For many decades, concerned by the undeniable deforestation data, environmental management has included re-vegetation activities in unforested areas
intended to (re)create a forest environment.

Thus, afforestation or reforestation has been for a long time one of the principal activities in watershed management policies, the provision of environmental services and hydrological regulation.

Natural Andean forests play an important role in hydrology and the control of erosion. It is thus presumed that afforestation or reforestation equally supports these environmental aspects.

What generated most concern were the various studies that showed that fast-growth forest plantations, which therefore had heavy water use, actually caused a negative eff ect on the watershed’s hydrological balance instead of the anti cipated improved water yield.