Berry plant abundance but not occupancy may decline under climate change: Predicting future conditions and promoting resilience in Southeast Alaskan forests

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 distribution and abundance remain largely unknown. Objectives I developed models to project changes in habitat suitability for blueberry ( Vaccinium alaskaense and V. ovalifolium ) and salmonberry ( Rubus spectabilis ) in Southeast Alaskan forests under future climate change and to evaluate climatic, topographic, and forest stand conditions associated with their aerial cover ( hereafter , cover). Methods I used species distribution models to compare projected habitat suitability for blueberry and salmonberry under historical climate (1990–2020) and future scenarios (SSP2-4.5, SSP 3–6.0 and SSP 5-8.5) for 2050, 2075, and 2100 in Southeast Alaskan forests. I compared projected suitability to cover and used models to evaluate environmental correlates of blueberry and salmonberry cover. Results Habitat suitability for blueberry and salmonberry declined in all future scenarios, but occupancy was projected to remain high. Habitat suitability was positively correlated with blueberry but not salmonberry cover. Forest stand attributes including forest type, shrub and tree cover, and stand age and size were often stronger predictors of cover than climate or topography. Conclusions While blueberry and salmonberry occupancy in Southeast Alaska are unlikely to decrease substantially over the 21st century, declining habitat suitability may drive reduced blueberry abundance. Relationships between forest conditions and blueberry and salmonberry cover suggest that management could support sustained abundance in the face of challenges posed by climate change.