title: Change in the Green-Up Dates for Quercus mongolica in Northeast China and Its Climate-Driven Mechanism from 1962 to 2012.
abstract: The currently available studies on the green-up date were mainly based on ground observations and/or satellite data, and few model simulations integrated with wide coverage satellite data have been reported at large scale over a long time period (i.e., > 30 years). In this study, we combined phenology mechanism model, long-term climate data and synoptic scale remote sensing data to investigate the change in the green-up dates for Quercus mongolica over 33 weather stations in Northeast China and its climate-driven mechanism during 1962-2012. The results indicated that the unified phenology model can be well parameterized with the satellite derived green-up dates. The optimal daily mean temperature for chilling effect was between -27°C and 1°C for Q. mongolica in Northeast China, while the optimal daily mean temperature for forcing effect was above -3°C. The green-up dates for Q. mongolica across Northeast China showed a delayed latitudinal gradient of 2.699 days degree-1, with the earliest date on the Julian day 93 (i.e., 3th April) in the south and the latest date on the Julian day 129 (i.e., 9th May) in the north. The green-up date for Q. mongolica in Northeast China has advanced 6.6 days (1.3 days decade-1) from 1962 to 2012. With the prevailing warming in autumn, winter and spring in Northeast China during the past 51 years, the chilling effect for Q. mongolica has been weakened, while the forcing effect has been enhanced. The advancing trend in the green-up dates for Q. mongolica implied that the enhanced forcing effect to accelerate green-up was stronger than the weakened chilling effect to hold back green-up while the changes of both effects were caused by the warming climate.
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Deqin
authors.initials: D
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Wenquan
authors.initials: W
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Zhoutao
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Donghai
authors.initials: D
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Yaozhong
authors.initials: Y
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China; College of Resources Science & Technology, Beijing Normal University, Beijing 100875, China.
authors.forename: Xiafei
authors.initials: X
authors.lastname: Zhou
mesh_terms: D002681:China; D057231:Climate Change; D063245:Plant Development; D029963:Quercus / Q000254:growth & development / Q000502:physiology*