Richard Keigley's Research Projects

Current research: Effect of Browsing Following Wildfire in the Missouri Breaks.

The purpose of this study is to determine if ungulate browsing will adversely affect plant communities that were established after the Black Pulaski Fire in 2006. The study area is located in eastern Montana and is managed by the Bureau of Land Management.

In the absence of fire, and when browsing pressure is light, plant species capable of growing through the browse zone grow to various heights depending on local site conditions and plant age. This potential height is determined by local site conditions, and can vary widely from place to place. If browsing pressure increases to a level that prevents young plants from attaining their potential stature, the structural diversity of the community will diminish as the mature (tall) plants die.

Wildfire accelerates the decline in structural diversity in two ways. First, vegetation established immediately after fire is attractive to both wild and domestic ungulates, potentially increasing browsing pressure above the pre-fire level. Heavy browsing may prevent these plants from attaining potential stature. Second, because the tall mature plants were killed by fire, the decline in structural diversity occurs over a short period. The study addressed the following general objectives:
1. Determine the long-term effect of browsing by wildlife.
2. Determine the long-term effect of browsing by livestock.
3. Determine the significance of deferring livestock grazing after wildfire.

It was determined that skunkbush will likely attain potential stature while chokecherry will not. Chokecherry is an important habitat component and by documenting its decline, this study may influence the setting of stocking rates, big game harvest levels, and the establishment of habitat. In addition, data indicate that weather conditions that occur during the late-Spring of the initial growing season may be an important determinant of the height to which plants ultimately grow.

This study also addressed the question of when certain browse evaluation techniques may be appropriate. A new method based on an analysis of growth rate was developed to assess potential growth of chokecherry during the early years following fire. Browsing level and LD Index data collected in 2008 corroborated the predictions based on 2007 growth rate data. It was determined that for the initial four years, an analysis of growth rate is the more appropriate method. After five years, browsing level and LD Index provide a better method of associating the effect of browsing on potential changes in structural diversity.