Longleaf pine management practices and their impact on small mammal populations

Rapid decline and degradation of longleaf pine ecosystems in the southeastern United States are conservation concerns. Prescribed fire is the primary management activity in this fire-dependent ecosystem, but prescribed fire is under increasing scrutiny, primarily due to air quality issues. There are concerns that prescribed fire may be removed, or replaced by herbicide, as a forest management tool without adequate understanding of the ecological consequences associated with such a change in management. We conducted a capture-mark-recapture study from April 1999 to April 2002 to examine experimentally the effect of prescribed fire, herbicide application and herbicide-prescribed fire combination on apparent survival rates of cotton mouse (Peromyscus gossypinus) and cotton rat (Sigmodon hispidus) populations. There was no evidence that herbicide application affected survival of cotton mice. Evidence to support effects of prescribed fire and herbicide-fire combination on survival of cotton mice was weak, although apparent monthly survival generally increased after these treatments. There was strong evidence that prescribed fire and herbicide-fire treatments affected survival of cotton rats, but the evidence for the effect of herbicide alone on survival was weak; survival rates declined in response to all three treatments but most strongly in response to the prescribed fire treatment. Fire alone had a stronger effect than an herbicide-fire treatment in both species. Without clear understanding of their ecological impacts, alternatives to prescribed fire should be employed with caution.

► Prescribed fire and herbicide + fire increased survival of cotton mice.
► Herbicide alone did not influence apparent survival rates of cotton mice.
► Fire, herbicide and herbicide + fire reduced cotton rat survival.
► Fire impacted cotton mouse and cotton rat survival more than herbicide + fire.