Fire, drought, and human history near the western terminus of the Cross Timbers, Wichita Mountains, Oklahoma, USA

Abstract

Dendrochronological methods were applied to reconstruct the historic occurrence of fires at a Cross Timbers forest-grassland transition site within the Wichita Mountains of southwestern Oklahoma, USA. Sixty fire events occurred within the period 1712 to 2006 (294 years). The mean fire interval (MFI) was 4.4 years for a pre-Euro-American settlement period (pre-1901) and increased to a MFI of 5.2 years after 1901. During the period between 1855 and 1880, which corresponds with the prolonged severe drought called the Civil War drought, the mean fire interval was 1.7 years. Although twentieth century fire frequency has not been significantly decreased, the severity of fires appears to be lessened due to alterations to the fire environment through grazing and fire exclusion. Eastern redcedar (Juniperus virginiana L.) expansion now poses significant challenges to forest and range management, particularly its control through prescribed fire. In the future, fire managers throughout the Cross Timbers region are likely to face similar challenges and look toward quantitative and science-based information about the historic fire regime for guidance.