Wildfire Severity, Recovery, and Grazing Management in the Dry-Mixed Grasslands of Southern Alberta and Saskatchewan
Date
2024-07-23
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0000-0001-5200-2129
Type
Thesis
Degree Level
Masters
Abstract
In the fall of 2017 two wildfires in southern Alberta and Saskatchewan burned approximately 28 000 hectares under extreme weather conditions. These fires completely burned over many ranches, and raise many questions, including how the fire severity and recovery are affected by topographic and soil gradients, and how biomass production and plant species diversity recover including the role of grazing management decisions in recovery. Fire severity in relation to slope, aspect, and available fuel was assessed utilizing the bare soil index (BSI) by calculating the difference between the amount of soil exposure from pre-fire to immediately after the fires. Recovery of biomass production in relation to fire severity, land capabilities, potential land productivity, and solar heat load was assessed utilizing the normalized difference vegetation index (NDVI) to compare post-fire vegetative greenness to that of baseline pre-fire peak biomass greenness. Recovery of live biomass and species metrics with and without fire and grazing were assessed using a factorial randomized complete block design. I found that fire severity increased with increased slope and decreased vegetative greenness. Fire severity was highest in areas with slopes steeper than 15 and aspects that were within the 45 flanks of the dominate wind direction. Recovery of biomass was best in areas of moderate fire severity and solar heat load. The complete recovery of live biomass was noted by year three of the study and the complete recovery of litter was not noted by year five. Grazing has no significant effect on recovery of either biomass or species metrics.
Description
Keywords
Wildfire, grazing, remote sensing, grassland, prairie, fire, fire severity, biomass, native grassland, sentinel 2
Citation
Degree
Master of Science (M.Sc.)
Department
Plant Sciences
Program
Plant Sciences