State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, 100875, China.
Joint Center for Global Change Studies (JCGCS), Beijing, 100875, China.
Int J Biometeorol. 2019 May;63(5):639-647. doi: 10.1007/s00484-017-1426-x. Epub 2017 Sep 5.
The start of thermal growing season (STGS) is an important indicator for climate change effects on regional plant growth and development. This study comprehensively investigated and compared the spatiotemporal variations in STGS at 0 °C (STGS_0), 5 °C (STGS_5), and 10 °C (STGS_10) thresholds for grassland on the Qinghai-Tibetan Plateau (QTP) during 1961-2014. Although elevation was the predominant influencing factor of the spatial variations of STGSs, the effect of latitude should not be ignored at the low-elevation regions, especially for the STGS with a low-temperature threshold (e.g., STGS_0). With the decrease of temperature thresholds, the effect of elevation became weaker, while the effect of latitude became stronger. Significant advancing trends were observed in all the three STGSs, with greater advancing rate for STGS_0 (0.23 days·year) than that of STGS_5 (0.15 days·year) and STGS_10 (0.16 days·year). More obvious advancing trends were found after 1980, which coincided with more rapid climate warming. The advancing trends weakened after 1998 when climate warming hiatus occurred. Since positive and negative impacts may be simultaneously induced by the advanced STGSs, more observations are still needed to analyze their impacts on the growth and development of alpine grassland on the QTP.
热生长季节（STGS）的开始是气候变化对区域植物生长和发育影响的一个重要指标。本研究全面调查和比较了青藏高原（QTP）草原在 1961-2014 年期间，0°C（STGS_0）、5°C（STGS_5）和 10°C（STGS_10）阈值的 STGS 的时空变化。虽然海拔是 STGS 空间变化的主要影响因素，但在低海拔地区，纬度的影响不容忽视，特别是对于低温阈值的 STGS（如 STGS_0）。随着温度阈值的降低，海拔的影响减弱，而纬度的影响增强。所有三个 STGS 都呈现出显著的提前趋势，其中 STGS_0（0.23 天·年）的提前率大于 STGS_5（0.15 天·年）和 STGS_10（0.16 天·年）。在 1980 年后，发现了更明显的提前趋势，这与气候变暖加速相一致。在 1998 年气候变暖暂歇后，提前趋势减弱。由于提前的 STGSs 可能同时引起正、负两方面的影响，因此仍需要更多的观测来分析其对青藏高原高山草原生长和发育的影响。
