Xie Jun Fei, Guo Jia
Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Ying Yong Sheng Tai Xue Bao. 2016 Apr 22;27(4):1203-1210. doi: 10.13287/j.1001-9332.201604.016.
In this study, the spatial distribution of fraction of absorbed photosynthetically active radiation (FPAR) of vegetation in Beijing during 2010-2012 was analyzed based on the MODIS-FPAR data with a resolution of 1 km and the functional classification of vegetation. The yearly dynamics of FPAR of different vegetation types were also investigated. Furthermore, the correlation between FPAR and leaf area index (LAI) was explored. The results showed that, there was a spatially descended trend from the northeast mountains to the central urban area of Beijing. The annual average FPAR of different vegetation types changed little during 2010-2012. These values varied in the ranges of 0.42-0.44, 0.38-0.39, 0.32-0.33, and 0.21-0.22 for coniferous forest, broadleaf forest, grassland, and crop, respectively. However, the range of variation was big for each vegetation type within the year. There was significant linear or logarithm relationship between FPAR and LAI of each vegetation type. Additionally, the smooth time series of MODIS-FPAR of vegetation types could better reflect seasonal variation, which was generated by Savitzky-Golay filtering in software Timesat.
本研究基于分辨率为1 km的MODIS - FPAR数据及植被功能分类，分析了2010 - 2012年北京地区植被光合有效辐射吸收比例（FPAR）的空间分布。同时，还研究了不同植被类型FPAR的年动态变化。此外，还探讨了FPAR与叶面积指数（LAI）之间的相关性。结果表明，从北京东北部山区到中心城区，FPAR呈空间下降趋势。2010 - 2012年期间，不同植被类型的年平均FPAR变化不大。针叶林、阔叶林、草地和农作物的这些值分别在0.42 - 0.44、0.38 - 0.39、0.32 - 0.33和0.21 - 0.22范围内。然而，各植被类型在一年内的变化范围较大。各植被类型的FPAR与LAI之间存在显著的线性或对数关系。此外，通过软件Timesat中的Savitzky - Golay滤波生成的植被类型MODIS - FPAR平滑时间序列能够更好地反映季节变化。
