Effectiveness of nature-based solutions for adaptation to climate-driven accelerated water erosion in Latin American semi-arid regions

Abstract

Climate change is intensifying rainfall erosivity and the frequency of extreme events across semi-arid regions of the Global South, amplifying the vulnerability of hillslopes and watersheds that sustain food and water security for more than 60 million people. Soil loss rates that already reach 36 Gt yr $$^{-1}$$ globally compromise agricultural productivity and water quality, directly affecting the well-being of rural communities and their livelihood opportunities. Nature-based solutions (NbS) constitute adaptation strategies endorsed by the IUCN, yet the dispersion of results across functional macro-groups and fibrous materials hinders prioritization in management programs and regional cooperation initiatives. This study assesses the comparative effectiveness of five functional NbS macro-groups in reducing soil loss in field trials with natural materials, and tests the geographic transferability of the predictive model across a database spanning 18 countries to inform climate adaptation strategies in semi-arid regions. We conducted a PRISMA 2020 meta-analysis comprising 93 control–treatment comparisons from 43 studies, classified into five functional macro-groups and seven aggregated intervention types. The random-effects model indicated a mean reduction of 84.8% in soil loss, with permeable bio-barriers reaching 97.1%, surface covers 89.7%, natural-fiber geoproducts 85.5%, and vegetative barriers 79.8%, whereas living bioengineering did not show a significant effect. The functional macro-group explained 18.2% of the heterogeneity, and slope showed a significant quadratic relationship, with peak effectiveness in the 30–50% range. Geographic cross-validation across 11 countries indicated an RMSPE of 1.32 lnRR, indicating variable transferability and the need for local calibration of climate adaptation strategies. The results suggest that NbS based on natural materials may constitute climate adaptation portfolios oriented toward the well-being of vulnerable communities in Latin America, although the high heterogeneity and the underrepresentation of Latin American sites reinforce the need for standardized field trials in the region.

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