Mountains - a fragile source EP3

Mountains and their forests play a major role in the preservation of biodiversity and provide important ecosystem services such as climate regulation. Major threats to mountains include climate change, land use needs, and economic and population growth. These pressures impact food and water security, the availability of other natural resources, and the very survival of species.

PEOPLE: Humans have exploited the timber, mining and pasturage resources of mountain environments for millennia. These activities and others have impacted mountain ecosystems to varying degrees. Today, the rapid flux of people and resources into and out of mountains compounds the challenges facing mountains.

POLLUTION: Human activities, even those carried out far from mountains, pollute remote mountain areas at high altitudes. Potentially harmful chemicals can be transported to mountains by orographic effects and may enrich in lake sediments and peat bogs. A range of climate variables, such as rainfall, snowfall, length of growth season, and wind patterns may play an important but little understood role in distribution and re-distribution of pollutants. Temperature dependent partitioning between air and atmospheric particles, snow surface, or water droplets determine dry and wet deposition rates that may lead to a fractionation and preferential deposition of different compounds at different altitudes. The pollution of mountain freshwater with chemical compounds - a key challenge humanity is facing, is therefore closely linked to climate change and climate extremes. Climate extremes play a key role in the re-distribution of chemical pollutants and are assumed to enhance release of pollutants stored in ice, soils or sediments through e.g. flood events. In addition, local activities, such as mining and pastoralism, pollute mountains more directly by releasing heavy metals or insecticides.

PATHOGENS: Food webs in destabilized mountain ecosystems can be strongly altered. For example, zooplankton communities are sensitive to pollution and to fish introductions. In changed communities, pathogens may increase in abundance. Such changes can result in the introduction of, and increased vulnerability to, pathogens affecting both humans and wildlife. The pressures and threats to our mountains are manifold. Exploitation, Pastoralism, Tourism, Fish stocking and Pollution. And as a result from all the threats: Eutrophication – an increased availability of nutrients. Protecting mountain ecosystems is protecting our future.