Evaluating Post-Fire Vegetation Recovery in North American Mixed Prairie Using Remote Sensing Approaches

Abstract

Research on the effects of fire on grassland ecosystems yields among the most controversial research results. This is caused by the global distribution of grasslands under different environmental conditions in addition to complex fire characteristics (time, severity, frequency, history etc.). Challenges and discrepancies arise from various temporal and spatial scales, as well as methods used. Moreover, the function of fire can be different from one grassland to another. In the large body of grassland fire literature, the Canadian northern mixed prairie is understudied, especially regarding the vegetation’s post-fire recovery. The wildfire in April 2013 provided an opportunity to study how the grassland responded to the burning, and particularly how remote sensing can provide potential solutions to grassland fire studies in this region. This research investigated the vegetation’s post-fire recovery using six years’ field survey data. Results indicate a quick overall recovery of the grassland, but with different vegetation forms recovering at various post-fire growing seasons. Green grass was the most resilient component that fully recovered one year post-fire, followed by forbs at two years post-fire, with shrubs and the soil organic crust taking longer than four years to recover. The ecosystem recovered to the unburned state roughly after four years. This conclusion agrees with the shortest fire interval of some research, probably because of the heavy fuel loading before the wildfire, due to Grasslands National Park’s long-term conservation practice. Both hyperspectral data and historical Landsat images were investigated to demonstrate their effective assessment of the post-fire grassland vegetation recovery trajectory.