Fire history differences in adjacent Jeffrey pine and upper montane forests in the eastern Sierra Nevada

Fire history and forest structural characteristics of adjacent Jeffrey pine (Pinus jeffreyi) and upper montane forests was investigated in the eastern Sierra Nevada at the University of California Valentine Natural Reserve. J effrey pine forests had lower canopy cover, higher amounts of fine fuels, a nd higher shrub cover when compared to upper montane forest that were domin ated by red fir (Abies magnifica). Fire dates were determined using standar d dendrochronolgy techniques from fire-scarred Jeffrey pine, lodgepole pine (Pinus contorta var. murrayana), red fir, and western white pine (Pinus mo nticola) trees, snags, stumps, and downed logs. Fires were recorded from 17 45 to 1889 and mean fire return intervals were 9 and 24.7 years for the Jef frey pine and upper montane forest types, respectively. The median fire ret urn interval was 9.0 years for Jeffrey pine and 24.0 years for upper montan e forests. Significant differences were found in mean fire intervals and fi re history distributions between the two similarly sized fire history plots even though they were only separated by approximately 100 m. This study su ggests that fire regimes can vary over very fine spatial scales. Difference s in fire regimes are likely due to differences in fuel beds and fire behav ior.