青藏高原冬小麦生产潜力及其对气候变化的响应

Potential yield of winter wheat in Qinghai-Tibet Plateau and its response to climate change

小麦是青藏高原第二大作物。青藏高原是气候变化的敏感地区。为研究青藏高原冬小麦生产潜力及气候变化对其的影响,我们用WOFOST模型模拟了冬小麦物候发育和产量。经模型验证,模拟的冬小麦各发育阶段天数和产量的标准均方根误差分别为4.9%和13.8%,一致性指数均大于0.92,模拟效果较好。采用校验好的WOFOST模型模拟1958-2017年青藏高原8个站点的冬小麦物候及产量,发现冬小麦播种~出苗、出苗~开花、开花~成熟及全生长季天数平均分别为18、241、52和311天;总体显著减少(α<0.001),平均每10年分别减少0.85、1.45、0.78和3.08天。冬小麦光温潜在产量变化范围在9~12 t hm^(-2),平均为11.25 t hm^(-2);总体显著下降(α<0.001),平均降幅为每10年0.27 t hm^(-2)。青藏高原气温低、辐射强,温度是冬小麦生长、发育的限制因子。升温使冬小麦生长季显著缩短,植株接收的辐射总量减少,不利于干物质的积累,从而导致冬小麦光温生产潜力显著下降。

Wheat is the second largest crop in Qinghai-Tibet Plateau(QTP),where is a sensitive area to climate change.In this study,winter wheat growth and development was simulated by using WOFOST model to investigate wheat potential yield in QTP and the impacts of climate change on it.Model validation result showed that simulated developing stage length and yield of winter wheat were in agreement with the observed values.WOFOST model was used to estimate potential yield of winter wheat in 8 sites of QTP from 1958 to 2017.It was found that mean emergence stage,vegetative growth stage,reproductive growth stage,and the whole growing season days of winter wheat were 18,241,52 and 311 days,respectively,all in significance decreases(α<0.001)with rates of 0.85,1.45,0.78 and 3.08 d decade^(-1),respectively.Photo-temperature potential yield of winter wheat ranged from 9 to 12 t hm^(-2),averaged 11.25 t hm^(-2),It decreased significantly(α<0.001),with a rate of 0.27 t hm^(-2) decade^(-1).In Qinghai-Tibet Plateau,it’s cold and has sufficient radiation,so temperature become the limiting factor for the growth and development of winter wheat in QTP.Warming led to a shorter growing season and less solar radiation received by winter wheat than before.The accumulation of dry matter declined,resulting in a significant decrease in the photo-temperature potential yield of winter wheat.