Other Uses of Forests

Watershed

Among other ecological benefits, the forests play a vital role as watersheds. A watershed, also known as a catchment basin, is the region of land that drains into a specified body of water, such as a river, lake, sea, or ocean.

Forests as watersheds

The bulk of the earth's rainfall is received by mountains, thus forming the headwaters of the land's water distribution channels. As a result, the mountain forests influence the quantity and quality of this precious freshwater resource. For example, forests are usually the best cover for safeguarding water quality from sediments and chemicals.

Flow of water from Forest catachment areas is complex, making generalizations difficult. However, there is evidence to suggest that cloud forests and some older natural forests can increase net water flow. Montane "cloud" or "fog" forests are special kinds of forests that scrape out moisture from the clouds or fog. This water extraction function is in addition to the vertical precipitation received by these forests. Having relatively low water use, these forests add to the water supply of a catchment.

In addition, forest cover can reduce the problem of flooding from many small, frequent storm events in headwater watersheds close to the forest area.

Water supply dependence

Currently, about a third of the world's largest cities (33 out of 105) source a significant proportion of drinking water directly from protected forest areas. These cities include: New York, Jakarta, Tokyo, Mumbai, Rio de Janeiro, Los Angeles, Barcelona, Nairobi, and Melbourne. At least five other cities obtain water from sources that originate in distant watersheds, and at least eight more from forests that are managed to give maximum importance to providing drinking water.

Economic value of watersheds

Forest catchment areas can accrue significant economic value, something that goes largely unrecognised most of the time. For instance, in some circumstances, it is possible to collect user fees from stakeholders (individuals as well as companies) who benefit from drinking water in order to help pay for catchment protection benefits provided by the protected area management.