Zhou Wenhao

                                                                                                     School of Life Sciences

Abstract: Human activities have led to the strengthening of the greenhouse effect and the acceleration of global climate change, which profoundly affects plant phenology. In order to obtain the law of plant phenology responding to climate change, and verify the feasibility of circular statistics applied to plant phenology research. Using the phenological observation data from 2003 to 2015, combined with the temperature, precipitation and CO2 concentration data during the same period, and using circular statistical methods, the phenological characteristics of herbaceous and woody plants in 21 ecological stations in China were studied. The results showed that: (1) In China's tropical and subtropical Ailao Moutain, Xishuangbanna, Heshan, Huitong, Dinghu Moutain, herbaceous and woody plants fruit or seed ripening phase occurs throughout the year without showing significant seasonality, while there is significant seasonality in every phenophases in other regions. (2) The mean date of germination phase of herbaceous plants and bud breaking phase of woody plants were positively correlated with latitude (p < 0.01). The mean date of autumn wilting phase of herbaceous plants was significantly negatively correlated with latitude (p < 0.01). The mean date of leaf falling phase of woody plants was significantly negatively correlated with latitude (p < 0.05). The length of growing season of herbaceous and woody plants was negatively correlated with latitude (p < 0.01). (3) In winter and spring, whether herbaceous or woody plants, the increase in temperature advanced the spring phenophases of most ecostations. The increase in precipitation delayed the spring phenophases of most ecostations. In addition, increased CO2 concentrations delayed the spring phenophases of most ecostations woody plants. (4) In summer and autumn, whether herbaceous or woody plants, the increase in temperature delayed the autumn phenophases of most ecostations. The increase in CO2 concentration advanced the autumn phenophases of most ecostations. Compared to temperature and CO2 concentration, the effect of increased precipitation on the autumn phenophases does not show a single relationship. Therefore, there are differences in the response of herbaceous and woody plant phenology to climate change in different regions of China. In the context of global warming, the extension of the plant growing season is due to the advance effect of temperature on the phenophases in spring and the delayed effect on the phenophases in autumn, although precipitation and CO2 concentration have opposite effects. In addition, circular statistics can be used as a method for plant phenology studies.

Read the full article here:       基于循环统计的植物物候影响因素研究.pdf