Using old fields for new purposes: ecosystem service outcomes of restoring marginal agricultural land to forests.

Context: Human activities, particularly intensive agriculture, have caused significant environmental degradation, reduced ecosystem diversity, and increased vulnerability to global change. Recent international policies, such as the Global Biodiversity Framework's 30 × 30 target, advocate for nature-based solutions (NbS) such as ecological restoration to address these impacts. In agricultural landscapes, however, there are concerns that restoration may impact food production. Objectives: We investigated how forest restoration, as an NbS, changes the supply of ecosystem services (ES), including potential trade offs with agricultural output. Using the Montérégie region of Québec (southeastern Canada) as a case study, we assessed the influence of restoration extent, spatial configuration, and the original agricultural site conditions on the ES outcomes. Methods: We modeled ES outcomes for seven ES (crop production, maple syrup production, deer hunting, water quality, carbon storage, pollination, and outdoor recreation) under nine scenarios, which varied by total amount of the landscape restored (3.3%, 10.8%, 30%) and initial conditions of the agricultural fields restored (randomly selected, degraded agricultural field, or abandoned agricultural field). Results: Our findings indicate that increasing the amount of land restored enhances provision of most ES, though improvement varied by service. The initial condition of restored sites minimally influences ES outcomes. However, the spatial pattern of restoration plays a significant role in determining ES delivery, as restored sites enhance most ES through spillover effects up to 500 m. Conclusion: This study underscores the potential for combining landscape ecology approaches and ES tools to forecast NbS outcomes and inform landscape planning. Supplementary Information: The online version contains supplementary material available at 10.1007/s10980-025-02121-0.