Stem diameter dynamics under varying shelterwood treatments in an upland hardwood forest on the Cumberland Plateau escarpment
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Managing forests on the Cumberland Plateau escarpment for select desirable species can be particularly onerous due to the high diversity of dominant tree species. We implemented 5 treatments to alter species composition and structure in an effort to favor Quercus and maintain its dominance in the stands. Treatments were shelterwood prescriptions that in the first stage retained a percentage of the basal area (100, 75, 50, 25 and 0 percent retentions). After 9 growing seasons, the residual trees in all but the 0 percent retention treatment were removed. We installed permanent vegetation measurement plots and recorded species and diameter for all trees 1.5 inches dbh and greater in 2001 (pretreatment); 2002 (first growing season post stage one harvest); 2009 (8 years post stage one harvest), 2011 (first growing season post stage two harvest) and in 2014 (4 years post stage two harvest). None of the treatments increased Quercus stems. In the 0 percent retention, or clearcut, Quercus stems changed from 37 stems per acre (SPA), to 5 SPA immediately after harvest, to 24 SPA thirteen years post-harvest; while Liriodendron tulipifera stems increased from 16 SPA pretreatment to 523 SPA thirteen years later. In the 75 percent retention treatment (midstory herbicide in first stage; residual commercial harvest in final stage), for all species, SPA declined from 320 to 35; there were no Quercus, Acer saccharum or L. tulipifera stems found in 2014. The residual stems were Carya ovalis, Fagus grandifolia, Fraxinus americana and Cercis canadensis. Clearcutting and the 25 percent retention shelterwood showed the highest potential for recruiting Quercus.