Spatial Tools for Management of Protected Natural Areas: Case Studies in Camping Management and Trail Impact Assessment
This dissertation comprises two distinct journal articles, each contributing significant advancements to recreation ecology by examining the effectiveness of various spatial tools in camping and trail management. The first article leverages strategic spatial planning, considering topography and spacing, to limit camping impacts and enhance visitor experiences. It investigates the long-term effectiveness of a sustainable camping management strategy on the Appalachian Trail, whereby protected area managers select and actively encourage or require visitors to camp on excavated "side-hill" campsites in sloping terrain. One of the most degraded camping locations along the popular Appalachian Trail was selected for this longitudinal study, which, in May 2002, involved the closure of 19 existing campsites in flat terrain, with use shifted to 14 newly constructed side-hill campsites in adjacent sloping terrain. Over the subsequent 17 years, the recovery of the closed campsites and the evolution of the newly established side-hill campsites were monitored and assessed. Results from this study reveal that a multifaceted approach integrating both direct and indirect management actions successfully achieved their management objectives to sustain the site's exceptionally high use while minimizing both resource and social impacts. This study highlights the ability of constructed side-hill campsites to resist expansion over time and provides valuable findings, insights, and "lessons learned" to guide protected area managers in selecting and implementing effective management strategies and actions in other high-use settings. The second study evaluates terrestrial photogrammetry as a spatial tool for trail impact assessment. Protected natural areas like Joshua Tree National Park (JTNP) rely heavily on trails to facilitate visitor access while spatially concentrating environmental impacts to their treads. Assessing the condition of these trails is difficult due to the logistical challenges inherent in conventional field data-gathering techniques. While technological advancements such as Uncrewed Aerial Vehicles (UAV) introduce Structure-from-Motion (SfM) capabilities for trail monitoring, they are not without limitations, including prohibitive costs, legal restrictions, and operational challenges, particularly when monitoring trails enveloped by canopy cover. This study presents a novel approach to trail assessment using terrestrial photogrammetry, wherein a consumer-grade camera captures high-resolution imagery that is processed using SfM techniques. The study compared manual measurements of 46 trail transects in JTNP with measurements from Digital Elevation Models (DEMs) generated from SfM point clouds. The outcomes revealed a high level of agreement between the two methods, with the measurements derived from photogrammetric DEM data exhibiting consistently higher values compared to the field measurements, especially in the central regions of the transects. A statistically significant positive relationship between transect width and mean differences between GIS and field tread incision measurements suggests that the disparity may arise from the sagging of the tape measure across the trail, indicating photogrammetric methods might offer greater accuracy. The paper outlines methods for capturing high-resolution 3D trail data using cost-effective techniques and discusses the practicality and possibilities of using the technique in trail monitoring programs. This has far-reaching implications and positions terrestrial photogrammetry as a compelling alternative to drone-based acquisitions, particularly in areas where UAV operations are restricted, discouraged, or impractical.