Background

Phenology research has provided important insights on the influence of climate change on ecosystems. Investigation of spatial and interspecific difference can help us to better understand the phenology change pattern. In this study, observational data for 190 species collected from 2003 to 2021 at eight ecological stations in China were assessed via linear regression to detect trends in first flowering date (FFD), air temperature, and precipitation. We then examined the relationship between FFD change patterns, air temperature and precipitation through redundancy analysis, calculated the relative importance of phylogenetic relatedness, climate change, site conditions and plant traits in explaining variations in FFD change intensity using boosted regression tree method.

Results

We found that (1) FFDs of nearly 40% of the observed species changed significantly (p < 0.05), with species showing advanced and delayed FFDs accounting for half. (2) Air temperature increased at most stations, particularly in spring and summer, while precipitation decreased in humid and subhumid temperate zones and increased during most seasons in arid temperate and subtropical zones. (3) Spatial differences were observed in FFD trends. At stations in Northeast, North, and Southwest China, which are regions with increased temperature, the percentage of species with advanced FFD was higher than that of species with delayed FFD, with the mean trend ranging from − 2.4 to − 6.5 d decade− 1. Conversely, at stations distributed in Northwest and South China, which are regions with increased precipitation, the percentage of species with advanced FFD was lower than that of species with delayed FFD, with the mean trend ranging from 1.3 to 7.1 d decade− 1. (4) Air temperature and precipitation had a stronger influence on FFD change in the temperate zone than in the subtropical zone. Climate factors with the greatest influence on FFD change patterns varied with the observation site. Interspecific variations in FFD change intensity were mostly explained by phylogenetic relatedness, although plant traits, site conditions, and climate change also had a certain effect.

Conclusions

Our research found that the first flowering phenology of large percent of the observed plants changed significantly from 2003 to 2021,showing spatial and interspecific differences across observation sites. Our research also demonstrated the importance of plant phylogeny on interspecific differences in phenological changes,plant traits such as growth form,plant height,and flowering time influence flowering phenology to a certain extent. These findings will help us to better understand phenological responses to climate change on a national scale,and help us better predict the response of various plants to climate change in the future.