This work is part of a broader project examining the potential for agricultural expansion of almonds under climate change. It was published in the International Journal of Biometeorology and the full paper can be accessed here.
What we did
Delineating locations viable for cultivating high-value crops such as almonds provides key information for economic and land use planning and water management. Three modeling approaches were used to identify the potential distribution and key thermal constraints on almond cultivation across the southwestern United States (US), including two empirical species distribution models (SDMs) – one using commonly-used bioclimatic variables (Traditional SDM) and the other using more physiologically relevant climate variables (Nontraditional SDM) – and a mechanistic model (MM) developed using published thermal limitations from field studies.
What we found
While all models showed comparable results over the majority of the domain, including over existing croplands with high almond densities, the MM suggested the greatest potential for the geographic expansion of almond cultivation, with frost susceptibility and insufficient heat accumulation being the primary thermal constraints in the southwestern US.
The Traditional SDM over-predicted almond suitability in locations shown by the MM to be limited by frost, whereas the Nontraditional model showed greater agreement with the MM in these locations, suggesting that incorporating physiologically relevant variables in SDMs can improve predictions.
Finally, opportunities for geographic expansion of almond cultivation under current climatic conditions in the region may be limited, suggesting that increasing production may rely on agronomical advances and densifying current almond plantations in existing locations.
Earlier work on using species distribution models to estimate the potential distribution of almonds was done for the WSU CEREO Interdisciplinary Poster Session. For that poster click here.