Table 2 Historical fire frequency statistics at sites on the Huron-Manistee National Forest, Michigan

Fire scar record (cal. years)

1565–1874

1523–1908^a

1664–1927

1672–1838

Fire years (n)

17

8

28

13

Total intervals (n)

16

7

27

12

Mean fire interval (years)

19.3

55.0

9.7

13.8

Minimum fire interval (years)

3

12

3

4

Maximum fire interval (years)

70

172

28

47

Weibull median (years)

14.4

39.4

9.1

12.2

Lower exceedance interval (years)

3.2

8.1

3.7

4.1

Upper exceedance interval (years)

39.2

113.1

16.4

25.3

Mean scarred (%)

53.0

50.9

42.0

56.4