Carbon Sequestration in Agroforestry Systems

TLDR: In this paper, the authors found that tree-based agricultural systems, compared to treeless systems, stored more carbon in deeper soil layers near the tree than away from the tree, higher soil organic carbon content was associated with higher species richness and tree density; and C3 plants (trees) contributed to more C in the silt-plus-clay-sized (SLCS) soil.

Abstract: Agroforestry—the practice of growing trees and crops in interacting combinations—is recognized worldwide as an integrated approach to sustainable land-use. It is estimated to be practiced over 1 billion hectares in developing countries, and to a lesser extent in the industrialized countries. Agroforestry systems (AFSs) are believed to have a higher potential to sequester carbon (C) because of their perceived ability for greater capture and utilization of growth resources (light, nutrients, and water) than single-species crop or pasture systems. The estimates of C stored in AFSs range from 0.29 to 15.21 Mg ha − 1  yr − 1 aboveground, and 30 to 300 Mg C ha − 1 up to 1-m depth in the soil. Recent studies under various AFSs in diverse ecological conditions showed that tree-based agricultural systems, compared to treeless systems, stored more C in deeper soil layers near the tree than away from the tree; higher soil organic carbon content was associated with higher species richness and tree density; and C3 plants (trees) contributed to more C in the silt- + clay-sized (