Pine regeneration following wildland fire
Pine regeneration following wildland fire continues to be a serious problem across the western and southeastern U.S. Frequency of large wildfires has increased over the last several decades and restoration of these burned areas is a major problem confronting land managers. Prescribed fires are used primarily to reduce heavy fuel loads and secondarily to reduce competition or prepare sites for natural or planted pine regeneration. In 1983, an experiment was initiated near the Fort Valley Experimental Forest to evaluate the growth of ponderosa pine (Pinus ponderosa1) seedlings planted after a severe wildfire. This study evaluated different herbaceous species effects on survival and growth of ponderosa pine seedlings. The study reported that competition from nonnative grass species (Dactylis glomerata and Agropyron desertorum) significantly reduced water and nitrogen availability and pine seedling growth; whereas, native grasses (Bouteloua gracilis and Sitanion hystrix) had no effect on soil resources or pines. In southern Appalachia, pine regeneration success after wildland fire varies depending on fire severity and growing season precipitation. After a high intensity, moderate severity fire on dry southern Appalachian ridges, pitch pine (Pinus rigida) seedling germination was high (3,000 seedlings/ha); however, most pine seedlings did not survive beyond the first year due to unusually low precipitation late in the growing season. Even in these mountains that normally receive high precipitation, drought can reduce pine seedling growth and induce mortality. More often, light and nitrogen are the limiting resources to pine seedling growth, and sprouting hardwoods are more competitive than herbaceous species with the regenerating pines. Further studies in southern Appalachia suggest that successful regeneration of pine (e.g., Pinus strobus, P. echinata, or P. rigida) after prescribed fire will not be achieved without planting pine seedlings and reducing fast growing hardwood competitors.