多数研究表明增温提前了青藏高原高寒植物的繁殖期（包括现蕾、开花和结实期），有人推测在气候变化和极端降温事件频发的背景下，由于增温导致的繁殖物候期改变可能会面临更大的冻害风险，并对其适合度产生负面影响，然而目前还缺乏直接的经验证据。本项目拟选择高寒草甸中花和晚花植物为研究对象，通过梯度增温实验研究增温对它们的繁殖物候的影响；同时，利用PVC管采集这些植物的现蕾期、花期和结实期的植株，然后置于冰柜中，模拟不同降温幅度及其持续时间，利用红外热成像仪拍摄记录不同处理下植物繁殖组织结冰的全过程；冻害实验结束后，采集植物叶片测定其生理生态特征；同时也将经历冻害实验的植株移到野外继续监测其生长发育特征及种子的生产、并进行萌发实验。通过上述研究，揭示未来气候变化情景下不同开花功能群植物不同繁殖阶段的耐寒过程和机理，并从适合度的角度检验冻害的生态后果，从而提高我们应对未来气候变化不利影响的能力。

Numerous studies have indicated that warming advanced the reproductive stages of alpine plants on the Tibetan Plateau (including first bud/boot set, flowering and fruiting), some speculate that in the context of frequent climate change and extreme cooling events, altered reproductive phenology that caused by warming may face greater risk of freezing injury, and may negatively affect fitness, however, there is no empirical evidence. This project chooses middle and late flowering functional group plants on the Tibetan Plateau as objects, study the effects of warming on the reproductive phenology through different gradient warming experiment. These plants will be collected in PVC tubes at first bud/boot setting, flowering and fruiting, put them in the freezer, simulate different cooling ranges and durations, and record the freezing processes of their reproductive tissues by infrared thermal camera. Afterward, the plant leaves will be collected to measure the physiological indexes. Meanwhile, plants that experienced the same freezing experiment will be moved to the field to monitor the growth and development characteristics, seed production, and conduct seed germination experiment as well. Through previous studies, this project will reveal the freezing tolerance processes and mechanisms of different flowering functional groups at different reproductive stages under future climate change, test the ecological consequences of freezing from the perspective of fitness, thus improve our ability to cope with the adverse effects of future climate change.