Kentucky Drought History



Drought History of Three Ponds and Blanton Forest Preserves: Investigation of an East-West Drought Gradient across Kentucky

- Funding through the Small Grant Program of the Kentucky State Nature Preserves Commission


Future climate change will likely have a consequential impact on forests across Kentucky. An alteration in the pattern, frequency or duration of drought will likely alter the return interval and severity of fire. A change in drought and forest fires will in turn alter disturbance regimes, age structure and species composition. Climate has been shown to be a dynamic factor of several different ecosystems (e.g., Swetnam and Betancourt, 1990; Jenkins and Pallardy, 1995; Allen and Breshears, 1998; Villalba and Veblen, 1998). The impact of climate change, therefore, has the potential to reverberate across Kentucky at multiple spatial and temporal scales.

In order to best anticipate how to manage and restore ecosystems in the face of climate change, it is best to study the historical interaction between climate and ecosystem dynamics. Before this can be accomplished, however, there needs to be high-resolution records of regional paleoclimate. Unfortunately, there has been little paleoclimatic research in Kentucky, especially at the high- resolution time scale (years to decades). Only two drought-sensitive tree-ring chronologies exist in Kentucky (Cook et al., 1999): one from Mammoth Cave National Park in Edmonson County, the other from Lilley Cornett Woods in Letcher County. Both of these reconstructions end in the early-1980s. Expanding, lengthening and updating the historical record of drought in Kentucky will be the first step in improving knowledge concerning the impact of climate change on its forests.

Research Objectives:

The main goal of this project is to reconstruct and study the drought history at Three Ponds (TPP) and Blanton Forest Preserves (BFP). These reconstructions will create a baseline for long-term drought history, which can then be used for studies of fire and stand dynamic histories. By combining these reconstructions with the two prior tree-ring collections, an examination of drought can be made across Kentucky from east to west. Despite the fact that global climate change is occurring, it is not necessarily true that such changes are occurring at the same pace or even changing in the same direction at local and regional scales. As Kentucky crosses a range of physiographic provinces from the western end of Appalachian Plateau to the eastern edge of the Interior Plains and up to the eastern border of the Interior Highlands (Vigil et al., 2004), the impact of global climate change on Kentucky's climate may differ from region to region.

Specific Questions:

  • "Has the pattern of drought been consistent across Kentucky over the past 300 years?"

  • "Has there been a significant trend in drought over the last 30 years as the Earth has warmed?"

  • "What are the significant periods of wet and dry conditions in eastern and western Kentucky?"

Images of Locations Sampled:

old-growth, mixed-mesophytic forest in Blanton State Nature Preserve