Rocky Mountain National Park Research Articles

Serological Survey for Antibodies to Mosquito-Borne Bunyaviruses Among US National Park Service and US Forest Service Employees

Serum samples from 295 employees of Great Smoky Mountains National Park (GRSM), Rocky Mountain National Park (ROMO), and Grand Teton National Park with adjacent Bridger-Teton National Forest (GRTE-BTNF) were subjected to serological analysis for mosquito-borne bunyaviruses. The sera were analyzed for neutralizing antibodies against six orthobunyaviruses: La Crosse virus (LACV), Jamestown Canyon virus (JCV), snowshoe hare virus (SSHV), California encephalitis virus, and Trivittatus virus (TVTV) belonging to the California serogroup and Cache Valley virus (CVV) belonging to the Bunyamwera serogroup. Sera were also tested for immunoglobulin (Ig) G antibodies against LACV and JCV by enzyme-linked immunosorbent assay (ELISA). The proportion of employees with neutralizing antibodies to any California serogroup bunyavirus was similar in all three sites, with the prevalence ranging from 28% to 36%. The study demonstrated a seroprevalence of 3% to CVV across the three parks. However, proportions of persons with antibodies to specific viruses differed between parks. Participants residing in the eastern regions had a higher seroprevalence to LACV, with 24% (18/75) GRSM employees being seropositive. In contrast, SSHV seroprevalence was limited to employees from the western sites, with 1.7% (1/60) ROMO and 3.8% (6/160) GRTE-BTNF employees being positive. Seroprevalence to JCV was noted in employees from all sites at rates of 6.7% in GRSM, 21.7% in ROMO, and 15.6% in GRTE-BTNF. One employee each from ROMO (1.7%) and GRTE-BTNF (1.9%) were positive for TVTV. This study also has illustrated the greater sensitivity and specificity of plaque reduction neutralization test compared to IgG ELISA in conducting serosurveys for LACV and JCV.

Trail impact monitoring in Rocky Mountain National Park, USA

Abstract. This paper examines impacts of increased visitation leading to human trampling of vegetation and soil along several trails in Rocky Mountain National Park (RMNP) to understand how abiotic factors and level of use can influence trail conditions. RMNP is one of the most visited national parks in the USA, with 3.3 million visitors in 2012 across 1075 km2 and 571 km of hiking trails. 95 % of the park is designated wilderness, making the balance between preservation and visitor use challenging. This research involves the application of trail condition assessments to 56 km of trails to determine prevailing factors and what, if any, connection between them exist. The study looked at a variety of inventory and impact indicators and standards to determine their importance and to develop a baseline condition of trails. The data can be used for future comparison and evaluation of development trends. We found that trail widening (mean trail width 88.9 cm) and soil loss (cross-sectional area 172.7 cm2) are the most visible effects of trail degradation. Further statistical analyses of data identified the role and influence of various factors (e.g., use level and topography). Insights into the influence of these factors can lead to the selection of appropriate management measures to avoid or minimize negative consequences from increased visitation.

Traffic Safety Along Tourist Routes in Rural Areas

Little is known about the safety of tourist drivers in the United States. Most domestic studies have focused on traffic deaths and injuries of U.S. citizens traveling abroad and cite factors such as driving on the left, lack of seat belt use, and alcohol consumption. U.S. states that have a number of tourist attractions and the roadways to reach them may be interested in whether traffic safety is problematic for drivers who are tourists. To that end, this research investigated the contributing factors for crash severity and crash likelihood of visiting drivers in or near three national parks in rural areas. Driver-level data from the Rocky Mountain National Park in Colorado and the Sequoia and Kings Canyon National Parks in California revealed risk factors for crash severity, including age, geometry, and seat belt use. The second data set offered a more microscopic view at the road level and was used to anticipate crash frequency of visiting drivers at the road link level. Moreover, the second data set contained road geometry, traffic volume, environment, and crash counts aggregated at the segment level along a 57.8-mi stretch of U.S. Hwy 89 (a primary route to the north gate of Yellowstone National Park) in Montana that is frequently used by tourists. Crash risk factors (e.g., geometry and traffic intensity) affected local and nonlocal (tourist) drivers in different ways. Further exploration of crash trends in specific parks would be valuable in understanding the overall trends and contributors to crashes in tourism areas and to determine effective improvement measures.

Relationships between vegetation type, peat hydraulic conductivity, and water table dynamics in mountain fens

AbstractThe ecohydrologic function of fens is characterized by feedbacks between biological and hydrologic processes. Vegetation composition is one important factor that is both responsive to the site hydrologic regime and, by providing the organic material that determines peat hydrophysical properties, influences hydrologic conditions. In this study, we investigated the relationship between vegetation type and peat soil hydraulic conductivity in fen wetlands within the Rocky Mountain National Park, Colorado. We used ponded infiltration tests to estimate the saturated hydraulic conductivity of near‐surface peat in mountain fens with differing vegetation, including large‐sedge fens dominated by Carex aquatilis and Carex utriculata, small‐sedge fens dominated by Eleocharis quinqueflora, and fens with an abundance of woody plants and mosses. Estimated hydraulic conductivities were lowest at the fens dominated by E. quinqueflora, with a median value of 1·3 × 10−3 cm s−1 compared with 1·3 × 10−2 and 9·6 × 10−3 cm s−1, respectively, at the large‐sedge and woody fens. These data help explain historical water table observations at each fen. The E. quinqueflora‐dominated fens in our study area maintain a high water table with saturated conditions throughout the summer growing season. Other fens with higher‐conductivity peat show a more dynamic water table that is below ground surface by late summer. Copyright © 2015 John Wiley & Sons, Ltd.

A hybrid modeling approach for estimating reactive nitrogen deposition in Rocky Mountain National Park

Abstract Changes in ecosystem function at Rocky Mountain National Park (RMNP) are occurring because of nitrogen deposition associated with emissions of nitrogen from sources in Colorado as well as other areas of the North American continent and beyond. Nitrogen species are in both reduced and oxidized forms. A year-long monitoring program was initiated to better understand their origins as well as the complex chemistry occurring during transport from source to receptor. Specifically, the goals of the study were to characterize the atmospheric concentrations of nitrogen species in gaseous, particulate, and aqueous phases in RMNP and to identify the emission sources of these various species. The apportionment strategy was designed to focus on differentiating between sources within and outside the state of Colorado and then further differentiate between sources along the Front Range of Colorado and the rest of Colorado. It was also desirous to identify the relative contributions to atmospheric nitrogen species from mobile sources, agricultural activities, and large and small point sources within the state of Colorado. The Particle Source Apportionment Technology (PSAT) module available in the chemical transport model, the Comprehensive Air quality Model with extensions (CAMx), is used to develop first-principle estimates of the contributions from different areas of North America. The CAMx_PSAT results are combined with measured species concentrations in a receptor modeling approach to develop final estimates of source apportionment of the various species' concentrations and deposition.

The genetic legacy of more than a century of stocking trout: a case study in Rocky Mountain National Park, Colorado, USA

Human introductions can obscure the diversity and distribution of native biota; hybridization with and replacement by introduced congeners is a primary conservation threat, particularly in salmonids. Cutthroat trout (Oncorhynchus clarkii) are an important component of biodiversity in the American West, and all recognized subspecies are targets for state and federal conservation efforts. Rocky Mountain National Park (RMNP) in northern Colorado is a microcosm of trout introductions that happened worldwide. We used a combination of extensive stocking records and molecular genetic data to ask whether native trout populations persist despite stocking and whether patterns in the distribution of cutthroat trout clades could be explained by source and intensity of stocking. Nearly 15 million cutthroat trout were stocked into RMNP from a mosaic of sources in the 20th century. A single lineage of cutthroat trout was historically native to each side of the Continental Divide in RMNP, but we detected at least five divergent clades of cutthroat trout in 34 localities on both sides of the Divide. The distribution of lineages was predicted by stocking pressure and source but not by which lineage was historically native. The future of mixed and non-native cutthroat trout populations in RMNP poses a substantial conservation challenge.

Making Rocky Mountain National Park: The Environmental History of an American Treasure

Making Rocky Mountain National Park: The Environmental History of an American Treasure

Trends in Rocky Mountain amphibians and the role of beaver as a keystone species

Despite prevalent awareness of global amphibian declines, there is still little information on trends for many widespread species. To inform land managers of trends on protected landscapes and identify potential conservation strategies, we collected occurrence data for five wetland-breeding amphibian species in four national parks in the U.S. Rocky Mountains during 2002–2011. We used explicit dynamics models to estimate variation in annual occupancy, extinction, and colonization of wetlands according to summer drought and several biophysical characteristics (e.g., wetland size, elevation), including the influence of North American beaver (Castor canadensis). We found more declines in occupancy than increases, especially in Yellowstone and Grand Teton national parks (NP), where three of four species declined since 2002. However, most species in Rocky Mountain NP were too rare to include in our analysis, which likely reflects significant historical declines. Although beaver were uncommon, their creation or modification of wetlands was associated with higher colonization rates for 4 of 5 amphibian species, producing a 34% increase in occupancy in beaver-influenced wetlands compared to wetlands without beaver influence. Also, colonization rates and occupancy of boreal toads (Anaxyrus boreas) and Columbia spotted frogs (Rana luteiventris) were ⩾2 times higher in beaver-influenced wetlands. These strong relationships suggest management for beaver that fosters amphibian recovery could counter declines in some areas. Our data reinforce reports of widespread declines of formerly and currently common species, even in areas assumed to be protected from most forms of human disturbance, and demonstrate the close ecological association between beaver and wetland-dependent species.

Network spread of invasive species and infectious diseases

Landscape heterogeneity, non-local spreading mechanisms, and long-distance transportation connections can affect the spread of an invasive species or infectious disease. In this paper, we introduce a mathematical model that combines a vector-based transportation network with models for continuous invasive spread. Given a strongly connected, directed graph of transportation rates, we assume that carriers can transport a biological invader to distant sites. Following a possible latent stage, the invader then possibly establishes in the new location and spreads outwards in the continuous domain. Numerical results are shown for the invasion of Bromus tectorum in Rocky Mountain National Park based on the presence probability model of Strickland et al. (2013) and compare favorably with data. Analysis of the network component of the model reveals a unique, stable steady-state solution of the infected vectors.

A tale of two markers: Population genetics of colorado rocky mountain bighorn sheep estimated from microsatellite and mitochondrial data

Five native herds of Rocky Mountain bighorn sheep (Ovis canadensis) occupy Rocky Mountain National Park and the immediate surrounding area. One of these herds, the Mummy herd, suffered a significant die-off following a suspected pneumonia outbreak in the mid-1990s with subsequent low population size and low yearling recruitment, as compared to the other 4 herds. To test the hypothesis that the Mummy herd's failure to thrive is due to decreased genetic variation as a result of a genetic bottleneck, we analyzed both microsatellite and mitochondrial data to estimate genetic differentiation, gene flow, and the extent of metapopulation substructure among all 5 herds. Our microsatellite analyses showed no evidence of a recent genetic bottleneck or inbreeding. Our comparisons of overall and pairwise population differentiation (Fst) and effective migration (Nm) from both microsatellite genotypes and mitochondrial haplotypes indicated that low population substructure was being maintained by moderate levels of gene flow among all 5 herds. Effective migration rates were both higher and more uniform among herds for microsatellite genotypes than for mitochondrial haplotypes, which exhibited an asymmetrical pattern among herds. A significant isolation-by-distance relationship for mitochondrial (but not microsatellite) data suggests that gene flow is primarily due to ram migration. Past translocations of sheep into, out of, and among these 5 herds are an important consideration when interpreting these results; however, our data clearly show that all 5 Rocky Mountain bighorn sheep herds have reasonable and equivalent levels of genetic variation. Thus, herd management and restoration efforts should be focused on other factors that might be detrimental to herd health, such as stress, nutritional deficiencies, habitat fragmentation, climactic factors, or disease. © 2015 The Wildlife Society.

Rocky Mountain National Park reduced nitrogen source apportionment

AbstractExcess wet and dry deposition of nitrogen‐containing compounds are a concern at a number of national parks. The Rocky Mountain Atmospheric Nitrogen and Sulfur Study Part II (RoMANS II) campaign was conducted from November 2008 to November 2009 to characterize the composition of reactive nitrogen and sulfur deposited in Rocky Mountain National Park (RMNP). RoMANS II identified reduced nitrogen as the major contributor to reactive nitrogen deposition in RMNP, making up over 50% of the total. Motivated by this finding, the particulate source apportionment technology within the Comprehensive Air Quality Model with extensions was used here to estimate source apportionment of reduced nitrogen concentrations at RMNP. Source apportionment results suggest that approximately 40% of reduced nitrogen deposition to RMNP comes from ammonia sources within Colorado. However, the model evaluation also suggests that this number could be underrepresenting ammonia sources in eastern Colorado due to the difficulty of capturing upslope airflow on the eastern side of the Continental Divide with meteorological models. Emissions from California, the western model boundary, and the Snake River Valley in Idaho, the next three most influential sources, contribute approximately 15%, 8%, and 7%, respectively, to total reduced nitrogen measured in RMNP. Within Colorado, about 61%, 26%, and 13% of the total Colorado contribution comes from sources to the east of the Continental Divide, sources to the west of the Continental Divide, and from the park itself.

Source limitation of carbon gas emissions in high-elevation mountain streams and lakes

Inland waters are an important component of the global carbon cycle through transport, storage, and direct emissions of CO2 and CH4 to the atmosphere. Despite predictions of high physical gas exchange rates due to turbulent flows and ubiquitous supersaturation of CO2—and perhaps also CH4—patterns of gas emissions are essentially undocumented for high mountain ecosystems. Much like other headwater networks around the globe, we found that high-elevation streams in Rocky Mountain National Park, USA, were supersaturated with CO2 during the growing season and were net sources to the atmosphere. CO2 concentrations in lakes, on the other hand, tended to be less than atmospheric equilibrium during the open water season. CO2 and CH4 emissions from the aquatic conduit were relatively small compared to many parts of the globe. Irrespective of the physical template for high gas exchange (high k), we found evidence of CO2 source limitation to mountain streams during the growing season, which limits overall CO2 emissions. Our results suggest a reduced importance of aquatic ecosystems for carbon cycling in high-elevation landscapes having limited soil development and high CO2 consumption via mineral weathering.

Book Review: Rothman and Miller, Death Valley National Park: A History; and Frank, Making Rocky Mountain National Park: The Environmental History of an American Treasure, by Robert W. Righter

Book Review: Rothman and Miller, Death Valley National Park: A History; and Frank, Making Rocky Mountain National Park: The Environmental History of an American Treasure, by Robert W. Righter

Phylogenetic turnover patterns consistent with niche conservatism in montane plant species

Summary A fundamental aim in community ecology is to elucidate the processes structuring communities. The key to understanding community patterns is to account for species differences and similarities in how they respond to large‐scale environmental gradients and partition local resources. Using phylogenetic relationships as a representation of species’ ecological differences, we use phylogenetic beta‐diversity (PBD) to examine how patterns of community relatedness change across space. Specifically, we examine how PBD informs our understanding of the processes (spatial or environmental) directing species assembly along montane environmental gradients – in particular, whether patterns are consistent with niche conservatism. Also, we examine the depth of phylogenetic turnover to see where in evolutionary history shared environmental tolerances appear conserved. For angiosperm communities situated to the east and west of the Continental Divide (CD) in the Rocky Mountain National Park in CO, USA, we compare nine beta‐diversity indices (taxonomic, TBD: Jaccard, Bray–Curtis and Gower; PBD: PhyloSor, UniFrac, Dnn, Dpw, Rao's D and Rao's H) to changes in space, environment and environment controlling for space with the partial PROTEST method. We find that PBD differs from taxonomic beta‐diversity and some PBD metrics were redundant with one another (i.e. Rao's D & Dpw and UniFrac & PhyloSor). The indices’ different sensitivities to evolutionary depth affected their responses to environmental and spatial gradients: TBD consistently associated greater with all factors (space, environment and environment controlled for space) than PBD metrics; PBD metrics more sensitive to recent changes were more highly correlated with all factors than those metrics sensitive to turnover deeper in the phylogeny. Generally, beta‐diversity associated strongest with environment and least with space. Synthesis. Taxonomic and phylogenetic beta‐diversity complements each other to provide an enhanced perspective of the process governing community structure. Together, they depict patterns expected under niche conservatism for the Rocky Mountain angiosperm communities, that is, species’ names change faster than their evolutionary relationships across space.

Using high-resolution future climate scenarios to forecast Bromus tectorum invasion in Rocky Mountain National Park.

National Parks are hallmarks of ecosystem preservation in the United States. The introduction of alien invasive plant species threatens protection of these areas. Bromus tectorum L. (commonly called downy brome or cheatgrass), which is found in Rocky Mountain National Park (hereafter, the Park), Colorado, USA, has been implicated in early spring competition with native grasses, decreased soil nitrogen, altered nutrient and hydrologic regimes, and increased fire intensity. We estimated the potential distribution of B. tectorum in the Park based on occurrence records (n = 211), current and future climate, and distance to roads and trails. An ensemble of six future climate scenarios indicated the habitable area of B. tectorum may increase from approximately 5.5% currently to 20.4% of the Park by the year 2050. Using ordination methods we evaluated the climatic space occupied by B. tectorum in the Park and how this space may shift given future climate change. Modeling climate change at a small extent (1,076 km2) and at a fine spatial resolution (90 m) is a novel approach in species distribution modeling, and may provide inference for microclimates not captured in coarse-scale models. Maps from our models serve as high-resolution hypotheses that can be improved over time by land managers to set priorities for surveys and removal of invasive species such as B. tectorum.

Investigating types and sources of organic aerosol in Rocky Mountain National Park using aerosol mass spectrometry

Abstract. The environmental impacts of atmospheric particles are highlighted in remote areas where visibility and ecosystem health can be degraded by even relatively low particle concentrations. Submicron particle size, composition, and source apportionment were explored at Rocky Mountain National Park using a High-Resolution Time-of-Flight Aerosol Mass Spectrometer. This summer campaign found low average, but variable, particulate mass (PM) concentrations (max = 93.1 μg m−3, avg. = 5.13 ± 2.72 μg m−3) of which 75.2 ± 11.1% is organic. Low-volatility oxidized organic aerosol (LV-OOA, 39.3% of PM1 on average) identified using Positive Matrix Factorization appears to be mixed with ammonium sulfate (3.9% and 16.6% of mass, respectively), while semi-volatile OOA (27.6%) is correlated with ammonium nitrate (nitrate: 4.3%); concentrations of these mixtures are enhanced with upslope (SE) surface winds from the densely populated Front Range area, indicating the importance of transport. A local biomass burning organic aerosol (BBOA, 8.4%) source is suggested by mass spectral cellulose combustion markers (m/z 60 and 73) limited to brief, high-concentration, polydisperse events (suggesting fresh combustion), a diurnal maximum at 22:00 local standard time when campfires were set at adjacent summer camps, and association with surface winds consistent with local campfire locations. The particle characteristics determined here represent typical summertime conditions at the Rocky Mountain site based on comparison to ~10 years of meteorological, particle composition, and fire data.

Post-fire response of riparian vegetation in a heavily browsed environment

Severe wildfires infrequently occur in large heterogeneous riparian valleys. Riparian areas may affect fire behavior and the pattern of burning due to saturated soils and patchy fuels that may have high moisture content in live and dead stems. We examined the effects of a severe fire on the dominant riparian vegetation: thin-leaf alder, river birch and willow, in a broad riparian valley in Rocky Mountain National Park, CO, USA. We mapped the canopy stem mortality and basal resprouting of 4507 first year post fire and 643 second year post fire individuals that had been the dominant woody canopy. To examine the effect of herbivory on resprouting willow stems, we established a paired experiment with 22 willows exclosed in cages to prevent browsing and 22 uncaged control plants. Aerial seed rain sticky traps were established on transects throughout the study area and pre-fire seed rain density was compared with post-fire seed rain densities.Fire effects on willow were severe, with 91% of individuals having complete canopy loss. Fifty-one percent of thin-leaf alder individuals and 71% of river birch individuals also had complete canopy loss. Seventy-four percent of river birch, 45% of willow and 35% of thin-leaf alder resprouted from the base in the first summer post fire. In the second year post fire, 84% of river birch, 62% of thin-leaf alder and 55% of willow had resprouted. Willows inside exclosures had greater biomass at the end of the growing season compared with willows outside exclosures. Summer browsing resulted in significantly lower willow biomass compared with exclosed plants and the additive effect of summer and winter browsing resulted in control plants having 64% reduction in biomass. Post-fire aerial seed rain was 90% lower than pre-fire densities.Fire dramatically altered the riparian vegetation. Willow seed rain was nearly eliminated because most stems were killed by fire. Resprouting woody riparian vegetation was prevalent however, ungulate browsing of the resprouting willow stems could limit the regrowth of a tall willow riparian overstory.

Jerry J. Frank. Making Rocky Mountain National Park: The Environmental History of an American Treasure.

Jerry J. Frank. Making Rocky Mountain National Park: The Environmental History of an American Treasure.

Spatial patterns of atmospheric deposition of nitrogen and sulfur using ion-exchange resin collectors in Rocky Mountain National Park, USA

Lakes and streams in Class 1 wilderness areas in the western United States (U.S.) are at risk from atmospheric deposition of nitrogen (N) and sulfur (S), and protection of these resources is mandated under the Federal Clean Air Act and amendments. Assessment of critical loads, which are the maximum exposure to pollution an area can receive without adverse effects on sensitive ecosystems, requires accurate deposition estimates. However, deposition is difficult and expensive to measure in high-elevation wilderness, and spatial patterns in N and S deposition in these areas remain poorly quantified. In this study, ion-exchange resin (IER) collectors were used to measure dissolved inorganic N (DIN) and S deposition during June 2006–September 2007 at approximately 20 alpine/subalpine sites spanning the Continental Divide in Rocky Mountain National Park. Results indicated good agreement between deposition estimated from IER collectors and commonly used wet + dry methods during summer, but poor agreement during winter. Snowpack sampling was found to be a more accurate way of quantifying DIN and S deposition during winter. Summer DIN deposition was significantly greater on the east side of the park than on the west side (25–50%; p ≤ 0.03), consistent with transport of pollutants to the park from urban and agricultural areas to the east. Sources of atmospheric nitrate (NO3−) were examined using N isotopes. The average δ15N of NO3− from IER collectors was 3.5‰ higher during winter than during summer (p < 0.001), indicating a seasonal shift in the relative importance of regional NOx sources, such as coal combustion and vehicular sources of atmospheric NO3−. There were no significant differences in δ15N of NO3− between east and west sides of the park during summer or winter (p = 0.83), indicating that the two areas may have similar sources of atmospheric NO3−. Results from this study indicate that a combination of IER collectors and snowpack sampling can be used to characterize spatial variability in DIN and S deposition in high-elevation wilderness areas. These data can improve our ability to model critical loads by filling gaps in geographic coverage of deposition monitoring/modeling programs and thus may enable policy makers to better protect sensitive natural resources in Class 1 Wilderness areas.

Making Rocky Mountain National Park: The Environmental History of an American Treasure. By Jerry J. Frank (Lawrence, University Press of Kansas, 2013) 272 pp. $34.95

<i>Making Rocky Mountain National Park: The Environmental History of an American Treasure.</i> By Jerry J. Frank (Lawrence, University Press of Kansas, 2013) 272 pp. $34.95