More than Yield: Ecosystem Services of Traditional versus Modern Crop Varieties Revisited

Agricultural intensification with modern plant breeding focuses on few high-yielding crops and varieties. The loss of traditional crop species and variety diversity contributes to the current decline of provisioning, regulating, and cultural ecosystem services, as reported in the Millennium Ecosystem Assessment. Access to local and adapted varieties is pivotal for resilient agroecosystems, in particular under current global change. We reviewed the scientific literature to understand the role of different crop varieties for ecosystem services, comparing the performance and perception of traditional landraces versus modern varieties and ask the following questions: 1. Do landraces and modern varieties differ in terms of provisioning and regulating ecosystem services? 2. When and why do farmers prefer cultural ecosystem services of landraces over high-yielding varieties? Based on 41 publications, our results document that modern varieties are preferred over landraces because of their typically higher provisioning services such as crop yield. However, landraces often guarantee higher provisioning services under non-optimal farming conditions. Landraces can show high resilience under harsh environmental conditions and are a trusted source achieving stable crop yield (e.g., under droughts stress). Regulating services such as resistance against pests and diseases appear to often become lost during breeding for high-yielding, modern varieties. Furthermore, small-scale farmers typically prefer local landraces due to regional cultural features such as family traditions and cooking characteristics for special dishes. In conclusion, both landraces and modern varieties have merit depending on the farmers’ priorities and the social-ecological context. In any case, maintaining and restoring the huge diversity of landrace varieties is necessary for sustaining current and future needs.