Agroforestry and Soil Health under Climate Change: A Review of Biological, Chemical, and Physical Indicators

Abstract

Agroforestry systems — intentional combinations of trees with crops and/or livestock — are increasingly recognised as multifunctional land-use strategies capable of sustaining agricultural productivity whilst mitigating the adverse effects of climate change on soil health. Soils represent the foundational resource underpinning global food security, and their biological, chemical, and physical integrity is vital to ecosystem functioning. Under conditions of accelerating climate change, conventional agriculture has demonstrated measurable deterioration in soil health indicators, prompting renewed interest in tree-based farming systems. This review critically examines the current state of knowledge regarding how agroforestry influences biological indicators (microbial biomass, enzyme activity, and soil fauna diversity), chemical indicators (soil organic carbon, nutrient availability, pH, and cation exchange capacity), and physical indicators (bulk density, aggregate stability, and water retention) of soil health. The review further explores how changing temperature and precipitation regimes modulate these indicator dynamics within agroforestry contexts. Evidence synthesised from peer-reviewed literature consistently demonstrates that well-designed agroforestry systems enhance soil biological activity, increase soil organic carbon stocks, improve soil structural stability, and confer greater resilience to climate-related stressors than their monocultural counterparts. However, the magnitude and direction of these effects are highly context-dependent, varying with agroforestry type, climatic zone, tree species composition, and management intensity. The review identifies critical research gaps, including the need for long-term observational studies, standardised soil health measurement frameworks, and mechanistic understanding of climate–agroforestry–soil interactions across diverse biomes. A more integrated and holistic approach to soil health assessment, incorporating minimum data sets tailored to agroforestry contexts, is advocated for future research and policy development.