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Environmental impact

Natural environments are often fragile and may be accidentally damaged, especially when a large number of hikers are involved. For example, years of gathering wood can strip an alpine area of valuable nutrients, and can cause deforestation; and some species, such as martens or Bighorn Sheep, are very sensitive to the presence of humans, especially around mating season. Generally, protected areas such as parks have regulations in place to protect the environment, so as to minimize such impact. Such regulations include banning wood fires, restricting camping to established campsites, disposing or packing out faecal matter, and imposing a quota on the number of hikers. Many hikers espouse the philosophy of Leave No Trace, following strict practices on dealing with food waste, food packaging, and other impacts on the environment. Human feces are often a major source of environmental impact from hiking, and can contaminate the watershed and make other hikers ill. ' Catholes ' dug 10 to 25 cm (4 to 10 inches) deep, depending on local soil composition and covered after use, at least 60 m (200 feet) away from water sources and trails, are recommended to reduce the risk of bacterial contamination.

Fire is a particular source of danger, and an individual hiker can have a large impact on an ecosystem. For example, in 2005, a Czech backpacker accidentally started a fire that burnt 5% of Torres del Paine National Park in Chile.