A projection of ozone-induced wheat production loss in China and India for the years 2000 and 2020 with exposure-based and flux-based approaches

• Published in: Global change biology Vol. 19; no. 9; pp. 2739 - 2752
• Main Authors: Tang, Haoye, Takigawa, Masayuki, Liu, Gang, Zhu, Jianguo, Kobayashi, Kazuhiko
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell Publishing Ltd 01.09.2013; Wiley-Blackwell
• Subjects: Agricultural production; Animal and plant ecology; Animal, plant and microbial ecology; AOT40; Biological and medical sciences; Chemical transport; China; Climate change; crop loss; Crop production; Crops, Agricultural - growth & development; dose response; Dose-Response Relationship, Drug; Emission inventories; Environmental impact; Forecasting; Fundamental and applied biological sciences. Psychology; General aspects; India; Ozone; Ozone - toxicity; stomatal flux; Triticum - growth & development; Triticum aestivum; Triticum aestivum L; Uncertainty; Wheat; Asia; China; South Asia; India; China, People's Rep; Monocotyledones; Loss; Ozone; Triticum aestivum L; Dose activity relation; India; O; dose response; Gramineae; China; crop loss; stomatal flux; Angiospermae; Cereal; Spermatophyta; AOT40; Wheat; Triticum aestivum; O3
• DOI: 10.1111/gcb.12252
• ISSN: 1354-1013

Using a high‐resolution (40 × 40 km) chemical transport model coupled with the Regional Emission inventory in Asia (REAS), we simulated surface ozone concentrations ([O3]) and evaluated O3‐induced wheat production loss in China and India for the years 2000 and 2020 using dose–response functions based on AOT40 (accumulated [O3] above 40 ppb) and PODY (phytotoxic O3 dose, accumulated stomatal flux of O3 above a threshold of Y nmol m−2 s−1). Two O3 dose metrics (90 days AOT40 and POD6) were derived from European experiments, and the other two (75 days AOT40 and POD12) were adapted from Asian studies. Relative yield loss (RYL) of wheat in 2000 was estimated to be 6.4–14.9% for China and 8.2–22.3% for India. POD6 predicted greater RYL, especially for the warm regions of India, whereas the 90 days AOT40 gave the lowest estimates. For the future projection, all the O3 dose metrics gave comparable estimates of an increase in RYL from 2000 to 2020 in the range 8.1–9.4% and 5.4–7.7% for China and India, respectively. The lower projected increase in RYL for India may be due to conservative estimation of the emission increase in 2020. Sensitivity tests of the model showed that the PODY‐based estimates of RYL are highly sensitive to perturbations in the meteorological inputs, but that the estimated increase in RYL from 2000 to 2020 is much more robust. The projected increase in wheat production loss in China and India in the near future is substantially larger than the uncertainties in the estimation and indicates an urgent need for curbing the rapid increase in surface [O3] in these regions.