Tourism, Recreation and Trail Impacts - Tourism and Trails: Cultural, Ecological and Management Issues - page 129

hooves are major environmental concerns (Sack & da Luz, 2003; Wilson &
Seney, 1994). When soils are compacted or trails widened through compres-
sion by hikers' feet, horse hooves or bike tires, it results in several undesirable
outcomes. Foremost among these is excess water runoff, which causes ero-
sion, flooding and in some extreme cases, mudslides. According to research by
Wallin and Hardin (1996: 520), runoff coefficients (ratios of runoff to rain-
fall) are highest on compacted trails versus off-trail areas. At their study sites,
average runoff was 12 times greater on trails than in off-trail areas, although
some sites' runoff coefficients were 40 times higher on trails than away from
the trails. At one site they estimated that 15 mm of rain falling in 30 minutes
would detach 3186 kg of trail soil and 4781 kg at another location.
A related outcome is altered soil composition. The chemical composition,
temperature, organic materials structure and moisture content of soil change
dramatically (Arocena et al. , 2006; Kutiel et al. , 1999). These, together with
root exposure, typically result in fewer plants, narrow vegetal diversity and
the invasion of ruderal species (Bhuju & Ohsawa, 1998).
Some ecosystems or environmental components undergo different
impacts than others. For example, the soils of heathlands and shrublands
are affected differently by horse trampling than dry grassland soils are
(Whinam et al. , 1994), and many observers believe that mid-latitude forests
are more resilient to impacts than arid environments (Sack & da Luz, 2003).
The most influential intrinsic factors affecting trail degradation include
path gradient, rockiness, soil parent material, texture, organic content, cli-
mate and vegetation types (Bryan, 1977; Gager & Conacher, 2001; Landsberg
et al. , 2001; Liu, 1995; Liu & Tseng, 2003; Marion & Leung, 2001, 2004;
Nepal, 2003; Nepal & Nepal, 2004; Nepal & Way, 2007a, 2007b; Price, 1983).
Negative impacts tend to be most pronounced on paths that are wet, steep
and unmaintained.
The nature and degree of negative impacts also depends on external
factors, including type of use, user behavior and amount of use (Marion &
Leung, 2001). As well, different transport modes and even footwear affect
trails differently. Levels of wear and tear have been shown to vary between
different footwear types, including shoes and even different types of hiking
boots (Kuss & Jenkins, 1984). Boots or four-wheel drive vehicles with one
person have different impacts than walking shoes or a vehicle with five
people on board. According to one study, equine traffic causes more damage
to established trails than do bicycles, hikers or motorcycles (Landsberg
et al. , 2001).
Landsberg et al. 's (2001: 39) experiment with horses on unmaintained
trails found that soil was damaged after 30 passes by two horses. Even snow-
mobiling, downhill skiing and cross-country skiing can effect changes to the
soils that lie beneath the snow trails, so that after the spring thaw the ground
remains compacted and altered in much the same way it is on footpaths and
tracks (Hornby & Sheate, 2001).