Journal of Geographical Sciences ›› 2010, Vol. 20 ›› Issue (6): 803-817.doi: 10.1007/s11442-010-0812-7

• Climate and Environmental Change •     Next Articles

Spatio-temporal variation of photosynthetically active radiation in China in recent 50 years

ZHU Xudong1,2, HE Honglin1, LIU Min1,2, YU Guirui1, SUN Xiaomin1, GAO Yanhua1   

  1. 1. Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2010-04-13 Revised:2010-05-08 Online:2010-12-15 Published:2010-12-15
  • Supported by:

    National Natural Science Foundation of China, No.41071251; National Basic Research Program of China, No.2010CB833504; Knowledge Innovation Program of the Chinese Academy of Sciences, No.KZCX2-YW-433-06; Information Project of the Chinese Academy of Sciences

Abstract:

Based on long-term measurement data of weather/ecological stations over China, this paper calculated and produced annually- and seasonally-averaged Photosynthetically Active Radiation (PAR) spatial data from 1961 to 2007, using climatological calculations and spatialization techniques. The spatio-temporal variation characteristics of annually- and seasonally-averaged PAR spatial data over China in recent 50 years were analyzed with Mann-Kendall trend analysis method and GIS spatial analysis techniques. The results show that: (1) As a whole, the spatial distribution of PAR is complex and inhomogeneous across China, with lower PAR in the eastern and southern parts of China and higher PAR in the western part. Mean annual PAR over China ranges from 17.7 mol m-2 d-1 to 39.5 mol m-2 d-1. (2) Annually- and seasonally-averaged PAR of each pixel over China are averaged as a whole and the mean values decline visibly with fluctuant processes, and the changing rate of annually-averaged PAR is –0.138 mol m-2 d-1/10a. The changing amplitudes among four seasons are different, with maximum dropping in summer, and the descending speed of PAR is faster before the 1990s, after which the speed slows down. (3) The analysis by each pixel shows that PAR declines significantly (α=0.05) in most parts of China. Summer and winter play more important roles in the interannual variability of PAR. North China is always a decreasing zone in four seasons, while the northwest of Qinghai-Tibet Plateau turns to be an increasing zone in four seasons. (4) The spatial distributions of the interannual variability of PAR vary among different periods. The interannual variabilities of PAR in a certain region are different not only among four seasons, but also among different periods.

Key words: Photosynthetically Active Radiation (PAR), Mann-Kendall trend analysis, China