A mechanistic model for estimating the potential geographic distribution of almond crops was run using data from 20 global climate models over early- (2010-2039) and mid- (2040-2069) 21st century periods under future scenario RCP 8.5 (i.e. ‘business-as-usual’) to assess how the distribution of suitable cultivation locations for almond crops may shift under climate change. Additionally, almond phenology and the limiting climatological factors to almond cultivation – and their heterogeneity over time and space – were explored.
Under RCP 8.5, a few models show high suitability (>80% of years are suitable) for NW almond cultivation in the early part of the 21st century. However, by mid-century there’s strong model agreement that much of the Willamette Valley will be thermally suitable for almonds, along with the Puget Lowlands of western Washington and portions of Southwestern Oregon.
Limiting areas of potential almond expansion and contraction to only current cropland locations, the Willamette Valley is a clear hotspot for potential expansion. While from a thermal perspective the Central Valley continues to be suitable into the mid-century, should water challenges like those seen in the mid-2010s arise (or continue) into the future, the Willamette may provide an opportunity for translocation.
The full paper, published in Climatic Change, can be found here.