Local berry plant abundance but not regional occupancy may decline under climate change: predicting future conditions and promoting resilience in Southeast Alaskan forests

Abstract Context Climate change may affect the distribution and performance of many high latitude species. Plants producing fleshy, edible fruits are ecologically, economically, and socially important components of Alaskan forests, but the potential impacts of climate change on their regional distribution and local abundance remain largely unknown. Objectives This study investigated how climate change may impact the regional occupancy and local abundance of blueberry ( Vaccinium alaskaense and V. ovalifolium ) and salmonberry ( Rubus spectabilis ) in Southeast Alaskan forests and evaluated environmental correlates of their local abundance. Methods Species distribution models were used to compare projected suitability for blueberry and salmonberry presence under historical (1990–2020) and future climate scenarios (SSP2-4.5, SSP 3–7.0 and SSP 5–8.5) for 2050, 2075, and 2100 in Southeast Alaskan forests. Relationships between projected suitability and local cover were assessed, as were environmental predictors of local cover. Results Suitability for blueberry and salmonberry presence declined in all future scenarios but was nonetheless projected to remain high. Suitability was positively correlated with the cover of blueberry but not salmonberry in Southeast Alaskan forests. Forest stand attributes including forest type, shrub and tree cover, and stand age and size were often stronger predictors of blueberry and salmonberry cover than climate or topography. Conclusions Regional blueberry and salmonberry occupancy in Southeast Alaska is unlikely to substantially decrease over the twenty-first century, but declining suitability may drive reduced local abundance of blueberry. Relationships between forest conditions and blueberry and salmonberry cover suggest that management actions could promote abundance despite challenges posed by climate change.