Integrating fire, silviculture, and regeneration in longleaf pine through fuels management

There is increasing interest in conservation-oriented approaches to management and restoration of forests for multiple values, including wildlife, biodiversity and ecological integrity, in addition to the production of forest products. Given the historically low canopy disturbance intensities in longleaf pine (Pinus palustris Mill.) forests various methods of multi-aged silviculture have been proposed to provide multiple values far into the future. In order to manage over long timeframes it is also necessary to obtain adequate regeneration of longleaf pine to allow for recruitment of individuals into the canopy over time. In addition, longleaf pine forests require the application of prescribed fire to maintain both pine dominance in the canopy and diversity in the plant and animal communities, so adequate fuels must be maintained in order to carry the periodic fire. In many instances, however, the different considerations for fire and silviculture are at odds. For example, given the putative shade intolerance of longleaf pine many assume the need for large canopy openings created through harvest in order for longleaf pine regeneration to establish and grow. Yet such large openings typically have reduced fuel loads, do not burn well, and subsequently can be overtaken by hardwoods and any longleaf regeneration lost. We have carried out detailed examinations of the relationship between fire, regeneration, and silvicultural manipulations, as integrated by fuel accumulations, using both standard field-based and newly developed techniques. Fuel bed characteristics resulting from different silvicultural manipulations were assessed using ground-based LIDAR to characterize fuel levels and distribution, and detailed measurements of fire intensity and residence time were obtained using video thermography. These measurements were correlated with analyses of seedling demography. The results show the strong interrelationships between canopy manipulations and fire continuity due to the consequent distribution of fuels.