New paper examines assessment of hiking trails
Walking holidays are often advertised as a low-impact, environmentally
responsible type of recreation and tourism. But anyone that has walked a popular
hiking trail in a mountain area can see the degradation that can be produced by
high numbers of walkers in a fragile environment. A large number of papers on
the Leisuretourism.com database look at the environmental impact of activities
such as hiking, camping and mountain biking, and a paper by Mende and Newsome
added to the database this week is the latest to examine the assessment and
monitoring of trail degradation.
Mende and Newsome say that no standard system for the assessment and
monitoring of trail degradation has yet been introduced worldwide, and they
apply a method similar to one developed in the USA to assess walking trails in
an Australian national park, in order to evaluate the method's suitability as an
international system for assessment and monitoring. Results indicate that the
method is well suited to a variety of trails, and provides an efficient system,
although the method becomes more resource intensive when used for trails longer
than 5 kilometres in length. The method provided detailed trail profiles
describing selected environmental variables, degradation problems and
maintenance.
A number of studies have looked at the impact of hiking on trails. In
Slovakia, Hudecova (2004) determined that a trail was severely impacted by heavy
usage, with a large part of the surface having no vegetation. The path had
widened, and the most common surface was compacted soil and basal rock. Some
precautions to minimize excessive damage are suggested.
Lynn and Brown (2003) in Canada examined how trail erosion and degradation
impacted hikers enjoyment of their experience in natural areas. Recreational use
impact had a negative impact on the hiking experience, with litter, tree and
plant damage, and fire rings having the most negative effects. Widening and
erosion of trails had a moderate impact on the experience, while muddiness had
least effect.
Factors affecting erosion of mountain trails were investigated in Japan by
Yoda and Watanabe (2000). Trail depth became deeper in snowy vegetated areas
(covered by shrub trees or snowy bed community vegetation) than in wind-beaten
bare ground areas. The existence and timing of runoff from snowmelt seemed to be
important to differential erosion, and trail slope also contributed to erosion.
The authors report that installing ropes along trails helped to mitigate erosion
by making hikers stay on the trail. In China, Deng et al. (2003) found that
visitor usage on trails in Zhangjiajie National Forest Park is proportionate to
trampling impacts, with the two most used trails (Yellowstone Village Trail and
Gold Whip Stream Trail) having the highest values in Soil Impact Index (SII) and
highest rate of scarred trees. The paper proposes management strategies for
improving the park's visitor and environmental management.
The effects of trampling on vegetation, and the rate of recovery of
vegetation, is an area that has seen extensive research. Cole and Bayfield, from
the US Forest Service, reported on standard experimental procedures in 1993. A
protocol based on extensive trials and discussion in the USA and UK, that can be
applied in a wide range of vegetation types, was developed to provide
information on both damage to vegetation in response to short-duration trampling
and subsequent recovery over a one-year period.
Longer-term monitoring of trampling impact on alpine vegetation is reported
by Hartley (2000) in a Rocky Mountain Research Station publication that has many
papers on the environmental impact of outdoor recreation. Hartley states that
vegetation cover recovered in 19 to 25 years when trampled 15 times per week for
six weeks in 1967 compared to 25 to 30 years where trampled 50 times per week.
It is suggested that the long-term consequences of human trampling on dry meadow
vegetation cannot be assessed from short-term observations.
In contrast to the differential recovery from different trampling intensities
reported by Hartley, Kuss and Hall (1991) found in New Hampshire over a
five-year period that recolonization of impacted areas that received 100
trampling passes as measured by plant cover, dominant indices, floristic
dissimilarity, and species diversity was similar to areas receiving four and
eight times more trampling, despite major differences in soil penetration
resistance. These data suggest limited use delivered at one time can be as
damaging as increasing levels of use delivered over time. Cole and Monz (2002)
also found in Wyoming that low levels of trampling caused substantial reductions
in vegetation cover and height, with rates of change decreasing as trampling
intensity increased. Different plant communities had varying degrees of
resilience to trampling, as also reported in Belgium by Roovers et al. (2004).
Apart from the effects on vegetation and on the enjoyment of hikers along a
trail, at its most severe level, erosion caused by hiking can cause a visual
scar on the landscape that creates an eyesore even for those viewing from miles
away. In such cases, remedial measures may require construction of artificial
surfaces, adding drainage ditches and features to prevent water running down the
trail causing further erosion, or closure of the path and construction of
alternatives that take a less visually obtrusive line. This has been done on the
Scottish mountain Schiehallion, now owned by conservation organization the John
Muir Trust, which has realigned the main path to the summit onto an older and
more sustainable line and is now in the third year of healing the scar caused by
the former trail.
Searching the Leisuretourism.com database for "trampling and
vegetation" currently returns 150 bibliographic records covering all
aspects of recreational impacts, effects on soil and vegetation, methods of
determining impact of hikers, and recovery of vegetation. Searching for
"hiking and environmental impact" returns 40 records, including a
selection on other types of environmental impact. The search "trails and
(erosion or degradation)" currently finds 129 records, including a
selection on the impact of horse-riding and cycling as well as hiking.