A few of the other problems and impacts associated with ski resorts include: Erosion/siltation: The deforestation caused by ski-run construction usually leads to severe and ongoing erosion come spring runoff. Beyond topsoil loss, this can lead to siltation problems in neighbouring lakes. Species disruption/loss of habitat: When development moves into wilderness, critical plant and animal habitat is invariably displaced or destroyed. Migration routes are also heavily impacted by high-traffic roads and human presence. Pollution runoff/watershed impact: The cumulative impact of a large human population developing a mountain environment is huge. Pollutants such as automotive fluids, sewage and salt can contaminate ground water and lakes downstream. Increased air pollution due to auto traffic: Most people drive their car to ski or ride. When they do they are pumping environmentally damaging hydrocarbons directly into the forests surrounding the resort. As airborne pollutants accumulate on the needles of upland conifers, the evergreens eventually weaken to a point where they succumb to insect and parasite attack.
Tourism has for many years been focused on mountain areas, which provide opportunities for hiking, white-water rafting, fly fishing, para-gliding and winter sports, especially skiing and related activities. Pressures from these activities on biological resources and their diversity are enormous and include: erosion and pollution from the construction of hiking trails, bridges in high mountains, camp sites, chalets and hotels. There has been increasing awareness of and publicity on the negative effects of tourism on mountains.
Special clean-up parties have been dispatched to Everest and the other popular Himalayan mountains specifically to remove some of the 16 tonnes of discarded equipment and trash from trekkers and climbers. Steel pegs are permanent traces in many well-climbed mountains.
70,000 trekkers a year in Nepal attract the services of 150,000 support staff. The trekkers' demand for Western hot food and showers forces the felling of more trees than are being planted. In 1993, it was predicted that Nepal's forests would be gone by the year 2000. The effect of trekking holidays on the local people is mainly inflated prices and shortages of materials.