Interplay Among Recent Trends in Climate Extremes, Vegetation Phenology, and Crop Production in Southern Mediterranean Region.

The southern Mediterranean region is among the most vulnerable areas to climate change globally. However, in this region, there is a need to further understand the complex interactions between climate, vegetation, and crops to fully assess the combined impacts of extreme climate events on the agricultural sector. Using daily Normalized Difference Vegetation Index (NDVI) data, we evaluate recent trends across 15 vegetation phenology indicators between 1982 and 2019. Subsequently, we analyse potential links between recent trends in vegetation phenology and land-use land-cover. We found significant increases in the maximum value of NDVI (MaxV), length of growing seasons (LengthGS), and duration from crop emergence to anthesis (BMaxT), particularly within croplands. These changes are positively correlated with regional crop production, especially in northern and coastal regions where croplands and forests are expanding. Conversely, southern areas bordering the Sahara show declining MaxV and an expansion of sparsely vegetated areas. We then conducted a comprehensive seasonal trend analysis of extreme climatic stresses and discussed how it aligns with recent trends in key phenological indicators. We found wetter conditions in northern and coastal regions throughout the year, ensuring sufficient water during the growing season. Meanwhile, southern areas near the Sahara experienced wetter autumns and winters but drier springs and summers. Additionally, the region experienced warmer conditions from spring to autumn, with fewer cold wave events. Analysing the frequency and duration of compound extreme events, we observed a trend toward more Dry/Hot days in spring and autumn and Wet/Hot days from summer to autumn. These conditions are significantly correlated with increased MaxV, improved crop productivity, and extended LengthGS and BMaxT. By improving our understanding of the impacts of recent climate change on vegetation phenology, crop production, and land use, providing valuable insights for guiding more informed decision-making and adaptive strategies in the southern Mediterranean region.