Simulating the Influence of Climatic Warming on Future Spring Frost Risk in Northern German Fruit Production

Spring frosts can cause severe losses in fruit production and the interannual variability of their appearance still is a challenge to fruit production scheduling and reliability. Hence information about future risk of spring frost damages in long-standing orchards can be essential in fruit production. Hereby frost damages during apple (Malus xdomestica) blossom are potentially increasing regionally in Lower Saxony (Germany) by 2045 as compared to 1971-2000, while on average no increase in frost risk was found. This result was obtained by computing the day of bloom for the IPCC emission scenario A1B using a temperature sum model calibrated with site observations (213 sites of phenological observation, 115 weather station records, German Meteorological Survey) and an ensemble of previously bias corrected hourly temperature series of two regional climate models (GCM: ECHAM5/MPI; RCMs: REMO: 3 runs, CLM: 1 run) with a resolution of approximately 0.088 degrees and 0.165 degrees respectively.