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Change in the Green-Up Dates for Quercus mongolica in Northeast China and Its Climate-Driven Mechanism from 1962 to 2012.

Fan D, Zhu W, Zheng Z, Zhang D, Pan Y, Jiang N, Zhou X - PLoS ONE (2015)

Bottom Line: The results indicated that the unified phenology model can be well parameterized with the satellite derived green-up dates.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus

The (A) internal and (B) external validations for the green-up dates of Q. mongolica forests simulated by the unified phenology model.
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pone.0130516.g003: The (A) internal and (B) external validations for the green-up dates of Q. mongolica forests simulated by the unified phenology model.

Mentions: We validated the simulated green-up dates using the NDVI-derived green-up dates (Fig 3). The correlation coefficient and RMSE between the simulated and the NDVI-derived green-up dates were 0.713 (P < 0.001) and 7.08 days (Fig 3A), respectively, if the same data as model parameterization (i.e., daily mean temperature and NDVI data from 2001 to 2006; internal validation) were used in the evaluation, and 0.660 (P < 0.001) and 7.30 days (Fig 3B), respectively, if the different data from model parameterization (i.e., daily mean temperature and NDVI data from 2007 to 2012; external validation) were used.


Change in the Green-Up Dates for Quercus mongolica in Northeast China and Its Climate-Driven Mechanism from 1962 to 2012.

Fan D, Zhu W, Zheng Z, Zhang D, Pan Y, Jiang N, Zhou X - PLoS ONE (2015)

The (A) internal and (B) external validations for the green-up dates of Q. mongolica forests simulated by the unified phenology model.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4476677&req=5

pone.0130516.g003: The (A) internal and (B) external validations for the green-up dates of Q. mongolica forests simulated by the unified phenology model.
Mentions: We validated the simulated green-up dates using the NDVI-derived green-up dates (Fig 3). The correlation coefficient and RMSE between the simulated and the NDVI-derived green-up dates were 0.713 (P < 0.001) and 7.08 days (Fig 3A), respectively, if the same data as model parameterization (i.e., daily mean temperature and NDVI data from 2001 to 2006; internal validation) were used in the evaluation, and 0.660 (P < 0.001) and 7.30 days (Fig 3B), respectively, if the different data from model parameterization (i.e., daily mean temperature and NDVI data from 2007 to 2012; external validation) were used.

Bottom Line: The results indicated that the unified phenology model can be well parameterized with the satellite derived green-up dates.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.

View Article: PubMed Central - PubMed

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.

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.

No MeSH data available.


Related in: MedlinePlus