The shifting influence of drought and heat stress for crops in northeast Australia

Lobell, David B., Hammer, Graeme L., Chenu, Karine, Zheng, Bangyou, McLean, Greg and Chapman, Scott C. (2015) The shifting influence of drought and heat stress for crops in northeast Australia. Global Change Biology, 21 11: 4115-4127. doi:10.1111/gcb.13022


Author Lobell, David B.
Hammer, Graeme L.
Chenu, Karine
Zheng, Bangyou
McLean, Greg
Chapman, Scott C.
Title The shifting influence of drought and heat stress for crops in northeast Australia
Journal name Global Change Biology   Check publisher's open access policy
ISSN 1365-2486
1354-1013
Publication date 2015-11-01
Year available 2015
Sub-type Article (original research)
DOI 10.1111/gcb.13022
Open Access Status Not yet assessed
Volume 21
Issue 11
Start page 4115
End page 4127
Total pages 13
Place of publication West Sussex, United Kingdom
Publisher Blackwell Publishing Ltd
Collection year 2016
Language eng
Formatted abstract
Characterization of drought environment types (ETs) has proven useful for breeding crops for drought-prone regions. Here, we consider how changes in climate and atmospheric carbon dioxide (CO2) concentrations will affect drought ET frequencies in sorghum and wheat systems of northeast Australia. We also modify APSIM (the Agricultural Production Systems Simulator) to incorporate extreme heat effects on grain number and weight, and then evaluate changes in the occurrence of heat-induced yield losses of more than 10%, as well as the co-occurrence of drought and heat. More than six million simulations spanning representative locations, soil types, management systems, and 33 climate projections led to three key findings. First, the projected frequency of drought decreased slightly for most climate projections for both sorghum and wheat, but for different reasons. In sorghum, warming exacerbated drought stresses by raising the atmospheric vapor pressure deficit and reducing transpiration efficiency (TE), but an increase in TE due to elevated CO2 more than offset these effects. In wheat, warming reduced drought stress during spring by hastening development through winter and reducing exposure to terminal drought. Elevated CO2 increased TE but also raised radiation-use efficiency and overall growth rates and water use, thereby offsetting much of the drought reduction from warming. Second, adding explicit effects of heat on grain number and grain size often switched projected yield impacts from positive to negative. Finally, although average yield losses associated with drought will remain generally higher than that for heat stress for the next half century, the relative importance of heat is steadily growing. This trend, as well as the likely high degree of genetic variability in heat tolerance, suggests that more emphasis on heat tolerance is warranted in breeding programs. At the same time, work on drought tolerance should continue with an emphasis on drought that co-occurs with extreme heat.
Keyword Adaptation
Climate change
Sorghum
Transpiration efficiency
Wheat
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Queensland Alliance for Agriculture and Food Innovation
Official 2016 Collection
 
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Citation counts: TR Web of Science Citation Count  Cited 7 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 10 times in Scopus Article | Citations
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