United States National Park Service Research Articles

A Dataset of Amphibian Species in U.S. National Parks

National parks and other protected areas are important for preserving landscapes and biodiversity worldwide. An essential component of the mission of the United States (U.S.) National Park Service (NPS) requires understanding and maintaining accurate inventories of species on protected lands. We describe a new, national-scale synthesis of amphibian species occurrence in the NPS system. Many park units have a list of amphibian species observed within their borders compiled from various sources and available publicly through the NPSpecies platform. However, many of the observations in NPSpecies remain unverified and the lists are often outdated. We updated the amphibian dataset for each park unit by collating old and new park-level records and had them verified by regional experts. The new dataset contains occurrence records for 292 of the 424 NPS units and includes updated taxonomy, international and state conservation rankings, hyperlinks to a supporting reference for each record, specific notes, and related fields which can be used to better understand and manage amphibian biodiversity within a single park or group of parks.

Response of grassland birds to management in national battlefield parks

AbstractGrassland birds are in steep decline, with population declines reported in 74% of North American grassland species in the past 50 years. Declines are particularly severe in the eastern United States where they are influenced by habitat loss and alteration due to urbanization, forest regrowth, and agricultural intensification. The United States National Park Service maintains civil war battlefields in the eastern United States as historical and cultural parks that may also provide habitat refuge for grassland birds within an increasingly urbanized matrix. To assess the conservation importance of battlefield parks and the role of park management in sustaining grassland birds, we surveyed for 2 declining grassland‐breeding species, eastern meadowlark (Sturnella magna) and grasshopper sparrow (Ammodramus savannarum), at 242 points across 4 battlefield parks in Maryland, Virginia, and West Virginia, USA, from 2014–2019 and in 2021. We modeled the effects of park management activities (prescribed fire, agricultural leases, and delayed harvest) and habitat and landscape characteristics on breeding‐season occupancy. There was support for the influence of local habitat features, landscape, and management. Breeding‐season occupancy of both species was consistently higher in hayfields and pasture than in row crops, and both species responded positively to hay and crop harvest delays intended for grassland bird conservation. Prescribed fire within the past 2 years had a positive effect on occupancy of grasshopper sparrows but did not influence eastern meadowlarks. Eastern meadowlarks responded to land cover at multiple spatial scales that are influenced by land use within and outside the parks. Management activities that maintain the parks' cultural goals, including partnerships between national parks and private agricultural operators, are likely to provide valuable habitat for these 2 obligate grassland birds.

How much noise is too much? Methods for identifying thresholds for soundscape quality and ecosystem services

The United States National Park Service mandate is to conserve park resources and provide superlative visitor experience. In the context of acoustic resources, Denali National Park and Preserve provides an advantageous opportunity to understand the effect of aircraft noise on visitor experience because it possesses high levels of air tour traffic in a park renowned for its remote, wilderness character. Park visitors in four different settings were asked to rate the acceptability of recordings of aircraft noise, presented in randomized order relative to noise level. A cumulative link mixed model fitted visitor assessments to acoustic and nonacoustic factors. In addition to noise level, interest in an air tour was an important predictor of sound clip acceptability. For visitors uninterested in an air tour, the probability of rating aircraft noise as unacceptable at 54 dB LAeq,30 s or higher was 26%. For reference, this aligns with federal guidance that identified 55 dB as a threshold for interference with outdoor activities at rural residences and schools. Predictions of visitor response were joined to a spatial model of aircraft noise propagation to map visitor acceptability of aircraft noise in Denali’s entrance area (frontcountry). This map can be used to assess the condition of park management zones, to inform hiking recommendations for visitors, and to predict the range of soundscape conditions experienced by park visitors.

Climate resources for camping: A resource-based theory perspective

Camping is a salient economic contributor to nature-based tourism that is also beholden to the natural environment. Climate resources are the combination of naturally occurring meteorological variables of empirically observable importance to firm performance. Tourism climatologist are at the forefront of climate resource research, where investigations have been primarily empirically derived rather than guided by theory. Accordingly, we introduce climate resources to the management discipline's resource-based theory, operationalizing climate resources as public goods in addition to other public goods like open access innovation. We investigate the value, rareness, and inimitability of climate resources at 36 managed United States National Park Service campgrounds from 1984 to 2019. Results spatially and temporally demonstrate (1) the value of climate resources to firm performance, (2) that climate resource value varies geographically, and (3) that climate resources are becoming rarer at lower latitude and altitude geographies. Implications, limitations, and future research directions are provided.

Indicator Species Reveal Environmental Health

When looking around outside, many people see reasons to worry about the environment. Often what they notice are the effects of pollution and climate change, which can be harmful to people, wildlife, and the ecosystems where they live. Understanding the condition of all living and non-living things in an ecosystem is important for maintaining a healthy environment. But collecting information on every element in an ecosystem takes time and effort and is not always possible. Luckily, the United States National Park Service scientists know that collecting data on the condition of one species, called an indicator species, can reveal a lot about the well-being of other species in an ecosystem. Based on what they learn from observing and studying indicator species, park managers can make decisions about restoring plants, using chemicals, and posting signs about fishing rules. In Indiana Dunes National Park (Indiana, United States), researchers rely on frogs as indicator species.

Correlating gut microbial membership to brown bear health metrics

The internal mechanisms responsible for modulating physiological condition, particularly those performed by the gut microbiome (GMB), remain under-explored in wildlife. However, as latitudinal and seasonal shifts in resource availability occur, the myriad micro-ecosystem services facilitated by the GMB may be especially important to wildlife health and resilience. Here, we use brown bears (Ursus arctos) as an ecological model to quantify the relationship between wildlife body condition metrics that are commonly used to assess individual and population-level health and GMB community composition and structure. To achieve these aims, we subsampled brown bear fecal samples collected during United States National Park Service research activities at three National Parks and Preserves (Katmai, Lake Clark, and Gates of the Arctic) and extracted microbial DNA for 16S rRNA amplicon sequencing and microbial taxonomic classification. We analyzed GMB communities using alpha diversity indices, subsequently using Spearman’s correlation analysis to examine relationships between alpha diversity and brown bear health metrics. We found no differences in GMB composition among bears with differing body conditions, nor any correlations between alpha diversity and body condition. Our results indicate that GMB composition reflects diverse foraging strategies while allowing brown bears to achieve similar body condition outcomes.

Intrinsic and extrinsic factors influence on an omnivore’s gut microbiome

Gut microbiomes (GMBs), complex communities of microorganisms inhabiting the gastrointestinal tracts of their hosts, perform countless micro-ecosystem services such as facilitating energy uptake and modulating immune responses. While scientists increasingly recognize the role GMBs play in host health, the role of GMBs in wildlife ecology and conservation has yet to be realized fully. Here, we use brown bears (Ursus arctos) as an ecological model to (1) characterize GMB community composition associated with location, season, and reproductive condition of a large omnivore; (2) investigate how both extrinsic and intrinsic factors influence GMB community membership and structure; and (3) quantify differences in GMB communities among different locations, seasons, sex, and reproductive conditions. To achieve these aims, we subsampled brown bear fecal samples collected during United States National Park Service research activities at three National Parks and Preserves (Katmai, Lake Clark, and Gates of the Arctic) and extracted microbial DNA for 16S rRNA amplicon sequencing and microbial taxonomic classification. We analyzed GMB communities using alpha and beta diversity indices, subsequently using linear mixed models to examine relationships between alpha diversity and extrinsic and intrinsic factors. Katmai brown bears hosted the greatest alpha diversity, whereas Gates brown bears hosted the least alpha diversity. Our results indicate that location and diet drive GMB variation, with bears hosting less phylogenetic diversity as park distance inland increases. Monitoring brown bear GMBs could enable managers to quickly detect and assess the impact of environmental perturbations on brown bear health. By integrating macro and micro-ecological perspectives we aim to inform local and landscape-level management decisions to promote long-term brown bear conservation and management.

(Re)Centering socioenvironmental justice: Thinking about co-management of and access to parks and protected areas in the United States

An international group of graduate students utilized the 2021 George Wright Society Student Summit to come together and discuss potential practices to bolster socioenvironmental justice implementation within the United States National Park Service (NPS). Focusing on accessibility and co-management perspectives, this group reflected on various definitions of terms, historical contexts of the Park Service nationally and globally, and how partnerships are essential to inclusivity and relevance building. This led to further discourse about potential methods of incorporating socioenvironmental justice aims into specific areas of NPS by reviewing its current practices and global case studies surrounding accessibility and co-management of protected areas. Major conclusions emphasize streamlining definitions surrounding access, accessibility, and co-management; understanding that co-management is not a monolithic framework but one dependent on local communities; continued recognition of historical exclusions of marginalized peoples; and embracing partnerships by providing stakeholders with equal positions of power, authority, and access. This thought piece aims to catalyze discourse surrounding a potential transition toward more inclusive co-management practices within US protected areas, while still remaining true to the missions and goals of their respective organizations. We recognize and do not intend to discredit any of the work that NPS and other organizations have produced towards improving sustainable co-management strategies, but rather suggest that there is always room for improvement. In doing so, we offer some potential strategies and big picture notions to be mindful of when engaging in socially just co-management practices.

Reconnaissance of cumulative risk of pesticides and pharmaceuticals in Great Smoky Mountains National Park streams

The United States (US) National Park Service (NPS) manages protected public lands to preserve biodiversity. Exposure to and effects of bioactive organic contaminants in NPS streams are challenges for resource managers. Recent assessment of pesticides and pharmaceuticals in protected-streams within the urbanized NPS Southeast Region (SER) indicated the importance of fluvial inflows from external sources as drivers of aquatic contaminant-mixture exposures. Great Smoky Mountains National Park (GRSM), lies within SER, has the highest biodiversity and annual visitation of NPS parks, but, in contrast to the previously studied systems, straddles a high-elevation hydrologic divide; this setting limits fluvial-inflows of contaminants but potentially increases visitation-driven contaminant deliveries. We leveraged the unique characteristics of GRSM to test further the importance of fluvial contaminant inflows as drivers of protected-stream exposures and to inform the relative importance of potential additional contaminant transport mechanisms, by comparing the estimated risks of 328 pesticides and pharmaceuticals in water at 16 GRSM stream locations to those estimated previously in SER streams. Extensive mixtures (31 compounds) were only observed in an atypical reach on the boundary of GRSM downstream of a wastewater discharge, while limited mixtures (2–5 compounds) were observed in one stream with elevated visitation pressure (recreational “tube floating”). The insecticide, imidacloprid, used to eradicate hemlock woolly adelgid, was detected in 8 (50%) streams. Infrequent exceedances of a cumulative ToxCast-based, exposure-activity ratio (ΣEAR) 0.001 screening-level of concern suggested limited risk to non-target, aquatic vertebrates, whereas exceedances of a cumulative benchmark-based, invertebrate toxicity quotient (ΣTQ) 0.1 screening level at 8 locations indicated generally high risk to invertebrates. The results are consistent with the importance of fluvial transport from extra-park sources as a driver of bioactive-contaminant mixture exposures in protected streams and illustrate the potential additional risks from visitation-driven and tactical-use-pesticides.

Climate change assessment using spatial climate datasets: Theodore Roosevelt National Park (South Unit), 1895-2019

Climate change poses a major challenge to park managers of the United States National Park Service. Several studies have surveyed system-wide climate change, but limited funds prevent the development of local-scale climate change studies. We examined climate change at Theodore Roosevelt National Park (South Unit) in Medora, North Dakota (USA), using spatial climate datasets. We surveyed the period 1895-2019 to provide a long-term perspective, and more closely analyzed the period 1960-2019, when the quality assurance of the database was highest, concerns over anthropogenic climate change effects were greatest, and relevance to current management was most critical. Our results show moderate changes over the past 60 yr. Interannual and decadal-scale climatic variation dominated long-term climate and weakened the statistical significance of most long-term climate trends. The most pronounced changes were an increase in mean annual minimum air temperature and a decrease in mean annual diurnal temperature range. Mean annual precipitation showed a small increase, while an increase in fall precipitation was the most pronounced seasonal precipitation change. Estimated snow water equivalent and snow fraction increased slightly. Climatic water balance results indicate an increase in mean annual soil moisture storage and annual moisture index. Vegetation growing season changes include an increase in the frost-free season length but a decrease in the length of the thermal growing season. The sign and magnitude of change of individual climate variables is sensitive to the period of record examined. Study results provide a baseline for park managers to assess climate change impacts upon grassland productivity, wildfire hazard, and invasive species, and reveal an opportunity to lengthen the tourism season in this summer peak tourism climate.

A National-Scale Assessment of Mercury Bioaccumulation in United States National Parks Using Dragonfly Larvae As Biosentinels through a Citizen-Science Framework.

We conducted a national-scale assessment of mercury (Hg) bioaccumulation in aquatic ecosystems, using dragonfly larvae as biosentinels, by developing a citizen-science network to facilitate biological sampling. Implementing a carefully designed sampling methodology for citizen scientists, we developed an effective framework for a landscape-level inquiry that might otherwise be resource limited. We assessed the variation in dragonfly Hg concentrations across >450 sites spanning 100 United States National Park Service units and examined intrinsic and extrinsic factors associated with the variation in Hg concentrations. Mercury concentrations ranged between 10.4 and 1411 ng/g dry weight across sites and varied among habitat types. Dragonfly total Hg (THg) concentrations were up to 1.8-fold higher in lotic habitats than in lentic habitats and 37% higher in waterbodies with abundant wetlands along their margins than those without wetlands. Mercury concentrations in dragonflies differed among families but were correlated (r2 > 0.80) with each other, enabling adjustment to a consistent family to facilitate spatial comparisons among sampling units. Dragonfly THg concentrations were positively correlated with THg concentrations in both fish and amphibians from the same locations, indicating that dragonfly larvae are effective indicators of Hg bioavailability in aquatic food webs. We used these relationships to develop an integrated impairment index of Hg risk to aquatic ecosytems and found that 12% of site-years exceeded high or severe benchmarks of fish, wildlife, or human health risk. Collectively, this continental-scale study demonstrates the utility of dragonfly larvae for estimating the potential mercury risk to fish and wildlife in aquatic ecosystems and provides a framework for engaging citizen science as a component of landscape Hg monitoring programs.

Exposure and potential effects of pesticides and pharmaceuticals in protected streams of the US National park Service southeast region

Globally, protected areas offer refugia for a broad range of taxa including threatened and endangered species. In the United States (US), the National Park Service (NPS) manages public lands to preserve biodiversity, but increasing park visitation and development of surrounding landscapes increase exposure to and effects from bioactive contaminants. The risk (exposure and hazard) to NPS protected-stream ecosystems within the highly urbanized southeast region (SER) from bioactive contaminants was assessed in five systems based on 334 pesticide and pharmaceutical analytes in water and 119 pesticides in sediment. Contaminant mixtures were common across all sampled systems, with approximately 24% of the unique analytes (80/334) detected at least once and 15% (49/334) detected in half of the surface-water samples. Pharmaceuticals were observed more frequently than pesticides, consistent with riparian buffers and concomitant spatial separation from non-point pesticide sources in four of the systems. To extrapolate exposure data to biological effects space, site–specific cumulative exposure-activity ratios (ΣEAR) were calculated for detected surface-water contaminants with available ToxCast data; common exceedances of a 0.001 ΣEAR effects-screening threshold raise concerns for molecular toxicity and possible, sub-lethal effects to non-target, aquatic vertebrates. The results illustrate the need for continued management of protected resources to reduce contaminant exposure and preserve habitat quality, including prioritization of conservation practices (riparian buffers) near stream corridors and increased engagement with upstream/up-gradient property owners and municipal wastewater facilities.

Highlights from 10+ Years of Lichenological Research in Great Smoky Mountains National Park: Celebrating the United States National Park Service Centennial

Abstract—Great Smoky Mountains National Park is renowned as one of the most biologically diverse tracts of land in North America and is the most visited national park in the United States. The park comprises ∼830 square miles, epitomizes eastern temperate hardwood forests of North America, and serves as a refuge for nearly 20,000 documented species from microbes to plants and mammals. Lichens comprise one particularly diverse group of organisms in the park. In this study, we review data from our 11 years of lichenological research in Great Smoky Mountains National Park. Based on approximately 6,000 new field collections generated, the park checklist now includes 920 species, a 129% increase over estimates made two decades ago. Nearly a quarter of the lichens reported in the park are known from only a single occurence whereas only 7% of the lichens are known from 20 or more occurences. An assessment of commonness/rarity for all 920 species indicates that nearly half of the park's lichens should be considered to be infrequent, rare, or exceptionally rare. We assessed the distributions of all 920 species and found that 54 are endemic to the southeastern United States, 30 are endemic to the southern Appalachians, and eight occur nowhere else than within the confines of the national park. We discuss biogeographical affinities of the park's lichen biota as a whole, delimiting six regional “floristic” connections. Our 11 years of research have resulted in the discovery of several species presumed to be extinct or near-extinct. We make one new combination (Fuscopannaria frullaniae) and describe five species as new to science, each commemorating National Park Service staff instrumental to the completion of the study: Heterodermia langdoniana, Lecanora darlingiae, Lecanora sachsiana, Leprocaulon nicholsiae, and Pertusaria superiana.

Small Islands and Marginality: Santa Barbara Island and its Role in the Prehistory of California’s Channel Islands

ABSTRACTAs the smallest of California’s Channel Islands, Santa Barbara Island has received limited attention from archaeologists. A United States National Park Service project designed to assess its 19 known sites evolved into an island-wide survey that increased the number to 63 sites that date between 4000 and 600 years ago. Most are small shell and lithic scatters, although some are larger shell middens with greater faunal and artifact diversity. Their constituents and geographic distribution indicate that the island not only served as a stopover during inter-island travel but was occupied for longer periods to target local resources such as marine mammal rookeries. Our research presents an opportunity to evaluate the significance of this island to prehistoric communities throughout the archipelago. On a broader level, it provides insights into the important roles that small islands have played in prehistoric lifeways as well as perceptions of marginality.

한국과 미국의 국립공원 해설사 교육훈련 체계의 역사적 변천과정과 그 요인

The purpose of this study was to compare how and why the United States National Park Service and the Korea National Park Service have changed their interpreter development programs in terms of curriculum, trainers and training methods, and training achievement evaluation. A close look at the historical documents and in-depth interviews with related people suggested that there have been four major eras in terms of the US NPS interpreter development programs: the beginning era (1925-1952), the establishment era (1953-1981), the development era (1982-1995), and the advancement era (1996-current). Results also indicated there have been two important ears in the KNPS interpreter development program: the beginning era (2000-2011), and the establishment era (2012-current). Results showed that legal, organizational, academic, and technological factors have influenced the changes of both institutions’ interpreter development programs. Practical implications for the innovation of the KNPS interpreter development program and limitations of the study are discussed at the end.

Discovering archaeological landscapes in parks and protected areas

Monitoring cultural resources in parks and protected areas is greatly enhanced using Light Detection and Ranging (LiDAR). For this example, a pilot inventory of cultural resources is illustrated for the United States National Park Service lands that protect the Appalachian Trail in Massachusetts. In Massachusetts, the trail stretches 145.2 kilometers (90.2 miles) and is protected by nearly 2052 hectares (5070 acres) of land. To aid in the resource monitoring, these remote sensing data are corroborated with historic records to identify the historical archaeological resources in the corridor. The inventory are then added to existing management plans to help protect the national park with a more complete understanding of the historical human impacts in the backcountry of New England.

Valuing Our National Parks: An Ecological Economics Perspective

The annual budget for the United States National Park Service was roughly $3 billion in 2016. This is distributed amongst 405 National Parks, 23 national scenic and historic trails, and 60 wild and scenic rivers. Entrance fees and concessions generate millions of dollars in income for the National Park Service; however, this metric fails to account for the total value of the National Parks. In failing to consider the value of the ecosystem services provided by the National Parks, we fail to quantify and appreciate the contributions our parks make to society. This oversight allows us to continue to underfund a valuable part of our natural capital and consequently damage our supporting environment, national heritage, monetary economy, and many of our diverse cultures. We explore a simple benefits transfer valuation of the United States’ national parks using National Land Cover Data from 2011 and ecosystem service values determined by Costanza et al. This produces an estimate suggesting the parks provide $98 billion/year in ecosystem service value. If the natural infrastructure ‘asset’ that is our national park system had a budget comparable to a piece of commercial real estate of this value, the annual budget of the National Park Service would be roughly an order of magnitude larger at something closer to $30 billion rather than $3 billion.

Effects of control on the dynamics of an adjacent protected wolf population in interior Alaska

Effects of control on the dynamics of an adjacent protected wolf population in interior Alaska

Old Field Communities and Restoration Potential at Mammoth Cave National Park, USA

Abstract Old fields (at least 67 years since abandonment) within Mammoth Cave National Park, USA are dominated by coniferous species (Juniperus virginiana L. and Pinus virginiana) instead of the desired deciduous species (Carya glabra, Quercus alba, Q. muehlenbergii, Q. prinus, and Q. velutina) that dominate much of the rest of the park. Species composition above ground and in the seedbank of old fields and adjacent desired future condition areas, (identified by the United States National Park Service (NPS) as oak and hickory-dominated) were evaluated and compared. Species composition and dominance have shifted from oak species toward conifer-dominated stands due to previous land conversion to agriculture and the exclusion of fire. Management practices that can be implemented by the NPS to alter the condition of the old fields to achieve the desired future condition include thinning treatments and reintroduction of the historic fire regime.

Development and validation of satellite-based estimates of surface visibility

Abstract. A satellite-based surface visibility retrieval has been developed using Moderate Resolution Imaging Spectroradiometer (MODIS) measurements as a proxy for Advanced Baseline Imager (ABI) data from the next generation of Geostationary Operational Environmental Satellites (GOES-R). The retrieval uses a multiple linear regression approach to relate satellite aerosol optical depth, fog/low cloud probability and thickness retrievals, and meteorological variables from numerical weather prediction forecasts to National Weather Service Automated Surface Observing System (ASOS) surface visibility measurements. Validation using independent ASOS measurements shows that the GOES-R ABI surface visibility retrieval (V) has an overall success rate of 64.5 % for classifying clear (V ≥ 30 km), moderate (10 km ≤ V < 30 km), low (2 km ≤ V < 10 km), and poor (V < 2 km) visibilities and shows the most skill during June through September, when Heidke skill scores are between 0.2 and 0.4. We demonstrate that the aerosol (clear-sky) component of the GOES-R ABI visibility retrieval can be used to augment measurements from the United States Environmental Protection Agency (EPA) and National Park Service (NPS) Interagency Monitoring of Protected Visual Environments (IMPROVE) network and provide useful information to the regional planning offices responsible for developing mitigation strategies required under the EPA's Regional Haze Rule, particularly during regional haze events associated with smoke from wildfires.