Impact of temperature increase on the yield of winter wheat at low and high altitudes in semiarid northwestern China

A field experiment was conducted to evaluate the effects of temperature on winter wheat ( Triticum aestivum L.) at the Tongwei County (35°13′N, 105°14′E), Gansu, in the semiarid northwest of China from 2006 to 2008. Two study sites were chosen: one at Tongwei experimental station, situated at 1798 m above sea level at the foot of LuLu Mountain, and the second at the summit of LuLu Mountain at an altitude of 2351 m. The objective of this study was to determine if temperature increases will significantly affect the development and production of winter wheat at different altitudes. The results of this study revealed that an increase in temperature will lead to a significant change in the growth stages and water use of winter wheat in semiarid northwestern China. Specifically, crop yields at both high and low altitudes will likely increase, although this increase in yields will be greater at higher elevations. Indeed, it is expected that by 2050 the increased temperature will have induced a 2.6% increase in wheat yields at low altitudes and a 6.0% increase in yields at high altitudes in the study area. In addition, the results of this study indicated that a 0.6–2.2 °C increase in temperature will improve the water use efficiency of winter wheat plants at the two altitudes evaluated here.