Impacts of Climate Warming on Climate Parameters Relevant to Extensive Fruit Growing in Two Selected Regions of Austria

Abstract For two Austrian regions (Amstetten South and Pöllauer valley), climate data from the periods 1961-1990 and 1991-2020 were analyzed and scenarios for +2 °C and +3 °C global warming ("global warming level") were calculated in order to find out which changes relevant to fruit growing can be expected due to global warming. The comparison of the periods 1961-1990 and 1991-2020 already showed relevant changes that will continue to intensify in both scenarios: higher temperatures and less severe frosts in winter, longer growing seasons and an earlier start to vegetation at all altitudes. Late frosts in spring are becoming less frequent, but due to the earlier start of vegetation at the same time, the risk of frost damage - especially in April - remains and may even increase in some areas. The higher temperatures lead to a reduction in the climatic water balance, particularly in summer and at lower altitudes; in dry years, heat and drought stress are to be expected. In the lower altitudes of the two regions, where extensive orchards have had their main distribution up to now, they will come under increasing pressure, particularly on soils with low water retention capacity. Due to warmer summers and winters and longer growing seasons, the climate that is favorable for many types of fruit is increasingly shifting to higher altitudes that were previously less suitable and less commonly used for fruit growing. The risks and uncertainties for fruit production will increase considerably if the temperature rises by +2 °C, and at +3 °C, traditional forms of cultivation could be at risk. Active climate protection that limits global warming to below +2 °C is therefore essential to ensure a future perspective for extensive fruit orchards in Austria.