Warming promotes divergent shift in sequential phenophases of alpine meadow plants

Abstract

Plant phenology is an important trait in the adaptation of species to climate change. Shifts in multiple sequential phenological events and phenological synchrony among species would influence ecosystem function. However, little is known about how climate change affects sequential phenological events and phenological synchrony among species, limiting our comprehensive understanding of the strategies of overall phenological responses to climate change. Here, we conducted a 3-year manipulative experiment of warming and precipitation changes in an alpine meadow on the Tibetan Plateau to investigate how the timing and duration of sequential phenophases of 10 common species, as well as the phenological synchrony among these species respond to climate change. We found that warming advanced sequential phenophases differently, the timing of early-season and reproductive phenophases was advanced more than late-season and vegetative phenophases. Warming extended reproductive phenophases by increasing the duration of flowering, while vegetative phenophases remained unchanged, resulting in an overall lengthening of the growing season. Moreover, warming reduced the synchrony of reproductive more than vegetative phenophases among species by inducing species-specific shifts in phenological timing. However, neither precipitation changes alone nor an interaction with warming had significant effects on any phenophase or synchrony. These results improve our understanding of overall phenological responses in alpine plants, and highlight that warming has divergent effects on multiple sequential phenophases of a plant's annual life cycle. Alpine plants will start growth and senescence earlier while allocate more time to reproduction under future warming. These divergent shifts in sequential phenophases may affect plant life histories and phenological overlap, and ultimately reshape species and trophic interactions.