Projected current and future climatic suitability for Lactarius indigo mycoforestry across the Mesoamerican–Nearctic transition zone

Abstract Agricultural expansion remains a major driver of deforestation, presenting a direct conflict between forest conservation and food-security goals. Tree-based cultivation of edible ectomycorrhizal fungi may contribute to multifunctional land-use strategies by combining food production with afforestation and restoration, whilst supporting conservation strategies. Lactarius indigo , the blue milkcap , is a native edible ectomycorrhizal fungus with potential for cultivation in mycoforestry systems across the Mesoamerican–Nearctic transition zone. However, identifying regions where this species may remain climatically suitable under future climate change is essential before promoting long-term cultivation. Here, we used MaxEnt ecological niche modelling, calibrated with curated GBIF occurrence records, to estimate current and future climatic suitability for L. indigo . Current climatic suitability covered 2.63 million km2 within the study region. Future projections indicated substantial contraction in suitable climatic area, with the magnitude of reduction increasing towards the end of the century and under higher-emission scenarios. By 2071–2100, projected suitable area declined to approximately 923,299 km2 under SSP1-2.6, 376,355 km2 under SSP3-7.0 and 202,017 km2 under SSP5-8.5. These projections indicate that climate change may substantially constrain the future climatic suitability of L. indigo , although the magnitude and spatial configuration of projected changes vary among climate models and scenarios. The results provide a preliminary climatic guide for identifying candidate regions for L. indigo mycoforestry, but they should be interpreted with caution. Integration of soil properties, compatible host-tree distribution, local fungal genotypes, dispersal processes, land-use history, and field validation remain necessary to assess the practical feasibility of cultivation under changing climate conditions.