Comparisons and Contrasts between the Foraging Behaviors of Two White-tailed Ptarmigan (Lagopus leucurus) Populations, Rocky Mountains, Colorado, and Sierra Nevada, California, U.S.A

We measured background 2H and 18O abundances and field metabolic rate (FMR) for White-tailed Ptarmigan (Lagopus leucurus) above 3600 m elevation in the Colorado Rocky Mountains between May and July. 18O abundances ranged from 1982.4 to 2018.6 ppm [Formula: see text], while 2H abundance ranged from 142.8 to 154.0 ppm [Formula: see text]. Mean 2H abundance followed closely (−0.3 ppm deviation) the level predicted by Tatner's empirical model relating 2H and ambient temperature. However, 18O was more enriched than predicted (+3.4 ppm), which may reflect 18O fractionation in the plant diet. FMR, measured by means of the doubly labelled water method, ranged from 206.4 to 442.7 kJ/d and was not related to body mass. However, for males, FMR was significantly and positively related to age. Because of high variation in background isotope levels, the use of mean 2H and 18O background abundances instead of individual backgrounds would introduce a mean error of 7.1% (range −8.9 to +11.4%) in calculations of CO2 production and FMR.

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Biogeography of White-Tailed Ptarmigan (Lagopus leucurus): Implications from an Introduced Population in the Sierra Nevada

Journal of Biogeography ◽

10.2307/2845146 ◽

1990 ◽

Vol 17 (6) ◽

pp. 649 ◽

Cited By ~ 7

Author(s):

Jennifer A. Clarke ◽

Richard E. Johnson

Keyword(s):

Sierra Nevada ◽

Lagopus Leucurus ◽

Introduced Population

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The Intermontane Western Tradition

American Antiquity ◽

10.2307/278371 ◽

1962 ◽

Vol 28 (2) ◽

pp. 144-150 ◽

Cited By ~ 11

Author(s):

Richard D. Daugherty

Keyword(s):

Conceptual Framework ◽

Sierra Nevada ◽

Great Basin ◽

Rocky Mountains ◽

Environmental Changes ◽

Glacial Period ◽

Western Tradition ◽

The West ◽

Northern Mexico ◽

The North

AbstractThe hypothesis of an Intermontane Western tradition is advanced as a conceptual framework within which it is possible to achieve a greater understanding of the cultural histories of the Plateau, Great Basin, and Southwest culture areas, including broad and specific relationships and also the developing differences.Geographically, the Intermontane Western tradition extended throughout the intermontane region between the Cascade-Sierra Nevada ranges on the west, and the Rocky Mountains on the east, and from southern British Columbia on the north to northern Mexico on the south. Temporally, the Intermontane Western tradition existed throughout the post-glacial period.Within the major tradition, the Southwest Agricultural, Desert, and Northwest Riverine Areal traditions are seen developing, partly in response to environmental changes.

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Regional analysis of inorganic nitrogen yield and retention in high-elevation ecosystems of the Sierra Nevada and Rocky Mountains

The Nitrogen Cycle at Regional to Global Scales ◽

10.1007/978-94-017-3405-9_10 ◽

2002 ◽

pp. 341-374 ◽

Cited By ~ 4

Author(s):

James O. Sickman ◽

John M. Melack ◽

John L. Stoddard

Keyword(s):

Sierra Nevada ◽

Rocky Mountains ◽

Inorganic Nitrogen ◽

Regional Analysis ◽

High Elevation ◽

Nitrogen Yield

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Mountain Climates of North America

Mountain Meteorology ◽

10.1093/oso/9780195132717.003.0008 ◽

2000 ◽

Author(s):

C. David Whiteman

Keyword(s):

United States ◽

North America ◽

Sierra Nevada ◽

Rocky Mountains ◽

Climatic Conditions ◽

Cascade Range ◽

Coast Range ◽

Alaska Range ◽

Mountain Ranges ◽

The Pacific

The basic climatic characteristics of the major mountain ranges in the United States—the Appalachians, the Coast Range, the Alaska Range, the Cascade Range, the Sierra Nevada, and the Rocky Mountains—can be described in terms of the four factors discussed in chapter 1. The mountains of North America extend latitudinally all the way from the Arctic Circle (66.5°N) to the tropic of Cancer (23.5°N) (figure 2.1). There are significant differences in day length and angle of solar radiation over this latitude belt that result in large seasonal and diurnal differences in the weather from north to south. Elevations in the contiguous United States extend from below sea level at Death Valley to over 14,000 ft (4270 m) in the Cascade Range, the Sierra Nevada, and the Rocky Mountains. Several prominent peaks along the Coast Range in Alaska and Canada (e.g., Mount St. Elias and Mount Logan) reach elevations above 18,000 ft (5486 m). Denali (20,320 ft or 6194 m) in the Alaska Range is the highest peak in North America. The highest peak in the Canadian Rockies is Mt. Robson, with an elevation of 12,972 ft (3954 m). The climates of the Coast Range, the Cascade Range, and the Sierra Nevada, all near the Pacific Ocean, are primarily maritime. The Appalachian Mountains of the eastern United States are subject to a maritime influence from the Atlantic Ocean and the Gulf of Mexico, but they are also affected by the prevailing westerly winds that bring continental climatic conditions. Only the climate of the Rocky Mountains, far from both the Pacific and Atlantic Oceans, is primarily continental. Each of the mountain ranges is influenced by regional circulations. For example, the Appalachians are exposed to the warm, moist winds brought northward by the Bermuda-Azores High and to the influence of the Gulf Stream. Similarly, the Coast Range feels the impact of the Pacific High, the Aleutian low, and the Japanese Current. A mountain range, depending on its size, shape, orientation, and location relative to air mass source regions, can itself affect the regional climate by acting as a barrier to regional flows.

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Systematic Patterns of the Inconsistency between Snow Water Equivalent and Accumulated Precipitation as Reported by the Snowpack Telemetry Network

Journal of Hydrometeorology ◽

10.1175/jhm-d-12-066.1 ◽

2012 ◽

Vol 13 (6) ◽

pp. 1970-1976 ◽

Cited By ~ 19

Author(s):

Jonathan D. D. Meyer ◽

Jiming Jin ◽

Shih-Yu Wang

Keyword(s):

Sierra Nevada ◽

Rocky Mountains ◽

Snow Water Equivalent ◽

Systematic Bias ◽

Mountain Ranges ◽

Wind Speeds ◽

Drifting Snow ◽

Snow Water ◽

Interior West ◽

One Year

Abstract The authors investigated the accuracy of snow water equivalent (SWE) observations compiled by 748 Snowpack Telemetry stations and attributed the systematic bias introduced to SWE measurements to drifting snow. Often observed, SWE outpaces accumulated precipitation (AP), which can be statistically and physically explained through 1) precipitation undercatchment and/or 2) drifting snow. Forty-four percent of the 748 stations reported at least one year where the maximum SWE was greater than AP, while 16% of the stations showed this inconsistency for at least 20% of the observed years. Regions with a higher likelihood of inconsistency contained drier snow and are exposed to higher winds speeds, both of which are positively correlated to drifting snow potential as well as gauge undercatch. Differentiating between gauge undercatch and potential drifting scenarios, days when SWE increased but AP remained zero were used. These drift days occurred on an average of 13.3 days per year for all stations, with 31% greater wind speeds at 10 m for such days (using reanalysis winds). Findings suggest marked consistency between SWE and AP throughout the Cascade Mountains and lower elevations of the interior west while indicating notable inconsistency between these two variables throughout the higher elevations of the Rocky Mountains, Utah mountain ranges, and the Sierra Nevada.

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Case study of spatial and temporal variability of snow cover, grain size, albedo and radiative forcing in the Sierra Nevada and Rocky Mountain snowpack derived from imaging spectroscopy

The Cryosphere ◽

10.5194/tc-10-1229-2016 ◽

2016 ◽

Vol 10 (3) ◽

pp. 1229-1244 ◽

Cited By ~ 18

Author(s):

Felix C. Seidel ◽

Karl Rittger ◽

S. McKenzie Skiles ◽

Noah P. Molotch ◽

Thomas H. Painter

Keyword(s):

Grain Size ◽

Spatial Variability ◽

Snow Cover ◽

Sierra Nevada ◽

Rocky Mountains ◽

Radiative Forcing ◽

Infrared Imaging ◽

Spatial And Temporal Variability ◽

Snow Albedo ◽

The Mean

Abstract. Quantifying the spatial distribution and temporal change in mountain snow cover, microphysical and optical properties is important to improve our understanding of the local energy balance and the related snowmelt and hydrological processes. In this paper, we analyze changes of snow cover, optical-equivalent snow grain size (radius), snow albedo and radiative forcing by light-absorbing impurities in snow and ice (LAISI) with respect to terrain elevation and aspect at multiple dates during the snowmelt period. These snow properties are derived from the NASA/JPL Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data from 2009 in California's Sierra Nevada and from 2011 in Colorado's Rocky Mountains, USA. Our results show a linearly decreasing snow cover during the ablation period in May and June in the Rocky Mountains and a snowfall-driven change in snow cover in the Sierra Nevada between February and May. At the same time, the snow grain size is increasing primarily at higher elevations and north-facing slopes from 200 microns to 800 microns on average. We find that intense snowmelt renders the mean grain size almost invariant with respect to elevation and aspect. Our results confirm the inverse relationship between snow albedo and grain size, as well as between snow albedo and radiative forcing by LAISI. At both study sites, the mean snow albedo value decreases from approximately 0.7 to 0.5 during the ablation period. The mean snow grain size increased from approximately 150 to 650 microns. The mean radiative forcing increases from 20 W m−2 up to 200 W m−2 during the ablation period. The variability of snow albedo and grain size decreases in general with the progression of the ablation period. The spatial variability of the snow albedo and grain size decreases through the melt season while the spatial variability of radiative forcing remains constant.

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A WRF simulation of the impact of 3-D radiative transfer on surface hydrology over the Rocky Mountains and Sierra Nevada

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-11709-2013 ◽

2013 ◽

Vol 13 (23) ◽

pp. 11709-11721 ◽

Cited By ~ 16

Author(s):

K. N. Liou ◽

Y. Gu ◽

L. R. Leung ◽

W. L. Lee ◽

R. G. Fovell

Keyword(s):

Water Resources ◽

Solar Radiation ◽

Radiative Transfer ◽

Sierra Nevada ◽

Rocky Mountains ◽

Snow Water Equivalent ◽

Solar Flux ◽

Surface Hydrology ◽

Elevation Range ◽

The Impact

Abstract. We investigate 3-D mountains/snow effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and Sierra Nevada. The Weather Research and Forecasting (WRF) model, applied at a 30 km grid resolution, is used in conjunction with a 3-D radiative transfer parameterization covering a time period from 1 November 2007 to 31 May 2008, during which abundant snowfall occurred. A comparison of the 3-D WRF simulation with the observed snow water equivalent (SWE) and precipitation from Snowpack Telemetry (SNOTEL) sites shows reasonable agreement in terms of spatial patterns and daily and seasonal variability, although the simulation generally has a positive precipitation bias. We show that 3-D mountain features have a profound impact on the diurnal and monthly variation of surface radiative and heat fluxes, and on the consequent elevation-dependence of snowmelt and precipitation distributions. In particular, during the winter months, large deviations (3-D-PP, in which PP denotes the plane-parallel approach) of the monthly mean surface solar flux are found in the morning and afternoon hours due to shading effects for elevations below 2.5 km. During spring, positive deviations shift to the earlier morning. Over mountaintops higher than 3 km, positive deviations are found throughout the day, with the largest values of 40–60 W m−2 occurring at noon during the snowmelt season of April to May. The monthly SWE deviations averaged over the entire domain show an increase in lower elevations due to reduced snowmelt, which leads to a reduction in cumulative runoff. Over higher elevation areas, positive SWE deviations are found because of increased solar radiation available at the surface. Overall, this study shows that deviations of SWE due to 3-D radiation effects range from an increase of 18% at the lowest elevation range (1.5–2 km) to a decrease of 8% at the highest elevation range (above 3 km). Since lower elevation areas occupy larger fractions of the land surface, the net effect of 3-D radiative transfer is to extend snowmelt and snowmelt-driven runoff into the warm season. Because 60–90% of water resources originate from mountains worldwide, the aforementioned differences in simulated hydrology due solely to 3-D interactions between solar radiation and mountains/snow merit further investigation in order to understand the implications of modeling mountain water resources, and these resources' vulnerability to climate change and air pollution.

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A NEW CALIFORNIA EUPHYDRYAS (LEPID., RHOPALOCERA)

The Canadian Entomologist ◽

10.4039/ent6144-2 ◽

1929 ◽

Vol 61 (2) ◽

pp. 44-45

Author(s):

J. D. Gunder

Keyword(s):

New Mexico ◽

Sierra Nevada ◽

Great Basin ◽

Rocky Mountains ◽

National Park ◽

Western Montana ◽

Sequoia National Park ◽

Parental Stock ◽

Sierra Nevada Mountains

The chain of Rocky Mountains extending south from Canada through western Montana. Wyoming, Colorado and into northern New Mexico produce a series of butterflies which are at prespnt referable under an anicia-brucei classification. Various races from this supposed parental stock are found in southwestern Colorado, Utah, the Great Basin of Nevada and elsewhere with members of the clan branching down into New Mexico. For several years I have been hoping to find representatives of this group reaching over into the Sierra Nevada Mountains of California. In 1927 when on Alta Peak in Sequoia National Park, I took two males and in 1928 Mr. Walter Ireland captured four females in the same locality which I find to be closely related to the above mentioned breed.

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Floristic similarity, diversity, and endemism as indicators of refugia characteristics and needs in the West

10.17077/pp.005160 ◽

2020 ◽

Author(s):

George P Malanson ◽

Dale L Zimmerman ◽

Daniel B Fagre

Keyword(s):

Sierra Nevada ◽

Great Basin ◽

Community Assembly ◽

Rocky Mountains ◽

Initial Conditions ◽

Geographic Distance ◽

Stepping Stones ◽

The West ◽

Floristic Similarity ◽

Mountain Ranges

The floras of mountain ranges, and their similarity, beta diversity, and endemism, are indicative of processes of community assembly; they are also the initial conditions for coming disassembly and reassembly in response to climate change. As such, these characteristics can inform thinking on refugia. The published floras or approximations for 42 mountain ranges in the three major mountain systems (Sierra-Cascades, Rocky Mountains, and Great Basin ranges) across the western USA and southwestern Canada were analyzed. The similarity is higher among the ranges of the Rockies while equally low among the ranges of the Sierra-Cascades and Great Basin. Mantel correlations of similarity with geographic distance are also higher for the Rocky Mountains. Endemism is relatively high, but is highest in the Sierra-Cascades (due to the Sierra Nevada as the single largest range) and lowest in the Great Basin, where assemblages are allochthonous. These differences indicate that the geologic substrates of the Cascade volcanoes, which are much younger than any others, play a role in addition to geographic isolation in community assembly. The pattern of similarity and endemism indicates that the ranges of the Cascades will not function well as stepping stones and the endemic species that they harbor may need more protection than those of the Rocky Mountains. The geometry of the ranges is complemented by geology in setting the stage for similarity and the potential for refugia across the West. Understanding the geographic template as initial conditions for the future can guide the forecast of refugia and related monitoring or protection efforts.

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