西北干旱区玉米对气候变暖的响应

摘要: 利用地面观测资料,就西北干旱区河西走廊绿洲作物玉米(Zea mays L.)对变暖的响应进行了初步的探讨。结果表明:近二十多年来,西北干旱区作物玉米对变暖的响应以生长季提前和生长期缩短为主要方式。但是,存在一个临界温度,当玉米生长期间平均气温小于临界温度时,增温使玉米生长期缩短;当玉米生长期间平均温度大于临界温度时,增温使玉米生长期有不再减小的趋势。未来的持续增温可能导致玉米生长期平均气温超过临界温度,从而可能使西北干旱区玉米生长期延长。西北干旱区作物玉米对变暖的响应还表现出一定的阶段差异,增温使玉米拔节期以前的营养生长阶段缩短,抽雄-槭乳熟期的生殖生长阶段延长, 乳熟-成熟期的生殖生长阶段缩短。西北干旱区作物玉米对变暖响应的这种特点可能与绿洲的气候特点、作物的生理特性及增温的季节差异有关,而其响应的生物学机制可能与变暖使自然植被秋季生长季延长的生物学机制不同。

Response of Corn to Climate Warming in Arid Areas in Northwest China

Based on surface observations, response of corn (Zea mays L.) to climate warming in the HexiCorridor in the arid northwest of China was investigated. Results show that in the last 20 yr and more theresponse of corn to climate warming took the form that its growing season came in advance and its growthperiod became shorter period. And such response is related to the critical temperature. In case the meantemperature during the corns growth period was less than the critical temperature, an increase in tem-perature shortened its growth period. When the mean temperature was higher than the critical temperature,then a rise in temperature no longer showed a tendency of shortening. The continuous increase intemperature in future may cause the mean temperature of corns growth period to exceed the criticaltemperature, thus leading to lengthening of corns growth period. In addition, response of corn to climatewarming varied in its different growing stages. An increase in temperature shortened corns phase ofvegetative growth prior to the tasselling phase, prolonged the generative growth phase in the tasselling-milk stage, and cut down the generative growth phase in the milk-maturity stage. These characteristicsmay correlate with the climatic condition in the arid areas in the northwestern of China, the cropsphysiological properties, and the variation of temperature increase in various seasons.