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

Assessing the Environmental Impacts, Condition and Sustainability of Mountain Biking Trails in an Urban National Park

Mountain biking is a popular recreational activity in natural areas, with thousands of formal trails designed, constructed and maintained by land managers. Increasingly, there are also rising numbers of informal trails created by riders. A challenge for land managers is identifying, assessing, and then mitigating environmental impacts created by trails, including in protected areas. Here we assessed mountain biking trails in a large, popular national park on the Gold Coast, Australia, addressing the currently limited research comparing the extent, environmental impacts, condition and sustainability of these trails. Impacts from the 31.4 km of formal and 33.7 km of informal trails through the forests in Nerang National Park (1659 ha) included soil erosion (16.48 m3) and loss of vegetation along and adjacent to the trails (90,955 m2). Formal trails were six times more popular and wider on average (1.1 m vs 0.7 m) than informal trails, but less incised than informal trails (4.6 cm deep vs 6.3 cm). Generalised Linear Models showed that Trail Grade, slope and alignment best-predicted trail condition, highlighting the importance of good trail design in minimising trail impacts. It is recommended most of the informal trails are closed and rehabilitated, as they were not well-designed, increase fragmentation and have environmental impacts, with some traversing ecologically sensitive areas. In addition, some formal trails need to be upgraded to deal with erosion and other impacts. More broadly, the increasing demand for mountain biking must be addressed, including exploring opportunities to promote areas outside of national parks while minimising environmental impacts and other challenges associated with the creation and use of informal mountain bike trails in protected areas.

Trail sustainability: A state-of-knowledge review of trail impacts, influential factors, sustainability ratings, and planning and management guidance

Protected areas (PAs) provide many important recreational, social, and economic benefits that are largely dependent on their ability to sustain visitation. Trail networks are a critical tourism infrastructure element that directly accommodate high quality recreation activities and experiences while providing access to and protection of irreplaceable natural and cultural resources. Unfortunately, most trail networks consist of historic "legacy" trails that were not sustainably designed and whose intensive use cause unacceptable impacts to PA resources, experiences, and values. This paper provides an international state-of-knowledge review of trail science research within the field of recreation ecology to describe common trail impacts and factors that influence trail degradation that trail stewards can manipulate to enhance the sustainability of trail networks. Two emerging models that seek to rate trail topographic sustainability are presented to illustrate their potential utility to PA managers. Expanding and incorporating trail science research into the sustainable trail planning, design, and Best Management Practice literature are also discussed.

Trail Use, Motivations, and Environmental Attitudes of 3780 European Mountain Bikers: What Is Sustainable?

Background: The extent to which mountain biking impacts upon the environment is largely determined by rider behaviours. The purpose of this study was to gain a better understanding of how mountain bikers interact with the natural environment and explore their attitudes towards sustainability. Methods: 3780 European mountain bikers completed an online cross-sectional survey. Results: Connection to nature was an important source of motivation and the use of mountain bike trails has increased rider’s appreciation of and willingness to protect nature, with a large majority having taken direct action to do so. Mountain bikers are prepared to contribute towards trail maintenance through the provision of labour or financially. Although most mountain bikers make use of wet trails and illegal trails, incidence of conflict is relatively low. A range of characteristics were identified as being fundamental elements of sustainable trails, both in relation to the sustainability of the trail itself and in terms of wider environmental sustainability. Conclusions: European mountain bikers care about the sustainability of the natural environment. Self-reported attitudes and behaviours suggest a willingness to reduce environmental impact and actively protect nature.

New social trails made during the pandemic increase fragmentation of an urban protected area

Urban protected areas are an important resource to people and wildlife, providing many ecosystem services. During the initial phase of the COVID-19 pandemic lockdown during March-June 2020, there was a major increase in the number of hikers and bicyclists in urban protected areas, including the Webster Woods in Newton, Massachusetts (USA), an 82.5-ha protected area. The Webster Woods is one of the largest protected areas near the center of Boston and is widely used in conservation textbooks as an example of the effects of habitat fragmentation on the amount of undisturbed habitat. Prior to the pandemic, the Webster Woods had been extensively fragmented by paved roads, dirt roads, and trails, with little interior habitat remaining. During the first four months of the pandemic, hikers and bicyclists made 4.9 km of new social (or informal) trails, an increase of 36%. This recent fragmentation represents a dramatic increase in the level of human impact on the area, reducing the amount of interior habitat from 3.2 to 2.1 ha. Levels of human activity returned to pre-pandemic levels in autumn 2020 and city officials have started closing access to some of the new trails, allowing vegetation to regrow. It is possible that similar increases in social trails and associated fragmentation have occurred in other protected areas (especially those in urban areas) around the world due to the pandemic, and these disturbances should be evaluated for their effects on plant and animal populations.

Improving understanding and management of the complex relationship between visitor motivations and spatial behaviors in parks and protected areas

Increases in use and changes in the behavior of visitors to parks and protected areas (PPAs) worldwide are challenging the ability of managers to provide for a quality visitor experience while also maintaining the integrity of natural resources. Understanding visitor motivations and spatial behaviors are important for effective management of PPA resources and visitor experiences, as differences in motivations and spatial behaviors can influence the distribution of impacts to a recreation landscape. However, the relationships between motivations and behaviors are not well understood. In this study, we investigated the relationship between motivations and spatial behavior patterns of recreationists within a system of urban and peri-urban PPAs in Orange County, California, USA. Data were collected using paired GPS-based tracking and visitor questionnaires. Factor analysis revealed seven primary motivations derived from a 36-item motivation scale, and classification of visitors by motivations suggests two primary types. A three-way Analysis of Variance examining the relationship between a suite of visitor spatial behaviors and activity type (mountain bike vs. pedestrian), motivation type, and recreation area visited showed that all three variables interacted to influence visitor spatial behavior patterns while recreating. A spatial analysis of visitor dispersion further illustrated these interactions. These results suggest that the relationship between visitor motivations and spatial behaviors is complex. Understanding the complexities of how motivations influence visitor spatial behavior can help land managers mitigate impacts and improve planning for outdoor recreation by predicting where use may increase, how visitors might behave, and highlight locations of future research.

Soil erosion on mountain trails as a consequence of recreational activities. A comprehensive review of the scientific literature

This article reviews the scientific literature on trail erosion and the magnitude of the erosive processes that occur on mountain trails due to recreational activities, mainly due to hiking. This work is necessary as a result of the increase in hiking and biking in forest, scrubland and grasslands, and the soil and vegetation degradation induced by these activities. We analysed results that have been compiled in the scientific literature, as well as other issues such as the geographical and temporal distribution of the research, the methods applied, the journals where the research was published, the types and quantity of uses of the pathways and the measures undertaken for damage mitigation. This paper highlights that there is a need for harmonization of methods. The results show that soil erosion rates are highly variable, high, and non-sustainable. Trail erosion research is growing at a rate of 3 papers per year and is published in a small group of scientific journals. Six journals published 47% of the papers on trail erosion, which show a high concentration in environmental journals. There are few papers published in the soil science and geomorphology disciplines, although the research topic and the science background are in these two disciplines. Reported world soil losses from trails ranged from 6.1 Mg ha^-1 y^-1 to 2090 Mg ha^-1 y^-1, all of which are not sustainable. Trail erosion has mainly been investigated in the USA and is a new topic in other regions of the world. There is a need to implement mitigation measures to avoid land degradation, and this should be researched in the near future as right now most of the research describes and quantifies the problem but does not provide solutions: mitigation, rehabilitation or restoration. From a pure scientific approach, we claim that there is a need to research the connectivity of flows and the role of the trails on runoff generation and then sediment yield at pedon, slope and watershed scales. There is a need to research the mechanisms of the soil erosion process in trails: trampling effect, wheel impact, factors and seasonal and temporal changes.

Mitigating Undesignated Trail Use: The Efficacy of Messaging and Direct Site Management Actions in an Urban-Proximate Open Space Context

The use and creation of undesignated recreational trails can lead to erosion, vegetation damage, unsafe trail conditions, and impacts to local wildlife. The mitigation of undesignated trail use is typically addressed indirectly through minimum-impact visitor education programs such as Leave No Trace, or directly through closures or sanctions. In this study, researchers collaborated with City of Boulder, Colorado Open Space and Mountain Parks (OSMP) staff to develop a quasi-experimental field study that examined the effectiveness of indirect (messaging) and direct (barriers) management approaches to mitigating undesignated trail use. The study applied a Theory of Planned Behavior framework, utilized Leave No Trace messaging, and employed a method to pair survey and direct observation data. A total of 2232 visitor parties were observed, and 147 surveys were collected. The combined direct (barrier) and indirect (messaging) intervention was the most effective at mitigating undesignated trail use. Implications for management and future research are discussed.

How Networks of Informal Trails Cause Landscape Level Damage to Vegetation

When visitors are not constrained to remain on formal trails, informal trail networks can develop and damage plant communities in protected areas. These networks can form in areas with low growing vegetation, where formal trails are limited, where there is limited regulation and where vegetation is slow to recover once disturbed. To demonstrate the extent of impacts from unregulated recreational use, we assessed damage to alpine vegetation by hikers and pack animals in the highest protected area in the southern Hemisphere: Aconcagua Park, in the Andes. Within the 237 ha area surveyed in the Horcones Valley, over 19 km of trails were found, nearly all of which (94%) were informal. This network of trails resulted in the direct loss of 11.5 ha of vegetation and extensive fragmentation of alpine meadows (21 fragments) and steppe vegetation (68 fragments). When levels of disturbance off these trails were quantified using rapid visual assessments, 81% of 102 randomly located plots showed evidence of disturbance, with the severity of disturbance greatest close to trails. As a result, vegetation in 90% of the Valley has been damaged by visitor use, nearly all of it from unregulated use. These results highlight the extent to which informal trails and trampling off-trail can cause landscape damage to areas of high conservation value, and hence the importance of better regulation of visitor use. The methodology used for off-trail impact assessment can be easily applied or adapted for other popular protected areas where trampling off-trail is also an issue.

Impacts of informal trails on vegetation and soils in the highest protected area in the Southern Hemisphere

There is limited recreation ecology research in South America, especially studies looking at informal trails. Impacts of informal trails formed by hikers and pack animals on vegetation and soils were assessed for the highest protected area in the Southern Hemisphere, Aconcagua Provincial Park. The number of braided trails, their width and depth were surveyed at 30 sites along the main access route to Mt Aconcagua (6962 m a.s.l.). Species composition, richness and cover were also measured on control and trail transects. A total of 3.3 ha of alpine meadows and 13.4 ha of alpine steppe were disturbed by trails. Trails through meadows resulted in greater soil loss, more exposed soil and rock and less vegetation than trails through steppe vegetation. Trampling also affected the composition of meadow and steppe vegetation with declines in sedges, herbs, grasses and shrubs on trails. These results highlight how visitor use can result in substantial cumulative damage to areas of high conservation value in the Andes. With unregulated use of trails and increasing visitation, park agencies need to limit the further spread of informal trails and improve the conservation of plant communities in Aconcagua Provincial Park and other popular parks in the region.

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.

Monitoring of vegetation impact due to trampling on Cadillac Mountain summit using high spatial resolution remote sensing data sets

Cadillac Mountain--the highest peak along the eastern seaboard of the United States--is a major tourist destination in Acadia National Park, Maine. Managing vegetation impact due to trampling on the Cadillac Mountain summit is extremely challenging because of the large number of visitors and the general open nature of landscape in this fragile subalpine environmental setting. Since 2000, more intensive management strategies--based on placing physical barriers and educational messages for visitors--have been employed to protect threatened vegetation, decrease vegetation impact, and enhance vegetation recovery in the vicinity of the summit loop trail. The primary purpose of this study was to evaluate the effect of the management strategies employed. For this purpose, vegetation cover changes between 2001 and 2007 were detected using multispectral high spatial resolution remote sensing data sets. A normalized difference vegetation index was employed to identify the rates of increase and decrease in the vegetation areas. Three buffering distances (30, 60, and 90 m) from the edges of the trail were used to define multiple spatial extents of the site, and the same spatial extents were employed at a nearby control site that had no visitors. No significant differences were detected between the mean rates of vegetation increase and decrease at the experimental site compared with a nearby control site in the case of a small spatial scale (≤30 m) comparison (in all cases P > 0.05). However, in the medium (≤60 m) and large (≤90 m) spatial scales, the rates of increased vegetation were significantly greater and rates of decreased vegetation significantly lower at the experimental site compared with the control site (in all cases P < 0.001). Research implications are explored that relate to the spatial extent of the radial patterns of impact of trampling on vegetation at the site level. Management implications are explored in terms of the spatial strategies used to decrease the impact of trampling on vegetation.