4. Discussion
Our results reveal that species-specific phenological firsts (leaf out
and first flower) and lasts (leaf senescence and last flower) are
differentially sensitive to climate warming on the cold Tibetan Plateau.
Importantly, warming-induced shifts in phenological lasts and full
phenological periods (growing season length and flower duration), rather
than the single phenological firsts, drive changes in species dominance.
Some studies have reported no relation between shifts in plant phenology
and community change by solely linking phenological firsts and community
coverage (McLean et al. 2016;
Block et al. 2019), whereas our
results can advance the understanding of the relationship between plant
phenology and community by linking the phenological lasts as well as the
full phenological periods with species dominance. Our results therefore
stress that (1) the current trend toward observations of only the first
dates of plant phenology provide an incomplete picture for assessing and
predicting response of plant phenology and plant community turnover to
climate warming and (2) shifts in the full phenological periods provide
powerful indicators of how climatic warming alters species dominance,
and by extension community structure.