the practice of growing trees and crops together. Agroforestry systems benefit from the ability of trees to protect soil from erosion and to capture and recycle plant nutrients. [fn]Source: (IISD 2005) from IISD website; http://www.iisd.org/sd/glossary.asp (updated: Aug 2005)[/fn].A wide variety of land-use systems combining tree, crop and/or animals on the same land.  Two characteristics distinguish agroforestry from other land uses: 1) the action involves the deliberate growing of woody perennial on the same unit of land as agricultural crops and/or animals either spatially or sequentially, and  2) there is significant interaction between woody and non-woody components, either ecological or economical.  To be counted as an agroforestry system, at least 15 percent of the system must be trees or woody perennials grown for a specific function (e.g., shade, fuel, fodder, windbreak). (Source: SMurray)