Effects of late rotation thinning on light availability and red oak regeneration within a minor stream bottom in MississippiThis article is part of a larger document. View the larger document here.
Recent studies suggest a troubling decline in the abundance of red oak species (Quercus spp., Section Erythrobalanus) in bottomland forests of the southeastern United States. We assessed red oak advance regeneration and associated tree species in relation to light availability in a 77-year-old oak-dominated stand 5 years after late rotation thinning. Residual basal areas across four thinning treatments ranged between 48 and 69 square feet per acre and were compared to an unthinned control (108 square feet per acre). Available understory light was significantly greater in the most intensive treatment (48 square feet per acre) compared to the unthinned control. Red oak advance regeneration was significantly taller in thinned areas. For the tallest height class (48+ inches), the control area contained only 44 red oak seedlings per acre, while the highest thinning intensity treatment contained more than six times the number of large red oaks (272 red oak seedlings per acre). Relative height of red oak seedlings (the tallest red oak as a proportion on the tallest non-oak seedling) did not differ among treatments. Higher intensity late rotation thinning regimes appeared to be beneficial to increasing red oak advance regeneration vigor, which may aid their progress into the overstory canopy level upon a harvest release. Further monitoring through harvest is needed. Late rotation thinning may provide managers an effective means for enhancing the regeneration of red oak species in future regeneration treatments.