1951年以来中国无霜期的变化趋势

宁晓菊, 张丽君, 杨群涛, 秦耀辰

Trends in the frost-free period in China from 1951 to 2012

Xiaoju NING, Lijun ZHANG, Quntao YANG, Yaochen QIN

图2 中国农区初、终霜日和无霜期累积距平

Fig. 2 Trends of the first frost date, last frost date and frost-free period in agricultural regions in China