By Emilie C. Vansant, Kai Mausch, Amy Ickowitz, Stepha McMullin, Alice Karanja, and Laura Vang Rasmussen
Today we are producing more food than ever before in history, and yet one third of the global population suffers from malnutrition. This problem has only worsened with the recent COVID-19 pandemic, particularly in low- and middle-income countries, where a large percentage of rural households depend on agriculture for their livelihoods. Policies designed to improve food security and nutrition in these regions often focus on increasing the productivity of a few select crop and livestock breeds. Yet this narrow focus has led to the simplification of both rural diets and landscapes – with agricultural expansion being a leading cause of deforestation and biodiversity loss. This has prompted an emerging research agenda into alternative strategies for synergistically promoting nature and nutrition: specifically how trees in farming systems can contribute to dietary quality through providing foods, sources of income, and ecosystem services to agriculture.
To contribute to this developing field, we conducted a systematic review of 36 papers that address linkages between tree-based farming systems and dietary quality. From our analysis, we can conclude:
- Maintaining trees in and around farmland – and using these trees for both the direct provision of foods and as a source of income – can serve as a key strategy for households to diversify food consumption and improve dietary quality.
- How much a tree-based farming system can influence diets is dependent on policies and institutions at the national scale, bioclimatic and geographical factors at the landscape scale, as well as socioeconomic factors at both the landscape and household level.
- Indigenous populations practicing traditional forms of tree-based farming (which are often diverse systems integrated with wild landscapes) seem to maintain high levels of dietary quality through sourcing food from both wild and cultivated areas.
Through identifying common trends in tree-based farming/diet research across disparate cultural and geographical contexts, our synthesis can direct future research to support sustainable production systems for healthier diets and ecosystems.