Response of sun-grown and shade-grown northern red oak seedlings to outplanting in clearcuts and shelterwoods in North AlabamaThis article is part of a larger document. View the larger document here.
The primary objective of this study was to determine if greenhouse light environment would affect outplanting success for northern red oak (Quercus rubra L.) in clearcuts and shelterwoods. In 2002, northern red oak seedlings were grown from acorns under full-ambient (sun) and half-ambient (shade) light conditions in a greenhouse. Seedlings grown under full sun conditions were significantly taller and had more leaves and more flushes than seedlings grown in shade. Rootcollar diameter of sun-grown seedlings did not differ significantly from those of shade-grown seedlings. In February 2003, both sun-grown and shade-grown seedlings were outplanted in a clearcut and under an oak shelterwood. Three replicates of the oak shelterwood were created in November 2002 by using herbicide to selectively remove mid-canopy species; no gaps were created in the overstory canopy. Three clearcut plots were harvested in winter 2002. The clearcuts averaged 1 m2/ha residual basal area, 32 percent canopy cover, and photosynthetically active radiation was reduced to 30 percent less than above-canopy levels. Residual basal area for the shelterwood averaged 19 m2/ha, with 98 percent canopy cover and photosynthetically active radiation reduced by 86 percent. After one field growing season, sun seedlings outplanted in clearcuts had significantly greater basal diameter growth than either sun or shade seedlings planted in shelterwoods. Prior exposure to higher ambient light levels did not result in greater light use by outplanted seedlings.