Rethinking the Impact of Large-Scale Tree-Planting on Soil Quality for the Chronically Poor

Abstract

This paper examines how large-scale tree-planting strategies shape soil quality (SQ) and how SQ, in turn, affects the world’s poorest communities. While afforestation and large-scale tree-planting efforts have been promoted as low-cost, climate-friendly solutions, their implications for SQ are complex and yield mixed results since SQ characteristics are largely context-specific. Nature-based solutions are only effective if they work for the people who live with them every day. However, when large-scale tree-planting degrades SQ and local livelihoods, these efforts fail to be “solutions” and instead widen the poverty gap. Using a systematic literature review of peer-reviewed empirical studies, this paper builds on previous unpublished research demonstrating that tree planting yields context-dependent soil quality outcomes and examines how poor soils create and perpetuate poverty traps. The paper then evaluates inorganic fertilization as a potential intervention but finds that, despite its effectiveness, cost barriers make it unaffordable for the communities that need it most. In response, this research identifies improved tree fallows, as well as the invasive species and hybrid fruit-bearing variants, as promising alternatives for soil restoration. In addition, these approaches require minimal cash investment, reduce labor demands, and provide valuable byproducts, making them accessible to even chronically poor farmers. The paper argues that a “business as usual” approach to large-scale tree-planting without regard to soil quality risks creating poverty traps for low-income farmers, and that improved, invasive, and hybrid fruit-bearing fallows offer a more people-centered, low-cash approach to restoring soils while contributing to reforestation goals.​