Present and Projected Suitability of Olive Trees in a Currently Marginal Territory in the Face of Climate Change: A Case Study from N-Italy

Expected climate change will impact the environmental suitability of different territories. This will be of particular importance for crop sustainability in agriculture, especially in territories that are currently marginal in the biogeographic distribution of cultivated crops; in some cases, the growing conditions may become more suitable due to the projected modified climatic conditions. This paper aims to reconstruct different scenarios of environmental suitability of olive trees under current and future climatic scenarios, considering for the first time a marginal area for this tree plant in Europe. This study represents a first attempt to assess the possible evolution of the suitability of one of the most important Mediterranean crop trees in a current marginal area. This area corresponds to a territory (Oltrep & ograve; Pavese, South Lombardy) located at northern edge of the typical geographical distribution. The results of the suitability scenarios, obtained by applying a data-driven method based on predictors representative of the main geological, geomorphological, climatic, and plant cover variables influencing olive tree presence in a territory, show that the future projections at different periods (short-term at 2050; medium-term at 2070; long-term at 2100) suggest an increase in the suitable areas for olive tree cultivation. The increased suitability in this geographical area is related to an increase in air temperature and a parallel decrease in the number of frost days projected for the future scenarios, guaranteeing an increase in suitable areas for olive trees especially in those sectors located at higher latitudes and altitudes than the ones currently more suitable to olive trees. This study could represent a useful basis to implement effective and sustainable strategies of land planning and of mitigation measures to limit the impacts of the climate change effects on cultivation, making the developed method a potential operational tool for the evaluation of the territories that are and will be more adapted to this cultivation according to actual and future climatic scenarios.