Larger responses of trees’ leaf senescence to cooling than warming: Results from a climate manipulation experiment

作者：Shuxin Wang, Zhaofei Wu, Yufeng Gong, Yangjing Nie, Zunchi Liu, Yansheng Chen, Hans J. De Boeck, Yongshuo H. Fu · 发表于：Agricultural and Forest Meteorology · 年份：2023 · DOI：10.1016/j.agrformet.2023.109568 · 被引用次数：12 · 研究领域：Plant and animal studies、Plant Water Relations and Carbon Dynamics、Plant responses to elevated CO2

Global warming generally delays autumn leaf senescence, which affects carbon and water cycles of terrestrial ecosystem and exerts feedbacks on the climate system. Nevertheless, several regions in the Northern Hemisphere have experienced autumn cooling since the start of the 21st century. Whether cooling affects leaf senescence to the same extent as warming is currently unclear. In this study, we conducted a manipulative experiment with warming or cooling treatments imposed during summer and autumn on saplings of ginkgo and oak to investigate the effects of seasonal warming and cooling on leaf senescence. In addition, two light intensity and photoperiod treatments were applied to study their interactive effects with temperature on leaf senescence. We found that the temperature sensitivity of leaf senescence ( S T ) was significantly larger in autumn (5.4–6.4 days ℃ −1 ) than in summer (0.6–2.4 days ℃ −1 ). Interestingly, cooling had a larger effect on leaf senescence than warming, with a significantly higher S T under cooling (1.7–3.5 days ℃ −1 in summer and 8.5–11.6 days ℃ −1 in autumn) than under warming (0.8–1.0 days ℃ −1 and 0.3–1.8 days ℃ −1 ). Furthermore, higher light intensity significantly decreased the temperature sensitivity of leaf senescence especially in autumn, i.e. S T was 3.8 and 6.1 days ℃ −1 under high light intensity condition, but the S T was 8.2 and 8.0 days ℃ −1 under low light intensity, for ginkgo and oak, respectively. Our results suggest unequal effe...