Welcome to visit Scientia Silvae Sinicae，Today is

Scientia Silvae Sinicae ›› 2015, Vol. 51 ›› Issue (2): 90-98.doi: 10.11707/j.1001-7488.20150211

Previous Articles     Next Articles

NDVI Recovery Process for Post-Fire Vegetation in Daxing'anling

Miao Qinglin, Tian Xiaorui, Zhao Fengjun   

  1. Key Laboratory of Forest Protection of State Forestry Administration Research Institute of Forest Ecology, Environment and Protection, CAF Beijing 100091
  • Received:2014-08-28 Revised:2014-11-13 Online:2015-02-25 Published:2015-03-11

PDF (PC)

822

Abstract:

【Objective】The remote sensing technology was used to monitor the vegetation restoration after fire, providing a scientific base for carrying out restoration measures in burned areas. The normalized difference vegetation index (NDVI) is an important index to reflect the growth condition and distribution of vegetation. It has been proved in previous studies that this index has a significant correlation with vegetation coverage. Thus the increasing biomass and the vegetation coverage in burned areas can be monitored through the satellite remote sensing images.【Method】 The Songling burned area, which was burned in spring of 2006, in Daxing'anling was selected as a case study. A series of NDVI data before and after the fire, which were extracted from the MODIS data, and the field investigation data were used to analyze the relationships between vegetation characteristics after fire, burned severity and vegetation types. Data of NDVI in the burned area were extracted before and just after the fire, and the fire severity was classified using the supervised classification method. The maximum NDVI in the same date of August in 2003-2005 was used as the contrast to analyze the vegetation index changes on the time series. 【Result】Low, moderate and high burning severities were accounted for 28.93%, 40.1% and 30.97% burned area, respectively. The dominated vegetation types with high-burning severity were evergreen coniferous forest, broadleaf and conifer mixed forest, and brushwood, which were accounted for 50.37%, 52.22%, and 59.49%, respectively. The proportion of high severity burned areas increased with the ascending slope. 【Conclusion】 The post-fire NDVI showed a increasing trend generally. NDVI value of each vegetation type in the area with high-burning severity was significantly lower than the low and moderate burning severity areas, except for the grassland. But there was no significant difference in NDVI between the areas with low and moderate burning severity. In the second year, the vegetation coverage in high burning severity areas reached the minimum. The NDVI of these vegetation types in low burning severity areas recovered to pre-fire level in 6 years after fire. The coverage of broadleaf and conifer mixed forests recovered faster than other forest types. Fire severity affected forest vertical structure. The burned forests had greater shrub coverage than un-burned ones, and this phenomenon was more obvious in the forests with high fire severity. The natural restoration of brushwood, grassland and marsh was faster than that of forests, thus these areas don't need artificial aids to update. Natural restoration of the tree layer in forests with high-burning severity is very slow, the artificial update will speed up the succession process of forest communities. Periodic drought has an influence on NDVI, especially for the post-fire grassland. The two-factor ANOVA showed that vegetation type and fire severity had a significant influence on the vegetation index. dNDVI can reflect the changes of the vegetation well, which has a good temporal and spatial availability and plays an important role in monitoring the post-fire vegetation restoration.

Key words: burned area, NDVI, vegetation restoration

CLC Number: