"[Forests] reduce the effects of floods, prevent soil erosion, regulate the water table and assure a high-quality water supply for people, industry and agriculture - said Eduardo Rojas-Briales, of the UN Food and Agriculture Organization (FAO) - Forests are part of the natural infrastructure of any country and are essential to the water cycle."

In addition, forests reduce the impact of droughts, while preventing desertification and salinization, while loss of tropical rainforests has been shown to decrease local rainfall. "The management of water and forests are closely linked and require innovative policy solutions which take into account the cross-cutting nature of these vital resources", Jan McAlpine, of the UN Forum on Forests said.

The UN has declared 2011 the International Year of Forests. According to the UN, one-third of the world's largest cities depend on forested areas for their water.

Fresh water scarcity is becoming an increasingly alarming problem as sources are polluted, consumption rises, and climate change impacts water availability due to glacier melt and desertification. According to the UN, within 15 years 1.8 billion people could suffer from 'absolute water scarcity', while two-thirds of the global population could see water scarcities. Currently, 20% of people in the developing world don't have access to clean water.