Book excerpt: In the late 1950's and early 1960's, a series of studies was installed in the central hardwood forest to determine if size of clearcut opening affects the growth rate and species composition of new stands. In 1991, about 30 years after cutting, stand data were collected in 89 openings ranging in size from 0.04 to 1.61 acres. Species composition varied from locations in West Virginia to those in Illinois and from Ohio to Kentucky. For example, there were more maple and birch in West Virginia than in Illinois, regardless of opening size. Some of the difference in species composition and growth rate is related to site quality but there also are differences due to size of opening. Most of the oak and hickory were on the poorer sites while yellow-poplar was more abundant on the better sites. The number of stems per acre increased with opening size; however, the number of stems of shade-tolerant species constituted a greater proportion of the stand in small openings (