Oak planting success varies among ecoregions in the Central Hardwood Region

Abstract

This paper compares the results of planting northern red oak (Quercus rubra L.) and white oak (Q. alba L.) in the Ozark Highlands of Missouri to planting northern red oak in the Shawnee Hills and Highland Rim of southern Indiana. In both regions, seedlings were planted beneath shelterwoods thinned to 60 percent stocking. Black oak site index for Missouri planting sites was 19 meters (at an index age of 50 years) and 23 meters for Indiana sites. A total of 5,120 seedlings were planted. Three years after planting the shelterwoods were removed. Six nursery treatments were applied to growing 2+0 northern red oak stock in which seedlings were: (1) not undercut nor top-clipped, (2) not undercut but topclipped the spring before planting, (3) undercut the first year in the nursery but not top-clipped, (4) undercut the first year and top-clipped, (5) undercut both years in the nursery but not topped clipped, and (6) undercut both years and top-clipped. Those treatments plus two additional treatments were applied to growing 3+0 white oak nursery stock in which seedlings were: (1) undercut the second year but not top-clipped, and (2) undercut the second year and top-clipped. Thirteen years after planting, survival of northern red oak ranged from 13 to 26 percent in Indiana plantings and from 50 to 77 percent in Missouri plantings, depending on treatment. Eleven years after planting, survival of white oak in Missouri ranged from 40 to 85 percent. Because survival by itself may not accurately reflect planted tree success, logistic regression was used to derive dominance probabilities for planted oaks. Accordingly, a planted tree was deemed dominant (and thus competitively successful) if it attained 80 percent of the mean height of dominant competitors a specified number of years after planting. In the Missouri plantings, estimated dominance probabilities for northern red oak increased with time since shelterwood removal and with increasing initial basal caliper of seedlings. After 13 years, probabilities for red oak seedlings with an initial caliper of 15 millimeters ranged from 0.45 to 0.60, depending on nursery treatment. Estimated probabilities for white oak did not change significantly with time. After 11 years, probabilities for white oak seedlings with an initial caliper of 15 millimeters ranged from 0.36 to 0.77. In contrast, estimated dominance probabilities for red oaks planted in Indiana declined with time. After 13 years, probabilities for seedlings 15 millimeters in initial caliper ranged from 0.02 to 0.04, depending on nursery treatment. Although effects of undercutting and top-clipping varied by species and planting region, their joint effects generally resulted in higher success probabilities than when neither treatment was applied. Low dominance probabilities for trees planted on Indiana sites resulted from high mortality and slow growth related to suppression by yellow-poplar (Liriodendron tulipifera L.) and aspen (Populus spp). In addition to nursery treatment and initial seedling size effects, the results emphasize the importance of recognizing variation in the outcome of interspecific competition among ecoregions and associated temporal changes in dominance probabilities of planted oaks.

Parent Publication

• 12th Central Hardwood Forest Conference

Citation

Weigel, Dale R. 1999. Oak planting success varies among ecoregions in the Central Hardwood Region. In: Stringer, Jeffrey W.; Loftis, David L., eds. 1999. Proceedings, 12th central hardwood forest conference; 1999 February 28-March 1-2; Lexington, KY. Gen. Tech. Rep. SRS-24. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 293 p.