External economic benefits and social goods from prairie shelterbelts.

Shelterbelts are a valuable resource to those who plant them and to other members of society. The external benefits to society can be worth as much as the private benefits to producers. However, the external benefits have not been quantified or monetized in a well-documented way. In this study, external benefits were estimated for tree seedlings distributed by the Agriculture and Agri-Food Canada Shelterbelt Centre in the Canadian Prairie Provinces for the period 1981–2001. Estimation of these benefits required information on the biophysical changes caused by shelterbelts and their valuation. Using literature, we estimated that the value of these external benefits amounted to over $140 million (2001 CDN$; CDN$1 = US$0.63). The majority of this value was derived from carbon sequestration ($73 million) and reduced soil erosion ($15 million) services with the remainder being contributed by biodiversity and water and air quality services. Other external benefits, such as health values, transportation safety, aesthetics and property values were identified but could not be estimated due to a lack of data. The estimated value for external benefits conferred by shelterbelts in this study indicates that they are large and suggests that both private and external benefits need to be considered in formulating policies or programs so that benefits to the society can be maximized. [ABSTRACT FROM AUTHOR]