干旱区生态环境知识资源中心

Grassland wildfires have profound immediate effects on ecosystems. A wildfire that occurred in Grasslands National Park (GNP) on April 27(th) 2013 has severely disturbed the local ecosystem. This study was thus conducted to evaluate impacts of the fire on this semi-arid grassland. Spectral indices including Normalized Burn Ratio (NBR), Mid-Infrared Burn Index (MIRBI), and Normalized Difference Vegetation Index (NDVI), derived from Landsat images were explored to evaluate the burn severity, to assess the relationship between pre-fire vegetation parameters and burn severity, and to analyze the vegetation recovery progress. Results indicated that while the selected spectral indices were all able to detect burn severity, the MIRBI showed the best performance. Severely burned areas were distributed along a river where a large amount of pre-fire dead biomass had accumulated. Overall the grassland ecosystem showed a strong resilience by recovering quickly after the fire.