甘肃东部气候变化及冬小麦生长发育响应特征

分析发现1971年以来陇东黄土高原变暖特征明显,其中西峰半湿润塬区1971～2005年增温线性趋势0.0525℃/a,环县半干旱川区增温线性趋势0.0367℃/a,平凉半湿润半干旱过渡地区增温线性趋势0.0411℃/a.除了环县川区夏季增温不明显,其余各区域四季增温均比较显著,西峰塬区四季增温幅度最大,增温趋势最明显,平凉次之.增温表现出夏季、秋季、春季、冬季依次增强的趋势.西峰半湿润塬区年降水量呈减少的趋势,环县半干旱川区年降水量呈增加的趋势,处于半湿润和半干旱过渡带的平凉年降水量则没有明显变化,不同区域秋季降水量均呈现出减少的趋势.气候变暖对陇东不同气候区域冬小麦生态影响既有相同之处,也有不同之处,相同之处主要表现在停止生长期和乳熟期均没有明显变化,起身期提前趋势明显.不同之处体现在西峰播种期明显推迟,返青期明显提前,而环县和平凉播种期和返青期均没有明显变化;西峰、平凉分蘖期明显推迟,抽穗期明显提前,而环县分蘖期和抽穗期没有明显变化;西峰、环县成熟期显著提前,全生育期日数显著缩短,而平凉成熟期和全生育期日数则没有明显变化;另外,西峰、平凉冬前及早春分蘖减少,越冬死亡率大幅度下降,产量显著增高,西峰、环县灌浆期显著延长,成熟期显著缩短,环县越冬死亡率较高时段对应秋春季降水偏少时段,产量增幅不大,增产趋势不明显.综合分析认为,西峰半湿润塬区气候变暖特征最明显,气候变暖对冬小麦的生态影响最显著.

Characters of climate change and winter wheat ecological response in East Gansu

Since 1971 year, the average temperature increased by 0.0525℃/a in semi-humid plateau (Xifeng) and 0.0367℃/a in semi-arid plain (Huanxian), while in the transition area of semi-humid and semi-arid climate (Pingliang) , the average temperature increased by 0.0411℃/a. The temperature increase was significant in different ar-eas in four seasons, but not significant in the river valley (Huanxian) in summer. The most extent and significance of in-crement is the air temperature in semi-humid plateau (Xifeng) in four seasons, and Pingliang next. The increment of air temperature follows the order of winter> spring> autumn> summer. The precipitation of the years was decreased in the plateau (Xifeng) and increased in river valley (Huanxian), but in the transition area of semi-humid and semi-arid cli-mate (Pingliang), the precipitation of the years showed inconspicuous change in the study period. The precipitation in study regions decreased in autumn. The climate wanning had sameness, but yet had difference to ecological response of winter wheat in different regions in Longdong loess plateau. The sameness behaved that the date of growth-stopping and milk-maturity had inconspicuous change, and the date of rise had an advance current distinctness. The date of planting delayed but the date of reviving advanced obviously in the plateau (Xifeng), while the date of planting and reviving had inconspicuous change in Huanxian and Pingliang. The tillering defer and the tassel advance was evident in Xifeng and Pingliang, but inconspicuous in Huanxian. The date of maturity advanced and the number of days in the whole growth duration shortened distinctly in Xifeng and Huanxian, but inconspicuously in Pingliang. In addition, the number of tiller-ing was lessened in winter and the next early spring, so the death rate through the winter descended and the yield in-creased significantly in Xifeng and Pingliang. The significant delaying of grouting period and shortening of maturity oc-curred in Xifeng and Huanxian. Through colligate analysis, it was considered that the semi-humid plateau (Xifeng) had the most conspicuous character of climate warming and the most significant biological effect on winter wheat.