Yang Zhongling, Jiang Lin, Su Fanglong, Zhang Qian, Xia Jianyang, Wan Shiqiang
State Key Laboratory of Cotton Biology, Key Laboratory of Plant Stress Biology, College of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Sci Rep. 2016 Mar 18;6:23267. doi: 10.1038/srep23267.
Drought events could have profound influence on plant community structure and ecosystem function, and have subsequent impacts on community stability, but we know little about how different climate warming scenarios affect community resistance and resilience to drought. Combining a daytime and nighttime warming experiment in the temperate steppe of north China with a natural drought event during the study period, we tested how daytime and nighttime warming influences drought resistance and resilience. Our results showed that the semi-arid steppe in north China was resistant to both daytime and nighttime warming, but vulnerable to drought. Nighttime warming, but not daytime warming, enhanced community resistance to drought via stimulating carbon sequestration, whereas neither daytime nor nighttime warming affected community resilience to drought. Large decline in plant community cover, primarily caused by the reduction in the cover of dominant and rare species rather than subordinate species during drought, did not preclude rapid ecosystem recovery. These findings suggest that nighttime warming may facilitate ecosystem sustainability and highlight the need to assess the effects of climate extremes on ecosystem functions at finer temporal resolutions than based on diurnal mean temperature.
干旱事件可能会对植物群落结构和生态系统功能产生深远影响，并随后影响群落稳定性，但我们对不同的气候变暖情景如何影响群落对干旱的抵抗力和恢复力知之甚少。结合中国北方温带草原的白天和夜间变暖实验以及研究期间的一次自然干旱事件，我们测试了白天和夜间变暖如何影响抗旱性和恢复力。我们的结果表明，中国北方的半干旱草原对白天和夜间变暖均具有抵抗力，但易受干旱影响。夜间变暖而非白天变暖通过刺激碳固存增强了群落对干旱的抵抗力，而白天和夜间变暖均未影响群落对干旱的恢复力。植物群落盖度大幅下降，主要是由干旱期间优势种和稀有种而非从属种的盖度降低所致，但这并不妨碍生态系统的快速恢复。这些发现表明，夜间变暖可能有助于生态系统的可持续性，并突出了以比基于日平均温度更精细的时间分辨率评估极端气候对生态系统功能影响的必要性。
