E. Chitu, M. Calinescu, I. Mazilu , M. Coman and E. Mateescu
The warming trends of Romania's climate create favourable conditions for growing sub-tropical species. Meanwhile, low temperatures during the winter period do not always follow a similar increasing tendency throughout the country. The objective of this work was to use some models that would identify areas where climate conditions are likely to be suitable for fig, Chinese persimmon and jujube orchards over Romania. The models identified the areas where temperatures (minimum and cardinal of growing season ones), growing season duration and rainfall conditions are likely to be suitable for fig, jujube and persimmon orchards over Romania. Low minimum temperatures, which drop once in four years in most areas below the frost resistance of fig and persimmon species during the winter, was the most important climatic factor, by limiting their spatial distribution in Romania. The irrigation of persimmon crops increased the maximum suitability score by 0.8 units (0-4 range) and expanded the favourable area of the species. Most of Romania's surface is suitable for jujube cultivation, excepting the mountainous and some areas where the minimum temperatures with 25% probabilities decrease below the frost resistance limit (-23°C). Nevertheless within the favourable climate regions, the thermal regime is variable and, therefore, there are some areas restricted by low minimum temperature. The heterogeneity and dynamics of climatic factors on the Romanian territory underlines the importance of models for calculating climatic suitability as a decision tool in establishing fig, Chinese persimmon and jujube orchards.