Response to commentary on the paper 'forests and water: The value of native temperate forests in supplying water for human consumption'

摘要

In Nunez et al. (2006) we estimated the economic value of water supply as an ecosystem service of Chilean temperate forests in the production of drinkable water. We used the change in productivity method (production function approach or also referred as to valuing the environment as an input) to derive benefit estimates per cubic meter of stream water, per household, and per hectare. Because the benefits of an ecosystem service can enhance an economic activity (i.e. drinkable water production), willingness to pay (WTP) for such service can be measured by estimating its value as an input factor in a productive activity (Freeman, 2003; Barbier, 2007). This represents the essence of the change in productivity method (Barbier, 2007).