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Climate change predictions indicate that extreme drought is likely to become more frequent in the future. In this study, the impact of drought on soil respiration (R-s) and its autotrophic (R-a) and heterotrophic components (R-h) were studied in a cultivated Black Chernozemic soil in central Alberta, Canada. The mean R-s was 24.4% lower in the drought relative to the plots with ambient precipitation (P<0.001), with a larger decrease in R-a (26.8%) relative to R-h (21.0%), and a higher (P<0.05) contribution of R-h to R-s under drought (52.8%) than under the ambient condition (47.7%). Both R-s and its R-a and R-h components had an exponential relationship with soil temperature and a quadratic relationship with soil water content. Drought caused a greater decrease in the tipping point of soil water content for R-h (a 39.6% reduction) than for R-a (a 15.1% reduction) relative to the ambient precipitation treatment. In addition, drought resulted in a greater increase in the temperature sensitivity (Q(10) values) of R-a (a 45.0% increase) than that of R-h (a 14.1% increase) relative to the ambient precipitation treatment. The results suggest that drought amplified the water limitation effect on CO2 emission, especially that from microbial respiration, and resulted in a tighter relationship between temperature and root or autotrophic respiration, based on this 1-year study. We conclude that it is important to assess the impact of drought on soil respiration components rather than the total soil respiration, and such differential effects of drought on soil respiration components should be incorporated into global carbon circulation models.