Climate change shifts almond bloom dates in Afghanistan

Climate change is reshaping the spring phenology of temperate fruit and nut trees worldwide, causing uneven bud break and yield losses across major production regions. Almond trees, including those cultivated in Afghanistan, are susceptible to these shifts. Afghanistan produces over 50 almond varieties, with official exports worth around USD 40 million in 2024. Yet, this value remains below potential due to multiple challenges along the value chain, one of which is the ongoing temperature increase affecting phenology and yields.

We projected the flowering dynamics of 51 Afghan almond cultivars using long-term temperature data (1980–2023) and phenological observations (2011–2023). Two historical reference periods (1980 and 2020) and future projections for 2050 and 2085 were simulated under three Shared Socioeconomic Pathway (SSP) scenarios (SSP1-2.6, SSP2-4.5, SSP5-8.5) based on 15 General Circulation Models. Bloom predictions were obtained using the PhenoFlex modeling framework with a recently developed combined-fitting approach. The model accurately reproduced observed bloom patterns, achieving a Root Mean Square Error of Prediction below four days for all cultivars. Compared to 1980, bloom dates advanced by roughly two weeks by 2020. Future projections suggest additional advances of up to 16 days for most cultivars, whereas a few exhibited delays of up to 12 days. Pronounced shifts exceeding seven days were found in about 25% of all predictions driven by specific cultivars, especially by 2085 under intermediate and high-emission scenarios. These results emphasize the significant and ongoing changes in almond phenology, highlighting the importance of adaptive management to sustain production and export potential under future climates.