Fire History of a Temperate Forest with an Endemic Fire-Dependent Herb

Abstract

A dendroecological fire history study was conducted for The Nature Conservancy's Narrows Preserve on Peters Mountain, Virginia, where the predominant vegetation is oak (Quercus L.)-dominated forest containing some other hardwoods and pines (Pinus L.). The site encompasses all the known habitat of the endangered and endemic Peters Mountain mallow (Iliamna corei Sherff.), a perennial herb that requires fire for seed germination and habitat maintenance. Fire scars from 73 pines indicate frequent burning in the past (Weibull median composite fire interval = 2.2 years), primarily during the dormant season. Fire frequency exhibited little temporal variability from the beginning of the fire chronology in 1794 until the 1940s, despite changing land uses. However, the incidence of fire declined subsequently with the advent of effective fire protection measures. Ageing trees near the mallow population indicates that the fire-tolerant chestnut oak (Quercus montana Willd.) recruited relatively continuously under frequent fire, but that other species were established primarily during the fire protection era. The decline in burning appears to have permitted an increase in tree density that likely inhibits the growth and recruitment of mallow plants. Our results suggest that reintroducing frequent fire would be an appropriate technique for managing the mallows and the greater Peters Mountain landscape.