were intercowelated. Two principal components accounted for 60So of the total interpopulation variance. Multiple regression analyses were used to relate genetic variation in 19 variables and two principal components to the elevation and geographic origin of the seed. The regression models produced values of R2 as large as .78 and accounted for more...


map background search result map search result map Soil Properties in Relation to Cryptogamic Groundcover in Canyonlands National Park Distribution of Sage-Grouse in North America A Break in the Nitrogen Cycle in Aridlands? Evidence from δ 15N of Soils Soil Properties in Relation to Cryptogamic Groundcover in Canyonlands National Park A Break in the Nitrogen Cycle in Aridlands? Evidence from δ 15N of Soils Distribution of Sage-Grouse in North America