Fire Ecology and Management of Shrub Bogs

Bog

Shrub bogs are distributed throughout the Gulf and Atlantic Coastal Plain. They occur in headwaters of stream systems within sandy uplands and within small depressions. These systems typically have long hydroperiods and may be fed by rainfall, runoff and seepage. Soils are generally wet and acidic and can be sandy or have organic accumulations. Vegetation is dominated by a dense shrub layer and a sparse to relatively dense canopy may be present. Herbs are generally sparse, but where these communities grade into surrounding, fire maintained uplands there is often an herbaceous ecotone. Amphibians and reptiles are known to use shrub bogs, otherwise, relatively little is known about animal use of shrub bogs.

The natural fire regime of shrub bogs was influenced by the fire regime of the surrounding communities. There is agreement that the edges of shrub bogs were burned relatively frequently, however, there is little agreement on the natural fire return interval for shrub bogs. This may be due to the variability of vegetation and situation in which shrub bogs occur. When entire shrub bogs burn, fires are intense. Many shrub bog plants are adapted to fire and can resprout following fires.

Alterations of fire regimes of communities that surround shrub bogs, namely decreases in frequency and changes from lightning to dormant season have lead to an increase in shrub cover and density. Shrubs recover from fires and fires have been shown to cause very little mortality in shrubs killing only the smallest individuals. Increases in shrub cover and densities affect herbaceous plant communities, and potentially hydrology. The maintenance of herbaceous portions of bogs, and early successional shrub bogs is important for the perpetuation of rare amphibian habitat.

Shrub bogs have not typically been the primary target of prescribed fire programs and were even routinely “protected” from fires by the construction of firebreaks. The practice of protecting shrub bogs from fire is now less prevalent than historically partly in recognition that shrub bog ecotones are important habitats for rare plant and animals. The frequency with which entire bogs are burned as opposed to edges depends on management goals for the bog community.