Geology topics
Publications and source records attributed to Jeffrey L. Marion.
The essential guide for enjoying the outdoors without harming the environment. - Details the seven core principles of Leave No Trace ethics and practices - Covers hiking, campfires, food storage, and personal hygiene - Endorsed by the USDI National Park Service, Bureau of Land Management, Fish & Wildlife Service, U.S. Geological Survey, and the USDA Forest Service
Parks are developing nature play areas to improve children's health and “connect” them with nature. However, these play areas are often located in protected natural areas where managers must balance recreation with associated environmental impacts. In this exploratory study, we sought to describe these impacts. We also investigated which ages, gender, and play group sizes most frequently caused impact and where impacts most frequently occur. We measured the lineal and aerial extent and severity of impacts at three play areas in the eastern United States. Methods included soil and vegetation loss calculations, qualitative searches and tree and shrub damage classifications. Additionally, we observed 12 h of play at five play areas. Results showed that measurable negative impacts were caused during 33% of the time children play. On average, 76% of groundcover vegetation was lost at recreation sites and 100% was lost at informal trails. In addition, approximately half of all trees and shrubs at sites were damaged. Meanwhile, soil exposure was 25% greater on sites and trails than at controls. Boys and small group sizes more frequently caused impact, and informal recreation sites were most commonly used for play. No statistically significant correlations were found between age or location and impact frequency. Managers interested in developing nature play areas should be aware of, but not deterred by these impacts. The societal benefits of unstructured play in nature may outweigh the environmental costs. Recommended management strategies include selecting impact-resistant sites, improving site resistance, promoting low impact practices, and managing adaptively.
Informal (visitor-created) trails represent a threat to the natural resources of protected natural areas around the globe. These trails can remove vegetation, displace wildlife, alter hydrology, alter habitat, spread invasive species, and fragment landscapes. This study examines informal and formal trails within Great Falls Park, VA, a sub-unit of the George Washington Memorial Parkway, managed by the U.S. National Park Service. This study sought to answer three specific questions: 1) Are the physical characteristics and topographic alignments of informal trails significantly different from formal trails, 2) Can landscape fragmentation metrics be used to summarize the relative impacts of formal and informal trail networks on a protected natural area? and 3) What can we learn from examining the spatial distribution of the informal trails within protected natural areas? Statistical comparisons between formal and informal trails in this park indicate that informal trails have less sustainable topographic alignments than their formal counterparts. Spatial summaries of the lineal and areal extent and fragmentation associated with the trail networks by park management zones compare park management goals to the assessed attributes. Hot spot analyses highlight areas of high trail density within the park and findings provide insights regarding potential causes for development of dense informal trail networks.
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The National Park Service (NPS) accommodates nearly 300 million visitors per year, visitation that presents managers with substantial challenges at some 394 park units across some 83.6 million acres of protected lands. An increasing number of visitors inevitably contribute negative effects to fragile natural and cultural resources. Such visitation - related resource impacts can degrade natural conditions and processes and the quality of recreation experiences. According to the NPS Management Policies: ―The fundamental purpose of the national park system , established by the Organic Act and reaffirmed by the General Authorities Act, as amended, begins with a mandate to conserve park resources and values...The fundamental purpose of all parks also includes providing for the enjoyment of park resources and values by the people of the United States.‖ (NPS 2006 b , Section 1.4.3). However, what might appear to be dual mandates, visitation and resource protection, are clarified to reveal the primacy of resource protection. The Management Policies acknowledge that so me resource degradation is an inevitable consequence of visitation, but directs managers to ―ensure that any adverse impacts are the minimum necessary, unavoidable, cannot be further mitigated, and do not constitute impairment or derogation of park resources and values‖ (NPS 2006 b ).
This report presents the results of research on the conditions of formal and informal (visitorcreated) trails conducted within the Great Falls Park (GFP) portion of George Washington Memorial Parkway (GWMP), Virginia, and the adjacent Maryland portions of the C&O Canal National Historical Park (CHOH). This research was prompted primarily by concerns about the impact of extensive informal trail networks within both parks on native vegetation and rare plant communities, rare flora and fauna, and historic and archaeological resources. Resource conditions on formal park trails were also assessed to provide information supporting the development of park planning and management decision-making.
Managers of the National Park Service (NPS) are directed by law to accommodate appropriate types and amounts of visitation while ensuring that: any adverse impacts are the minimum necessary, unavoidable, cannot be further mitigated, and do not constitute impairment or derogation of park resources and values. (NPS 2006). The increasing popularity of the national park system presents substantial management challenges. High visitatation may cause unacceptable impacts to fragile natural and cultural resources, and may also cause crowding and other social impacts, which can also degrade the quality of visitor experiences. Responding to these concerns, NPS managers at Chesapeake & Ohio Canal National Historical Park (CHOH) and George Washington Memorial Parkway (GWMP) sponsored this research within the upper Potomac Gorge portions of these parks to investigate visitation-related impacts to the park?s cliff resources. The cliffs and rocky areas within the Great Falls and Mather Gorge areas provide important habitats for numerous sensitive rare plants and plant communities. A recent General Management Planning process for Great Falls Park (GFP), a portion of GWMP, highlighted the potential impacts of cliff-associated recreational activities, including hiking, climbing, and fishing, on sensitive cliff resources. The planning process identified the need for development of a Climbing Management Plan and a Trail Plan to more specifically address site and visitor management actions needed to protect rare and sensitive natural and cultural resources. Good science to assess cliff-associated rare plants and communities and to determine the existing and potential effects of cliff-related recreational activities is required for these new planning efforts. This research is designed to specifically address these informational needs and to assist park managers on both sides of the river with current and future cliff and recreation management decisions.
Trails are a common recreation infrastructure in protected areas and their conditions affect the quality of natural resources and visitor experiences. Various trail impact indicators and assessment protocols have been developed in support of monitoring programs, which are often used for management decision-making or as part of visitor capacity management frameworks. This paper reviews common indicators and assessment protocols for three types of trails, surfaced formal trails, unsurfaced formal trails, and informal (visitor-created) trails. Monitoring methods and selected data from three U.S. National Park Service units are presented to illustrate some common trail impact indicators and assessment options.
At Acadia National Park, changing visitor use levels and patterns have contributed to an increasing degree of visitor use impacts to natural and cultural resources. To better understand the extent and severity of these resource impacts and identify effective management techniques, the park sponsored this research to develop monitoring protocols, collect baseline data, and identify suggestions for management strategies. Formal and informal trails were surveyed and their resource conditions were assessed and characterized to support park planning and management decision-making.
Recreation ecology examines the effects of recreation on protected area ecosystems. One core focus of recreation ecology research is trail science, including the development of efficient protocols to assess and monitor the type and severity of resource impacts, analyses to improve knowledge of factors that influence trail conditions, and studies to assist land managers in improving trail design, maintenance, and visitor management. This article reviews alternative trail survey methodologies most useful for the management of wilderness and backcountry trail networks. Illustrations and implications from survey data for trail planning, design, and management are included.
Managers at Alaska?s Denali National Park and Preserve (DENA) sponsored this research to assess and monitor visitor-created informal trails (ITs). DENA is located in south-central Alaska and managed as a six million acre wilderness park. This program of research was guided by the following objectives: (1) Investigate alternative methods for monitoring the spatial distribution, aggregate lineal extent, and tread conditions of informal (visitor-created) trails within the park. (2) In consultation with park staff, develop, pilot test, and refine cost-effective and scientifically defensible trail monitoring procedures that are fully integrated with the park?s Geographic Information System. (3) Prepare a technical report that compiles and presents research results and their management implications. This report presents the protocol development and field testing process, illustrates the types of data produced by their application, and provides guidance for their application and use. The protocols described provide managers with an efficient means to document and monitor IT conditions in settings ranging from pristine to intensively visited.
Mountain summits present a unique challenge to manage sustainably: they are ecologically important and, in many circumstances, under high demand for recreation and tourism activities. This article presents recent advances in the assessment of resource conditions and visitor disturbance in mountain summit environments, by drawing on examples from a multiyear, interdisciplinary study of summits in the northeastern United States. Primary impact issues as a consequence of visitor use, such as informal trail formation, vegetation disturbance, and soil loss, were addressed via the adaption of protocols from recreation ecology studies to summit environments. In addition, new methodologies were developed that provide measurement sensitivity to change previously unavailable through standard recreation monitoring protocols. Although currently limited in application to the northeastern US summit environments, the methods presented show promise for widespread application wherever summits are in demand for visitor activities.
Recreation ecology, the study of environmental consequences of outdoor recreation activities and their effective management, is a relatively new field of scientific study having emerged over the last 50 years. During this time, numerous studies have improved our understanding of how use-related, environmental and managerial factors affect ecological conditions and processes. Most studies have focused on vegetation and soil responses to recreation-related trampling on trails and recreation sites using indicators such as percent vegetation cover and exposed mineral soil. This applied approach has and will continue to yield important information for land managers. However, for the field to advance, more attention needs to be given to other ecosystem attributes and to the larger aspects of environmental conservation occurring at landscape scales. This article is an effort at initiating a dialog on needed advances in the field. We begin by reviewing broadly generalizable knowledge of recreation ecology, to separate what is known from research gaps. Then, based on the authors’ perspective of research in the USA and North America, several research directions are suggested as essential for continued progress in this field including theoretical development, broadening scale, integration with other disciplines, and examination of synergistic effects.
Recreational uses of unsurfaced trails inevitably result in their degradation, with the type and extent of resource impact influenced by factors such as soil texture, topography, climate, trail design and maintenance, and type and amount of use. Of particular concern, the loss of soil through erosion is generally considered a significant and irreversible form of trail impact. This research investigated the influence of several use-related, environmental, and managerial factors on soil loss on recreational trails and roads at Big South Fork National River and Recreation Area, a unit of the U.S. National Park Service. Regression modeling revealed that trail position, trail slope alignment angle, grade, water drainage, and type of use are significant determinants of soil loss. The introduction of individual and groups of variables into a series of regression models provides improved understanding and insights regarding the relative influence of these variables, informing the selection of more effective trail management actions. Study results suggest that trail erosion can be minimized by avoiding “fall-line” alignments, steep grades, and valley-bottom alignments near streams, installing and maintaining adequate densities of tread drainage features, applying gravel to harden treads, and reducing horse and all-terrain vehicle use or restricting them to more resistant routes. This research also sought to develop a more efficient Variable Cross-Sectional Area method for assessing soil loss on trails. This method permitted incorporation of CSA measures in a representative sampling scheme applied to a large (24%) sample of the park's 526 km trail system. The variety of soil loss measures derived from the Variable CSA method, including extrapolated trail-wide soil loss estimates, permit an objective quantification of soil erosion on recreational trails and roads. Such data support relational analyses to increase understanding of trail degradation, and long-term monitoring of the natural and recreational integrity of the trail system infrastructure.
The U.S. Geological Survey's Patuxent Wildlife Research Center (PWRC) conducted a study for the National Park Service (NPS) Southeast Region, Atlanta, GA, and Cape Hatteras National Seashore (CAHA) in North Carolina to review, evaluate, and summarize the available scientific information for selected species of concern at CAHA (piping plovers, sea turtles, seabeach amaranth, American oystercatchers, and colonial waterbirds). This work consisted of reviewing the scientific literature and evaluating the results of studies that examined critical life history stages of each species, and focused on the scientific findings reported that are relevant to the management of these species and their habitats at CAHA. The chapters that follow provide the results of that review separately for each species and present scientifically based options for resource management at CAHA. Although no new original research or experimental work was conducted, this synthesis of the existing information was peer reviewed by over 15 experts with familiarity with these species. This report does not establish NPS management protocols but does highlight scientific information on the biology of these species to be considered by NPS managers who make resource management decisions at CAHA. To ensure that the best available information is considered when assessing each species of interest at CAHA, this review included published research as well as practical experience of scientists and wildlife managers who were consulted in 2005. PWRC scientists evaluated the literature, consulted wildlife managers, and produced an initial draft that was sent to experts for scientific review. Revisions based on those comments were incorporated into the document. The final draft of the document was reviewed by NPS personnel to ensure that the description of the recent status and management of these species at CAHA was accurately represented and that the report was consistent with our work agreement. The following section summarizes the biological information relevant to resource management for the species of concern at CAHA.
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No abstract available.