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At least 487 records · Page 27Linked to original sources

USGS1984

Quantitative analysis of the hydrothermal system in Lassen Volcanic National Park and Lassen Known Geothermal Resource Area

The conceptual model of the Lassen system is termed a liquid-dominated hydrothermal system with a parasitic vapor-dominated zone. The essential feature of this model is that steam and steam-heated discharge at relatively high elevations in Lassen Volcanic National Park (LVNP) and liquid discharge with high chloride concentrations at relatively low elevations outside LVNP are both fed by an upflow of high-enthalpy two-phase fluid within the Park. Liquid flows laterally away from the upflow area towards the areas of high-chloride discharge, and steam rises through a vapor-dominated zone to feed the steam and steam-heated features. Numerical simulations show that several conditions are necessary for the development of this type of system, including (1) large-scale topographic relief, (2) an initial period of convective heating within an upflow zone followed by some change in hydrologic or geologic conditions that initiates drainage of liquid from portions of the upflow zone, and (3) low permeability barriers that inhibit the movement of cold water into the vapor zone. Simulations of thermal fluid withdrawal south of LVNP, carried out in order to determine the effects of such withdrawal on portions of the hydrothermal system within the Park, showed decreases in pressure and liquid saturation beneath the vapor zone which result in a temporary increase and subsequent decrease in the rate of upflow of steam.

California↗

USGS1985

Sensitivity of stream basins in Shenandoah National Park to acid deposition

Six synoptic surveys of 56 streams that drain the Shenandoah National Park, Virginia, were conducted in cooperation with the University of Virginia to evaluate sensitivity of dilute headwater streams to acid deposition and to determine the degree of acidification of drainage basins. Flow-weighted alkalinity concentration of most streams is below 200 microequivalents per liter, which is considered the threshold of sensitivity. Streams draining resistant siliceous bedrocks have an extreme sensitivity (alkalinity below 20 microequivalents/L); those draining granite and granodiorite have a high degree of sensitivity (20 to 100 microequivalents/L); and streams draining metamorphosed volcanics have moderate to marginal sensitivity (100 to 200 microequivalents/L). A comparison of current stream water chemistry to that predicted by a model based on carbonic acid weathering reactions suggests that all basins in the Park shows signs of acidification by atmospheric deposition. Acidification is defined as a neutralization of stream water alkalinity and/or an increase in the base cation weathering rate. Acidification averages 50 microequivalents/L, which is fairly evenly distributed in the Park. However, the effects of acidification are most strongly felt in extremely sensitive basins, such as those underlain by the Antietam Formation, which have stream water pH values averaging 4.99 and a mineral acidity of 7 microequivalents/L. (USGS)

Water-Resources Investigations Report↗

USGS1986

Flood analysis along the Little Missouri River within and adjacent to Theodore Roosevelt National Park, North Dakota

The Little Missouri River flows through Theodore Roosevelt National Park t which consists of three separate units: South Unit, Elkhorn Ranch Site, and North Unit. The park is located in the Little Missouri badlands. Discharges and water-surface elevations for 100- or 500-year floods or both were computed for selected reaches along the Little Missouri River and three of its tributaries (Knutson Creek, Paddock Creek, and Squaw Creek) within and adjacent to Theodore Roosevelt National Park. The 100- and 500-year flood discharges for the Little Missouri River were determined from streamflow records. The 100-year flood discharges for the three creeks were estimated using a multiple-regression equation based on drainage area and soil-infiltration index. Water-surface elevations were determined by the step-backwater method. The effects of ice jams on water-surface elevations were estimated from streamflow records.

Water-Resources Investigations Report↗

USGS2016

Comparison of methods to monitor the distribution and impacts of unauthorized travel routes in a border park

The distribution and abundance of human-caused disturbances vary greatly through space and time and are cause for concern among land stewards in natural areas of the southwestern border-lands between the USA and Mexico. Human migration and border protection along the international boundary create Unauthorized Trail and Road (UTR) networks across National Park Service lands and other natural areas. UTRs may cause soil erosion and compaction, damage to vegetation and cultural resources, and may stress wildlife or impede their movements. We quantify the density and severity of UTR disturbances in relation to soils, and compare the use of previously established targeted trail assessments (hereafter — targeted assessments) against randomly placed transects to detect trail densities at Coronado National Memorial in Arizona in 2011. While trail distributions were similar between methods, targeted assessments estimated a large portion of the park to have the lowest density category (0–5 trail encounters per/km 2 ), whereas the random transects in 2011 estimated more of the park as having the higher density categories (e.g., 15–20 encounters per km 2 category). Soil vulnerability categories that were assigned, a priori, based on published soil texture and composition did not accurately predict the impact of UTRs on soil, indicating that empirical methods may be better suited for identifying severity of compaction. While the estimates of UTR encounter frequencies were greater using the random transects than the targeted assessments for a relatively short period of time, it is difficult to determine whether this difference is dependent on greater cross-border activity, differences in technique, or from confounding environmental factors. Future surveys using standardized sampling techniques would increase accuracy.

Arizona↗

USGS2017

Fire and the distribution and uncertainty of carbon sequestered as above-ground tree biomass in Yosemite and Sequoia & Kings Canyon National Parks

Fire is one of the principal agents changing forest carbon stocks and landscape level distributions of carbon, but few studies have addressed how accurate carbon accounting of fire-killed trees is or can be. We used a large number of forested plots (1646), detailed selection of species-specific and location-specific allometric equations, vegetation type maps with high levels of accuracy, and Monte Carlo simulation to model the amount and uncertainty of aboveground tree carbon present in tree species (hereafter, carbon) within Yosemite and Sequoia & Kings Canyon National Parks. We estimated aboveground carbon in trees within Yosemite National Park to be 25 Tg of carbon (C) (confidence interval (CI): 23–27 Tg C), and in Sequoia & Kings Canyon National Park to be 20 Tg C (CI: 18–21 Tg C). Low-severity and moderate-severity fire had little or no effect on the amount of carbon sequestered in trees at the landscape scale, and high-severity fire did not immediately consume much carbon. Although many of our data inputs were more accurate than those used in similar studies in other locations, the total uncertainty of carbon estimates was still greater than ±10%, mostly due to potential uncertainties in landscape-scale vegetation type mismatches and trees larger than the ranges of existing allometric equations. If carbon inventories are to be meaningfully used in policy, there is an urgent need for more accurate landscape classification methods, improvement in allometric equations for tree species, and better understanding of the uncertainties inherent in existing carbon accounting methods.

California↗

USGS2022

A synthesis of coral reef research at Buck Island Reef National Monument and Salt River Bay National Historical Park and Ecological Preserve, St. Croix, U.S. Virgin Islands: 1961 to 2022

This synthesis focuses on the history of research on coral reefs within two U.S. National Park Service units in St. Croix, U.S. Virgin Islands: Buck Island Reef National Monument (from 1961 to 2022) and Salt River Bay National Historical Park and Ecological Preserve (from 1980 to 2022). Buck Island Reef National Monument (BUIS) is off the north shore of the island of St. Croix, in the U.S. Virgin Islands. Established in 1961 and expanded in 2001, it is under the jurisdiction of the National Park Service (NPS). Long-term monitoring programs maintained by the NPS and jointly by the University of the Virgin Islands (UVI) and the Virgin Islands Department of Planning and Natural Resources (VIDPN).

U.S. Virgin Islands, Buck Island Reef National Mon↗

USGS2025

Sampling dragonflies for mercury analysis in Grand Canyon National Park, 2018–2024: A contribution of the Dragonfly Mercury Project

The Dragonfly Mercury Project is a collaborative initiative that utilizes dragonfly larvae as biosentinels to monitor mercury concentrations across 180 national parks and other protected lands, including Grand Canyon National Park (GRCA). These indicators serve as surrogates for environmental risk and can indicate where fish consumption could pose health risks through exposure to mercury. From 2018–2024, citizen scientists and staff from the National Park Service and U.S. Geological Survey helped collect close to 400 larvae from 25 GRCA sites across nearly 300 river miles, revealing mercury concentrations ranging 3.0–1337 ng/g (parts per billion) dry weight. Results were available for 20 sites. Upon comparing mercury concentrations to an impairment index, most sites were classified as low or no risk for ecological impairment, though 10% (2 sites) exceeded moderate or severe risk benchmarks (Pete’s Pocket and Buck Farm Canyon, respectively). Sources of mercury to GRCA likely stem from a combination of atmospheric deposition, upstream discharge from Lake Powell, and other watershed contributions. In addition, food web dynamics, underlying water chemistry, and environmental disturbances (e.g., floods) contribute to mercury mobilization, production, and bioaccumulation. Report findings provide a baseline for connecting ongoing science in the Colorado River watershed, informing management actions, and enhancing public engagement through citizen science.

Arizona↗

USGS2025

White-nose syndrome surveillance and bat monitoring activities in North Coast and Cascades Network parks 2016–2024

Pseudogymnoascus destructans (Pd), the causative agent of white-nose syndrome (WNS) in bats, has caused serious declines in bat populations across North America. We conducted WNS surveillance in five different park units in the North Coast and Cascades Network (NCCN) from 2016 to 2024, following the initial detection of Pd and WNS in Washington State in 2016. We captured and swabbed bats, swabbed roost materials, and collected guano and tested these samples for Pd DNA using qPCR. We confirmed WNS through histopathology of tissue samples and carcasses. We detected Pd at five locations in Mount Rainier National Park, starting in 2017. We confirmed WNS at four of these locations, with the first clinical signs detected in 2022. We detected Pd for the first time in Olympic and North Cascades National Parks in 2024. From these efforts, we generated information that can be compared to other datasets, helping us advance our knowledge of WNS/Pd epidemiology. We also conducted three field and laboratory-based experiments to inform early detection/rapid response (EDRR) planning. The first was a field experiment using non-infective Pd DNA to evaluate the rate of DNA degradation and the probability of detecting Pd DNA in the field. Experimental degradation rates for Pd DNA ranged from 1.6% to 8.2% and were lower in protected sites. The second was a laboratory-based experiment to understand Pd growth on four different substrates. We detected increasing levels of Pd in autoclaved guano and in plywood, suggesting these substrates may be environmental reservoirs. Pd remained stable in fresh guano but in soil it decreased, suggesting microbial interactions that may influence Pd growth in these substrates. We also collected wood shavings from a Pd positive bat box in June and August to evaluate viable Pd persistence in wood in a summer roost. Despite the characterization that Pd required cold conditions to persist, viable Pd was present in wood shavings collected during the summer season. Finally, we evaluated the National White-Nose Syndrome Decontamination Protocol through experiments. We found that ethanol was not effective as a sporicidal agent in any of the concentrations we tested and that a 1:10 dilution of bleach did not kill Pd spores, though higher concentrations did. These findings resulted in changes to the national protocol.

Oregon, Washington↗

USGS2013

Factors influencing the distribution of native bull trout and westslope cutthroat trout in western Glacier National Park, Montana

The widespread declines of native bull trout ( Salvelinus confluentus ) and westslope cutthroat trout ( Oncorhynchus clarkii lewisi ) populations prompted researchers to investigate factors influencing their distribution and status in western Glacier National Park, Montana. We evaluated the association of a suite of abiotic factors (stream width, elevation, gradient, large woody debris density, pool density, August mean stream temperature, reach surface area) with the occurrence (presence or absence) of bull trout and westslope cutthroat trout in 79 stream reaches in five sub-drainages containing glacial lakes. We modeled the occurrence of each species using logistic regression and evaluated competing models using an information theoretic approach. Westslope cutthroat trout were widely distributed (47 of 79 reaches), and there appeared to be no restrictions on their distribution other than physical barriers. Westslope cutthroat trout were most commonly found in relatively warm reaches downstream of lakes and in headwater reaches with large amounts of large woody debris and abundant pools. By contrast, bull trout were infrequently detected (10 of 79 reaches), with 7 of the 10 (70%) detections in sub-drainages that have not been compromised by non-native lake trout ( S. namaycush ). Bull trout were most often found in cold, low-gradient reaches upstream of glacial lakes. Our results indicate that complex stream habitats in sub-drainages free of non-native species are important to the persistence of native salmonids in western Glacier National Park. Results from this study may help managers monitor and protect important habitats and populations, inform conservation and recovery programs, and guide non-native species suppression efforts in Glacier National Park and elsewhere.

Montana↗

USGS2017

Introduced American Bullfrog distribution and diets in Grand Teton National Park

Introduced American Bullfrogs (Lithobates catesbeianus) have been present in Grand Teton National Park since approximately the 1950s, but little is known about their distribution and potential impacts. In this study, we surveyed the current bullfrog distribution and spatial overlap with sympatric native amphibians in the park, and characterized post-metamorphic bullfrog diets from July – September 2015. Despite surveys in multiple large rivers and floodplain habitats, we only documented bullfrogs in a geothermal pond and 5 km of stream channel immediately downstream of this pond. In these waters, bullfrogs overlapped with native amphibians at the downstream end of their distribution, and we did not document native amphibians in bullfrog stomach contents. Larger bullfrogs (SVL ≥ 96 mm) primarily consumed native rodents (especially meadow voles, Microtus pennsylvanicus ), while smaller bullfrogs frequently consumed native invertebrates and less frequently consumed non-native invertebrates and fish. Taken together, these data indicate that the distribution and implications of the bullfrog invasion in Grand Teton National Park are currently localized to a small area, so these bullfrogs should therefore be vulnerable to eradication.

Wyoming↗

USGS2008

An integrated geophysical approach for groundwater and seismic hazard management in Joshua Tree National Park, southern California

Two‐dimensional inversion of audiomagnetotelluric (AMT) sounding data define buried resistivity distributions that reflect subsurface geology and structure within the upper kilometer beneath Pleasant Valley, a 1–2 km‐deep pull‐apart basin in Joshua Tree National Park, southern California. The Park lies within the Eastern California Shear Zone just east of the San Andreas Fault, and is surrounded by developing desert communities. Understanding the subsurface in and around the Park is important for management of groundwater resources, for mitigation of seismic hazards, and for unraveling the tectonic evolution of the region. Our resistivity models, interpreted in conjunction with gravity inversions, show transitions between coarse‐grained and fine‐grained alluvium, resistive (> 400 ohm‐m) crystalline rocks, and the locations of range‐front and intra‐basin faults.

California↗

USGS2019

Estimating visitor use and economic contributions of National Park visitor spending

This chapter provides an overview of the National Park Service (NPS) methods for estimating visitor spending and calculating economic contributions of visitor spending in terms of jobs supported, wage and labor income, and total economic activity. The Visitor Spending Effects model combines visitor spending patterns and trip characteristic data with visitor use data to estimate total visitor spending. Economic contributions measure the total economic activity within a regional economy stemming from visitor spending, and include the effects of spending by both local visitors who live within gateway regions and non-local visitors who travel to NPS sites from outside of gateway regions. The Social Science Program collaborates with individual parks to develop visitor counting instructions that contain the procedures for measuring, compiling, and recording required visitor use data. Visitor surveys are used to collect the essential visitor spending and trip characteristic data necessary for developing spending profiles to represent distinct visitor spending patterns for each park.

Book chapter↗

USGS1982

Status and distribution of ants in the Crater District of Haleakala National Park

The Crater District of Haleakala National Park was surveyed for ants. Three species were found. Argentine ants (Iridomyrmex humilis) occurred only within I km of the park headquarters and the nearby research facility. Hypoponera opaciceps was found in small numbers throughout the Crater District. Cardiocondyla emeryi was present only at the head of Kaupo Gap. Possible impacts of these ant species on the endemic, flightless insects of the park are discussed.

Hawaii↗

USGS2004

Relative spatial distributions and habitat use patterns of sympatric moose and white-tailed deer in Voyageurs National Park, Minnesota

We examined the distribution and home range characteristics of moose ( Alces alces ) and white-tailed deer ( Odocoileus virginianus ) at Voyageurs National Park, Minnesota. Pellet count transects revealed low densities of moose and higher densities of white-tailed deer, and provided evidence of partial spatial segregation between moose and white-tailed deer possibly due to habitat heterogeneity. There was limited interspecific overlap in the relatively large annual home ranges of radio-collared moose and white-tailed deer. Both moose and white-tailed deer exhibited significant selection for spruce ( Picea spp.) and balsam fir ( Abies balsamea ) vegetation types at the home range scale. White-tailed deer significantly selected a 12-20 m canopy height over all others while moose significantly selected 5-11 m and 21-30 m canopy heights over the 12-20 m canopy height. Moose significantly selected open/discontinuous canopy cover and white-tailed deer selected both closed/continuous and open/discontinuous canopy covers over dispersed/ sparse canopy cover. Differential habitat selection between moose and white-tailed deer at Voyageurs National Park might be related to the differences between these species' abilities to cope with a northern mid-continental climate. Spatial segregation between moose and white-tailed deer at Voyageurs National Park may allow moose to persist despite the presence of meningeal worm (P arelaphostrongylus tenuis ) in white-tailed deer.

Minnesota↗

USGS1961

The trout fishery in Shenandoah National Park

Populations of brook trout in streams of Shenandoah National Park were reduced drastically early in the past decade by a succession of unusually severe droughts and floods. The drying of stream beds, predation, and scouring were principal factors in the loss of fish. The park was closed to fishing in 1954 and 1955 to protect survivors. The small numbers of survivors quickly repopulated the streams after drought conditions abated. The stocking of hatchery-reared fingerling trout in selected waters failed to augment the recovery of populations. Survival and growth of young, wild trout were especially good. Their redistribution through miles of previously dry streams was rapid. The park was opened again to fishing in 1956 under regulations which restrict the take but afford an increase in sporting opportunity. Two streams were placed under fishing-for-fun-only regulations in 1961. The welfare of the trout populations is dependent mostly on the weather cycle . Fish may be abundant in wet years but very scarc e in dry ones. Thus, the stream must be managed a s marginal for trout.

Virginia↗

USGS1981

The status and distribution of ants in the Crater District of Haleakala National Park

Hawaii↗

USGS1995

Wolves and caribou in Denali National Park, Alaska

Management of gray wolves ( Canis lupus ) and their prey in interior Alaska has been controversial for three decades (Harbo and Dean 1983). Recently, debate was rekindled with renewed interest in wolf control to bolster two populations of caribou ( Rangifer tarandus ). Our research in Denali National Park provides insights into the declines in caribou numbers over the last few years that are the basis of recent wolf control proposals. Our observations of fluctuating populations also illustrate the complexity of managing these predator-prey systems to meet a diverse array of public interests. Wolves and caribou are two components of the large mammal community of Denali National Park that also includes grizzly bears ( Ursus arctos ), moose ( Alces alces ), and Dall sheep ( Ovis dalli ). With the 1980 park expansion to more than 18,800 km2 (7,300 mi2) of central Alaska, this large mammal system became the only one of its kind that is virtually unaffected by human harvest. Therefore, Denali provides a unique opportunity to understand the natural interactions of these species and serves as a baseline for comparison with areas where hunting or other active wildlife management occurs. We have studied Denali's wolves and caribou since 1986 to determine their numbers and status and understand their natural interactions in this protected subarctic ecosystem. Our studies began near the end of more than a decade of mostly light winter snowfalls of around 100 cm (39 in)/yr. Since winter 1988-89, we have experienced five consecutive winters with above-average snowfalls, including two record-setting years. During winters 1990-91 and 1992-93, more than 390 cm (154 in) of snow fell, four times as much as in the early years of our study. This change in snowfall had profound effects on the wildlife in central Alaska. The population trends of Denali's caribou and wolves are strong evidence of the natural fluctuations to be expected in species inhabiting such dynamic and variable environments.

Alaska↗

USGS1997

Fossil zooplankton and the historical status of westslope cutthroat trout in a headwater lake of Glacier National Park, Montana

Surviving pure-strain populations of westslope cutthroat trout Oncorhynchus clarki lewisi in headwater lakes of Glacier National Park could play an important role in the managed recovery of regional cutthroat trout fisheries. However, uncertainty exists about whether native trout could have naturally invaded several park lakes where they now occur. This study used paleolimnological techniques to address the question of whether the population of native trout in Avalanche Lake is indigenous or became established through an undocumented introduction. The validity of using fossil diapause eggs (ephippia) of the fish-sensitive cladocerans Daphnia spp. as indicators for the historical presence of zooplanktivorous fish was tested with a survey of live zooplankton and corresponding surface-sediment fossil assemblages in eight Glacier Park lakes with or without trout. Analysis of a sediment core from Avalanche Lake dated by lead radioisotopes, historical wildfires, and a flood allowed reconstruction of zooplankton dynamics from about 1700 A.D. to the present. Fossil Daphnia ephippia were rare or absent in Avalanche Lake sediments deposited before 1910, suggesting intense zooplanktivory due to sustained presence of an indigenous population of native cutthroat trout. Fossil evidence for larger Daphnia populations in the 1930s and early 1940s revealed a temporary disturbance of the lake's normal food web interactions during which zooplanktivory was significantly reduced. This disturbance may have resulted from a collapse of the native trout population caused indirectly by failed attempts between 1915 and 1943 to stock Avalanche Lake with Yellowstone cutthroat trout O. clarki bouvieri.

Transactions of the American Fisheries Society↗