The paleoecology of fire and oaks in eastern forests

Abstract

Oaks (Quercus spp.) currently dominate eastern deciduous forests, but are widely perceived as declining, with regeneration inadequate to perpetuate many stands. Most stands regenerated following fire in the 19th and early 20th centuries, and a lack of recent fire is viewed as contributing to the shortage of sapling and pole-size stands. But paleoecological studies provide conflicting evidence for the role of fire in the long-term maintenance of oak forests. Here I describe the methods used in reconstructing past vegetation and fire regimes, review the results of previous studies, and present new results for sites from Virginia to Maine. Oaks have dominated mixed mesophytic forests in western Virginia for more than 6,000 years, with sedimentary charcoal levels suggesting a fire regime dominated by infrequent, light surface fires. The arrival of European settlers and a presumed increase in fire activity had little effect on oak abundance. At a higher elevation on more xeric soils, increased fire with settlement caused a shift from oak to pine dominance. On Long Island, NY, oaks have dominated xeric soils for thousands of years, but with more fire than in western Virginia. However, a dramatic increase in fire activity with settlement increased the importance of pines relative to oaks in southeastern Massachusetts? outwash plains. On the Maine coast, where oaks have been minor component of the vegetation for thousands of years, fires appear to have caused slight increases in oak importance both before and especially since European settlement. These results suggest that, depending on the landscape context, fire can favor or select against oaks, and that managers should carefully consider how fires will interact with climate, topography, and other factors before prescribing fire as a solution to the current lack of oak regeneration. It is likely that burn severity and fire return intervals, as they impact both oaks and their potential competitors, will determine whether or not individual oak stands will benefit from the reintroduction of fire.

Parent Publication

• Fire in eastern oak forests: delivering science to land managers

Citation

Patterson, William A. III. 2006. The paleoecology of fire and oaks in eastern forests. In: Dickinson, Matthew B., ed. 2006. Fire in eastern oak forests: delivering science to land managers, proceedings of a conference; 2005 November 15-17; Columbus, OH. Gen. Tech. Rep. NRS-P-1. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station: 2-19.