Table 1.

Fire index and climate in Sierra Nevada lower montane forests in the fire regime periods identified by the regime shift analysis and in socioecological periods identified in documentary records

Fire regime periodFire indexPDSI indexWNAT anomaly, °C
 1600–17750.042 ± 0.036*0.054 ± 2.081−0.392 ± 0.470
 1776–18650.073 ± 0.064−0.126 ± 2.208−0.133 ± 0.374*
 1866–19030.034 ± 0.033*0.272 ± 2.171−0.185 ± 0.422*
 1904–20150.009 ± 0.009−0.052 ± 2.2270.031 ± 0.420
Land use period
 Presettlement0.042 ± 0.037*0.051 ± 2.100−0.412 ± 0.468
 Spanish-Colonial0.072 ± 0.067−0.138 ± 2.219−0.139 ± 0.379†*
 Gold Rush–Settlement0.043 ± 0.037*0.189 ± 2.078−0.129 ± 0.392*
 Fire Suppression0.009 ± 0.010−0.053 ± 2.2370.030 ± 0.422
  • Values are presented as mean ± SD. The climate variables were summer moisture (PDSI) (60), and summer temperature (WNAT) (59). Means in a column with different symbols (*,†,‡) were significantly different (P < 0.05) as determined using ANOVA and Tukey’s post hoc tests. Presettlement, 1600–1768 CE; Spanish Colonial, 1769–1847 CE; Gold Rush–Settlement, 1848–1904 CE; Fire Suppression, 1905–2015 CE.