A history of recurrent, low-severity fire without fire exclusion in southeastern pine savannas, USA

Keywords: Dendrochronology, tree-ring science, longleaf pine, Pinus palustris, wildfire, fire history
Session Type: Virtual Paper
Day: Wednesday
Session Start / End Time: 4/7/2021 09:35 AM (Pacific Time (US & Canada)) - 4/7/2021 10:50 AM (Pacific Time (US & Canada))
Room: Virtual 9

Abstract

The reintroduction and maintenance of historical surface fire regimes are primary goals of ecological restoration across many open, pine-dominated ecosystems in North America. In the United States, these ecosystems often experienced long periods of fire exclusion in the 20th century, leaving few locations to serve as reference sites for ecological conditions associated with a continuous history of recurrent, low-severity fire. Here, we present a tree-ring perspective of uninterrupted surface fire activity from three pine savanna sites in the Red Hills Region of northern Florida and southwestern Georgia, USA. Documentary records for burning at these sites are limited to recent decades and are often incomplete. Fire-scarred cross sections from externally-scarred stumps, dead trees, and live trees provided tree-ring evidence of frequent fires occurring from the beginning of our fire-scar record in the late 19th century onward. Both fire frequency and seasonality were relatively consistent throughout time and among sites. Biennial and annual fire intervals were the most common with some longer intervals also present. Most fire scars occurred in the dormant and early-earlywood portions of the rings, indicating that these fires were human-set fires that occurred before the main lightning-fire season. Our findings regarding post-settlement fire frequency are consistent with previous estimates of fire frequency during earlier centuries, resulting from lightning and Native American ignitions.