Will olive groves have a future under climate change conditions in the North Aegean sub-region, a Mediterranean agricultural environment of Turkey?

Abstract

Abstract The study is aim at investigating future changes in sustainability of olive farming by means of climate change, and changes in suitableness and phenology of olive tree cultivation in the study area characterised mainly with Mediterranean climate. According to projected changes based on RCP8.5 scenario, air temperatures will increase significantly, and in the 2073–2098 period, projected warming reaches an average of 5–6°C with a most negative condition on olives in terms of warming during 2073–2098 period. Annual precipitation projections based on RCP8.5 scenario indicated that present suitable areas of olive groves will decrease in the period of 2049–2073, and almost the entire study area will be in the category of medium suitable in the period of 2073–2098. With respect to projected Emberger Bioclimate classification, for RCP 8.5 scenario, in the period of 2049–2073, there will be a significant increase in dry-sub humid areas. This increase will cover up the coastal areas in the period of 2074–2098, and even all the study area was determined as the dry-sub humid and semi-arid Mediterranean bioclimatic layer except for some coastal areas. An increase of about 6°C is expected in maximum values of maximum air temperatures during the swelling periods, especially in the periods after 2050 for RCP8.5 scenario. This increase in extreme maximum temperatures may cause olive trees to bloom earlier and prolong growth period. By regarding the high vernalization requirement of main olive variety in the study area, a 6°C temperature increase may significantly decrease olive yields and will force farmers to transition to new varieties with relatively low vernalization requirements. According to both RCP scenarios, there is a possibility of extension of suitable areas for olive cultivation towards low to mid-altitude plateaus and middle-altitude slopes of mountainous areas and high plateaus particularly facing suitable aspects to lower negative effects of projected warming and dryness.