|MARKLEIN, ALISON - Lawrence Berkeley National Laboratory|
|ABATZOGLOU, JOHN - University Of Idaho|
|DIALESANDRO, JAKE - University Of California|
|BROWN, JOEL - Natural Resources Conservation Service (NRCS, USDA)|
|STEELE, CAITI - New Mexico State University|
Submitted to: Journal of Climate Change
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2017
Publication Date: 11/28/2017
Citation: Elias, E.H., Marklein, A., Abatzoglou, J.T., Dialesandro, J., Brown, J., Steele, C., Rango, A., Steenwerth, K.L. 2017. Vulnerability of field crops to midcentury temperature changes and yield effects in the Southwestern USA. Journal of Climate Change. 148(3):405-417. https://doi.org/10.1007/s10584-017-2108-8.
Interpretive Summary: Projected midcentury temperatures will impact where field crops can grow and decrease yield potential. There will be more heat stress for crops. While parts of the region will be outside historic thermal ranges where specific crops are grown, other areas will emerge that are within the current thermal range. Potential cultivation area and yeild for maize will decline. While the thermal range for the area presenting growing cotton will nearly double, heat stress could reduce cotton yields by 38% of yield potential by midcentury.
Technical Abstract: Increased temperatures in the Southwestern United States will impact future crop production via multiple pathways. We used four methods to provide an illustrative analysis of midcentury temperature impacts to eight field crops. By midcentury, cropland area thermally suitable for maize cultivation is projected to decrease, while area suitable for cotton cultivation expands northward and nearly doubles in extent. The increase in area exposed to daily temperatures >35°C was highest for oat and maize. Estimates of yield reduction from heat stress for both maize and cotton indicate that historically, SW heat stress reduced cotton yield by 26% and maize yield by 18% compared to potential yield. By midcentury we predict yield reduction from heat stress will reduce cotton and maize yields by 37% and 27%, respectively, compared to potential yield. Our results contradict the notion that the warmest counties will be the most impacted from a field crop perspective. Rather, future temperature, total crop area and crop sensitivity contribute to more complex county-level impacts. Identification of representative target environments under future temperature regimes can inform development of farm-based networks to evaluate new crop germplasm with increased heat tolerance and viable adaptation and management strategies to respond effectively to future temperatures.