关键词: 小麦, 叶绿素含量, 不同年代品种, 衰老, 光系统Ⅱ

Abstract: As to the complexity of wetland remote sensing on high mountain wetlands, an objectoriented hierarchical segmentation based on climate division was proposed in this study to extract information of high mountain wetlands. Time series of MODIS normalized difference vegetation index (NDVI) and the data of Digital Elevation Model (DEM) were deployed to extract wetlands on the basis of climate division, and the temporalspatial changes and causes of wetlands in Daxing’an Mountains during 2001-2013 were quantitatively analyzed. The objectoriented method with characteristics of MODIS images showed better accuracy than maximum likelihood method and Logistic model with pixels in wetland extraction. The cartographic accuracy of Daxing’an Mountains reached 82% by the objectoriented method, and the Kappa coefficient was 0.74. The Daxing’an Mountains wetland area was 414.89 hm² in 2001 and then decreased to 340.39 hm² in 2013. The area of wetlands increased and decreased differently in various regions. Increased wetland area mainly distributed in Tahe and Huma counties due to higher annual rainfall in 2013, while decreased wetland area mainly concentrated in Gannan and Longjiang counties due to conversion of wetlands into cultivated lands. This study provides technical support for information extraction of spatial and temporal dynamics of mountain wetlands.

Key words: PSII, chlorophyll content, varieties from different ages, wheat, senescence