The response of reproductive phenology and success of alpine plants to warming and precipitation changes on the Tibetan Plateau

Changes in reproductive phenology induced by warming are happening across the globe with significant implications for plant sexual reproduction, however, the response of plant reproductive output (number of flowers and fruits) and success (successful fruits/total flowers) in response to climate change have not been well-characterized. Here, we conducted a warming and altered precipitation experiment in an alpine meadow on the eastern Tibetan Plateau to investigate the effects of climate change on the reproductive phenology and success of six common species belonging to two flowering functional groups (FFGs). We found that warming advanced the start of flowering in both FFGs and the start of fruiting in mid-summer flowering (MSF) plants. Warming reduced the reproductive output of early-spring flowering (ESF) plants but did not change their reproductive success, while the effects of warming and altered precipitation on the reproductive output and success of MSF plants were year-dependent, and the fruiting phenology regulated the response of the MSF plant’s reproductive success to climate change. The findings highlight the critical role of fruiting phenology in the reproductive success of alpine plants and imply that alpine plants may reduce their fitness by producing fewer flowers and fruits under climate warming, especially for later flowering plants.