Introduction. Challenges and Achievements in Agroforestry in the New Millennium

Agroforestry systems (AFS) are broadly defined as a set of land uses and practices that integrate trees and other woody vegetation into agricultural systems. They are becoming increasingly relevant worldwide as society recognizes their multiple roles and functions: food and energy production, biodiversity conservation, ecosystem restoration, climate change adaptation and mitigation, and tools for rural development. This chapter summarizes advances in agroforestry research and practice and poses questions on the effectiveness of AFS to solve the development and environmental challenges the world presents us with today. Beginning in the 1970s, academic research into AFS emphasized their function as a viable productive alternative to industrial agriculture. Studies focused on AFS design, multipurpose tree/shrub species, and advancing financial evaluations. Later, research turned to alleviating poverty and improving food security. In the last decade, focus has shifted to AFS’s role in restoring degraded landscapes, conserving biodiversity, and adapting to and mitigating climate change. Current challenges to successful AFS include difficulties integrating traditional knowledge with current scientific expertise, the lack of a market for AFS products and services, a need to properly monitor the achievement of set goals, and barriers to scaling up successful AFS. These challenges require innovative solutions from varying perspectives and knowledge bases in order for AFS to successfully bring about multifaceted, beneficial change at multiple scales. The science and practice of agroforestry is evolving rapidly, and the second edition of this book reflects these changes. The appreciation of AFS is increasing among practitioners and decision-makers who can effectively promote their implementation, gaining momentum toward their biodiversity conservation and food sovereignty-harmonizing goals.