Predicting climatic suitability for apples in Finland under climate change
Villa Soto, Robin Ivan (2025)
2025
Master's Programme in Computing Sciences and Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2025-11-18
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-2025111710682
https://urn.fi/URN:NBN:fi:tuni-2025111710682
Tiivistelmä
Climate change is expected to have negative effects on apple farming throughout many important areas where these fruits are currently grown, as temperatures are starting to rise above the optimal temperatures for apple development. At the same time, only the south of Finland is currently suitable for apple farming, due to the cold temperatures throughout most of the country. However, there is growing evidence that climate change might expand the areas with appropriate temperatures for apples to develop properly and consistently in the coming decades. Still, studies on this topic for this geographic region are rare and typically ignore how inter-year variability might affect their predictions.
The changes in climatic suitability for apples in Finland were modeled between 2007 and 2100, using CMIP5 climatic data projections and a sequential chilling-forcing phenological model to determine whether the temperatures were appropriate to meet the thermal requirements for apple trees at different times of the year. Specifically, Growing Degree Days were calculated for each year over the entirety of Finland to determine whether enough heat will be accumulated over the growing season for apples to develop and mature enough for harvest. Then, linear regression models were fit at each location in Finland to identify trends and inter-year variability.
The modeled values indicate that by the end of the century, the majority of the Finnish territory will be suitable for farming at least some varieties of apple, except for some regions in the north of the country. A more conservative estimate incorporating the effects of the inter-year variability was also produced. This safe estimate identified the locations where the thermal requirements will be met at least 90% of the time, making them appropriate for farming development. These estimates also predicted an increase in the area suitable for apples by 2100, although limited to the southern half of the country.
The changes in climatic suitability for apples in Finland were modeled between 2007 and 2100, using CMIP5 climatic data projections and a sequential chilling-forcing phenological model to determine whether the temperatures were appropriate to meet the thermal requirements for apple trees at different times of the year. Specifically, Growing Degree Days were calculated for each year over the entirety of Finland to determine whether enough heat will be accumulated over the growing season for apples to develop and mature enough for harvest. Then, linear regression models were fit at each location in Finland to identify trends and inter-year variability.
The modeled values indicate that by the end of the century, the majority of the Finnish territory will be suitable for farming at least some varieties of apple, except for some regions in the north of the country. A more conservative estimate incorporating the effects of the inter-year variability was also produced. This safe estimate identified the locations where the thermal requirements will be met at least 90% of the time, making them appropriate for farming development. These estimates also predicted an increase in the area suitable for apples by 2100, although limited to the southern half of the country.