Concerns have been raised about the decline of oak forests in the eastern USA. Much of this decline can be traced to maturing forests (succession), species replacement, cutting, and ineffective fire management. More specifically, I have looked closely at white oak (Quercus alba L.) forests in Kentucky and Tennessee, one area considered a central region of best development and highest volumes. An important element in identifying at-risk white oak forests is an assessment of the status of accumulated white oak advanced regeneration (saplings ≥2.54 cm but <12.7cm in diameter). I used data from the USDA Forest Service, Forest Inventory and Analysis (FIA) program to determine the amount of white oak advanced regeneration and describe the structural components of this regeneration phase. Operating from a premise that all overstory stand components originated from the advanced regeneration stage, an evaluation of the sapling component is essential for evaluating, understanding, and managing for the future sustainability of the white oak ecosystem. My assessment determined the amount of white oak forest land across Kentucky and Tennessee; the structural component of the advanced regeneration in these forests was defined by sapling density, sapling basal area, sapling dominance, and species richness (S) metrics.
Results/Conclusions
Across Kentucky and Tennessee there were 4,370,386 (±34,963 C.I.) ha of forest land with at least 14 white oak trees per ha (TPH) that were ≥2.54 cm dbh (equivalent to one tree per sample unit [SU]). However, there were only 2,563,162 (±29,830 C.I.) ha where white oak was the number 1, 2, or 3 ranked canopy dominant. Of these latter forest stands only 418,963 (±15,443 C.I.) ha had advanced white oak regeneration present. Here, the overall sapling layer structure showed an average density of 1,710 sapling TPH, average basal area (BA) = 5.2 sq.m.ha-1 and sapling (S)=6.6 SU-1, while the white oak component averaged 558 TPH with a BA averaging 1.8 sq.m.ha-1. Even where white oak advanced regeneration was present, many stands showed low densities. There were 255,320 (±16,722 C.I.) ha (61 percent) with less than 500 accumulated white oak saplings ha-1, an amount of vigorous rooted saplings considered adequate for successful stand replacement after disturbance. This means if these white oak stands were disturbed now, many would be in danger of not regenerating into a replacement white oak forest. Describing and documenting baseline states of ecosystem components is an important first step in ecosystem risk assessment.