Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Chaoyang District, Beijing, 100101, China.
College of Resources and Environment, University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing, 100049, China.
Int J Biometeorol. 2019 May;63(5):649-658. doi: 10.1007/s00484-017-1417-y. Epub 2017 Oct 2.
Vegetation growth and phenology are largely regulated by base temperature (T) and thermal accumulation. Hence, the growing degree-days (GDD) and growing season (GS) calculated based on T have primary effects on terrestrial ecosystems, and could be changed by the significant warming during the last century. By choosing 0, 5, and 10 °C, three key T for vegetation growth, the GDD and GS in China during 1960-2011 were developed based on 536 meteorological stations with homogenized daily mean temperatures. Results show that both the GDD and GS showed positive sensitivity to the annual mean temperature. The start of the growing season (SOS) has advanced by 4.86-6.71 days, and the end of the growing season (EOS) has been delayed by 4.32-6.19 days, lengthening the GS by 10.76-11.02 days in China as a whole during 1960-2011, depending on the T chosen. Consistently, the GDD has totally increased 218.92-339.40 °C days during the 52 years, with trends more pronounced in those based on a lower T. The GDD increase was significant (Mann-Kendall test, p < 0.01) over China except for the north of Southwest China, while the significant GS extension only scattered over China. Whereas the extensions of GS and GS were dominated by the advance in SOS, the GS extension was closely linked to the delay in EOS. Regionally, the GS extension in the eastern monsoon zone and northwest arid/semi-arid zone was driven by the advance in SOS and delay in EOS, respectively. Moreover, each variation has a substantial acceleration mostly in 1987 or 1996, and a speed reduction or even a trend reversal in the early 2000s. Changes in the thermal growing degree-days and season are expected to have great implications for biological phenology, agricultural production, and terrestrial carbon cycle in the future.
植被生长和物候主要受基础温度（T）和热积累的调节。因此，基于 T 计算的生长度日（GDD）和生长季节（GS）对陆地生态系统有主要影响，并可能因上个世纪的显著变暖而改变。选择 0°C、5°C 和 10°C 三个关键植被生长温度，基于 536 个气象站的日平均气温均匀化数据，计算了 1960-2011 年中国的 GDD 和 GS。结果表明，GDD 和 GS 对年平均温度均表现出正敏感性。生长季节开始（SOS）提前了 4.86-6.71 天，生长季节结束（EOS）延迟了 4.32-6.19 天，导致 1960-2011 年中国整个生长季节延长了 10.76-11.02 天，具体取决于所选的 T。一致地，52 年间 GDD 总共增加了 218.92-339.40°C·天，其中基于较低 T 的趋势更为明显。除中国西南地区北部外，中国大部分地区的 GDD 增加均呈显著趋势（Mann-Kendall 检验，p<0.01），而 GS 的显著延长则分散在中国各地。GS 和 GS 的延长主要是由 SOS 的提前和 EOS 的延迟所驱动的。区域上，季风区和西北干旱/半干旱区的 GS 延长是由 SOS 的提前和 EOS 的延迟所驱动的。此外，每种变化都有很大的加速，主要发生在 1987 年或 1996 年，而在 21 世纪初则减速甚至趋势逆转。未来，热生长度日和季节的变化预计将对生物物候、农业生产和陆地碳循环产生重大影响。
