Phenological evidence from China to address rapid shifts in global flowering times with recent climate change

Climate-related flowering phenology has attracted increasing concerns due to its irreplaceable contribution to innovative theory and application of plant phenology at global scale. Most of previous long-term observations were focused on interannual variations in flowering time in Europe and North America, however, very few of them in China were so far reported. Here, we present a meta-analysis through compiling the extended data set from 62 ground-based observations including 136 plant species from 217 observational sites across 8 climatic zones from 1963 to 2013 in China. Quantitative trends in 649 time series (1963-2013) of flowering phases and corresponding temperature changes were analyzed. The results indicated that the beginning, peak and ending of flowering were generally advanced by 2.2, 2.3 and 1.4 days decade(-1), respectively, as a result of temperature increase. Flowering duration tended to be prolonged, mainly due to higher temperature sensitivity and greater advancement in the beginning of flowering rather than the ending of flowering. Particularly, the most pronounced advancement in flowering time was observed in east China, up to 3.6 days decade(-1) as a result of contemporaneous warming. Specifically, flowering time of herbaceous plants displayed an advancing trend by 0.7 day decade(-1) per degree of increasing latitude. Furthermore, early-flowering speciestended to flower earlier than late-flowering ones did. Wind-pollinated and herb species showed greater phonological advancement and temperature sensitivity than insect-pollinated species and other growth forms did. Our results were to some extent different from those in Europe and North America, but played a critical and complementary role at global scale. Our findings and database presented should be powerful complements to address climate-associated flowering shifts and their ecological impacts at global scale.