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At least 55 records · Page 3Linked to original sources
USGS2002

Management practices that concentrate visitor activities: Camping impact management at Isle Royale National Park, USA

This study assessed campsite conditions and the effectiveness of campsite impact management strategies at Isle Royale National Park, USA. Protocols for assessing indicators of vegetation and soil conditions were developed and applied to 156 campsites and 88 shelters within 36 backcountry campgrounds. The average site was 68 m 2 and 83% of sites lost vegetation over areas less than 47 m 2 . We believe that management actions implemented to spatially concentrate camping activities and reduce camping disturbance have been highly successful. Comparisons of disturbed area/overnight stay among other protected areas reinforces this assertion. These reductions in area of camping disturbance are attributed to a designated site camping policy, limitation on site numbers, construction of sites in sloping terrain, use of facilities, and an ongoing program of campsite maintenance. Such actions are most appropriate in higher use backcountry and wilderness settings.

Isle Royale National Park↗
USGS2012

The impact of antecedent fire area on burned area in southern California coastal ecosystems

Frequent wildfire disasters in southern California highlight the need for risk reduction strategies for the region, of which fuel reduction via prescribed burning is one option. However, there is no consensus about the effectiveness of prescribed fire in reducing the area of wildfire. Here, we use 29 years of historical fire mapping to quantify the relationship between annual wildfire area and antecedent fire area in predominantly shrub and grassland fuels in seven southern California counties, controlling for annual variation in weather patterns. This method has been used elsewhere to measure leverage: the reduction in wildfire area resulting from one unit of prescribed fire treatment. We found little evidence for a leverage effect (leverage = zero). Specifically our results showed no evidence that wildfire area was negatively influenced by previous fires, and only weak relationships with weather variables rainfall and Santa Ana wind occurrences, which were variables included to control for inter-annual variation. We conclude that this is because only 2% of the vegetation burns each year and so wildfires rarely encounter burned patches and chaparral shrublands can carry a fire within 1 or 2 years after previous fire. Prescribed burning is unlikely to have much influence on fire regimes in this area, though targeted treatment at the urban interface may be effective at providing defensible space for protecting assets. These results fit an emerging global model of fire leverage which position California at the bottom end of a continuum, with tropical savannas at the top (leverage = 1: direct replacement of wildfire by prescribed fire) and Australian eucalypt forests in the middle (leverage ∼ 0.25).

California↗
USGS2010

Spawning by walleye (Sander vitreus) and white sucker (Catostomus commersoni) in the Detroit River: Implications for spawning habitat enhancement

Few active fish spawning grounds have been found in channels connecting the Great Lakes. Here, we describe one near Belle Isle in the Detroit River, part of the channel connecting lakes Huron and Erie. There, in 2005, we collected 1,573 fish eggs, cultured them, and identified the hatched larvae as walleye (Sander vitreus) and white sucker (Catostomus commersoni). Walleye spawning peaked during the week of April 12-19; white sucker spawning peaked on May 10. Average areal rate of egg deposition by walleye and white sucker at this spawning ground in 2005 was 346 and 25 eggs/m2, respectively. Our environmental measurements showed that bottom substrates on this spawning ground were largely sand, not optimal for fish reproduction. We hypothesize that reproduction of these fish at this spawning ground could be enhanced by adding rock and gravel substrates for protection of deposited fish eggs and suggest that reproduction by walleye in the Detroit River may add resilience to production of walleye in western Lake Erie. ?? 2010.

Journal of Great Lakes Research↗
USGS2024

Trail sustainability broadly defined

In this paper we provide a concise yet comprehensive examination of the importance and sustainability of trail networks, considering a diverse array of perspectives. Sustainability related to recreation infrastructure elements has been variously defined, with different disciplines often only considering one or two aspects of sustainability. In the context of trail networks, we suggest that there must be an equilibrium or harmony between human uses and the long-term sustainable management of the trail network's infrastructure, its protections of environmental and historic/cultural resources, and provision of diverse socio-economic benefits to visitors and surrounding communities. While trail sustainability has often been narrowly defined as accommodating visitation while minimizing environmental degradation, we emphasize a broader definition that encompasses four interconnected domains: managerial, resource, social, and economic. We suggest that a network of trails cannot be truly sustainable until scientists, land managers, and trail stewards fully consider and effectively address each of these dimensions.

Journal of Outdoor Recreation and Tourism↗
USGS2013

Effects of climate change and urban development on the distribution and conservation of vegetation in a Mediterranean type ecosystem

Climate and land-use changes are projected to threaten biodiversity over this century. However, few studies have considered the spatial and temporal overlap of these threats to evaluate how ongoing land-use change could affect species ranges projected to shift outside conservation areas. We evaluated climate change and urban development effects on vegetation distribution in the Southwest ecoregion, California Floristic Province, USA. We also evaluated how well a conservation network protects suitable habitat for rare plant species under these change projections and identified primary sources of uncertainty. We used consensus-based maps from three species distribution models (SDMs) to project current and future suitable habitat for 19 species representing different functional types (defined by fire-response – obligate seeders, resprouting shrubs – and life forms – herbs, subshrubs), and range sizes (large/common, small/rare). We used one spatially explicit urban growth projection; two climate models, emission scenarios, and probability thresholds applied to SDMs; and high-resolution (90 m) environmental data. We projected that suitable habitat could disappear for 4 species and decrease for 15 by 2080. Averaged centroids of suitable habitat (all species) were projected to shift tens (up to hundreds) of kilometers. Herbs showed a small-projected response to climate change, while obligate seeders could suffer the greatest losses. Several rare species could lose suitable habitat inside conservation areas while increasing area outside. We concluded that (i) climate change is more important than urban development for vegetation habitat loss in this ecoregion through 2080 due to diminishing amounts of undeveloped private land in this region; (ii) the existing conservation plan, while extensive, may be inadequate to protect plant diversity under projected patterns of climate change and urban development, (iii) regional assessments of the dynamics of the drivers of biodiversity change based on high-resolution environmental data and consensus predictive mapping, such as this study, are necessary to identify the species expected to be the most vulnerable and to meaningfully inform regional-scale conservation.

California↗
USGS2024

Droughts reshape apex predator space use and intraguild overlap

1. Droughts are increasing in frequency and severity globally due to climate change, leading to changes in resource availability that may have cascading effects on animal ecology. Resource availability is a key driver of animal space use, which in turn influences interspecific interactions like intraguild competition. Understanding how climate-induced changes in resource availability influence animal space use, and how species-specific responses scale up to affect intraguild dynamics, is necessary for predicting broader community-level responses to climatic changes. 2. Although several studies have demonstrated the ecological impacts of drought, the behavioral responses of individuals that scale up to these broader-scale effects are not well known, particularly among animals in top trophic levels, such as large carnivores. Furthermore, we currently lack understanding of how the impacts of climate variability on individual carnivore behavior are linked to intraguild dynamics, in part because multi-species datasets collected at timescales relevant to climatic changes are rare. 3. Using 11 years of GPS data from four sympatric large carnivore species in southern Africa – lions ( Panthera leo ), leopards ( Panthera pardus ), African wild dogs ( Lycaon pictus) , and cheetahs ( Acinonyx jubatus ) – spanning 4 severe drought events, we test whether drought conditions impact 1) large carnivore space use, 2) broad-scale intraguild spatial overlap, and 3) fine-scale intraguild interactions. 4. Drought conditions expanded space use across species, with carnivores increasing their monthly home range sizes by 35% (wild dogs) to 66% (leopards). Drought conditions increased the amount of spatial overlap between lions and subordinate felids (cheetahs and leopards) by up to 119%, but only lion-cheetah encounter rates were affected by these changes, declining in response to drought. 5. Our findings reveal that drought has a clear signature on the space use of multiple sympatric large carnivore species, which can alter spatiotemporal partitioning between competing species. Our study thereby illuminates the links between environmental change, animal behavior, and intraguild dynamics. While fine-scale avoidance strategies may facilitate intraguild coexistence during periodic droughts, large carnivore conservation may require considerable expansion of protected areas or revised human-carnivore coexistence strategies to accommodate the likely long-term increased space demands of large carnivores under projected increases in drought intensity.

Okavango Delta↗
USGS2014

Consequences of habitat change and resource selection specialization for population limitation in cavity-nesting birds

Resource selection specialization may increase vulnerability of populations to environmental change. One environmental change that may negatively impact some populations is the broad decline of quaking aspen Populus tremuloides , a preferred nest tree of cavity-nesting organisms who are commonly limited by nest-site availability. However, the long-term consequences of this habitat change for cavity-nesting bird populations are poorly studied. I counted densities of woody plants and eight cavity-nesting bird species over 29 years in 15 high-elevation riparian drainages in Arizona, USA. I also studied nest-tree use and specialization over time based on 4946 nests across species. Aspen suffered a severe decline in availability over time, while understorey woody plants and canopy deciduous trees also declined. The decline of plants resulted from increased elk Cervus canadensis browsing linked to declining snowfall. Woodpeckers exhibited very high specialization (>95% of nests) on aspen for nesting, and densities of all six species declined with aspen over time. Mountain chickadees Poecile gambeli and house wrens Troglodytes aedon exhibited increasingly less specialization on aspen. Chickadees strongly increased in density over time, despite a relatively high specialization on aspen. House wren densities declined moderately over time, but nest-box addition experiments demonstrated that nest-site availability was not limiting their population. House wren densities increased with understorey vegetation recovery in elk exclosures via increased generality of nest-site use, demonstrating that the decline in understorey vegetation on the broader landscape was the cause of their population decline. Synthesis and applications . Management should target species that specialize in resource selection on a declining resource. Species with greater resource selection generalization can reduce population impacts of environmental change. Resource generalization can allow a species like the wren to take advantage of habitat refuges, such as those provided by the elk exclosures. Yet, resource generalization cannot offset the negative impacts of broad-scale declines in habitat quality on the landscape, as demonstrated by the general decline of wrens. Ultimately, aspen is an important habitat for biodiversity, and land management programmes that protect and aid recovery of aspen habitats may be critical.

Journal of Applied Ecology↗
USGS2013

Effects of grazing on leaf area index, fractional cover and evapotranspiration by a desert phreatophyte community at a former uranium mill site on the Colorado Plateau

This study employed ground and remote sensing methods to monitor the effects of grazing on leaf area index (LAI), fractional cover (f c ) and evapotranspiration (ET) of a desert phreatophyte community over an 11 year period at a former uranium mill site on the Colorado Plateau, U.S. Nitrate, ammonium and sulfate are migrating away from the mill site in a shallow alluvial aquifer. The phreatophyte community, consisting of Atriplex canescens (ATCA) and Sarcobatus vermiculatus (SAVE) shrubs, intercepts groundwater and could potentially slow the movement of the contaminant plume through evapotranspiration (ET). However, the site has been heavily grazed by livestock, reducing plant cover and LAI. We used livestock exclosures and revegetation plots to determine the effects of grazing on LAI, f c and ET, then projected the findings over the whole site using multi-platform remote sensing methods. We show that ET is approximately equal to annual precipitation at the site, but when ATCA and SAVE are protected from grazing they can develop high f c and LAI values, and ET can exceed annual precipitation, with the excess coming from groundwater discharge. Therefore, control of grazing could be an effective method to slow migration of contaminants at this and similar sites in the western U.S.

Colorado Plateau↗
USGS2007

Development of an SPE/CE method for analyzing HAAs

A method to analyze haloacetic acids (HAAs) in drinking water was developed using a capillary electrophoresis (CE) ion analyzer for analyte separation and detection. The effects of background electrolyte (BGE) composition, sample injection approach, and on- and offcapillary preconcentration techniques on HAA peak resolution and method sensitivity were evaluated. The recommended BGE consists of 25 mM phosphate buffer at pH 5.7 with 1 mM tetradecyltrimethylammonium hydroxide as the electroosmotic flow modifier. Aqueous samples were preconcentrated using solid-phase extraction (SPE) and then loaded onto an extended light path capillary (75-μm inside diameter ÷ 56-cm effective length) using pressure injection (50 mbar for 12 s). The estimated method detection limits were in the range of 1.5–3.5 μg/L. The SPE/CE method was used to analyze ambient and spiked water samples from a water distribution system, and results were in good agreement with those using US Environmental Protection Agency method 552.2. The main advantage of the SPE/CE method over the currently approved HAA analysis methods is that it does not require HAA derivatization, which involves potentially hazardous chemicals and conditions. Disadvantages of the SPE/CE method are that it does not offer a significant time savings (because of the need for off-capillary sample preconcentration) and chlorodibromoacetic acid could not be quantified because of interference from a contaminant peak.

Journal - American Water Works Association↗
USGS2025

Suspended sediment and fisheries: An exploration of empirical relationships

Objective: Sediment has an important role in aquatic ecosystems, however, excess sediment can negatively impact fish and other aquatic life. Quantifying the response of aquatic life, particularly fish, to suspended sediment is important for natural resource managers tasked with developing sediment management guidelines to protect aquatic ecosystems. Our goal was to assess the ability of established, revised, and alternate severity of ill effect (SEV) dose-response models to predict the impact of suspended sediment on fish. Methods: We synthesized existing literature to develop an expansive dataset that relates suspended sediment concentration and exposure duration to biological effects on fishes and assessed the predictive ability of established and revised SEV dose-response models. We investigated potential sources of variation in biological responses to suspended sediment dose and explored two alternative approaches for assessing the effects of suspended sediment on fish: 90th quantile SEV dose-response regression models and logistic SEV dose-response models. Results: We found that both established and revised linear SEV dose-response models poorly quantify fish biological response to suspended sediment. Quantile SEV dose-response regressions also performed poorly. More promising are logistic dose-response models that identify sediment thresholds where major effects of sediment on fish can be expected to occur. We demonstrate that fish biological response to suspended sediment is modulated by sediment particle size, water temperature, and dissolved oxygen levels, suggesting additional environmental and biological variables to consider when evaluating the effects of suspended sediment on fish. Conclusion: We contribute revised and novel empirically derived tools for predicting the effects of suspended sediment on fish and demonstrate how environmental variables and life stage may modulate fish biological response. Our work illustrates challenges associated with predictive modeling and some potential sources of variation. While empirical models integrating biological stress response to suspended sediment may help natural resource managers capture potential impacts of this stressor, a cautious approach that considers co-acting stressors may be most effective for sediment management that is protective of fish.

North American Journal of Fisheries Management↗
USGS2005

Glyphosate, other herbicides, and transformation products in Midwestern streams, 2002

The use of glyphosate has increased rapidly, and there is limited understanding of its environmental fate. The objective of this study was to document the occurrence of glyphosate and the transformation product aminomethylphosphonic acid (AMPA) in Midwestern streams and to compare their occurrence with that of more commonly measured herbicides such as acetochlor, atrazine, and metolachlor. Water samples were collected at sites on 51 streams in nine Midwestern states in 2002 during three runoff events: after the application of pre‐emergence herbicides, after the application of post‐emergence herbicides, and during harvest season. All samples were analyzed for glyphosate and 20 other herbicides using gas chromatography/mass spectrometry or high performance liquid chromatography/mass spectrometry. The frequency of glyphosate and AMPA detection, range of concentrations in runoff samples, and ratios of AMPA to glyphosate concentrations did not vary throughout the growing season as substantially as for other herbicides like atrazine, probably because of different seasonal use patterns. Glyphosate was detected at or above 0.1 μg/1 in 35 percent of pre‐emergence, 40 percent of post‐emergence, and 31 percent of harvest season samples, with a maximum concentration of 8.7 μg/1. AMPA was detected at or above 0.1 μg/1 in 53 percent of pre‐emergence, 83 percent of post‐emergence, and 73 percent of harvest season samples, with a maximum concentration of 3.6 μg/1. Glyphosate was not detected at a concentration at or above the U.S. Environmental Protection Agency's maximum contamination level (MCL) of 700 μg/1 in any sample. Atrazine was detected at or above 0.1 μg/1 in 94 percent of pre‐emergence, 96 percent of post‐emergence, and 57 percent of harvest season samples, with a maximum concentration of 55 μg/1. Atrazine was detected at or above its MCL (3 μg/1) in 57 percent of pre‐emergence and 33 percent of post‐emergence samples.

Illinois, Indiana, Iowa, Kansas, Michigan, Minneso↗
USGS2013

Deriving Chesapeake Bay Water Quality Standards

Achieving and maintaining the water quality conditions necessary to protect the aquatic living resources of the Chesapeake Bay and its tidal tributaries has required a foundation of quantifiable water quality criteria. Quantitative criteria serve as a critical basis for assessing the attainment of designated uses and measuring progress toward meeting water quality goals of the Chesapeake Bay Program partnership. In 1987, the Chesapeake Bay Program partnership committed to defining the water quality conditions necessary to protect aquatic living resources. Under section 303(c) of the Clean Water Act, States and authorized tribes have the primary responsibility for adopting water quality standards into law or regulation. The Chesapeake Bay Program partnership worked with U.S. Environmental Protection Agency to develop and publish a guidance framework of ambient water quality criteria with designated uses and assessment procedures for dissolved oxygen, water clarity, and chlorophyll a for Chesapeake Bay and its tidal tributaries in 2003. This article reviews the derivation of the water quality criteria, criteria assessment protocols, designated use boundaries, and their refinements published in six addendum documents since 2003 and successfully adopted into each jurisdiction's water quality standards used in developing the Chesapeake Bay Total Maximum Daily Load.

Chesapeake Bay↗
USGS1996

Trail degradation as influenced by environmental factors: A state-of-the-knowledge review

Excerpt: Human use and misuse of land has been causing extensive degradation of the very natural resources on which we depend. National parks, wilderness and other protected natural or semi-natural areas (referred to as natural areas hereafter) represent efforts to preserve our natural heritage from further exploitation. Such areas also provide outstanding recreational, research, and educational opportunities. However, resource impacts resulting from overuse and inappropriate management increasingly threaten these protected areas and erode their natural and cultural values. Among the many forms of recreational impact, those associated with trail development and use are often a major concern of natural area managers and visitors. Such impacts impair and degrade the functions that trails serve, including (1) protecting resources by concentrating traffic on a hardened tread, (2) providing recreational opportunities along aesthetically pleasing trail routes, and (3) facilitating recreational use by providing a transportation network. The extensive distribution of trails and their degrading condition in many natural areas can have pervasive environmental effects through alteration of natural drainage patterns, erosion and deposition of soil, introduction of exotic vegetation, and increasing human-wildlife conflicts. Degraded trails also threaten the quality of visitor experiences by making travel difficult or unsafe, or by diminishing visitors ?

Journal of Soil and Water Conservation↗
USGS1999

Effectiveness of an existing estuarine no-take fish sanctuary within the Kennedy Space Center, Florida

Approximately 22% of the waters of the Merritt Island National Wildlife Refuge, which encompasses the Kennedy Space Center, Florida, have been closed to public access and fishing since 1962. These closed areas offer an opportunity to test the effectiveness of “no-take” sanctuaries by analyzing two replicated estuarine areas. Areas open and closed to fishing were sampled from Nov 1986 to Jan 1990 with 653 random trammel-net sets, each enclosing 3,721 m 2 . Samples from no-fishing areas had significantly (P < 0.05) greater abundance and larger fishes than fished areas. Relative abundance (standardized catch per unit effort, CPUE) in protected areas (6.4 fish/set) was 2.6 times greater than in the fished areas (2.4 fish/set) for total game fish, 2.4 times greater for spotted seatrout Cynoscion nebulosus , 6.3 times greater for red drum Sciaenops ocellatus, 12.8 times greater for black drum Pogonias cromis , 5.3 times greater for common snook Centropomus undecimalis , and 2.6 times greater for striped mullet Mugil cephalus . Fishing had the primary effect on CPUE, independent of habitat and other environmental factors. Salinity and depth were important secondary factors affecting CPUE, followed by season or month, and temperature. The importance of specific factors varied with each species. Median and maximum size of red drum, spotted seatrout, black drum, and striped mullet were also significantly greater in the unfished areas. More and larger fish of spawning age were observed in the unfished areas for red drum, spotted seatrout, and black drum. Tagging studies documented export of important sport fish from protected areas to fished areas.

Florida↗
USGS1997

Logistic model of nitrate in streams of the upper-midwestern United States

Nitrate in surface water can have adverse effects on aquatic life and, in drinking-water supplies, can be a risk to human health. As part of a regional study, nitrates as N (NO3-N) was analyzed in water samples collected from streams throughout 10 Midwestern states during synoptic surveys in 1989, 1990, and 1994. Data from the period immediately following crop planting at 124 sites were analyzed during logistic regression to relate discrete categories of NO3-N concentrations to characteristics of the basins upstream from the sites. The NO3-N data were divided into three categories representing probable background concentrations (<3 mg L-1), elevated concentrations (3-10 mg L-1), and concentrations that exceeded the U.S. Environmental Protection Agency maximum contaminant level (MCL) for drinking water (>10 mg L-1). Nitrate-N concentrations were positively correlated to streamflow, upstream area planted in corn (Zea mays L.), and upstream N- fertilizers application rates. Elevated NO3-N concentrations were associated with poorly drained soils and were weakly correlated with population density. Nitrate-N and streamflow data collected during 1989 and 1990 were used to calibrate the model, and data collected during 1994 were used for verification. The model correctly estimated NO3-N concentration categories for 79% of the samples in the calibration data set and 60% of the samples in the verification data set. The model was used to indicate where NO3-N concentrations might be elevated or exceed the NO3-N MCL in streams throughout the study area. The potential for elevated NO3-N concentrations was predicted to be greatest for streams in Illinois, Indiana, Iowa, and western Ohio.

Journal of Environmental Quality↗
USGS2016

Disease epidemics: Lessons for resilience in an increasingly connected world

In public health, the term resilience often refers to the personality traits that individuals possess which help them endure and recover from stressors. However, resilience as a system characteristic, especially in regards to complex social-ecological systems, can be informative for public health at scales larger than the individual. Acute shocks to systems occur against a background of existing conditions, which are crucial determinants of the eventual public health outcomes of those shocks, and in the context of complex dependencies among and between ecological and societal elements. Many components of a system's baseline condition are chronic public health concerns themselves and diminish the capacity of the system to perform in the face of acute shocks. The emerging field of resilience management is concerned with holistically assessing and improving a system's ability to prepare for and absorb disruption, and then recover and adapt across physical, information, environmental and social domains. Integrating resilience considerations into current risk- and evidence-based approaches to disease control and prevention 1 can move public health efforts toward more proactive and comprehensive solutions for protecting and improving the health of communities. Here, we look to the case of the Black Death as an illustrative case of a dramatic transformation in human history, an acute shock to a system that was underlain by chronic social maladies, to derive lessons about resilience management for public health in contemporary systems.

Journal of Public Health↗
USGS2016

Enabling science support for better decision-making when responding to chemical spills

Chemical spills and accidents contaminate the environment and disrupt societies and economies around the globe. In the United States there were approximately 172,000 chemical spills that affected US waterbodies from 2004 to 2014. More than 8000 of these spills involved non–petroleum-related chemicals. Traditional emergency responses or incident command structures (ICSs) that respond to chemical spills require coordinated efforts by predominantly government personnel from multiple disciplines, including disaster management, public health, and environmental protection. However, the requirements of emergency response teams for science support might not be met within the traditional ICS. We describe the US ICS as an example of emergency-response approaches to chemical spills and provide examples in which external scientific support from research personnel benefitted the ICS emergency response, focusing primarily on nonpetroleum chemical spills. We then propose immediate, near-term, and long-term activities to support the response to chemical spills, focusing on nonpetroleum chemical spills. Further, we call for science support for spill prevention and near-term spill-incident response and identify longer-term research needs. The development of a formal mechanism for external science support of ICS from governmental and nongovernmental scientists would benefit rapid responders, advance incident- and crisis-response science, and aid society in coping with and recovering from chemical spills.

Journal of Environmental Quality↗
USGS2004

National Wildlife Refuge System: Ecological context and integrity

The Refuge Improvement Act of 1997 established a statutory mission and management standards for the National Wildlife Refuge system. The U.S. Fish and Wildlife Service subsequently issued a policy for ensuring the biological integrity, diversity, and environmental health of the system. This policy requires understanding the management objectives of each refuge in a local, regional, and national context. An assessment of the refuge system in a national and regional context reveals that refuges are typically smaller than many conservation holdings and are unevenly distributed across the conterminous U.S. Western rangelands, coastal wetlands, and northern grasslands; wetlands are the best-represented ecosystems, while temperate forests have the poorest representation. In contrast to other agency holdings or management designations in the national protected areas network (e.g., national parks, national forests, wilderness areas), refuges tend to occupy sites at lower elevations and that have higher productivity and soil quality. This difference points to the important contribution of the refuges in providing much needed ecological balance within the national protected areas network. However, the ecological integrity of the refuge system is challenged by the proximity of individual refuges to development. Overall, the refuges are becoming islands in a landscape matrix of urban and agricultural development. This creates future challenges for meeting management objectives to ensure the biological integrity, diversity, and environmental health of the system. If the policy to ensure biological integrity, diversity, and environmental health of the refuge system is to be successful, it may be more important to address issues about what happens on adjacent lands than uses within refuges.

Natural Resources Journal↗