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Long-Term Fire History In Great Basin Sagebrush Reconstructed From Macroscopic Charcoal In Spring Sediments, Newark Valley, Nevada, Scott Mensing, Stephanie Livingston, Pat Barker

Western North American Naturalist

We use macroscopic charcoal analysis to reconstruct fire history in sagebrush (Artemisia tridentata var. wyomingensis and A. tridentata var. tridentata), in Newark Valley, Nevada. We analyzed charcoal at continuous 1-cm intervals (~7–127 years), and pollen at 2- to 10-cm intervals (~70–263 years) in a core spanning the last 5500 cal yr BP (calendar years before present). A charcoal peak in the historic period was associated with a >1400-ha fire dated to 1986 that burned in the watershed. We reconstructed the prehistoric fire history by inferring fires from similar charcoal peaks that were significantly greater than the background charcoal …

Aspects Of Sacramento Pikeminnow Biology In Nearshore Habitats Of The Sacramento–San Joaquin Delta, California, Matthew L. Nobriga, Frederick Feyrer, Randall D. Baxter

Western North American Naturalist

We documented distribution, relative abundance, diet composition, and body condition of Sacramento pikeminnow Ptychocheilus grandis during 2001 and 2003 at 5 sites in the Sacramento–San Joaquin Delta, California. Sacramento pikeminnow densities in nearshore habitats were higher in 2003 than 2001. In both years, spatial distribution of beach seine densities was similar. There were no significant differences in density among sampling sites except for the southernmost site where the catch was near zero. Based on rotary screw-trap data from a 6th site, we found relative abundance of Sacramento pikeminnow entering the Delta via an artificial floodplain was positively correlated with flow. …

Estimating Spatial Curve Number For Hydrologic Response Analysis Of A Small Watershed

Journal of Spatial Hydrology

An approach to estimate the curve number (CN) at each pixel unit of a satellite imagery, which is a key parameter in the widely used Soil Conservation Service Curve Number (SCS- CN) hydrologic model, is proposed. Instead of mapping land use and its temporal dynamics from satellite imageries, this approach linearly unmixes the multi-spectral radiances into three fractional layers which primarily control the degree of saturation within a watershed occurring due to a 25 cm-depth storm event, i.e., physically interpreted as the CN. The fraction layers used are water, sand and pure vegetation. In order to obtain a relationship between …

Reproductive Characteristics Of Two Syntopic Lizard Species, Sceloporus Gadoviae And Sceloporus Jalapae (Squamata: Phrynosomatidae), From Tehuacán Valley, Puebla, México, Aurelio Ramírez-Bautista, América L. Ortíz-Cruz, Ma. Del Coro Arizmendi, Jorge Campos

Western North American Naturalist

We studied the reproductive characteristics of 2 syntopic lizard species, Sceloporus gadoviae and Sceloporus jalapae (Phrynosomatidae). Specimens of S. gadoviae (N = 105) and S. jalapae (N = 41) were collected in a tropical arid forest from Tehuacán Valley, Puebla, México. Males of S. gadoviae reached sexual maturity at the same snoutvent length (SVL; 45.0 mm) as S. jalapae, and a similar pattern occurred in females of both species (SVL; 41.0 and 42.0 mm, respectively). Males of S. gadoviae exhibited reproductive activity throughout the year, with a longer activity during the dry (November to May) and part …

Competitive Interactions Between Endangered Kit Foxes And Nonnative Red Foxes, Howard O. Clark Jr., Gregory D. Warrick, Brian L. Cypher, Patrick A. Kelly, Daniel F. Williams, David E. Grubbs

Western North American Naturalist

We investigated interference and exploitative competition between endangered San Joaquin kit foxes (Vulpes macrotis mutica) and nonnative red foxes (V. vulpes). Seven kit foxes and 16 red foxes were radio-collared and tracked via radiotelemetry near Lost Hills, California. One kit fox was killed by a red fox. Home ranges of the 2 species did not overlap extensively. Although both species used similar habitats, they used different parcels of land. Kit foxes and red foxes primarily consumed rodents on the study site, and dietary overlap was considerable. Red foxes also may have been using dens formerly used …

Fish Assemblage Structure Following Impoundment Of A Great Plains River, Michael C. Quist, Wayne A. Hubert, Frank J. Rahel

Western North American Naturalist

Understanding the upstream and downstream effect of impoundments on stream fish assemblages is important in managing fish populations and predicting the effects of future human activities on stream ecosystems. We used information collected over a 41-year period (1960–2001) to assess changes in fish assemblage structure resulting from impoundment of the Laramie River by Grayrocks Reservoir. Prior to impoundment (i.e., 1960–1979), fish assemblages were dominated by native catostomids and cyprinids. After impoundment several exotic species (e.g., smallmouth bass [Micropterus dolomieu], walleye [Sander vitreus; formerly Stizostedion vitreum], yellow perch [Perca flavescens], brown trout [Salmo …

Notes On Significant Collections And Additions To The Flora Of Glen Canyon National Recreation Area, Utah And Arizona, Between 1992 And 2004, John R. Spence

Western North American Naturalist

Symphyotrichum expansum (Puepp ex Spreng.) Nesom is reported new to Utah from the Escalante River drainage. A major range extension is reported for Aralia racemosa L. in the Escalante drainage, and additional populations are reported of the rare species Imperata brevifolia Vasey in Utah, including the 1st record for the Grand Staircase–Escalante National Monument. Heterotheca grandiflora Nutt. is reported new to north central Arizona. New locations and notes on an additional 22 rare species in Glen Canyon National Recreation Area are listed.

Distribution Of Chemistry And Sexual Fecundity In The Lichenized-Fungi, Xanthoparmelia Cumberlandia And Xanthoparmelia Coloradoensis On Boulder Mountain, Aquarius Plateau, Ut, Heather Bird Jackson

Theses and Dissertations

Three aspects of Xanthoparmelia cumberlandia and Xanthoparmelia coloradoënsis populations found at two elevations are explored: clustering of secondary chemicals and the resulting implications for taxonomic distinctions, the usefulness of thallus size as an indirect measure of sexual fecundity, and the frequency of sexual reproduction.

First, we use clustering of 46 chemicals produced by X. cumberlandia and X. coloradoënsis to evaluate the adequacy of the current taxonomic distinction between them. Using principal components analysis and UPGMA, we find that the currently recognized species boundaries indicated by the presence of stictic acid in X. cumberlandia and salazinic acid in X. coloradoënsis are …

Dynamics Of A Dwarf Bear-Poppy (Arctomecon Humilis) Population Over A Sixteen-Year Period, K. T. Harper, Renée Van Buren

Western North American Naturalist

A population of the dwarf bear-poppy (Arctomecon humilis Coville, Papaveraceae) at Red Bluff, Washington County, Utah, was monitored twice annually between 1987 and 2002. This is a narrowly endemic, gypsophilous species that has been formally listed as endangered since 1979. During the 16 years of observation, density of this species has fluctuated between 3 and 1336 individuals on the 0.07-ha monitoring plot. Moderate to large recruitments of seedlings occurred in 1992, 1995, and 2001. Seedling recruitments from a large, long-lived seed bank are triggered by abundant precipitation during the February–April period. At least 5.0 cm of rainfall is required …

Fleas (Siphonaptera) In Nests Of Voles (Microtus Spp.) In Montane Habitats Of Three Regions Of Utah, Glenn E. Haas, James R. Kucera

Western North American Naturalist

As a parallel study of a survey of fleas of trapped small mammals in montane southern Utah, we removed 77 adult fleas from 12 of 13 nests of voles (Microtus longicaudus, M. montanus and M. richardsoni) collected from montane meadows in the Abajo and La Sal Mountains, the Markagunt Plateau and Pine Valley Mountains, and the Uinta Mountains, May 1991–July 2002. Six species and subspecies of fleas parasitic on Microtus spp. were found, 1–3 species in each nest. Three specimens of the ubiquitous deer mouse (Peromyscus spp.) flea Aetheca wagneri (Baker) were also found. We collected the …

On The Local Coexistence Of Species In Plant Communities, J. Yoshimura, K. Tainaka, M. Shiyomi, T. Suzuki

International Congress on Environmental Modelling and Software

Coexistence of many competitive species is very common in natural plant communities. For example, almost all forests and grasslands consist of various species. Extremely high biodiversity is seen in tropical rain forests. Grassland communities also often consist of many species. In plant communities, spatially competitive species of plants coexist in a mosaic pattern. Communities with a single species are very extremely rare in nature. However, mathematical studies show that the local coexistence of spatially competitive species is rarely achieved even with two competitive species. Many studies have introduced external factors to promote coexistence, such as immigration of seeds, seed dormancy, …

Towards Sustainable Management Of Wastes: Results Of A Modelling Case Study, And The Emerging Environmental Decision Support System Based On The Energy Footprint, V. Krivtsov, P. Dacombe, C. Banks, S. H. Spiller, S. Heaven

International Congress on Environmental Modelling and Software

Here we present an emerging EDSS, based on the energy and materials flow model forevaluation of alternatives for processing domestic and commercial waste. The input information for themodel is obtained through a literature search, consultations with stakeholders, and also using aspecially designed expert system (ES) - The ‘Smart Waste Questionnaire’. The ES implements an ITbasedinterrogative data acquisition methodology built using a custom-designed expert system softwareand integrated databases. In this paper we present the results of an ongoing case study of the model’sapplication to the management of specific waste types in the area of Southampton (England, UK). Themodel has been designed …

Predicting Predation Efficiency Of Biocontrol Agents: Linking Behavior Of Individuals And Population Dynamics, Brigitte Tenhumberg

International Congress on Environmental Modelling and Software

Behavioral ecology and population ecology are two separate branches of ecology; studies linkingthe effect of individual behavior and population dynamics are rare. This paper connects a stochastic optimalforaging model of insect predators with an age structured population model of its prey. I modeled syrphidlarvae feeding on cereal aphids, an interaction critical to cereal crops in Germany. The key stochastic elementin this model is the foraging success of predators, which influences survival and developmental time ofpredators and mortality of the prey population. The model predicts that the level of control incurred bypredators is highest if predators arrive when prey numbers are …

Effect Of Cryptobiotic Crust Type On Microarthropod Assemblages In Piñon-Juniper Woodland In Central New Mexico, S. L. Brantley, U. L. Shepherd

Western North American Naturalist

Cryptobiotic crusts make up an important part of the ground cover in arid systems. Along with their roles of retarding soil erosion and enhancing soil fertility, crusts may also be supporting local and regional arthropod biodiversity. We inventoried arthropod species in mossy, lichen, and mixed (lichen and mossy) cryptobiotic crusts at 2 sites in central New Mexico piñon-juniper habitat. We collected 240 crust samples and used a heptane flotation technique to extract the microarthropods. We found 39 species of microarthropods and small macroarthropods, with significantly fewer species on lichen. Species richness was higher in March than in August, but diversity …

Habitat Use By Brush Mice (Peromyscus Boylii) In Southeastern Arizona, Amy B. Gottesman, Michael L. Morrison, Paul R. Krausman

Western North American Naturalist

No abstract provided.

Full Issue, Vol. 64 No. 2

Western North American Naturalist

No abstract provided.

Contribution To The Morphology And Descriptive Biology Of Caurinella Idahoensis (Ephemeroptera: Ephemerellidae), Luke M. Jacobus, W. P. Mccafferty

Western North American Naturalist

Reared specimens from Bridge Creek, Idaho County, Idaho, provide the bases for the first descriptions of Caurinella idahoensis egg and alate stages and redescription of the larval stage. Larvae are distinguished from other Nearctic Ephemerellinae species by the distinctive posterolateral projections on abdominal segment 9. Male adults have a unique combination of characters associated with their genitalia. Larvae were associated with the colonial bluegreen alga Nostoc parmelioides in a clear, cold headwater stream. Several other Diptera, Ephemeroptera, Plecoptera, and Trichoptera also were found in cohabitation with C. idahoensis. Amorphous detritus appears to be a major component of the diet …

Habitat Of Three Rare Species Of Small Mammals In Juniper Woodlands Of Southwestern Wyoming, Kevin M. Rompola, Stanley H. Anderson

Western North American Naturalist

Southwestern Wyoming constitutes the northern limit of the ranges of the cliff chipmunk (Tamias dorsalis), pinyon mouse (Peromyscus truei), and canyon mouse (P. crinitus). In addition to trying to determine their presence in the region, we wanted to identify habitat characteristics commonly used by each of these species. We used Sherman live-traps to sample 14 sites representing 2 distinct habitat types in 1998 and 1999: juniper-rocky slopes and juniper cliffs. Seventeen habitat characteristics were measured at capture locations for each species and compared with randomly located points. Best subsets multiple logistic regression was used …

Growth In Sonoran Desert Populations Of The Common Chuckwalla (Sauromalus Obesus), Brian K. Sullivan, Matthew A. Kwiatkowski, Paul S. Hamilton

Western North American Naturalist

No abstract provided.

Population Structure And Paternity In An American Black Bear (Ursus Americanus) Population Using Microsatellite Dna, Elizabeth A. Sinclair, Hal L. Black, Keith A. Crandall

Western North American Naturalist

We report genetic microsatellite data from analysis of 71 American black bears (Ursus americanus) from the East Tavaputs Plateau in eastern Utah. Heterozygosity was 52.9%, which is lower than other mainland North American populations and possibly reflects low recruitment into the study area. We used a combination of known pedigrees (mother/cubs), relatedness estimates, and paternity estimation using CERVUS to infer single and possible multiple paternity within litters, breeding by pairs over consecutive years, and the possibility of a single male successfully breeding with multiple females in a single year. Estimates of inbreeding effective population size indicate the East …

Habitat Features And Predictive Habitat Modeling For The Colorado Chipmunk In Southern New Mexico, Marina Rivieccio, Bruce C. Thompson, William R. Gould, Kenneth G. Boykin

Western North American Naturalist

Two subspecies of Colorado chipmunk (state threatened and federal species of concern) occur in southern New MeXico: Tamias quadrivittatus australis in the Organ Mountains and T. q. oscuraensis in the Oscura Mountains. We developed a GIS model of potentially suitable habitat based on vegetation and elevation features, evaluated site classifications of the GIS model, and determined vegetation and terrain features associated with chipmunk occurrence. We compared GIS model classifications with actual vegetation and elevation features measured at 37 sites. At 60 sites we measured 18 habitat variables regarding slope, aspect, tree species, shrub species, and ground cover. We used logistic …

Geobotany Of The Niobrara Chalk Barrens In Colorado: A Study Of Edaphic Endemism, Sylvia Kelso, Nathan W. Bower, Kirsten E. Heckmann, Paul M. Beardsley, Darren G. Greve

Western North American Naturalist

The chalk barrens of the Niobrara Formation in the Arkansas River valley of Colorado exhibit a high degree of plant endemism and rarity. We examined their geochemistry and structure as well as the reproductive ecology of their signature species Mirabilis rotundifolius to assess factors influencing endemism. While no single component consistently identified the barren soils, the natural locations that support Mirablilis can be identified using elemental profiles from a cluster analysis of soil extracts. Because seeds germinate and plants proliferate in transplant gardens with non-calcic soils, bedrock and soil chemistry do not appear to be determinant components of endemism. Mirabilis …

Fall Diet Of Chukars (Alectoris Chukar) In Eastern Oregon And Discovery Of Ingested Lead Pellets, Hanspeter Walter, Kerry P. Reese

Western North American Naturalist

No abstract provided.

Horned Lark (Eremophila Alpestris L.) Predation On Alkali Bees, Nomia Melanderi Cockerell, Richard W. Rust

Western North American Naturalist

Horned Larks (Eremophila alpestris L.), sampled during the first 2 weeks of alkali bee (Nomia melanderi Cockerell) emergence at bee nesting sites in 2 alfalfa seed-growing regions in central Nevada, ate significantly more male than female alkali bees. Exploitation rates suggest that individual Horned Larks consume 10 to 200 alkali bees per day and feed an additional 300 to 1000 bees per day to nestlings nestlings.

Environmental Characteristics And Benthic Invertebrate Assemblages In Colorado Mountain Lakes, Brenda Moraska Lafrancois, Daren M. Carlisle, Koren R. Nydick, Brett M. Johnson, Jill S. Baron

Western North American Naturalist

Twenty-two high-elevation lakes (>3000 m) in Rocky Mountain National Park and Indian Peaks Wilderness Area, Colorado, were surveyed during summer 1998 to explore relationships among benthic invertebrates, water chemistry (particularly nitrate concentrations), and other environmental variables. Water samples were collected from the deepest portion of each lake and analyzed for ions and other water chemistry parameters. Benthic invertebrates were collected from the littoral zone using both a sweep net and Hess sampler. Physical and geographical measurements were derived from maps. Relationships among benthic invertebrate assemblages and environmental variables were examined using canonical correspondence analysis, and the importance of sampling …

Effects Of Grass Bug Feeding And Drought Stress On Selected Lines Of Crested Wheatgrass, Robert S. Nowak, James D. Hansen, Cheryl L. Nowak

Western North American Naturalist

The sequential effects of feeding by grass bugs (Irbisia pacifica [Hemiptera: Miridae]) and of drought stress on the growth of 2 crested wheatgrasses (the hybrid Agropyron cristatum × desertorum and A. cristatum cv. 'Fairway') were investigated in a controlled greenhouse experiment. Growth rates of genotypes that were previously selected for resistance to grass bug feeding were not consistently greater than those of unselected genotypes when plants were exposed to bug feeding. Thus, the mechanism of resistance to bug feeding for the selected genotypes does not appear to be "tolerance," i.e., rapid growth rates that allow the resistant genotypes to …

Full Issue, Vol. 63 No. 2

Western North American Naturalist

No abstract provided.

Nesting Phenology And Productivity Of Birds In The White And Inyo Mountains, California, As Assessed With Nest-Boxes, Linnea S. Hall, Michael L. Morrison

Western North American Naturalist

Nest-boxes were monitored from 1988 to 1992 on 5 grids in the pinyon-juniper (Pinus-Juniperus) woodlands of the White and Inyo Mountains, California, to determine breeding phenology and productivity of cavity-nesting birds, and characteristics of used and non-used nest-boxes. We found a total of 112 nests of 6 species. Bewicks Wrens (Thryomanes bewickii; 64 nests), Mountain Chickadees (Poecile gambeli; 18), Ash-throated Flycatchers (Myiarchus cinerascens; 12), and Juniper Titmice (Baeolophus ridgwayi; 11) were the most common species utilizing the boxes. Nest phenology and numbers of young were similar to values reported elsewhere …

Mammals Of The Grand Staircase–Escalante National Monument: A Literature And Museum Survey, Jerran T. Flinders, Duke S. Rogers, Jackee L. Webber-Alston, Harry A. Barber

Monographs of the Western North American Naturalist

This is the first treatment of the mammals of the Grand Staircase–Escalante National Monument (GSENM). GSENM was established in 1996 as a 1.7-million-acre (680,000-ha) federal land reserve under the jurisdiction of the Bureau of Land Management (BLM). To successfully manage this new monument, the BLM is presently developing a management action plan. To provide information for the proper management of mammal species of the area, we have reviewed background literature for each mammal potentially found within the Monument boundaries. We propose that a core area, surrounded by a buffer matrix, be used in GSENM and surrounding public lands to preserve …

Exergy And Information Indices: A Comparison For Use In Structurally Dynamic Models, Brian D. Fath

International Congress on Environmental Modelling and Software

Ecosystems are open, dynamic systems changing both their structure and their function over time. A model, which is an abstraction of the system manifest at the time of its construction, can project future dynamics so long as the fundamental structure of the system does not change. A primary modelling challenge arises when the system structure changes, i.e., internal reorganization, as a result of external perturbation. Ideally, one could include algorithms in the model to anticipate such changes, but that would entail knowing a great deal more about the system and disturbances to it than is possible. Other methods to anticipate, …