Sheep sorrel is probably top-killed by fire.
Several studies describe establishment or increase of sheep sorrel after fire.
Very severe fire may kill sheep sorrel. In New Brunswick a woodlot was clearcut in the fall of 1949 and prescribed burned in April 1951. In New Brunswick understory layers of 11 mixed hardwood stands representing an age sequence of 7 to 57 postfire years were examined. Sampling occurred in July and August 1973 and 1974. Fourteen sites were examined in June 1974 and June 1976.