Northwestern Utah Research Articles

Enhancing local governance through community‐based conservation: lessons learned from a Utah local working group

AbstractBecause home ranges for many sensitive wildlife species often transcend jurisdictions, species conservation requires collaborative efforts to engage multiple stakeholders. The West Box Elder County Coordinated Resource Management (CRM) in northwestern Utah initially organized as a greater sage‐grouse (Centrocercus urophasianus) local working group (LWG), evolved through a CRM process, to enhance local governance across jurisdictional boundaries by engaging a wider range of public and private partners in species conservation and community development. By completing landscape scale management and development projects, the CRM has benefitted wildlife and local ranchers and contributed to enhancing the social and economic well‐being of rural residents in the county. In 2019, to identify the operational mechanisms of governance that enabled the CRM to achieve long‐term sustainability while meeting community and species conservation needs, we interviewed 17 key stakeholders (8 private, 6 state, and 3 federal) who had been involved in both the LWG and CRM since their inception. Each interview addressed the CRM's origin, support and synergy, administration, communications, outcomes, and improvements. Qualitative analysis of responses revealed that 1) participation by representatives of federal and state government agencies was paramount for funding and program structure, 2) landowner involvement was necessary for long‐term stability and persistence, 3) intergroup communication has improved, and 4) trust of local landowners between state and federal agencies has been enhanced. However, respondents were concerned that the CRM governance process should be re‐evaluated periodically to mitigate stakeholder burnout and group cohesion deterioration. The re‐evaluation could help temper unrealistic expectations relative to sustaining momentum the CRM has achieved over the last decade and establish new goals to better address current conservation issues. Our results may be applicable by other rural communities who desire enhanced local governance to identify and address emerging community development needs and species conservation.

Role of fluids on deformation in mid-crustal shear zones, Raft River Mountains, Utah

AbstractFluids are commonly invoked as the primary cause for weakening of detachment shear zones. However, fluid-related mechanisms such as pressure-solution, reaction-enhanced ductility, reaction softening and precipitation of phyllosilicates are not fully understood. Fluid-facilitated reaction and mass transport cause rheological weakening and strain localization, eventually leading to departure from failure laws derived in laboratory experiments. This study focuses on the Miocene Raft River detachment shear zone in northwestern Utah. The shear zone is localized in the Proterozoic Elba Quartzite, which unconformably overlies the Archaean basement, and consists of an alternating sequence of quartzite and muscovite-quartzite schist. In this study, we characterize fluid-related microstructures to constrain conditions that promoted brittle failure in a plastically deforming shear zone. Thin-section analyses reveal the presence of healed microcracks, transgranular fluid inclusion planes and grain boundary fluid inclusion clusters. Healed microcracks occur in three sets, one sub-perpendicular to the mylonitic foliation, and a set of two conjugate microcracks oriented at ∼40–60° to the mylonitic foliation. Healed microfractures are filled with quartz, which has a distinct fabric, suggesting that microcracks healed while the shear zone was still at conditions favourable for quartz crystal plasticity. Transgranular fluid inclusion planes also occur in three sets, similar in orientation to the healed microfractures. Fluid inclusions commonly decorate grain and subgrain boundaries as inter- and intragranular clusters. Our results document ductile overprint of brittle microstructures, suggesting that, during exhumation, the Raft River detachment shear zone crossed the brittle–ductile transition repeatedly, providing pathways for fluids to permeate through this shear zone.

Sediment routing and provenance of shallow to deep marine sandstones in the late Paleozoic Oquirrh Basin, Utah

The Oquirrh-Wood River Basin is a Pennsylvanian to Permian clastic and carbonate basin in northwestern Utah and southern Idaho, USA. The basin is commonly considered the northwesternmost expression of the Ancestral Rocky Mountains (ARM). Basin fill is locally up to 9 km thick. Facies range from shelf carbonates to deep marine debrites, and generally deepen from basin initiation to the beginning of the Permian. Unlike other ARM basins, no basin-bounding fault or highland has been identified as the source of these thick deposits and the tectonic drivers of basin subsidence are poorly understood.Tectonic subsidence analysis was performed on 10 stratigraphic sections across the basin, resulting in a two-phase tectonism model. Pennsylvanian subsidence is interpreted as being related to strike-slip deformation; whereas Permian subsidence in the western part of the basin may be related to the uplift and unconformity sequence documented in northeastern Nevada.Detrital zircon geochronology and thin section point counts are relatively uniform in Middle Pennsylvanian and early Permian samples, suggesting local tectonism did not alter dominant sediment routing patterns. Oquirrh Group sandstones are compositionally mature and contain sparse feldspar or lithic grains, leading to the interpretation that sample sediments were derived from recycled orogenic sources. UPb ages on detrital zircons from three Pennsylvanian and three Permian samples suggest sediment was overwhelmingly derived from multiple Laurentian basement provinces to the north and east, consistent with interpretations from the Wood River Basin. Paleocurrent data indicate a prevailing southward ocean current, suggesting a combination of sediment recycling and sediment transport across Laurentia from orogenic highlands in the northeast to the Oquirrh-Wood River Basin throughout the late Paleozoic.

Devils playground, Box Elder County

Why take your kids to the neighborhood playground, when you can visit a playground that inspires their sense of geologic adventure? Devils Playground is not your ordinary community playground, but a wonderland of granitic rock weathered into fantastic forms and weird shapes. Occupying an assortment of Bureau of Land Management, state, and private land in the Bovine Mountains, Devils Playground is a relatively unknown geologic curiosity found in a remote corner of northwestern Utah. Devils Playground is situated in the physiographic region known as the Great Basin province that extends across western Utah, Nevada, and to the Sierra Nevada Mountains in eastern California. The area is composed mostly of granitic rocks of the Emigrant Pass intrusion. A combination of granitic rock, faulting, and weathering under a semiarid climate created favorable conditions for the creation of Devils Playground. Desert plants such as sagebrush,Utah juniper, pinyon pine, Mormon tea, and cheatgrass are common throughout the area.

TRACE FOSSILS OF PROBLEMATIC ORIGIN: ASSESSING SILICIFIED TRACE FOSSILS FROM THE PERMIAN OF UTAH, U.S.A.

ABSTRACTSilicification is a diagenetic process that can affect the fidelity of trace fossil preservation. The combination of compaction and oversilicification associated with chert precipitation can alter the original fabric created by the trace producers. Sedimentary structures and trace fossils in mixed chert-carbonate systems are especially prone to these processes, leading to the preservation of a limited or biased ichno-assemblage and the omission of important paleoecologic detail. We summarize useful criteria for identifying chert-associated trace fossils and present a formal naming scheme. Using this nomenclature, we identified silicified trace fossils in the chert-rich Permian strata from northwestern Utah. An assemblage of burrows is present in outcrops of the Trapper Creek Formation, consisting of nodule-like growths of microcrystalline quartz in close association with bioturbated horizons. Thin section micro-textures of burrow fill lend additional support to the bioturbated origin of chert nodules. Silicified Thalassinoides fossils are present, as are chert nodules with a Rhizocorallium-like morphology.

Translocation of Boreal Toad (Anaxyrus boreas boreas) into Two Springs in the Grouse Creek Mountains, Utah, Including Demographic Observations

The Boreal Toad (Anaxyrus boreas boreas) is widely distributed in western North America and has declined throughout portions of the Rocky Mountains. One mechanism to expand populations is to translocate toads into unoccupied habitats. Wild-captured juvenile (n = 229) and subadult/adult (n = 42) Boreal Toads were translocated into 2 unoccupied spring-fed ponds located near 10 known breeding populations in the Grouse Creek Mountains, northwestern Utah. Boreal Toad egg strands were observed at one pond in 8 of 9 years following the last translocation of toads (n = 1–5 egg strands deposited per year) and in 3 of 5 years in the second pond (n = 1–4 egg strands deposited per year). Both translocations were considered short-term successes. Between 1999 and 2017, 1964 Boreal Toads >55 mm SVL were PIT-tagged in the Grouse Creek Mountains, and recaptures were used to develop a growth curve that explained 79% of the size-age variability in this population. The growth curve will allow managers to reasonably identify age-1 and age-2 toads based on SVL and better evaluate Boreal Toad recruitment during population monitoring. Eight Boreal Toads were documented to have lived 11–16 years, and movements up to 7.6 km were documented across a relatively arid sagebrush/juniper landscape.

Northern Cedar Mountains Red Beds, Tooele County

Recent mapping for the Tooele 30' x 60' quadrangle geologic map revealed more information about interesting exposures of red beds cropping out in an 11-mile (18-km) swath along the northwestern flank of the Cedar Mountains (Clark and others, 2017, 2019 in review). They are unusual because such rocks are seldom preserved in northwestern Utah, an area known for thick thrust sheets of Paleozoic marine carbonate and sandstone. These rocks were first mapped by Robert Maurer for his Ph.D. dissertation on the geology of the Cedar Mountains (Maurer, 1970). He called them North Horn (?) Formation and noted the presence of fresh-water snails (Gyraulus sp.) that a paleontologist said were probably of late Paleocene or Eocene age. The North Horn Formation is considered Late Cretaceous (Maastrichtian age) to Paleocene or Eocene (~70 to 60 Ma) in age. However, recent detrital zircon analysis from sandstone in the unit suggest a much older age, with the youngest grains (maximum depositional age) of 117 Ma, or Early Cretaceous, Aptian (UGS and O’Sullivan, 2017). Two samples of gray mudstone taken for fossil pollen in the unit did not produce any usable material. Inspection of these rocks by Don DeBlieux (Utah Geological Survey paleontologist) revealed no bone or other biological material at this location.

Simulated and Observed Surface Energy Fluxes and Resulting Playa Breezes during the MATERHORN Field Campaigns

AbstractWeather Research and Forecasting (WRF) Model simulations of the autumn 2012 and spring 2013 Mountain Terrain Atmospheric Modeling and Observations Program (MATERHORN) field campaigns are validated against observations of components of the surface energy balance (SEB) collected over contrasting desert-shrub and playa land surfaces of the Great Salt Lake Desert in northwestern Utah. Over the desert shrub, a large underprediction of sensible heat flux and an overprediction of ground heat flux occurred during the autumn campaign when the model-analyzed soil moisture was considerably higher than the measured soil moisture. Simulations that incorporate in situ measurements of soil moisture into the land surface analyses and use a modified parameterization for soil thermal conductivity greatly reduce these errors over the desert shrub but exacerbate the overprediction of latent heat flux over the playa. The Noah land surface model coupled to WRF does not capture the many unusual playa land surface processes, and simulations that incorporate satellite-derived albedo and reduce the saturation vapor pressure over the playa only marginally improve the forecasts of the SEB components. Nevertheless, the forecast of the 2-m temperature difference between the playa and desert shrub improves, which increases the strength of the daytime off-playa breeze. The stronger off-playa breeze, however, does not substantially reduce the mean absolute errors in overall 10-m wind speed and direction. This work highlights some deficiencies of the Noah land surface model over two common arid land surfaces and demonstrates the importance of accurate land surface analyses over a dryland region.

Inter-seasonal movements in tri-state greater sage-grouse: implications for state-centric conservation plans

The U.S. Fish and Wildlife Service (USFWS) designated greater sage-grouse (Centrocercus urophasianus) as a candidate species to receive protection under the Endangered Species Act in 2010. Several states in the western United States have developed management plans to mitigate the listing factors identified by the USFWS. However, sage- grouse populations inhabit sagebrush (Artemisia spp.) ecosystems that may transcend multiple state boundaries. If sage-grouse inter-seasonal movements encompass habitats in multiple states and if state-centric wildlife management strategies differ, species conservation may be further complicated. Additionally, if these populations are located in peripheral state boundary areas, they may also receive less management focus both because of their remoteness and state agency emphasis on interior populations. The Grouse Creek sage- grouse population that inhabits extreme northwestern Utah where the state borders eastern Nevada and southern Idaho exemplifies this situation. We monitored 50 radio-collared sage- grouse from 2005 to 2006 to document inter-seasonal movements relative to sex and age and state boundaries. Radio-collared sage-grouse migrated an average of 13.1 km from breeding (range = 0.2 to 69.3, SE = 14.4) to summer range, 22.6 km from summer (range = 0.2 to 46.1, SE = 12.6) to winter range, and 25.4 km from winter (range = 1.1 to 37.2, SE = 13.4) to return to spring range. Ten radio-marked birds (20%) used seasonal habitats in Idaho, Nevada, and Utah. Males were more likely to engage in long-distance movements than females during the breeding season. We confirmed that within a geographically defined state population, individuals may exhibit diverse inter-seasonal migration strategies. Our results support the need for increased coordination among states that share occupied sagebrush habitats to develop interstate sage-grouse conservation plans.

Multiscale Characteristics of Surface Winds in an Area of Complex Terrain in Northwest Utah

AbstractClimatological features of the surface wind on diurnal and seasonal time scales over a 17-yr period in an area of complex terrain at Dugway Proving Ground in northwestern Utah are analyzed, and potential synoptic-scale, mesoscale, and microscale forcings on the surface wind are identified. Analysis of the wind climatology at 26 automated weather stations revealed a bimodal wind direction distribution at times when thermally driven circulations were expected to produce a single primary direction. The two modes of this distribution are referred to as the “northerly” and “southerly” regimes. The northerly regime is most frequent in May, and the southerly regime is most frequent in August. January, May, and August constitute a “tripole seasonality” of the wind evolution. Although both regimes occur in all months, the monthly changes in regime frequency are related to changes in synoptic and mesoscale phenomena including the climatological position of the primary synoptic baroclinic zone in the western United States, interaction of the large-scale flow with the Sierra Nevada, and thermal low pressure systems that form in the Intermountain West in summer. Numerous applications require accurate forecasts of surface winds in complex terrain, yet mesoscale models perform relatively poorly in these areas, contributing to poor operational forecast skill. Knowledge of the climatologically persistent wind flows and their potential forcings will enable relevant model deficiencies to be addressed.

Notice of release of Fanny germplasm, Carmel germplasm, and Bonneville germplasm Searls prairie clover: selected class of natural germplasm

Three natural-track selected germplasms of Searls’ prairie clover ( Dalea searlsiae (A. Gray) Barneby [Fabaceae]) have been released by the USDA’s Agricultural Research Service (ARS) for use in revegetation and restoration of semiarid rangelands in the western US. Searls’ prairie clover is a perennial leguminous forb that is native to Utah, Nevada, Arizona, and California. Data from common-garden and DNA-marker studies were used to develop and document these releases. The ARS Forage and Range Research Laboratory was asked by the USDI Bureau of Land Management (BLM) and Colorado Plateau land managers to identify genetically similar collections within geographical regions and to subsequently release germplasms of Searls’ prairie clover for the Great Basin (Fanny germplasm) and Colorado Plateau (Carmel germplasm). In addition, several collections originating from near the Great Salt Lake in northwestern Utah were genetically distinct from Fanny and Carmel germplasms. Thus, Bonneville germplasm was identified to represent this distinct genetic group. This species is new to the commercial seed trade, and these are the first releases of this species for rangeland improvement.

A Mesoscale Model-Based Climatography of Nocturnal Boundary-Layer Characteristics over the Complex Terrain of North-Western Utah.

Nocturnal boundary-layer phenomena in regions of complex topography are extremely diverse and respond to a multiplicity of forcing factors, acting primarily at the mesoscale and microscale. The interaction between different physical processes, e.g., drainage promoted by near-surface cooling and ambient flow over topography in a statically stable environment, may give rise to special flow patterns, uncommon over flat terrain. Here we present a climatography of boundary-layer flows, based on a 2-year archive of simulations from a high-resolution operational mesoscale weather modelling system, 4DWX. The geographical context is Dugway Proving Ground, in north-western Utah, USA, target area of the field campaigns of the MATERHORN (Mountain Terrain Atmospheric Modeling and Observations Program) project. The comparison between model fields and available observations in 2012–2014 shows that the 4DWX model system provides a realistic representation of wind speed and direction in the area, at least in an average sense. Regions displaying strong spatial gradients in the field variables, thought to be responsible for enhanced nocturnal mixing, are typically located in transition areas from mountain sidewalls to adjacent plains. A key dynamical process in this respect is the separation of dynamically accelerated downslope flows from the surface.

Transgressive stratigraphic record and possible oscillations of late Pleistocene Lake Bonneville, Northern Hogup Mountains, Utah, U.S.A.

Abstract Distinct, mappable facies changes make the stratigraphic record of the shorezone of late Pleistocene Lake Bonneville the most robust indicator for past lake level oscillations. Unfortunately, clear stratigraphic evidence of transgressive and regressive deposits has been generally lacking. New stratigraphic and chronological data within the lacustrine shorezone sediments of the Hogup Mountains of northwestern Utah provide some of the best evidence yet for oscillations within the overall transgressive phase of the lake. This study documents two previously unknown oscillations, hereby named the Lower Hogup (~ 22 cal ka) and Upper Hogup (~ 20.6 cal ka) oscillations and provides further evidence for the previously proposed U2 oscillation (~ 21.3 cal ka). The study suggests that the water level of the lake changed dramatically (up to 25% of the lake’s total volume) during the transgressive phase (~ 30–15 cal ka). With the additional oscillations documented in this study, there are seven proposed oscillatory events during the transgressive phase of the lake. These events likely correlate to rapid but short term regional climatic fluctuations during the broader climatic trends of the Last Glacial Maximum. However, it is still unknown what specific climatic drivers are causing these oscillations and if these events can be correlated to other global climatic events.

Widespread ingestion of lead pellets by wild chukars in Northwestern Utah

ABSTRACTThe use of lead ammunition has generated much debate because lead is toxic and elevated lead exposure is documented in >130 wildlife species. We expanded on prior reports of ingested lead in chukars (Alectoris chukar) to assess lead exposure at greater spatial and temporal extents. Our specific objectives concerning lead exposure in chukars from northwestern Utah, USA (approx. 49,000 km2) were to: 1) approximate a threshold for background versus elevated lead exposure; 2) investigate spatial and temporal variation of lead exposure; and 3) assess the utility of combining frequencies of ingested gizzard lead and elevated liver lead to estimate lead ingestion rates. We obtained hunter and volunteer‐harvested chukars collected during July–January, 2003–2011. Using liver lead residues from wild chukars, we estimated a threshold of 1 μg/g wet weight to separate background versus elevated lead exposure for our data set. For wild chukars, we documented elevated lead exposure (ingested gizzard lead or elevated liver lead) in 5 counties and 8 mountain ranges in years 2003–2007. We estimated lead ingestion rates of 9.3% (43 of 461) using ingested gizzard lead and 8.3% (10 of 121) employing elevated liver lead (≥1 μg/g wet weight), respectively. These frequencies were respectively 1.5% and 2.5% less than the combined frequency of ingested gizzard lead and elevated liver lead (10.8%; 52 of 481). Our observed rates of elevated lead exposure were among the highest in the literature for upland birds, suggesting that chukars in northwestern Utah risk lead poisoning. These results corroborate previous findings identifying elevated lead exposure as an issue affecting non waterfowl avian species. © 2015 The Wildlife Society.

Determinants of Habitat Selection by Desert Horned Lizards (Phrynosoma platyrhinos): The Importance of Abiotic Factors Associated with Vegetation Structure

Abstract The degree to which microhabitat elements such as shade from shrubs are used by lizards and the relative importance of such factors compared to others (e.g., prey availability) remains poorly understood. We examined habitat associations of Desert Horned Lizards (Phrynosoma platyrhinos) to evaluate the determinants of lizard occurrence using surveys along a shrub-steppe bajada in northwestern Utah. We then examined microhabitat preferences of lizards maintained in an experimental arena to explore further the potentially influential factors explaining habitat choice. Greater shrub cover, open understory, and greater cover by cryptobiotic soil crusts were the best predictors of lizard occurrence. While the role of soil crusts is unclear, these other factors may benefit lizards by providing open space for unhindered locomotion and opportunities for temperature regulation through sun/shade shuttling and burrowing. In contrast ants, a primary food source, did not appear to be a significant determinant ...

Similarities between the Th/U map of the western US crystalline basement and the seismic properties of the underlying lithosphere

In order to elucidate the nature and history of the different geological units in the western USA and correlate geochemical signatures with features identified in seismic models developed from USArray, we compiled from the literature Pb isotope compositions of ores, granitic K-feldspars, and felsic plutonic rocks and complemented the database by analyzing Pb isotopes for 82 felsic xenoliths and plutonic rocks from the Colorado Plateau and its immediate vicinity. The raw Pb isotope abundances for the complete data set were converted into model ages T (time of last U/Pb fractionation), 238U/204Pb (μ), and 232Th/238U (κ) with computed representative values for grid cells of 1°×1°. The model ages reflect the old formation ages in the Mojave and Yavapai blocks and the Archean Wyoming craton. Model ages are reset wherever the Moho is relatively shallow, most notably west of the Rocky Mountains, likely as a result of metamorphic reheating ± melting above the Pb closure temperature (∼550–650 °C). The κ values correlate with the uppermost mantle VP/VS ratio. High κ values are found in the Snake River basin and central Colorado. High κ values also form a ridge trending south from northwestern Utah through the Great Basin into the Mojave and Yavapai blocks. This ridge may represent exhumation of deep-seated rocks as a result of regional extension and collapse. Alternatively, it may signal the presence of igneous and metamorphic material associated with a channel of flowing crust originating beneath the Colorado Plateau and spreading north.

A Web-Based Resource for Investigating Environmental Change: The Emigrant Pass Observatory

ABSTRACT We present a user-friendly, data-driven Web site (http://thermal.gg.utah.edu/facilities/epo/) for a geothermal, climate change observatory that is educational for the general public, students, and researchers alike. The Emigrant Pass Observatory (EPO), located in the Grouse Creek Mountains in northwestern Utah, gathers both meteorological data (solar radiation, air temperature, rainfall, wind speed and direction, and snow depth) and subsurface temperatures in shallow drillholes. Our website has three main functions: (1) it provides a tutorial for understanding both local climate and climate change, and their relation to diffusion of temperatures into the Earth's subsurface; (2) it facilitates user-defined accessibility to download available climate data; and (3) it contains lesson ideas for using real data to understand local climate. EPO data and resources are ideal for active learning projects. Additionally, our collaboration with ongoing outreach projects (e.g., NSF-sponsored GK–12) in Utah promote the use and understanding of climate change data among students and educators, thus filling a valuable niche in local education.

Land-Use Legacies and Vegetation Recovery 90 Years After Cultivation in Great Basin Sagebrush Ecosystems

Agricultural land use is known to alter ecological processes, and native plant communities can require decades to centuries to recover from the disturbance of cultivation. ‘‘Recovery’’ is typically measured by comparison to undisturbed adjacent sites as a control. Recovery following cultivation in sagebrush ecosystems of the Great Basin remains largely unexamined even though nearly a half million hectares of land were dry-farmed and abandoned in the early 1900s. We tested the hypothesis that the native vegetation has not recovered from this exotic disturbance by evaluating differences in canopy cover of shrubs, grasses, and forbs between paired sets of historically dry-farmed land and adjacent never-cultivated areas. Paired sites were located in three ecological sites in northwestern Utah. We found that vegetation recovery from cultivation is variable by growth form, species, and ecological site. Shrub recovery was different among sagebrush (Artemisia) species. Yellow rabbitbrush (Chrysothamnus viscidiflorus [Hook.] Nutt.) and black greasewood (Sarcobatus vermiculatus [Hook.] Torr.), which often increase following disturbance, maintained higher cover inside old fields. At one of the paired sets, shrub composition was altered from a mix of four species to dominance of mainly Wyoming big sagebrush (Artemisia tridentata Nutt. subsp. wyomingensis Beetle & Young). Total forb cover was generally lower in cultivated areas and some species, such as spiny phlox (Phlox hoodii Richardson), had not recovered. The most common grass species encountered across all ecological sites, bottlebrush squirreltail (Elymus elymoides [Raf.] Swezey), had higher cover in cultivated areas. Surprisingly, exotic annual species, such as cheatgrass (Bromus tectorum L.), did not dominate these sites as they have for decades after cultivation in other areas of the Great Basin. This study demonstrates that the land-use legacy of dry farming on vegetation remains nearly a century after cultivation has ceased, and has direct implications for describing ecological site conditions.

Synthetic 3,5-Dimethyldodecanoic Acid Serves as a General Attractant for Multiple Species of Prionus (Coleoptera: Cerambycidae)

Abstract Males of the longhorned beetle Prionus californicus Motschulsky (Coleoptera: Cerambycidae) are significantly attracted to the female-produced sex pheromone (3R,5S)-3,5-dimethyldodecanoic acid. Males respond equally well to the synthetic blend of the four stereoisomers of 3,5-dimethyldodecanoic acid as to the single natural enantiomer, suggesting that the unnatural isomers are not inhibitory. Males of the congener Prionus lecontei Lameere also are attracted to the (3R,5S)-enantiomer but not to the (3S,5R)-enantiomer, suggesting that the (3R,5S)-enantiomer is also an important pheromone component of that species. Here, we report the results of field trials that test the hypothesis that synthetic 3,5-dimethyldodecanoic acid will serve as a general attractant for males of other Prionus species. We conducted field bioassays of synthetic 3,5-dimethyldodecanoic acid at study sites in six different regions of North America and one site in the United Kingdom. Traps baited with the synthetic pheromone blend captured males of P.californicus (southwestern Idaho, southern California, and northwestern Utah), P. lecontei (southern California and northwestern Utah), and six additional species of Prionus: Prionus integer LeConte (southwestern Idaho), Prionus imbricornis (L.) (Georgia), Prionus laticollis (Drury) (Georgia), Prionus linsleyi Hovore (north central Arizona), Prionus aztecus Casey (northern Mexico), and Prionus coriarius (L.) (East Anglia, United Kingdom). These findings demonstrate that synthetic 3,5-dimethyldodecanoic acid can be used to assess the geographic distribution and local abundance of many Prionus species and therefore may be of value for monitoring threatened and endangered species of this genus, and for managing those that are pests.

Searls Prairie Clover (Dalea searlsiae) for Rangeland Revegetation: Phenotypic and Genetic Evaluations

ABSTRACTFew North American legumes are available for use in rangeland revegetation in the western USA, but Searls prairie clover [Dalea searlsiae (A. Gray) Barneby] is one that holds promise. Commercial‐scale seed production of this species could address the issues of unreliable seed availability and high seed costs associated with its wildland seed collection. To evaluate its utility for revegetation, we collected Searls prairie clover at 20 locations across Utah and Nevada. Amplified fragment length polymorphisms (AFLP) and morphological and phenotypic traits (measured in common‐garden plots) were used to clarify the role of evolutionary forces responsible for its genetic structure. Collections were evaluated for dry‐matter yield, inflorescence weight, number of inflorescences, plant height, foliage diameter, flowering date, acid‐detergent fiber, neutral‐detergent fiber, and crude protein at two common‐garden locations in northern Utah. Collections from southern Utah and eastern Nevada exhibited high phenotypic values, whereas collections from western Nevada and northwestern Utah had low phenotypic values. Collections from northwestern Utah were genetically differentiated from those of southern Utah and Nevada via AFLP markers. Strong isolation by distance between collections suggests that genetic drift and gene flow are important factors in determining population structure in Searls prairie clover.