The flight periodicity, attack patterns, and life history of Dryocoetes confusus Swaine (Coleoptera: Curculionidae: Scolytinae), the western balsam bark beetle, in north central Colorado

Dryocoetes confusus Swaine, the western balsam bark beetle, is an important bark beetle associated with Abies lasiocarpa (Hook.) Nutt. (subalpine fir) in western North America. Little information is available on the life cycle and ecology of this insect in Colorado. In this study in north central Colorado, we examined its flight periodicity, attack patterns, and life cycle in downed trees. Flight season, as indicated by pheromone-trap catches, began in early June. Peak flight was observed during early to mid-July. A second peak in flight was observed in some years, but its occurrence was not consistent. Preferred attack sites on downed trees were the underside or side of the log and through branch stubs. The life cycle for this beetle was completed in 2 years, consistent with earlier observations from British Columbia. Sex ratio was 1:1, but a higher percentage of males fly earlier in the season.     

Compositional similarity within the oakbrush type in central and northern Utah

Indices of similarity were used to evaluate the similarity of oakbrush stands throughout the Uinta National Forest and to compare oak communities in central and northern Utah. Results show that Gambel oak stands in central Utah differ significantly among themselves in respect to quantitative aspects of the vegetation. Those differences can be correlated with elevation, slope exposure, and fire history. Nevertheless, there is currently inadequate justification for recognizing more than one habitat type for the species in the study area. There is a need to develop a model capable of predicting growth rate of oak on specific sites.     

Status of the northern rock deermouse, Peromyscus nasutus (Rodentia: Cricetidae), in Utah

Peromyscus nasutus has been considered to occur in Utah since it was first reported in the state in 1935. Authors since then have considered the distribution of P. nasutus to include southeastern Utah. However, the original Utah specimen was later reidentified as Peromyscus boylii . A query of museums revealed only 1 other specimen considered to be P. nasutus from Utah. This specimen was examined and found to be P. boylii . Thus, there is no evidence of the occurrence of P. nasutus in Utah, and the northwesternmost accepted records of this species are in the Chuska Mountains of northeastern Arizona.     

Some aspects of succession in the spruce-fir forest zone of northern Utah

A site in the Rocky Mountain subalpine forest zone with which a series of hypotheses concerning ecosystem succession was tested is characterized. Succession from herb-dominated meadows to climax forests of Engelmann spruce and subalpine fir can follow at least four identified pathways. After fire, spruce and fir may reinvade a site directly, follow invasion by aspen, or follow invasion by lodgepole pine, the pathway depending on a combination of physical and biotic factors. In other cases, succession begins with long-established meadows which do not owe their existence to fire. In this latter pathway, aspen invades meadows by suckering and changes the environment near the soil surface so as to facilitate establishment of the climax tree species. The biota and soils of four characteristic seral stages (meadow, aspen, fir, spruce-fir) in this latter pathway are described.     

Biogeographic significance of low-elevation records for Neotoma cinerea from the northern Bonneville Basin, Utah

The existence of low-elevation populations of Neotoma cinera in the northern Bonneville Basin shows either that these mammals can survive thousands of years in xeric habitats or that they can move across xeric lowlands far more readily than has been appreciated, or both. Current models of Great Basin small mammal biogeography are far too static to encompass properly the interaction of the wide range of geographical and biological variability that has produced the modern distribution of those mammals that have, for several decades, been treated as ""montane"" within the Great Basin.     

Plant community zonation in response to soil gradients in a saline meadow near Utah Lake, Utah County, Utah

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Patterns of zonation along a saline meadow slope were studied. Different species associations were distributed in five zones along the slope which paralleled Utah Lake. The five zones, distinguished on the basis of dominant species and/or life form, were: saltgrass–annual weed, saltgrass-alkaligrass, saltgrass-forb, saltgrass, and spikerush. Soil, vegetation, and plant species data were taken. Patterns of change with respect to these factors were observed along the downslope gradient. Soil pH and soluble salts decreased downslope, while organic matter and moisture increased. Individual ions showed varying patterns. Vegetation and species patterns also varied with slope position. Annuals dominated the ridge tops, while sedge and rush cover were restricted to the slope base. Perennial forb distribution was shown to be correlated with elevated levels of micronutrients in the soil.     

Fire frequency and the vegetative mosaic of a spruce-fir forest in northern Utah

Fire scar and vegetative analysis were used to construct a fire history for the Engelmann spruce/subalpine fir ( Picea engelmannii/Abies lasciocarpa ) vegetation type of Utah State University (USU) T. W. Daniel Experimental Forest. Three distinct periods of fire frequency were established-presettlement (1700-1855), settlement (1856-1909), and suppression (1910-1990). Mean fire interval (MFI) decreased during the settlement period and greatly increased during the suppression era. The difference was attributed to the influx of ignition sources during the settlement of nearby Cache Valley, located 40 km to the west. Logging and livestock grazing appear to have led to the reduced MFI, which in turn worked as a factor to create the vegetative mosaic now observed on the study area. The increase in MFI during the suppression ear permitted the advancement of shade-tolerant species in the understory of the shade-intolerant lodgepole pine ( Pinus contorta var. latifolia ) and quaking aspen ( Populus tremuloides ). Continued suppression of disturbance from wildfire will allow the lodgepole pine cover type, which experience the lowest MFI during the settlement period, to be further invaded by shade-intolerant species, decreasing spatial stand diversity and increasing the risk of more intense fires.     

Spruce beetle ( Dendroctonus rufipennis ) outbreak in Engelmann spruce ( Picea Engelmannii ) in central Utah, 1986-1998

Extensive Engelmann spruce ( Picea engelmannii Parry ex Engelm.) mortality caused by the spruce beetle ( Dendroctonus rufipennis Kirby) has been occurring at the southern end of the Wasatch Plateau in central Utah. This spruce beetle outbreak is the largest recorded in Utah history. An extensive ground survey was conducted in 1996 on the Manti-LaSal National Forest, Sanpete and Ferron Ranger Districts, to document mortality and impact of a major spruce beetle outbreak on post-outbreak forest composition. In 1998 the same sites were resurveyed. Survey results indicate Engelmann spruce basal area (BA) loss averaged 78% in trees ≥5 inches diameter breast height (DBH) in 1996. Ninety percent of BA ≥5 inches DBH was lost within the same sites by 1998. Tree mortality of spruce ≥5 inches DBH expressed in trees per acre (TPA) averaged 53% in 1996. In 1998 TPA ≥5 inches DBH mortality averaged 73%. Before the outbreak live Engelmann spruce BA ≥5 inches DBH averaged 99 square feet, and TPA ≥5 inches DBH averaged 97. In the sites surveyed in 1996 and resurveyed in 1998, Engelmann spruce BA ≥5 inches DBH averaged 21 and 9 square feet, and TPA ≥5 inches DBH averaged 43 and 25, respectively. Overstory tree species composition changed from stands dominated by spruce to subalpine fir. Stand ratings for potential spruce beetle outbreaks were high to mostly medium hazard pre-outbreak and medium to primarily low hazard by 1998, as a result of reduction in average spruce diameter, total basal area, and overstory spruce.     

Beetles from the environs of Lake Powell in southern Utah and northern Arizona

Sixty-eight species of beetles of 14 families were collected in pit traps in 12 major vegetative communities during environmental monitoring studies in the summers of 1971 to 1973 in southern Utah and northern Arizona. Seasonal and plant community differences and correlations in population and composition were noted for the 16 sites studied. Highest populations and the most species were found in a grass community, but occurred in different months in each of the three years. Lowest populations were found in a Coleogyne community, and fewest species in an Artemisia- grass community.     

Douglas-fir tussock moth ( Orgyia pseudotsugata McDunnough) on subalpine fir in northern Utah

Douglas-fir tussock moth ( Orgyia pseudotsugata McDunnough) defoliation was detected by aerial survey on three areas of the Wasatch-Cache National Forest in 1990 and 1991. These are the first documented tussock moth outbreaks in Utah. Ground surveys revealed that subalpine fir ( Abies lasiocarpa [Hook.] Nutt.) was heavily defoliated during the outbreak. Douglas-fir ( Pseudotsuga menziesii [Mirb.] Franco), though minor component in the affected areas, had noticeably less defoliation and mortality. Adjacent stands of Douglas-fir had little or no visible tussock moth activity. Defoliation on subalpine fir was typically found evenly distributed throughout the crown rather than concentrated at the top. Ninety-four percent of subalpine fir with defoliation ratings of 90% or more were killed. Top-kill occurred on nearly one-half of subalpine firs defoliated 25-89%. Heavy defoliated trees tended to occur in pockets bounded by areas of light defoliation. After three consecutive years of defoliation, tussock moth populations collapsed. No life stages were detected in 1993 from visual inspections of foliage or in pheromone traps.     

Ruffed grouse ( Bonasa umbellus ) foraging in aspen stands during winter in northern Utah

Ruffed Grouse ( Bonasa umbellus ) population densities are lower in the Intermountain West than elsewhere in the species' range. Throughout much of its range, the Ruffed Grouse is closely associated with quaking aspen ( Populus tremuloides ), in part because aspen buds are an important winter food. Because population fluctuations of Ruffed Grouse have been associated with changes in aspen abundance or chemical composition, we studied winter foraging of the species in the Intermountain West where it has received little attention. Aspen buds were the most prominent forage in the bird's diet, although in contrast to other Ruffed Grouse food habits studies, reproductive buds were not eaten more than vegetative buds, and buds of other deciduous plants were also important (>20% of the diet). Excretion of high concentrations of ammonium nitrogen suggests that grouse in northern Utah are ingesting higher levels of secondary plant compounds than reported elsewhere. Our results show aspen is important in the winter ecology of Ruffed Grouse in northern Utah and suggest that continued loss of aspen may impact grouse populations.     

Competitive displacement as a factor influencing phytoplankton distribution in Utah Lake, Utah

Phytoplankton studies during the summer of 1974 in Utah Lake, Utah, demonstrated the development of disjunct distributions of Aphanizomenon flos-aquae and Ceratium hirundinella. Differential response to environmental factors and competitive displacement are proposed as probable explanations for this phenomenon.     

Vegetational response to three environmental gradients in the salt playa near Goshen, Utah County, Utah

The plant communities and individual plant species in and around a salt playa near Goshen, Utah County, Utah, were studied in relation to gradients for soluble salts, soil moisture, and pH. Forty-eight stands were sampled. Frequency data were taken for all plant species. Soil samples were collected from each site and analyzed to establish the environmental gradients. Results indicate that the vegetational types respond differentially to the three gradients and can be segregated on the basis of one or more of the gradients. The total soluble salts gradient was found to be the most influential of the three sampled. Correlation analysis indicates that 45 percent of the variation in plant diversity can be accounted for by the three gradients. Distributional patterns of individual plant species are strongly influenced by the three gradients. Niche width measurements exhibited no correlation with the measured gradients.     

Parasites of mottled sculpin, Cottus bairdi Girard, from five locations in Utah and Wasatch counties, Utah

Between 1983 and 1985, 97 mottled sculpin, Cottus bairdi Girard, were examined from five collection sites in central Utah for parasites. Eight different species of parasites were observed, representing seven genera of Protozoa ( Plistophora, Myxidium, Myxobolus, Ichthyophthirius, Trichodina, Apiosoma, Eimeria ) and one genus of Nematoda ( Rhabdochona ). The highest number of parasites was found in sculpin from the Provo River near residential areas, while the lowest number was recorded from Hobble Creek, a nearby pristine area. A complete list of parasites for C. bairdi with literature citations is presented. Each observed parasite is discussed emphasizing pathogenesis to the host.     

Engelmann spruce cone losses caused by insects in northern Utah in a year of low cone production

The impacts and timing of insect infestation were determined in developing Engelmann spruce cones throughout the summer of a year of low cone production in northern Utah. The major insects found were the western spruce budworm, Choristoneura occidentalis Freeman (Lepidoptera: Tortricidae); fir coneworm, Dioryctria abietivorella Grote (Lepidoptera: Pyralidae); and the spruce seed moth, Laseyresia youngana Kearfott (Lepidoptera: Olethreutidae). Insects reduced the survival of cones to 11.48 cones out of 100. The high percentage of seeds and cones lost to insect predation supported previous studies of a similar nature.     

Type specimens of recent mammals in the Utah Museum of Natural History, University of Utah

A detailed list of holotypes of Recent mammals housed in the Utah Museum of Natural History is presented.     

Pinus longaeva in the Stansbury Mountains, Utah

A new record of Pinus longaeva D. K. Bailey in the Stansbury Mountains, north of the known range of the species, is reported.     

Pinyon-juniper woodlands in Zion National Park, Utah

Juniperus osteosperma-Pinus monophylla or P. edulis (P-J) woodlands are the most widespread plant community in Zion National Park (ZNP), southwestern Utah. These woodlands dominate nearly half of the park's land area. Our study of this vegetational complex is based on a sample consisting of 115 macroplots (each 0.01 ha in area) objectively distributed across the entire area of ZNP. We recognize 3 subtypes within the P-J complex: Juniperus osteosperma (Utah juniper) alone, juniper with P. monophylla (single-leaf pinyon), and juniper with P. edulis (two-leaf pinyon). The 2 pinyon pines rarely occur together, and thus the foregoing subtypes do not overlap geographically to a significant extent. The first 2 subtypes occur primarily below 1800 m elevation, while the latter is most commonly found above that elevation. Because of the scarcity of sizable expanses (over ～ 10 ha) of well-developed soils in ZNP, the P-J complex occurs primarily on sites where exposed bedrock covers a large portion of the habitat. As a result, over 90% of stands assigned to the P-J complex support less than 50% tree canopy cover (64% have less than 25% tree cover). Shrub cover increases along the woodland successional gradient. Pinyon cover increases faster than juniper cover. Microbiotic soil crust cover is consistently greater in J. osteosperma-P. monophylla woodlands than in J. osteosperma-P. edulis woodlands, but total living cover increases significantly along the successional gradient in both communities. To enhance plant and animal biodiversity, we recommend that pinyon-juniper woodlands of Zion National Park be managed so that late seral stages do not dominate large tracts.     

Vegetal change on a northern Utah foothill range in the absence of livestock grazing between 1948 and 1982

Reexamination of a semiarid foothill rangeland, first evaluated in 1948, indicated that secondary succession continues to shift toward a perennial grass-forb community formerly dominated by xeric shrubs, particularly big sagebrush ( Artemisia tridentata spp. vaseyana ). The direct role in livestock grazing in establishment and maintenance of shrub-dominant plant communities appears confirmed in the decline of shrubs upon cessation of livestock grazing in summer and continued browsing by mule deer in winter. The reduction of shrub forages on mule deer winter ranges is a major factor in population declines.     

Algal populations in Bottle Hollow Reservoir, Duchesne County, Utah

Bottle Hollow Reservoir contains a diverse algal flora. A total of 289 taxa was observed, 227 of which were diatoms. Both littoral and planktonic communities had high diatom diversity. During summer months filamentous Chlorophvta were diverse and high in biomass in the littoral zone. Phytoplankton collections in Bottle Hollow Reservoir were dominated by four species: Asterionella formosa, Cyclotella comta, Dinobryon divergens, and Fragilaria crotonensis. Plankton samples contained mostly small diatoms in early spring, with larger algae succeeding these as the summer progressed. No blue - green algae were important in this succession. Two peak production periods were observed, one in the fall and one in the spring. Bottle Hollow Reservoir appears to be a healthy mesotrophic system based on the evidences of moderately high algal diversity, insignificance of blue-green algae, and the presence of a suite of diatom species indicative of mesotrophic conditions.