Table 1 Observed vs. expected number of times NAFSN sites burned from 1984–2022

From: A fire deficit persists across diverse North American forests despite recent increases in area burned

Ecoregion

Observed number of times burned (O)

Expected number of times burned (E)

Percent of expected (O/E)

Eastern Temperate Forests (92 sites)

63

450

14

Great Plains (26 sites)

36

56

64

Mediterranean California (39 sites)

43

77

56

North American Deserts (96 sites)

52

243

21

Northern Forests (155 sites)

3

281

1

NW Forested Mountains (1097 sites)

426

2281

19

Southern Semiarid Highlands (188 sites)

252

516

49

Taiga & Hudson Plain (35 sites)

51

32

159

Temperate Sierras (122 sites)

63

543

12

All sites (n = 1851)

989

4346

23

  1. The expected number of times burned is based on the mean annual proportion of sites that burned during the historical period (pre-1880). The difference between the observed and expected number of times burned is statistically significant (p ≤ 0.05) in all ecoregions, noting that the only ecoregion with a higher observed number of times burned than expected is the Taiga & Hudson Plain
  2. NAFSN North American tree-ring fire-scar network.
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