Integrating Climatic Suitability and Early Spring Frost Risk to Assess the Cultivation Potential of Actinidia arguta in Europe

The present study aimed to evaluate the climatic suitability of Actinidia arguta (mini kiwifruit) across Europe. We first calibrated a species distribution model (SDM) on occurrence records from the native East Asian range and then transferred it to the European domain. Alongside standard bioclimatic variables, we incorporated a custom spring frost indicator into the modeling workflow. The five algorithms (GLM, RF, MAXNET, GAM, GBM) showed moderate-to-good predictive performance, with mean validation TSS values ranging from 0.618 to 0.656 and mean AUC values from 0.884 to 0.912. Temperature seasonality (BIO4) was the most influential predictor, with precipitation of the warmest quarter (BIO18) and spring minimum temperature (spring_min) showing similarly high secondary importance. Spatial projections indicated broad areas of climatic suitability across Central and Southeastern Europe; however, a considerable share of these suitable areas also coincided with zones where temperatures during critical phenological stages of A. arguta regularly fall to potentially damaging levels. Taken together, these results indicate that climatic suitability alone tends to overestimate actual cultivation potential, and that the risk of late-spring frost must be treated as an explicit component of any species distribution modeling framework for perennial crops.