Southern Colorado Research Articles

Nest Site Selection Influences Cinnamon Teal Nest Survival in Colorado

ABSTRACTNest survival of ducks is partially a function of the spatiotemporal characteristics of the site at which a bird chooses to nest. Nest survival is also a fundamental component of population growth in waterfowl but is relatively unstudied for cinnamon teal (Spatula cyanoptera). We investigated cinnamon teal nest survival in a managed wetland complex in southern Colorado, USA, and assessed nest site selection to determine whether nest site characteristics were adaptive. We monitored 85 nests in 2015–2017 on Monte Vista National Wildlife Refuge, Colorado and did not detect a difference in nest survival across years. Based on nest site selection data from 2017, cinnamon teal selected nest sites characterized by a lower proportion of forbs than available sites. The relationships between habitat characteristics and nest survival were variable. Microhabitat characteristics exhibited only weak effects on nest survival during the laying stage. Nest survival during incubation was negatively related to the proportion of forbs at the nest site and, to a lesser extent, the proportion of grasses. Nest site selection was predictive of future nest survival based on the percent of forbs and grasses around the nest site, suggesting teal select nest locations to benefit reproductive success. These results have the potential to guide local habitat management actions for breeding waterfowl. © 2020 The Wildlife Society.

Balancing the Scales: Harmonizing Heritage Management, Site-Specific Research, and the Mitigation of Adverse Effects

The Southern Colorado River Basin context published in 1999 offered a remarkable overview of Mesa Verde regional archaeology. It reviewed the available research for each main period of occupation and, at the end of each summary, outlined some of the most important questions for future research. For the late Basketmaker and early Pueblo periods many of those research questions have been addressed or are now outdated. Current questions are not just about research, but also about how to balance long-term heritage management goals with site-specific research. The accelerating loss of cultural landscape to irrigated fields, energy development, and the expansion of country homes requires us to both broaden the scope of our preservation planning and the scale of our research questions to the landscape level. In this review I propose changes to the extent and nature of the Southern Colorado River Basin context area, as well as offer amendments to the previous period chronologies based on what we have learned. Lastly, I suggest an array of research themes for future work. Although this is not a state-approved context, it is offered as a challenge to us—whether we represent the state, a federal agency, a university, or a CRM firm—to think big about the research we do in the greater Mesa Verde region.

Limitations to recovery following wildfire in dry forests of southern Colorado and northern New Mexico, USA.

Climate warming is contributing to increases in wildfire activity throughout the western United States, leading to potentially long-lasting shifts in vegetation. The response of forest ecosystems to wildfire is thus a crucial indicator of future vegetation trajectories, and these responses are contingent upon factors such as seed availability, interannual climate variability, average climate, and other components of the physical environment. To better understand variation in resilience to wildfire across vulnerable dry forests, we surveyed conifer seedling densities in 15 recent (1988-2010) wildfires and characterized temporal variation in seed cone production and seedling establishment. We then predicted postfire seedling densities at a 30-m resolution within each fire perimeter using downscaled climate data, monthly water balance models, and maps of surviving forest cover. Widespread ponderosa pine (Pinus ponderosa) seed cone production occurred at least twice following each fire surveyed, and pulses of conifer seedling establishment coincided with years of above-average moisture availability. Ponderosa pine and Douglas-fir (Pseudotsuga menziesii) seedling densities were higher on more mesic sites and adjacent to surviving trees, though there were also important interspecific differences, likely attributable to drought and shade tolerance. We estimated that postfire seedling densities in 42% (for ponderosa pine) and 69% (for Douglas-fir) of the total burned area were below the lowest reported historical tree densities in these forests. Spatial models demonstrated that an absence of mature conifers (particularly in the interior of large, high-severity patches) limited seedling densities in many areas, but 30-yr average actual evapotranspiration and climatic water deficit limited densities on marginal sites. A better understanding of the limitations to postfire forest recovery will refine models of vegetation dynamics and will help to improve strategies of adaptation to a warming climate and shifting fire activity.

Magmato-tectonic links: Ignimbrite calderas, regional dike swarms, and the transition from arc to rift in the Southern Rocky Mountains

AbstractRadial and linear dike swarms in the eroded roots of volcanoes and along rift zones are sensitive structural indicators of conduit and eruption geometry that can record regional paleostress orientations. Compositionally diverse dikes and larger intrusions that radiate westward from the polycyclic Platoro caldera complex in the Southern Rocky Mountain volcanic field (southwestern United States) merge in structural trend, composition, and age with the enormous but little-studied Dulce swarm of trachybasaltic dikes that continue southwest and south for ∼125 km along the eastern margin of the Colorado Plateau from southern Colorado into northern New Mexico. Some Dulce dikes, though only 1–2 m thick, are traceable for 20 km. More than 200 dikes of the Platoro-Dulce swarm are depicted on regional maps, but only a few compositions and ages have been published previously, and relations to Platoro caldera have not been evaluated. Despite complications from deuteric alteration, bulk compositions of Platoro-Dulce dikes (105 new X-ray fluorescence and inductively coupled plasma mass spectrometry analyses) become more mafic and alkalic with distance from the caldera. Fifty-eight (58) new 40Ar/39Ar ages provide insight into the timing of dike emplacement in relation to evolution of Platoro caldera (source of six regional ignimbrites between 30.3 and 28.8 Ma). The majority of Dulce dikes were emplaced during a brief period (26.5–25.0 Ma) of postcaldera magmatism. Some northeast-trending dikes yield ages as old as 27.5 Ma, and the northernmost north-trending dikes have younger ages (20.1–18.6 Ma). In contrast to high-K lamprophyres farther west on the Colorado Plateau, the Dulce dikes are trachybasalts that contain only anhydrous phenocrysts (clinopyroxene, olivine). Dikes radial to Platoro caldera range from pyroxene- and hornblende-bearing andesite to sanidine dacite, mostly more silicic than trachybasalts of the Dulce swarm. Some distal andesite dikes have ages (31.2–30.4 Ma) similar to those of late precaldera lavas; ages of other proximal dikes (29.2–27.5 Ma) are akin to those of caldera-filling lavas and the oldest Dulce dikes. The largest radial dikes are dacites that have yet younger sanidine 40Ar/39Ar ages (26.5–26.4 Ma), similar to those of the main Dulce swarm.The older andesitic dikes and precaldera lavas record the inception of a long-lived upper-crustal magmatic locus at Platoro. This system peaked in magmatic output during ignimbrite eruptions but remained intermittently active for at least an additional 9 m.y. Platoro magmatism began to decline at ca. 26 Ma, concurrent with initial basaltic volcanism and regional extension along the Rio Grande rift, but no basalt is known to have erupted proximal to Platoro caldera prior to ca. 20 Ma, just as silicic activity terminated at this magmatic locus. The large numbers and lengths of the radial andesitic-dacitic dikes, in comparison to the absence of similar features at other calderas of the San Juan volcanic locus, may reflect location of the Platoro system peripheral to the main upper-crustal San Juan batholith recorded by gravity data, as well as its proximity to the axis of early rifting. Spatial, temporal, and genetic links between Platoro radial dikes and the linear Dulce swarm suggest that they represent an interconnected regional-scale magmatic suite related to prolonged assembly and solidification of an arc-related subcaldera batholith concurrently with a transition to regional extension. Emplacement of such widespread dikes during the late evolution of a subcaldera batholith could generate earthquakes and trigger dispersed small eruptions. Such events would constitute little-appreciated magmato-tectonic hazards near dormant calderas such as Valles, Long Valley, or Yellowstone (western USA).

Effects of a Nutrition Program on School Cafeteria Lunch: An Expanded Commentary.

The aim of this commentary is to expand upon results of previously published work on improving nutrition of cafeteria lunches in elementary schools of a high-need school district in southern Colorado, USA, between 2009 and 2015. The intent of the program was to improve the quality of school lunches by training cafeteria staff to prepare meals from scratch using fresh produce and minimally processed proteins as well as to reduce the sodium, sugar, and fat content of the food prepared. The program was successful in improving the quality and nutritional content of school lunch entrees by providing more entrees made from scratch with fresher options and decreasing the amount of processed foods served. This study shows that interventions aimed at changing the food preparation policies of school cafeterias can improve the nutrition of school lunches, and future research should expand on the benefits schools may experience by investing in similar programs.

Protracted magmatism and magnetization around the McClure Mountain alkaline igneous complex

AbstractThe McClure Mountain–Iron Mountain igneous complex is an alkalic intrusive center in the northern Wet Mountains of southern Colorado. It was emplaced in early Cambrian time into gneissic/granitic 1.75–1.45 Ga Proterozoic host rocks. Numerous dikes are associated with the complex, primarily along the western side. Although the main intrusive nepheline-syenite body is well dated, the ages of the surrounding dikes are poorly known. Crosscutting relationships and poorly defined K-Ar dates suggest that the dikes are younger than the main intrusion. Paleomagnetic samples were collected from dikes associated with the McClure Mountain igneous complex. Geochronologic samples were also collected from two dikes sampled for their paleomagnetism. We obtained U-Pb zircon ages of 526 ± 8 Ma for a lamprophyric extracomplex dike and 483 ± 2 Ma for a trachytic extracomplex dike. These ages suggest either multistage or protracted dike intrusion around the ca. 524 Ma McClure Mountain complex. Our paleomagnetic data are consistent with previously published results. Dikes of the complex primarily exhibit southeast and shallow paleomagnetic directions, with variable declinations. Results from several baked contact tests indicate that the magnetizations are secondary. A steeply inclined magnetization is pervasive and was acquired over a protracted interval from late Laramide time to the present day.

The Sustainable Harvest of Wild Populations of Oshá (Ligusticum porteri) in Southern Colorado for the Herbal Products Trade

It is a challenge to both use and conserve wild-harvested medicinal plants, especially when it appears they may be threatened by harvest pressure, and there is often limited biological information available to inform management decisions. Osha (Ligusticum porteri) is an important medicinal plant whose roots are harvested in the southwest USA and Mexico as an herbal remedy to treat flu, sore throat, and other illnesses. We studied population structure, root production, and the ability of osha to recover from harvest in different environmental contexts at two high-elevation southern Colorado sites with a goal of understanding what a sustainable rate of harvest might be. We experimentally harvested roots of mature osha plants at four different rates. Results indicate that low rates of harvest allow for stable osha populations over the short term (3–5 year) at our sites. Due to management interest by the USDA Forest Service, we propose a possible sustainable harvest rate of 50% of mature plants every 10 years. Given variability due to weather and other environmental factors, we recommend that future osha harvest should be planned and adjusted after careful monitoring.

Establishment of Salsola tragus on aeolian sands: A Southern Colorado Plateau case study

AbstractRussian-thistle (Salsola tragus L.), is a nonnative, C4 photosynthesizing, annual plant that infests disturbed and natural areas in the arid U.S. Southwest. Land managers of natural areas may need to decide whether a S. tragus infestation is potentially harmful and whether it should be actively managed. One factor informing that decision is an understanding of the conditions under which this weed emerges and establishes and how those processes affect where and when infestations occur. We studied S. tragus establishment on aeolian (windblown) sandy soils at Petrified Forest National Park, AZ. Our sites were a previously disturbed sand sheet and a semistabilized sand dune. Measurements in plots on these sites over two growing seasons revealed a similar number of S. tragus seedlings emerging on both sites early in the 2015 growing season. As the season progressed, S. tragus cover (seedling survival and growth) was lower on the sand dune, except for a plot placed entirely on a coppice mound. In 2016, S. tragus seedling emergence and development of cover, measured on plots at both sites, was exceptionally low, as was summer rainfall. A growth chamber assay of seedling emergence from soil and litter samples collected at each site showed emergence was greatest from samples collected where S. tragus litter remained on the soil surface, and otherwise was infrequent. Our study suggests that S. tragus emergence and early establishment are sensitive to low precipitation and that soil-surface microtopography and grass and shrub cover may be determinants of the spatial pattern of infestation on sandy soils. As aeolian sands occur throughout drylands of the U.S. Southwest, deeper understanding of the conditions under which S. tragus seedlings emerge and establish can inform management of this invasive annual in those habitats.

A Cautionary Tale: Discriminatory Lending against Hispanic Farmers and Ranchers in Southern Colorado

AbstractDespite legal and civil emancipation, minorities in the United States continue to face extremely unequal opportunity structures in the financial realm. Evidence of this is found in the fact that segregation between Anglos and minorities has changed little since the civil rights era. This is particularly true for Hispanics, who have actually witnessed an increase in segregation in recent years. Although many factors have contributed to this outcome, unequal access to financial credit has played a particularly important role in maintaining the status quo between Hispanics and Anglos. In this article, I analyze the lasting impact of discriminatory lending within Hispanic communities in southern Colorado. I examine how unfavorable access to credit has contributed to wealth disparities in this region. My results demonstrate that lenders systematically denied Hispanic farmers and ranchers access to subsidized loans throughout the twentieth century. The lack of access to formal banking, the underappreciation of homes and land, and the deliberate isolation of Hispanics from formal institutions forced many Hispanic families to leave the area altogether. Ultimately, unequal access to credit has fostered deep inequalities between Anglos and Hispanics in the region, which, in turn, has reinforced ethnic tension between these two groups.

Stable isotope ratios and speleothem chronology from a high-elevation alpine cave, southern San Juan Mountains, Colorado (USA): Evidence for substantial deglaciation as early as 13.5 ka

Deglaciation ages for valley glaciers from the last glacial maximum are difficult to obtain with precision. The unequal or non-uniform loss of glacial ice cover (spatial heterogeneity) during glacial retreat results in exposure of considerable land surface area prior to complete deglaciation. New U-series dates from an 11cm long stalagmite in a shallow, high elevation (3242 m) cave in the southern San Juan Mountains of southwestern Colorado (USA), indicate that substantial, high-elevation glacial ice ablation occurred prior to 13.5 ka. The stalagmite dates compare well with other deglaciation studies in central and southern Colorado that show deglaciation occurred between ca. 13 ka to 15 ka. Low δ¹³C values from 13.5 ka speleothem growth bands, relative to the δ¹³C value of the host carbonate, suggest that alpine plant and soil cover was established at this location, aspect, and elevation prior to 13.5 ka. Calcite luminescence in the 13.5 ka growth bands indicates the presence of humic and fulvic acids released by the roots of living plants and decomposition of vegetative matter. The carbon isotope ratios, calcite luminescence, and U-series dates suggest that the southern San Juan Mountains, at this high elevation site and southern aspect were substantially ice-free prior to 13.5 ka.

El "continuum" oralidad-“literacidad” en entornos biculturales y bilingües: el gallego y el español nuevo mexicano tradicional

In the Iberian Peninsula, Galician, a language spoken in Northwest Spain that, after reaching a high point of development as a written language in the Middle Ages, survived as a mostly oral language for centuries, finds itself today looking for a standard variety that would help it survive and define its own space between Portuguese and Castilian Spanish. In the United States, Traditional New Mexican Spanish (TNMS), a variety of Spanish associated with New Mexico and Southern Colorado and recognized as the oldest known variety of Spanish in the Americas, is about to disappear, or has already disappeared, immersed within different linguistic varieties and standard forms of Spanish and English. Both Galician and TNMS have historically gone through stages of literacy and orality. With the goal to examine the relationship between cultural and linguistic identity as it relates to the orality-literacy continuum, this article shares preliminary results of a research project in progress that includes a comparative look at the socio-linguistic situations of Galician in Spain and Traditional New Mexican Spanish in the US.

An introduced plant affects aquatic-derived carbon in the diets of riparian birds.

Non-native plants can impact riparian ecosystem function through diverse terrestrial and aquatic pathways, with cascading effects on food webs. Invasion-mediated vegetation changes can depress terrestrial arthropod communities and alter arthropod flux across the aquatic-terrestrial interface. We investigated the effects of a non-native woody plant, Robinia neomexicana, on insect contributions to riparian songbird diets. This plant was introduced over 100 years ago to the Clear Creek drainage in northwestern Colorado (USA) from its native range, which extends into southern Colorado. We used stable isotope analysis of insects and avian feces to 1) assess whether the relative contributions of aquatic- and terrestrial-derived arthropod prey differed between reference sites and sites invaded by R. neomexicana, and 2) quantify the amount of aquatic- and terrestrial-derived resources consumed by an insectivorous songbird assemblage. Two species of insectivorous songbirds consumed more aquatic insects in invaded sites compared to reference sites. This change in terrestrial- and aquatic-derived prey in bird diets in response to a near-range plant invasion suggests that the introduction of novel species from more distant native ranges could produce similar or stronger effects. Overall, the songbird community consumed approximately 34% aquatic resources, which highlights the importance of these subsidies to riparian consumers. Our investigation of insect subsidies demonstrates how introduced species can indirectly affect food webs and provides insight into the plasticity of riparian consumer responses.

Increasing temperature seasonality may overwhelm shifts in soil moisture to favor shrub over grass dominance in Colorado Plateau drylands.

Ecosystems in the southwestern U.S. are predicted to experience continued warming and drying trends of the early twenty-first century. Climate change can shift the balance between grass and woody plant abundance in these water-limited systems, which has large implications for biodiversity and ecosystem processes. However, variability in topo-edaphic conditions, notably soil texture and depth, confound efforts to quantify specific climatic controls over grass vs. shrub dominance. Here, we utilized weather records and a mechanistic soil water model to identify the timing and depth at which soil moisture related most strongly to the balance between grass and shrub dominance in the southern Colorado Plateau. Shrubs dominate where there is high soil moisture availability during winter, and where temperature is more seasonally variable, while grasses are favored where moisture is available during summer. Climate change projections indicate consistent increases in mean temperature and seasonal temperature variability for all sites, but predictions for summer and winter soil moisture vary across sites. Together, these changes in temperature and soil moisture are expected to shift the balance towards increasing shrub dominance across the region. These patterns are strongly driven by changes in temperature, which either enhance or overwhelm effects of changes in soil moisture across sites. This approach, which incorporates local, edaphic factors at sites protected from disturbance, improves understanding of climate change impacts on grass vs. shrub abundance and may be useful in other dryland regions with high edaphic and climatic heterogeneity.

Intermarriage, Technological Diffusion, and Boundary Objects in the U.S. Southwest

This article draws upon ethnographic accounts of female potters’ movement and intermarriage into multi-ethnic Pueblo communities in the U.S. Southwest to illustrate how marriage networks created opportunities for innovation through the production, distribution, and consumption of boundary objects. These objects did not define boundaries but facilitated boundary crossing or bridging by potters. I argue that the concept of boundary objects is more useful than hybridity for understanding the processes of culture contact and material culture diffusion. Archaeological evidence for late twelfth through thirteenth century migrations from the Four Corners to the southern Colorado Plateau is used to make a case for a high degree of intermarriage and post-marital movement of women. Such patrilocality challenges normative views of post-marital residence, including those employed by early ceramic sociologists working in the same area of the Southwest and even at the same sites. The case that I discuss provides a contrast to other Southwest examples in which conformist transmission was more common, and helps to solve a paradox in explanations of the Southwest Pueblo Sprachbund. I conclude that the concept of boundary objects complements formal social network approaches in archaeology by bringing out the active role of objects in linking social actors.

Using Teleneurology to Deliver Chronic Neurologic Care to Rural Veterans: Analysis of the First 1,100 Patient Visits.

A challenge confronting the United States is delivery of quality specialty healthcare to citizens living in rural areas. The Veterans Administration (VA) developed a large national telehealth network to address 5.2 million rural veterans. New Mexico's Albuquerque VA Neurology Service developed a teleneurology program for their rural veterans. This article analyzes our first 1,100 teleneurology patient visits. Veterans living in remote areas of New Mexico, southern Colorado, eastern Arizona, and western Texas were offered follow-up teleneurology care at 16 rural VA community-based outpatient clinics (CBOCs) following an initial evaluation at the Albuquerque VA neurology outpatient clinic. Surveys were sent after all teleneurology visits focused on quality of care, ease of communication, satisfaction, and staff's ability to deliver same quality care as in person. Problems encountered, differences between face-to-face clinics and teleneurology, and cost savings were examined. Regarding the 701 (64%) returned surveys, we found 90% perceived they received good care, 91% felt there was good communication, 88% liked the convenience, and 87% reported they desired to continue teleneurology care. Ninety-six percent reported saving time, money, or both through CBOC visits instead of driving to Albuquerque. All providers felt that they could deliver excellent care through teleneurology. We found emergency room visits for neurologic problems was similar for both groups. Our rural veteran patients and neurology staff overwhelmingly found high quality patient care can be delivered via teleneurology for a variety of chronic neurologic problems and was comparable to care delivered in neurology face-to-face clinics.

Multiphysics data modeling and imaging for exploration in the southern Rocky Mountains

We carried out a multidata geophysics study in southern Colorado to explore for [Formula: see text] reservoirs in an area where seismic imaging is very limited due to the mountainous terrain, the presence of high-velocity volcanic rocks, and difficulty in obtaining land access permits. We have developed a modeling/interpretation methodology using ground magnetotelluric data as well as airborne magnetic and electromagnetic data combined with public domain gravity data and existing well and seismic data. We used the integration of these data sets to produce a series of 2D and 3D geophysical models that reveal basin architecture previously poorly defined through the analysis of limited seismic and well data alone. We found that this type of analysis aids in decreasing uncertainty in the interpreted geologic cross sections and a better understanding of the structural complexities of the region. Through the application of machine learning methods, we are also able to integrate several data sets into a mathematical framework resulting in a predictive model of spatial [Formula: see text] distribution. The integration of the interpretations from all data sets, predictive analytics results, and knowledge of [Formula: see text] production, allows us to delineate areas of interest for further exploration.

The Upper Jurassic Morrison Formation in north-central New Mexico–Linking Colorado Plateau stratigraphy to the stratigraphy of the High Plains

Most study of the Upper Jurassic Morrison Formation has focused on its spectacular and extensive outcrops on the southern Colorado Plateau. Nevertheless, outcrops of the Morrison Formation extend far off the Colorado Plateau, onto the southern High Plains as far east as western Oklahoma. Outcrops of the Morrison Formation east of and along the eastern flank of the Rio Grande rift in north-central New Mexico (Sandoval, Bernalillo, and San­ta Fe Counties) are geographically intermediate between the Morrison Formation outcrops on the southeastern Colorado Plateau in northwestern New Mexico and on the southern High Plains of eastern New Mexico. Previous lithostratigraphic correlations between the Colorado Plateau and High Plains Morrison Formation outcrops using the north-central New Mexico sections encompassed a geographic gap in outcrop data of about 100 km. New data on previously unstudied Morrison Formation outcrops at Placitas in Sandoval County and south of Lamy in Santa Fe County reduce that gap and significantly add to stratigraphic coverage. At Placitas, the Morrison Formation is about 141 m thick, in the Lamy area it is about 232 m thick, and, at both locations, it consists of the (ascending) sandstone-dominated Salt Wash Member, mudstone-dominated Brushy Basin Member, and sandstone-dominat­ed Jackpile Member. Correlation of Morrison strata across northern New Mexico documents the continuity of the Morrison depositional systems from the Colorado Plateau eastward onto the southern High Plains. Along this transect, there is significant stratigraphic relief on the base of the Salt Wash Member (J-5 unconformity), the base of the Jackpile Member, and the base of the Cretaceous strata that overlie the Morrison Formation (K unconfor­mity). Salt Wash Member deposition was generally by easterly-flowing rivers, and this river system continued well east of the Colorado Plateau. The continuity of the Brushy Basin Member, and its characteristic zeolite-rich clay facies, onto the High Plains suggests that localized depositional models (e.g., “Lake T’oo’dichi’) need to be re-eval­uated. Instead, envisioning Brushy Basin Member deposition on a vast muddy floodplain, with some localized lacustrine and palustrine depocenters, better interprets its distribution and facies.

Mapping Progression and Severity of a Southern Colorado Spruce Beetle Outbreak Using Calibrated Image Composites

An ongoing spruce beetle (Dendroctonus rufipennis Kirby.) epidemic in southern Colorado has resulted in the death of thousands of acres of forests primarily dominated by Engelmann spruce (Picea engelmannii Parry.). To evaluate the ecological and economic impacts of this massive mortality event, researchers and land managers need to efficiently track its progression, spread, and severity across large spatial extents. In this study, mortality severity (0–100% dead) was successfully mapped at the Landsat pixel scale (30 × 30 m) across a large (5000 km2), persistently cloud-covered study area using multi-sensor (Landsat 5 Thematic Mapper (TM), Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and Landsat 8 Operational Land Imager (OLI)) harmonized tasseled cap image composites as spectral predictors of gray stage spruce beetle mortality. Our maps display the distribution and severity of this landscape-scale mortality event in 2011 (R2 = 0.48, root mean squared error (RMSE) = 7.7) and 2015 (R2 = 0.55, RMSE = 11.6). Potential applications of this study include efficient landscape-scale forest health monitoring, targeted forest and timber management, and assessment of ecological impacts of bark beetle outbreaks.

Identification of circular single-stranded DNA viruses in faecal samples of Canada lynx (Lynx canadensis), moose (Alces alces) and snowshoe hare (Lepus americanus) inhabiting the Colorado San Juan Mountains

The San Juan Mountains of southern Colorado provide subalpine habitat for a suite of mammalian species including Canada lynx (Lynx canadensis), moose (Alces alces) and snowshoe hare (Lepus americanus). In the winter field season of 2016 five faecal samples from lynx, and one each from moose and snowshoe hare were collected to identify small single-stranded DNA viruses associated with these three prominent species. Thirty-two novel viruses were identified and classified as members of two well established ssDNA families Genomoviridae (n = 22) and Microviridae (n = 10) and one recently proposed new family, Smacoviridae (n = 1). In addition one highly novel circular ssDNA virus was identified which at present does not group with any known family. A high level of genomovirus diversity was identified from faeces collected between and across the three mammal species, with full genome-wide pairwise comparisons showing 57%–97% identity. Twenty genomoviruses can be assigned to the genus Gemycircularvirus and represent 11 species, and two into a distinct species in the genus Gemykolovirus. The single smacovirus identified from moose also represents a distinct smacovirus species. Ten microviruses, seven from moose, one from snowshoe hare and two from lynx, all are part of the Gokushovirinae subfamily. The two from lynx are highly similar to a microvirus previously detected in domestic cat (sharing 88%–90% genome-wide identity), indicating this may be a common felid gut microbiome associated virus. Our findings highlight the broad range of diverse ssDNA viruses present in three mammals inhabiting the San Juan Mountains.

The Upper Jurassic Morrison Formation in north-central New Mexico–Linking Colorado Plateau stratigraphy to the stratigraphy of the High Plains

Most study of the Upper Jurassic Morrison Formation has focused on its spectacular and extensive outcrops on the southern Colorado Plateau. Nevertheless, outcrops of the Morrison Formation extend far off the Colorado Plateau, onto the southern High Plains as far east as western Oklahoma. Outcrops of the Morrison Formation east of and along the eastern flank of the Rio Grande rift in north-central New Mexico (Sandoval, Bernalillo, and San­ta Fe Counties) are geographically intermediate between the Morrison Formation outcrops on the southeastern Colorado Plateau in northwestern New Mexico and on the southern High Plains of eastern New Mexico. Previous lithostratigraphic correlations between the Colorado Plateau and High Plains Morrison Formation outcrops using the north-central New Mexico sections encompassed a geographic gap in outcrop data of about 100 km. New data on previously unstudied Morrison Formation outcrops at Placitas in Sandoval County and south of Lamy in Santa Fe County reduce that gap and significantly add to stratigraphic coverage. At Placitas, the Morrison Formation is about 141 m thick, in the Lamy area it is about 232 m thick, and, at both locations, it consists of the (ascending) sandstone-dominated Salt Wash Member, mudstone-dominated Brushy Basin Member, and sandstone-dominat­ed Jackpile Member. Correlation of Morrison strata across northern New Mexico documents the continuity of the Morrison depositional systems from the Colorado Plateau eastward onto the southern High Plains. Along this transect, there is significant stratigraphic relief on the base of the Salt Wash Member (J-5 unconformity), the base of the Jackpile Member, and the base of the Cretaceous strata that overlie the Morrison Formation (K unconfor­mity). Salt Wash Member deposition was generally by easterly-flowing rivers, and this river system continued well east of the Colorado Plateau. The continuity of the Brushy Basin Member, and its characteristic zeolite-rich clay facies, onto the High Plains suggests that localized depositional models (e.g., “Lake T’oo’dichi’) need to be re-eval­uated. Instead, envisioning Brushy Basin Member deposition on a vast muddy floodplain, with some localized lacustrine and palustrine depocenters, better interprets its distribution and facies.