For two Austrian regions (Amstetten South and P & ouml;llauer valley), climate data from the periods 1961-1990 and 1991-2020 were analyzed and scenarios for +2 degrees C and +3 degrees 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 degrees C, and at +3 degrees C, traditional forms of cultivation could be at risk. Active climate protection that limits global warming to below +2 degrees C is therefore essential to ensure a future perspective for extensive fruit orchards in Austria.

In this study, climate data from the periods 1961-1990 and 1991-2020 as well as scenarios for +2 degrees C and +3 degrees C global warming (global warming level gwl) were analyzed to find out what changes relevant to fruit growing can be expected in the Lungau region due to global warming. A favorable development due to climate change is already evident in the altitude level be- tween 1000 and 1200 m, which is the most relevant for fruit growing, and this will continue assuming the gwl +2 degrees C scenario. The minimum temperatures in winter will rise by an average of 4.6 degrees C compared to 1961-90, which is why extreme winter frosts will no longer be a limiting factor for most types of fruit. The growing season will be on average 24 days longer than compared to 1961-90, which favors fruit ripening and also enables the cultivation of varieties with a longer development period. The slightly negative climatic water availability already observed in spring is increasing due to the temperatures in spring and summer being around 2 degrees C higher and can lead to heat and drought stress in trees in particularly dry years, which is why the choice of deep soils for fruit growing without additional irrigation is recommended in the future. In the gwl +2 degrees C scenario, the opportunities for extensive orchards in the region outweigh the risks. This opens up the potential for Lungau to develop into a new Mostviertel (author's note: traditional Austrian perry growing region). Although 5 days less with <-2 degrees C are to be expected in April compared to 1961-90, the risk of frost damage remains or may even increase due to the vegetation start being around 14 days earlier and the inner-alpine location, especially in April. The seemingly favourable developments in the region caused by global warming will intensify under the assumption of the +3 degrees C scenario, but at the same time a further increase in extreme events is to be expected, which will significantly relativise the opportunities caused by climate change. In this respect, such a scenario cannot be considered desirable from a regional fruit growing perspective either.

The wine sector, among the most profitable agricultural segments, has been markedly affected by the ongoing climate change impacts, such as warmer climate conditions with higher frequency of extreme temperatures and a trend of decreasing precipitation. All this results in higher evaporative demand and therefore higher occurrence of water stress events leading to advancement of temperature-sensitive phenological stages (e.g., budburst and ripening). Such negative effects eventually affect berry development and quality, especially in historically valuable viticultural areas, forcing winegrowers to work within a compressed harvest period to maintain wine typicity. In this work we examined the relationship between environmental variables (air and soil temperature, relative humidity, precipitation, and solar radiation), phenology, berry, and wine quality for the two varieties (Chardonnay and Teroldego) in Trentino Alto-Adige/South Tyrol (Italy) over 36 years. Huglin Index (a bioclimatic heat index), growing degree days (measure of heat accumulation), and overall mean temperature showed linear increase (p < 0.001) in the last years, while no variations were recorded for precipitations. Despite no major effects being observed for phenological interval lengths, the onset of most of the phenological stages for both varieties had significantly (p < 0.001) advanced. However, i) early budburst pushed the budburst-flowering interphase by-1.2 days every two years toward putative colder periods with increased late frost probability and potential slower phenological progression towards flowering, and ii) early veraison shifted the veraison-ripening interphase by 0.25 day per year into warmer periods that oppositely impose faster phenological advancement. Hence, a substantial equilibrium in the seasonal growing length over years was maintained. Potential carry-over effects from the previous season were observed, particularly associated with heat requirements to unlock early phenological events, raising additional concerns on the additive effects of climate change to viticulture. Generally, white wine quality increased (p < 0.05) over the years, while red and sparkling wines remained unaffected. This was putatively related to accurate harvest date decision-making dictated by berry quality parameters: sugar-to-acidity ratio for Chardonnay and bunch sanitary status for Teroldego. Overall, this work provides evidence of the dynamics involved in climate change, and, to our knowledge, its overlooked effects on viticulture, thus providing new insights that can contribute to further developing adaptive strategies.