Using GIS to Generate Spatially Balanced Random Survey Designs for Natural Resource Applications

Sampling of a population is frequently required to understand trends and patterns in natural resource management because financial and time constraints preclude a complete census. A rigorous probability-based survey design specifies where to sample so that inferences from the sample apply to the entire population. Probability survey designs should be used in natural resource and environmental management situations because they provide the mathematical foundation for statistical inference. Development of long-term monitoring designs demand survey designs that achieve statistical rigor and are efficient but remain flexible to inevitable logistical or practical constraints during field data collection. Here we describe an approach to probability-based survey design, called the Reversed Randomized Quadrant-Recursive Raster, based on the concept of spatially balanced sampling and implemented in a geographic information system. This provides environmental managers a practical tool to generate flexible and efficient survey designs for natural resource applications. Factors commonly used to modify sampling intensity, such as categories, gradients, or accessibility, can be readily incorporated into the spatially balanced sample design.     

Trail Impacts in Sagarmatha (Mt. Everest) National Park,Nepal: A Logistic Regression Analysis

A trail study was conducted in the Sagarmatha (Mt. Everest) National Park, Nepal, during 1997–1998. Based on that study, this paper examines the spatial variability of trail conditions and analyzes factors that influence trail conditions. Logistic regression (multinomial logit model) is applied to examine the influence of use and environmental factors on trail conditions. The assessment of trail conditions is based on a four-class rating system: (class I, very little damaged; class II, moderately damaged, class III, heavily damaged; and class IV, severely damaged). Wald statistics and a model classification table have been used for data interpretation. Results indicate that altitude, trail gradient, hazard potential, and vegetation type are positively associated with trail condition. Trails are more degraded at higher altitude, on steep gradients, in areas with natural hazard potential, and within shrub/grassland zones. Strong correlations between high levels of trail degradation and higher frequencies of visitors and lodges were found. A detailed analysis of environmental and use factors could provide valuable information to park managers in their decisions about trail design, layout and maintenance, and efficient and effective visitor management strategies. Comparable studies on high alpine environments are needed to predict precisely the effects of topographic and climatic extremes. More refined approaches and experimental methods are necessary to control the effects of environmental factors.     

Spatially Characterizing Visitor Use and Its Association with Informal Trails in Yosemite Valley Meadows

Ecological impacts associated with nature-based recreation and tourism can compromise park and protected area goals if left unrestricted. Protected area agencies are increasingly incorporating indicator-based management frameworks into their management plans to address visitor impacts. Development of indicators requires empirical evaluation of indicator measures and examining their ecological and social relevance. This study addresses the development of the informal trail indicator in Yosemite National Park by spatially characterizing visitor use in open landscapes and integrating use patterns with informal trail condition data to examine their spatial association. Informal trail and visitor use data were collected concurrently during July and August of 2011 in three, high-use meadows of Yosemite Valley. Visitor use was clustered at statistically significant levels in all three study meadows. Spatial data integration found no statistically significant differences between use patterns and trail condition class. However, statistically significant differences were found between the distance visitors were observed from informal trails and visitor activity type with active activities occurring closer to trail corridors. Gender was also found to be significant with male visitors observed further from trail corridors. Results highlight the utility of integrated spatial analysis in supporting indicator-based monitoring and informing management of open landscapes. Additional variables for future analysis and methodological improvements are discussed.     

Comparing Onsite and Offsite Methods for Measuring Norms for Trail Impacts

This study examined the comparability of onsite and offsite methods for measuring norms for trail impacts using photo/survey techniques. A total of 449 subjects participated in a study of Mudeung-Mountain Provincial Park, Gwang-Ju, Korea. For the overall photo evaluation method (OPEM), respondents rated the acceptability of bare soil area for each of a series of photographs. For the specific photo evaluation method (SPEM), respondents selected a photograph that illustrated the largest acceptable proportion of bare soil area from a series of 10 photographs. Overall, there were no substantial differences in maximum acceptable impacts between onsite (onsite-I visitor group surveyed at the actual trail points and onsite-II departing visitor group surveyed at the exit area) and offsite (students surveyed in a laboratory setting) groups for the two norm measurement alternatives (OPEM and SPEM). Subjects’ difficulty ratings were low for both methods, and there were no substantial differences in norms between individuals with high and low levels of experience at the park. The offsite method appears to be substitutable for onsite methods in this particular study area, which is a frontcountry setting with a relatively simple range of recreation opportunities. Implications and further studies are discussed.     

Proactive monitoring and adaptive management of social carrying capacity in Arches National Park: an application of computer simulation modeling

Public visits to parks and protected areas continue to increase and may threaten the integrity of natural and cultural resources and the quality of the visitor experience. Scientists and managers have adopted the concept of carrying capacity to address the impacts of visitor use. In the context of outdoor recreation, the social component of carrying capacity refers to the level of visitor use that can be accommodated in parks and protected areas without diminishing the quality of the visitor experience to an unacceptable degree. This study expands and illustrates the use of computer simulation modeling as a tool for proactive monitoring and adaptive management of social carrying capacity at Arches National Park. A travel simulation model of daily visitor use throughout the Park's road and trail network and at selected attraction sites was developed, and simulations were conducted to estimate a daily social carrying capacity for Delicate Arch, an attraction site in Arches National Park, and for the Park as a whole. Further, a series of simulations were conducted to estimate the effect of a mandatory shuttle bus system on daily social carrying capacity of Delicate Arch to illustrate how computer simulation modeling can be used as a tool to facilitate adaptive management of social carrying capacity.     

Toward the Improvement of Trail Classification in National Parks Using the Recreation Opportunity Spectrum Approach

Trail settings in national parks are essential management tools for improving both ecological conservation efforts and the quality of visitor experiences. This study proposes a plan for the appropriate maintenance of trails in Chubusangaku National Park, Japan, based on the recreation opportunity spectrum (ROS) approach. First, we distributed 452 questionnaires to determine park visitors’ preferences for setting a trail (response rate = 68 %). Respondents’ preferences were then evaluated according to the following seven parameters: access, remoteness, naturalness, facilities and site management, social encounters, visitor impact, and visitor management. Using nonmetric multidimensional scaling and cluster analysis, the visitors were classified into seven groups. Last, we classified the actual trails according to the visitor questionnaire criteria to examine the discrepancy between visitors’ preferences and actual trail settings. The actual trail classification indicated that while most developed trails were located in accessible places, primitive trails were located in remote areas. However, interestingly, two visitor groups seemed to prefer a well-conserved natural environment and, simultaneously, easily accessible trails. This finding does not correspond to a premise of the ROS approach, which supposes that primitive trails should be located in remote areas without ready access. Based on this study’s results, we propose that creating trails, which afford visitors the opportunity to experience a well-conserved natural environment in accessible areas is a useful means to provide visitors with diverse recreation opportunities. The process of data collection and analysis in this study can be one approach to produce ROS maps for providing visitors with recreational opportunities of greater diversity and higher quality.     

Managing Recreational Trail Environments for Mountain Bike User Preferences

N  = 406), highlight some important issues concerning the design and management of wildland recreation environments that are primarily used for mountain biking. For example, bikers were found to significantly prefer water bars above all other tested soil erosion management techniques; trail erosion factors, including the presence of rocks, roots, and gullies, all added to biking experiences on average; trail design factors, such as the presence of turns, bumps, jumps, and obstacles, all added to biking experiences in general. These findings were used to address questions that resource managers should consider when striving to effectively manage wildland recreation areas primarily used for mountain biking.     

The influence of use-related,environmental, and managerial factors on soil loss from recreational trails

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.     

Visitor Assessment of the Mandatory Alternative Transportation System at Zion National Park

Transportation infrastructure in national parks has historically been designed for the automobile. With more vehicles in the parks, visitors found themselves in circumstances more reminiscent of a city than a park. Traffic jams, overcrowding, illegal parking, horn honking, and idling vehicles became common, creating stress and contributing to air and noise pollution, the very things visitors were hoping to get away from. Park managers began searching for alternatives, including shuttle systems. Many national parks have implemented optional shuttle systems, but relatively few have completely closed roads to vehicles, transporting visitors on mandatory shuttles. Zion National Park instituted a mandatory shuttle system in May 2000 to relieve crowding and congestion in the main canyon and to protect natural resources. Taking a longitudinal approach, attributes of the shuttle (e.g., crowding, accessibility, freedom, efficiency, preference, and success) were assessed with experiential park factors (e.g., scenic beauty, naturalness, solitude, tranquility, air quality, and soundscape) in 2000, 2003, and 2010 by surveying shuttle-riding park visitors. While visitors initially reported a few reservations about the shuttle system, by 2003, the majority rated the system successful. Ratings of all shuttle-related variables, except crowding, improved over the decade. Improvements were greatest for freedom, accessibility, and efficiency. Multiple regression found overall shuttle success to be mediated by preference, freedom, accessibility, efficiency, and comfort. Experiential variables assessing park conditions followed a similar pattern, with improved ratings as the decade progressed. Results provide important insights into the visitor experience with mandatory alternative shuttle systems in national parks.     

A spatial exploration of informal trail networks within Great Falls Park, VA

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?     

Developing a Monitoring Protocol for Visitor-Created Informal Trails in Yosemite National Park,USA

Informal trails created or perpetuated by visitors is a management challenge in many protected natural areas such as Yosemite National Park. This is a significant issue as informal trail networks penetrate and proliferate into protected landscapes and habitats, threatening ecological integrity, aesthetics, and visitor experiences. In order to develop effective strategies for addressing this problem under an adaptive management framework, indicators must be developed and monitoring protocol must be established to gather timely and relevant data about the condition, extent, and distribution of these undesired trail segments. This article illustrates a process of developing and evaluating informal trail indicators for meadows in Yosemite Valley. Indicator measures developed in past research were reviewed to identify their appropriateness for the current application. Information gaps in existing indicator measures were addressed by creating two new indices to quantify the degree of informal trailing based on its land fragmentation effects. The selected indicator measures were applied to monitoring data collected between 2006 and 2008. The selected measures and indices were evaluated for their ability to characterize informal trail impacts at site and landscape scales. Results demonstrate the utility of indicator measures in capturing different characteristics of the informal trail problem, though several metrics are strongly related to each other. The two fragmentation indices were able to depict fragmentation without being too sensitive to changes in one constituent parameter. This study points to the need for a multiparameter approach to informal trail monitoring and integration with other monitoring data. Implications for monitoring programs and research are discussed.     

Giving Voice to Wildlands Visitors: Selecting Indicators to Protect and Sustain Experiences in the Eastern Arctic of Nunavut

Many public land management agencies are committed to understanding and protecting recreation visitor experiences. Parks Canada is deeply committed to that objective for visitors to Canada’s National Parks. This 2004 study, informed by a 2003 qualitative study of visitor experiences and influences on those experiences at Auyuittuq National Park in Nunavut, worked to bring 50 potential elements of visitor experiences down to five articulated dimensions of the experience that is currently being received at this remote eastern arctic park. A hypothesized set of 17 influences on experiences, also reduced to just two factors with similar response patterns, and with some items that did not flow into the two factors, were used in a regression analysis to understand the relationship between experiences and factors of influence. A sample of 61.8% (84) of the total recreation visitor population 16 years of age or older was surveyed during deregistration after the trip. Knowledge about the dimensions of the experiences currently received and factors of influence on those experiences can be used to guide selection of indicators for describing objectives and prescribing monitoring protocol.     

Estimating the Economic Value of National Parks with Count Data Models Using On-Site,Secondary Data: The Case of the Great Sand Dunes National Park and Preserve

We estimate an individual travel cost model for Great Sand Dunes National Park and Preserve (GSD) in Colorado using on-site, secondary data. The purpose of the on-site survey was to help the National Park Service better understand the visitors of GSD; it was not intended for a travel cost model. Variables such as travel cost and income were estimated based on respondents’ Zip Codes. Following approaches found in the literature, a negative binomial model corrected for truncation and endogenous stratification fit the data the best. We estimate a recreational benefit of U.S. $89/visitor/year or U.S. $54/visitor/24-h recreational day (in 2002 U.S. $). Based on the approach presented here, there are other data sets for national parks, preserves, and battlefields where travel cost models could be estimated and used to support National Park Service management decisions.     

Evaluating the effects of spatial monitoring policy on groundwater quality portrayal

What size sample is sufficient for spatially sampling ambient groundwater quality? Water quality data are only as spatially accurate as the geographic sampling strategies used to collect them. This research used sequential sampling and regression analysis to evaluate groundwater quality spatial sampling policy changes proposed by California's Department of Water Resources. Iterative or sequential sampling of a hypothetical groundwater basin's water quality produced data sets from sample sizes ranging from 2.8% to 95% coverage of available point sample sites. Contour maps based on these sample data sets were compared to an original (control), mapped hypothetical data set, to determine at which point map information content and pattern portrayal are not improved by increasing sample sizes. Comparing series of contour maps of ground water quality concentration is a common means of evaluating the geographic extent of groundwater quality change. Comparisons included visual inspection of contout maps and statistical tests on digital versions of these map files, including correlation and regression products. This research demonstrated that, down to about 15% sample site coverage, there is no difference between contour maps produced from the different sampling strategies and the contout map of the original data set.     

The influence of use,environmental and managerial factors on the width of recreational trails

This paper evaluates the relative influences of use, managerial and environmental factors on trail width, from a survey of all formal trails in Acadia National Park, Maine, USA. A Trimble GPS was used to navigate to and collect data at sample points spaced at a 152.4 m (500 ft) interval across all National Park Service trails on Mount Desert Island. Regression analyses focus on increasing understanding of factors that influence the width of formal hiking trails. ANOVA analyses demonstrate differences in trail width based on trail surface type (class), and the presence or absence of trail borders. A novel approach of comparing intended widths to actual widths enabled us to look specifically at the avoidable and undesirable impacts associated with having a trail that is wider than intended.     

Utilization of Photographs for Determining Impact Indicators for Trail Management

Indicators are a key component of resource management, but selecting them can be difficult and controversial. This study explores different methods for selecting impact indicators for management of trail conditions by comparing photo survey methods (PSM) with written survey methods (WSM). A total of 661 subjects participated in interviews conducted within Mudeung- Mountain Provincial Park in Kwang-ju, Korea. PSM explained variation in acceptability better than WSM. Six major photo components (in order of importance: area of large rocks on trail, area of wood steps, area of bare roots, area of bare soil, area of small stones, and area of stone steps) explained 84.7% of the variation in acceptability of trail management conditions. This study suggests that PSM can be a useful tool for selecting impact indicators. Supported by the grant of Post-Doctoral Program, Chonbuk National University (2001)     

Influence of Llamas, Horses, and Hikers on Soil Erosion from Established Recreation Trails in Western Montana, USA

/ Various types of recreational traffic impact hiking trails uniquely and cause different levels of trail degradation; however, trail head restrictions are applied similarly across all types of packstock. The purpose of this study was to assess the relative physical impact of hikers, llamas, and horses on recreational trails. Horse, llama, and hiker traffic were applied to 56 separate plots on an existing trail at Lubrecht Experimental Forest in western Montana. The traffic was applied to plots at intensities of 250 and 1000 passes along with a no-traffic control under both prewetted and dry trail conditions. Soil erosion potential was assessed by sediment yield and runoff (using a Meeuwig type rainfall simulator), changes in soil bulk density, and changes in soil surface roughness. Soil moisture, slope, and rainfall intensity were recorded as independent variables in order to evaluate the extent that they were held constant by the experimental design. Horse traffic consistently made more sediment available for erosion from trails than llama, hiker, or no traffic when analyzed across wet and dry trail plots and high and low intensity traffic plots. Although total runoff was not significantly affected by trail user, wet trail traffic caused significantly greater runoff than dry trail traffic. Llama traffic caused a significant increase in sediment yield compared to the control, but caused erosion yields not significantly different than hiker traffic. Trail traffic did not increase soil compaction on wet trails. Traffic applied to dry trail plots generally resulted in a significant decrease in soil bulk density compared to the control. Decreased soil bulk density was negatively correlated with increased sediment yield and appeared to result in increased trail roughness for horse traffic compared to hiker or llama traffic. Differences described here between llama and horse traffic indicate that trail managers may want to consider managing packstock llamas independent of horses.KEY WORDS: Recreational impacts; Sediment yield; Trail degradation     

Evaluation of US EPA Environmental Monitoring and Assessment Program's (EMAP)-Wetlands sampling design and classification

The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) will monitor the nation's resources by evaluating the status and trends of selected indicators of condition using a probability-based sampling design. The EMAP-Wetlands program will monitor the condition of the nation's wetlands. The EMAP classification system is an aggregation of the many subclasses of the US Fish and Wildlife Service's National Wetlands Inventory (NWI) classification system. This aggregation results in fewer wetland classes with more wetlands per class than the NWI system. Aggregation of the NWI classification was based primarily on dominant vegetation cover, flooding regimes, dominant water source, and adjacency to rivers and lakes. We evaluated the EMAP classification system and sampling design using NWI digital wetlands data for portions of Illinois, Washington, North Dakota, and South Dakata. Relative numbers of wetlands, total areas, average areas, and common versus rare classes were compared between the EMAP and NWI classification systems. As expected, the EMAP classification provided fewer wetland polygons, each with larger areas, without altering total wetland area. Summary statistics comparing sample estimates to true population parameters (represented by the NWI data) demonstrated the effectiveness of the EMAP sampling design with the exception of rare EMAP classes in the selected regions. Although simple random sampling is inadequate for both large and small wetlands, the EMAP sampling design is readily adapted to provide better estimates for these categories. Aggregating the NWI classification to the EMAP classification provides fewer wetland classes, with more wetlands per class, for EMAP's annual reports and statistical summaries. The research in this report has been funded by the United States Environmental Protection Agency (EPA) under contracts 68-C8-0006 to ManTech Environmental Technology, Inc. and 68-03-3532 to The Bionetics Corporation. Mention of trade names does not constitute endorsement or recommendation for use.     

Cooperation or conflict? Interagency relationships and the future of biodiversity for US parks and forests

Cooperation between the United States Department of Agriculture (USDA) Forest Service and the United States Department of Interior (USDI) National Park Service is most often advocated to protect biological diversity on national forests and parks, but the agencies, so far, have done little to implement the biodiversity mandates of such laws as the Endangered Species Act and the National Forest Management Act. The ideological and political history of the Forest Service and Park Service is explored to determine the roots of interagency conflicts. Several recent models of cooperative reform are also critiqued and found to be insufficient to stimulate better working relationships. To protect biodiversity, cooperation must be framed within conservation biology and must place primary emphasis on ecosystem patterns and processes as well as on individual species. Increased education of agency managers, ecosystem-level research, local and regional public participation, scientific oversight committees, new legislation, and enlightened leadership also play important roles. Ultimately, management policies must be reframed within a context of ecocentric values.     

APPLICATION OF A MULTIPURPOSE UNEQUAL PROBABILITY STREAM SURVEY IN THE MID‐ATLANTIC COASTAL PLAIN1

ABSTRACT: A stratified, spatially balanced sample with unequal probability selection was used to design a multipurpose survey of headwater streams in the Mid‐Atlantic Coastal Plain. Objectives for the survey include unbiased estimates of regional stream conditions, and adequate coverage of unusual but significant environmental settings to support empirical modeling of the factors affecting those conditions. The design and field application of the survey are discussed in light of these multiple objectives. A probability (random) sample of 175 first‐order nontidal streams was selected for synoptic sampling of water chemistry and benthic and riparian ecology during late winter and spring 2000. Twenty‐five streams were selected within each of seven hydrogeologic subre‐gions (strata) that were delineated on the basis of physiography and surficial geology. In each subregion, unequal inclusion probabilities were used to provide an approximately even distribution of streams along a gradient of forested to developed (agricultural or urban) land in the contributing watershed. Alternate streams were also selected. Alternates were included in groups of five in each subregion when field reconnaissance demonstrated that primary streams were inaccessible or otherwise unusable. Despite the rejection and replacement of a considerable number of primary streams during reconnaissance (up to 40 percent in one subregion), the desired land use distribution was maintained within each hydrogeologic subregion without sacrificing the probabilistic design.