Authors: Hang Li*, Department of Earth and Environmental Systems, Indiana State University, James H Speer, Department of Earth and Environmental System, Indiana State University
Topics: Biogeography, Hazards, Risks, and Disasters, Landscape
Keywords: Greater Yellowstone Ecosystem, Resilience, Disturbance, Fire, Remote sensing
Session Type: Paper
Start / End Time: 9:35 AM / 10:50 AM
Room: Virtual Track 11
Presentation File: No File Uploaded
Ecological memory is central to how forest communities respond to ecological disturbances like the Yellowstone forest fires in 1988. Numerous publications have shown how forests gradually come back. But few researches have examined the non-recovery areas as an example of a lack of resilience. We extracted areas that have not recovered from the fire in the past thirty years to examine the causes for this lack of recovery. After computing Normalized Difference Vegetation Index (NDVI) and the Difference Normalized Burn Ratio (dNBR), we classified non-recovery and recovery areas. We randomly assigned 11000 samples for recovery and non-recovered areas from which we extracted values related to topography, climate, and subsequent soil conditions. ANOVA and Chi-Square tests were applied to determine the statistically significant drivers of a lack of recovery. We found that non-recovery areas have lower elevation (2387.46 m), steeper slope (19.14°), higher bulk density (762.71 kg/m3), higher pH (6.10), lower soil organic (212.54 g/kg), and lower total Nitrogen (61.15 mg/L). Douglas fir (Psuedotsuga menziesii) took up 15% in non-recovery areas but 6% in recovery areas. Mollisols made up 47% in non-recovery areas but only 22% in recovery area. Our study indicated that high severity fires could remove forest and potentially force an area to revert back to an earlier grassland vegetation.