Methods Open-top chambers (OTCs) and artificial drainage ditches were used to simulate the warmer and drier climate in the field. After two years of experimental warming and drainage, we recorded the flowering phenology and growth indices of four typical shrub grass plants. Flowering phenology included the first flowering date, peak flowering date, last flowering date, flowering duration and maximum flowering number. The growth indices of plants included height, coverage, frequency and above-ground biomass.

Important findings Our results revealed that: 1) Under experimental warming and drainage treatment, the first flowering dates for Carex diandra and Ribes procumbens were advanced due to early elimination of the temperature limit, which for Saussurea neoserrata were delayed by the water stress. Moreover, the Ledum palustre had longer flowering duration and more followers under the experimental warming and drainage because of the adverse shift in flowering phenology of the earlier flowering plant and the later flowering plant. 2) The Carex diandra, Saussurea neoserrata and Ledum palustre had higher coverage and frequency under experimental warming and drainage, especially in Ledum palustre, while the coverage and frequency of Ribes procumbens were declined. 3) There was no significant interaction effect between the warming and drainage on plant flowering phenology, but the responses of plant growth characteristics to warming were affected by drainage. These results indicated that species respond differently to warmer and drier climate due to different flower functional groups they belong to. The first flowering date of the early flowering plants had been progressed, and that of the late flowering plants was delayed. On the one hand, these changes can change niches in the community and interspecific competition and further alter the composition and structure of the community. On the other hand, these changes could be a way for the community to regulate community phenology to adapt climate change.