Sustainability, Vol. 11, Pages 2293: Hi-sAFe: A 3D Agroforestry Model for Integrating Dynamic Tree-Crop Interactions (Sustainability)

Agroforestry, the intentional integration of trees with crops and/or livestock, can lead tomultiple economic and ecological benefits compared to trees and crops/livestock grown separately.Field experimentation has been the primary approach to understanding the tree-crop interactionsinherent in agroforestry. However, the number of field experiments has been limited by slow treematuration and difficulty in obtaining consistent funding. Models have the potential to overcomethese hurdles and rapidly advance understanding of agroforestry systems. Hi-sAFe is a mechanistic,biophysical model designed to explore the interactions within agroforestry systems that mix treeswith crops. The model couples the pre-existing STICS crop model to a new tree model that includesseveral plasticity mechanisms responsive to tree-tree and tree-crop competition for light, water,and nitrogen. Monoculture crop and tree systems can also be simulated, enabling calculation of theland equivalent ratio. The model`s 3D and spatially explicit form is key for accurately representingmany competition and facilitation processes. Hi-sAFe is a novel tool for exploring agroforestrydesigns (e.g., tree spacing, crop type, tree row orientation), management strategies (e.g., thinning,branch pruning, root pruning, fertilization, irrigation), and responses to environmental variation(e.g., latitude, climate change, soil depth, soil structure and fertility, fluctuating water table). Byimproving our understanding of the complex interactions within agroforestry systems, Hi-sAFe canultimately facilitate adoption of agroforestry as a sustainable land-use practice.