Middle Rockies Research Articles

Prescribed Fire Case Studies From Wyoming, USA: Diverse Applications and Common Themes at the Great Plains-Rocky Mountains Interface

Prescribed fire is an important management tool for rangelands and forests in North America and globally. However, the application of prescribed fire is a complex endeavor that involves significant planning, partnerships, and risk. Recent evidence suggests that not enough prescribed fire is being applied to reduce wildfires, in part, because risk and bureaucracy continue to hinder application. While common in the eastern and central Great Plains, prescribed fire is less common in the western United States. Therefore, we summarized 11 prescribed fire projects in Wyoming, USA (or immediately adjacent to in one case) across five U.S. Environmental Protection Agency Ecoregions (High Plains, Northwestern Great Plains, Wyoming Basin, Southern Rockies, and Middle Rockies)—a state where the prairies converge with the western mountains. Fires were conducted from 2014 to 2022 and ranged in size from <1 acre to 3,000 acres (a total of 8,795 acres). Fires occurred on a variety of land ownerships including private ranch, university, state trust, Army, Bureau of Land Management, Forest Service, Bureau of Reclamation, and U.S. Department of Agriculture. Crew sizes ranged from 1 to 40 people. Approximately half of the burns were in the spring, a third were in the fall, and two were in the winter; no summer burns were reported. Duration of planning ranged from a few months to 5 years. Drip torches were the most common ignition device used; however, we noted the use of propane torches, terratorches, helitorches, and drones for lighting fires. Weather prescriptions varied across fires with some choosing low humidity to make up for low fuel loads and others choosing moderate humidity to minimize risk. A wide variety of plant communities, purposes, and applications were noted. Weather prescriptions particularly in the spring were consistently challenging and the importance of partnerships with neighbors and other agencies for planning and implementation was noted frequently. Across these unique prescribed fire case studies, we have noted commonalities that can communicate important practicalities of applying fire across complex land types and jurisdictions. Sharing such information is important in a state with the least population density in the country to enhance the professional application of prescribed fire across a diversity of situations.

Management and Limnology Interact to Drive Water Temperature Patterns in a Middle Rockies River‐Reservoir System

AbstractThis study seeks to improve understanding of temperature patterns in reservoir outflows. We examined water temperatures in an irrigation storage reservoir, Island Park Reservoir, and its outflow, Henry’s Fork of the Snake River in eastern Idaho. Our objectives were to (1) quantify the extent to which daily temperature ranges in the reservoir outflow deviated from other reaches of the Henry’s Fork, and (2) test whether the reservoir’s net volume change during the summer — expressed as the volume of water remaining in the reservoir on September 1 — predicted mean summer temperature in the outflow. Two years of temperature data showed dampened diel temperature cycles in the reservoir outflow. Model selection with 17 years of climatic, hydrologic, and reservoir management variables found mean summer temperature in the outflow was best predicted by September 1 reservoir volume and average summer air temperature. Two years of weekly reservoir thermal profiles indicated large changes in reservoir volume eliminated cool hypolimnetic water and encouraged mixing, allowing warm epilimnetic water to be discharged into the outflow. Increases in future drought frequency and severity and increases in summer air temperatures could increase the frequency of occurrence of high mean summertime water temperatures in the outflow. Our study provides important information for local managers by quantifying influences on outflow temperatures and the downstream river ecosystem.

The compounding consequences of wildfire and climate change for a high‐elevation wildflower (Saxifraga austromontana)

AbstractAimHigh‐elevation plants are disproportionally affected by climate change. As temperatures rise, the amount of available alpine habitat in the Rocky Mountains will decrease resulting in potential local extinctions of plant species. In addition to the direct effects of climate‐driven habitat loss, alpine plants must also respond to indirect effects, such as changes in disturbance regimes. One notable shift is the increase of wildfire frequency in regions where fire was previously rare or absent, including the alpine. We hypothesized that direct climatic changes compounded with increased wildfire frequency will reduce the future suitable habitat of high‐elevation plants more than if climate was considered alone.LocationRocky Mountain Floristic Region, western North America.TaxonSaxifraga austromontana (Saxifragaceae), a wildflower endemic to high elevations of the Rocky Mountain Floristic Region.MethodsOur approach integrated historical herbarium records, field surveys, remote sensing, species distribution models, historic wildfire data, and predictive models.ResultsOur results indicate wildfire has significantly reduced the abundance and increased the likelihood of extirpation for S. austromontana. Increased fire frequency compounded with direct climatic changes will likely reduce the range of the species by approximately 43% by 2050 compared to 38% due to climate alone, under a moderate CO2 emissions scenario. The influence of wildfire varies regionally. For instance, the Middle Rockies will likely lose 74% of its suitable habitat of which 16% may be lost due to fire, while other regions, such as the northern range, will be less negatively affected by direct and indirect effects.Main ConclusionsOur evidence that increased wildfire frequency will compound the impacts of climate change on alpine taxa in North America led to the development of a new, general hypothesis on the fundamental interaction between direct and indirect effects of climate change on species range reductions.

Next‐Generation Intensity‐Duration‐Frequency Curves for Hydrologic Design in Snow‐Dominated Environments

AbstractThere is a renewed focus on the design of infrastructure resilient to extreme hydrometeorological events. While precipitation‐based intensity‐duration‐frequency (IDF) curves are commonly used as part of infrastructure design, a large percentage of peak runoff events in snow‐dominated regions are caused by snowmelt, particularly during rain‐on‐snow (ROS) events. In these regions, precipitation‐based IDF curves may lead to substantial overestimation/underestimation of design basis events and subsequent overdesign/underdesign of infrastructure. To overcome this deficiency, we proposed next‐generation IDF (NG‐IDF) curves, which characterize the actual water reaching the land surface. We compared NG‐IDF curves to standard precipitation‐based IDF curves for estimates of extreme events at 376 Snowpack Telemetry (SNOTEL) stations across the western United States that each had at least 30 years of high‐quality records. We found standard precipitation‐based IDF curves at 45% of the stations were subject to underdesign, many with significant underestimation of 100 year extreme events, for which the precipitation‐based IDF curves can underestimate water potentially available for runoff by as much as 125% due to snowmelt and ROS events. The regions with the greatest potential for underdesign were in the Pacific Northwest, the Sierra Nevada Mountains, and the Middle and Southern Rockies. We also found the potential for overdesign at 20% of the stations, primarily in the Middle Rockies and Arizona mountains. These results demonstrate the need to consider snow processes in the development of IDF curves, and they suggest use of the more robust NG‐IDF curves for hydrologic design in snow‐dominated environments.

Patterns in stream greenhouse gas dynamics from mountains to plains in northcentral Wyoming

AbstractQuantification of small stream contributions to global carbon cycling is key to understanding how freshwater systems transmit and transform carbon between terrestrial and atmospheric pools. To date, greenhouse gas emissions of carbon dioxide and methane from freshwaters, particularly in mountainous regions, remain poorly characterized due to a lack of direct field observations. Using a unique longitudinal approach, we conducted field surveys across two ecoregions (Middle Rockies and Great Plains) in the Clear Creek watershed, a subwatershed of Wyoming's Powder River Basin. We took direct measurements of stream gases using headspace sampling at 30 sites (8 June to 23 October). We observed the lowest and most variable concentrations in headwaters, which flow through a federally designated alpine wilderness area. By contrast, the Great Plains exhibited 1.45 and 4 times higher pCO2 and pCH4 concentrations and the relative contributions of methane increased downstream. Fluxes during snowmelt were 45% and 58% higher for CO2 and CH4 than during base flow but overall were lower than estimates for other systems. Variability for pCO2 was highest during late summer and in the uppermost sections of the headwaters. The high heterogeneity and common undersaturation observed through space and time, especially in the mountains, suggest that downscaled regional estimates may fail to capture variability in fluxes observed at these smaller scales. Based on these results, we strongly recommend higher resolution time series studies and increased scrutiny of systems at near equilibrium, inclusive of winter storage and ice‐off events, to improve our understanding of the effects of seasonal dynamics on these processes.

Talk About the Weather: Comparative Constructions in the Middle Rockies

This study examines comparative constructions that appear in the Linguistic Atlas of the Middle Rockies, a linguistic survey conducted with native informants in Colorado, Utah, and Wyoming from 1988 to 2004. In particular, it analyzes responses to three prompts targeting expressions used to describe extremes in temperature and aridity in the region. As part of this investigation, linguistic patterns in the range of responses to each prompt are identified, and several social characteristics of the informants, including sex and religion of informant, are tested for correlations with individual linguistic items as well as groups of categories extracted via the linguistic analysis. While the word hell is pervasive in these responses (e.g., the weather is hotter than hell), and thus has not become obsolete like some earlier scholars predicted, variation in its distribution among social groups and metadata suggest that the word is still considered taboo by some speakers.

Ascending kinship terminology in Middle Rocky Mountain English

This study uses the tools of corpus linguistics to investigate ascending kinship terminology in the Linguistic Atlas of the Middle Rockies, a collection of interviews gathered in Colorado, Utah, and Wyoming as part of a dialectological survey of the American West. Relying in part on the framework of Dahl and Koptjevskaja-Tamm (2001), particularly with respect to their notion of a parental kin prototype, the study examines lexical and grammatical variation in the use of terms for parents and grandparents in different interviewing contexts in an effort to identify patterns in these distributions. The study finds important quantitative differences in the distribution of mother and father, as well as differences in the grammatical behavior of these and other kinship variants. While these results provide some support for a parental kin prototype, they also suggest the benefits that survey data collected within a variationist framework offer such a prototype, both with respect to the counterexamples to broad generalizations that such datasets inevitably include as well as the variable patterns that often emerge from such data that might go unobserved using formal methods.

Development and Validation of an Aquatic Fine Sediment Biotic Index

The Fine Sediment Biotic Index (FSBI) is a regional, stressor-specific biomonitoring index to assess fine sediment (<2mm) impacts on macroinvertebrate communities in northwestern US streams. We examined previously collected data of benthic macroinvertebrate assemblages and substrate particle sizes for 1,139 streams spanning 16 western US Level III Ecoregions to determine macroinvertebrate sensitivity (mostly at species level) to fine sediment. We developed FSBI for four ecoregion groupings that include nine of the ecoregions. The grouping were: the Coast (Coast Range ecoregion) (136 streams), Northern Mountains (Cascades, N. Rockies, ID Batholith ecoregions) (428 streams), Rockies (Middle Rockies, Southern Rockies ecoregions) (199 streams), and Basin and Plains (Columbia Plateau, Snake River Basin, Northern Basin and Range ecoregions) (262 streams). We excluded rare taxa and taxa identified at coarse taxonomic levels, including Chironomidae. This reduced the 685 taxa from all data sets to 206. Of these 93 exhibited some sensitivity to fine sediment which we classified into four categories: extremely, very, moderately, and slightly sensitive; containing 11, 22, 30, and 30 taxa, respectively. Categories were weighted and a FSBI score calculated by summing the sensitive taxa found in a stream. There were no orders or families that were solely sensitive or resistant to fine sediment. Although, among the three orders commonly regarded as indicators of high water quality, the Plecoptera (5), Trichoptera (3), and Ephemeroptera (2) contained all but one of the species or species groups classified as extremely sensitive. Index validation with an independent data set of 255 streams found FSBI scores to accurately predict both high and low levels of measured fine sediment.

Changing temperatures influence suitability for modeled mountain pine beetle (Dendroctonus ponderosae) outbreaks in the western United States

Insect outbreaks are significant disturbances in forests of the western United States, with infestation comparable in area to fire. Outbreaks of mountain pine beetle (Dendroctonusponderosae Hopkins) require life cycles of one year with synchronous emergence of adults from host trees at an appropriate time of year (termed “adaptive seasonality”) to overwhelm tree defenses. The annual course of temperature plays a major role in governing life stage development and imposing synchrony on mountain pine beetle populations. Here we apply a process‐based model of adaptive seasonality across the western United States using gridded daily temperatures from the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP) over the period 1895–2100. Historical locations of modeled adaptive seasonality overlay much of the distribution of lodgepole pine (Pinus contorta Douglas), a favored host, indicating that suitable temperatures for outbreak occurred in areas of host availability. A range of suitable temperatures, both in the mean and over an annual cycle, resulted in adaptive seasonality. Adaptive seasonality typically occurred when mean annual temperatures were 3°–6°C, but also included locations where mean temperatures were as low as 1°C or as high as 11°C, primarily as a result of variability in winter temperatures. For most locations, years of adaptive seasonality were uncommon during 1895–1993. We analyzed historical temperatures and adaptive seasonality in more detail in three northern forest ecoprovinces. In the Northern and Middle Rockies, areas of adaptive seasonality decreased at lower elevations and increased at higher elevations during warmer periods, resulting in a movement upward in elevation of adaptive seasonality. In contrast, the Cascade Mountains exhibited overall declines in adaptive seasonality with higher temperatures regardless of elevation. Projections of future warming (5°C in the western United States) resulted in substantial reductions in the overall area of adaptive seasonality. At the highest elevations, predicted warmer conditions will result in increases in the area of adaptive seasonality. Our findings suggest that future climate change may alter forest ecosystems indirectly through alteration of these important disturbances.

The Alpine Flora of the Rocky Mountains Volume 1, The Middle Rockies, by Richard W. Scott [Review

The Alpine Flora of the Rocky Mountains Volume 1, The Middle Rockies, by Richard W. Scott [Review

The alpine flora of the Rocky Mountains: v.1: The Middle Rockies

The alpine flora of the Rocky Mountains: v.1: The Middle Rockies

The Alpine Flora of the Rocky Mountains. Vol. 1. The Middle Rockies

The Alpine Flora of the Rocky Mountains. Vol. 1. The Middle Rockies

The Alpine Flora of The Rocky Mountains, Volume 1, The Middle Rockies, by Richard W. Scott

The Alpine Flora of The Rocky Mountains, Volume 1, The Middle Rockies, by Richard W. Scott

The Distribution of Western North American Hepaticae. Endemic Taxa and Taxa with a North Pacific Arc Distribution

The Distribution of Western North American Hepaticae. Endemic Taxa and Taxa with a North Pacific Arc Distribution

Relation of Petroleum to Tectonic Development of Rocky Mountain and Western Plains Region of North America: ABSTRACT

Structural and depositional history of miogeosynclinal and cratonic areas of the Rocky Mountain-Western Plains region controls petroleum origin and entrapment. Extensive source beds associated with timely traps have characterized exceptional periods of petroleum entrapment--Devonian, late Paleozoic, and Cretaceous. Late Precambrian marine sedimentary rocks were deposited in the Cordilleran geosyncline, and eastward extensions of the sea occupied parts of the region. In the western part of the geosyncline, deposition was continuous into Cambrian time, but on the east a period of erosion was followed by a Middle Cambrian-to-Early Ordovician marine invasion. Major tectonic elements that developed early in Paleozoic time include the Peace River, Alberta, and Transcontinental arches. Middle Ordovician-to-Silurian depositional patterns indicate early development of the Williston basin. The Upper Ordovician-Silurian section is the oldest oil-producing interval; significant production is restricted to the Williston basin. Middle Devonian-Mississippian carbonates and evaporites record another major marine invasion. Upper Devonian reefs, with associated evaporites and marine shale, contain more than half the oil reserves of the northern part of the region (largely in Alberta). Oil and gas in Mississippian rocks are found in bioclastic carbonates (associated with anhydrite), at or near unconformities, and in large anticlines. Southwest of the Williston basin, Devonian and Mississippian oil production is limited, but the potential has not been adequately evaluated. Late Paleozoic rocks have limited distribution in the northern part of the region. Pennsylvanian and Permian tectonic activity (Ancestral Rockies) was most pronounced in the southern part of the region. Pennsylvanian-Permian petroleum is trapped in a wide variety of clastic and carbonate structural and stratigraphic traps in the middle and southern Rockies, and offers many opportunities for future exploration. Triassic miogeosynclinal deposits are restricted to the western edge of the region. Jurassic marine invasions from the Arctic extended as far south as the southern Rockies. Continental deposits dominate the Triassic and Jurassic sequence and account for the relatively small percentage of petroleum reserves in these rocks. During Early Cretaceous time the sea again invaded from the north and in late Early Cretaceous joined a Gulf of Mexico sea. Coastal-plain, deltaic, and shallow-marine clastics that were deposited in this vast seaway form the source and reservoir rocks for some of the largest petroleum accumulations of the region. The present tectonic framework of uplifts, intermontane basins, and thrust faults on the west was formed during Late Cretaceous and early Tertiary time (Laramide orogeny). Many petroleum accumulations that had been stratigraphically trapped before the Laramide orogeny remigrated to their present structural positions. Reconstruction of migration paths should lead to significant additional petroleum discoveries in Cretaceous rocks. Important petroleum accumulations have been found in Tertiary lake deposits of the middle and southern Rockies. Despite their relative shallowness, Tertiary rocks have been very incompletely explored. End_of_Article - Last_Page 468------------

Discussion: Geology along the Southern Margin of the Absaroka Range, Wyoming

This contribution by John David Love' to geology of southern part of Absaroka Range adds materially to our understanding of stratigraphy and geological history of Yellowstone Park. Covering a scope of structure, stratigraphy, and geologic history it is of a type that is most needed to understand complex history of Middle Rockies. The meat of this paper, however, might have been presented in a much shorter manner. There is much drawing upon literature on other areas that does not add to geology of area mapped. In some cases it is doubtful if conclusions reached are correct for Middle Rockies. For example, to quote: Upper Mesaverde and younger Cretaceous rocks are not present here, and time did not permit a study of them in adjacent area three miles east of Red Creek. Yet author proceeds to discuss pulses of Laramide by reference to work of others from central Utah to Montana and Dakotas. Hence first three items listed in his summary are based on testimony of others on other localities. Although these particular conclusions may be correct, they are illustrative of lengthy paper which expands blanket of its discoveries to cover a much larger region than area studied. Even while so doing he states the Laramide Revolution was not a movement affecting all mountain ranges simultaneously.' (This statement is not proven.) It would be better to confine his discussions to contribution which his area makes to a better understanding of Middle Rockies themselves. A number of new formation names have been used for Eocene