Table 3 Fire return interval analyses by group. All composite analyses are based on a minimum of three recording samples and at least two fire scars. Statistics for BRIS and LOW groups are reported for the full analysis periods as well as the common period, 1715–1879, shared by all groups. NA, not applicable
From: Fire regimes over a 1070-m elevational gradient, San Francisco Peaks/Dook’o’oosłííd, Arizona, USA
Composite parameters | BRIS | HIGH | LOW | ||
|---|---|---|---|---|---|
Dates of analysis | 1506–1879 | 1715–1879 | 1715–1879 | 1684–1879 | 1715–1879 |
Total number of intervals | 19 | 15 | 29 | 49 | 47 |
Mean fire interval (yr) | 19.6 | 10.9 | 5.7 | 4.0 | 3.5 |
Median fire interval (yr) | 12.0 | 9.0 | 4.0 | 3.0 | 3.0 |
Standard deviation (yr) | 19.6 | 8.5 | 3.7 | 3.3 | 2.2 |
Fire frequency (yr− 1) | 0.05 | 0.09 | 0.18 | 0.25 | 0.3 |
Coefficient of variation | 1.0 | 0.8 | 0.7 | 0.8 | 0.6 |
Skewness | 1.4 | 1.2 | 1.0 | 2.6 | 1.4 |
Kurtosis | 1.4 | 1.5 | −0.9 | 8.8 | 2.5 |
Minimum fire interval (yr) | 1 | 1 | 2 | 1 | 1 |
Maximum fire interval (yr) | 72 | 32 | 14 | 19 | 11 |
Weibull mean (yr) | 19.6 | 10.9 | 5.7 | 4.0 | 3.5 |
Weibull median (yr) | 13.8 | 9.0 | 5.1 | 3.4 | 3.2 |
Individual-sample parameter | |||||
Point mean fire interval (yr) | 36.9a | NA | 32.9 | 15.1 | NA |