Historically, most Illinois woodland areas were dominated by shade-intolerant oak and hickory species that required periodic fires for their maintenance. Cessation of fires associated with European settlement permitted aggressive invasion of these forests by fire sensitive but shade-tolerant sugar maples, which have displaced other native tree species. Management of these forests to restore historic conditions is of concern, especially because of the loss of tree species diversity as sugar maple dominates the tree canopy. However, as these successional changes proceed further toward complete sugar maple dominance, it is unclear if woodlands reach a stage where restoration activities would be of little use since the original species composition has been eliminated. Thus, prior assessment of the possible responses to management activities on potential restoration sites is desirable. I present data that indicates the degree and direction of this successional trend collected from an unmanaged wooded Illinois Nature Preserve in Funks Grove, IL. Additionally, I present current vegetation data from several Illinois woodlands of different species composition and structure. To predict future vegetation changes in these different woodland types, I will use vital attributes modeling. The stochastic modeling system VAFS/STANDSIM (Vital Attributes Fuzzy Systems STAND Simulator) predicts species-specific vegetation composition changes under different burning regimes. By changing the initial species composition and age-structure of the model, the effects of cutting and planting can also be modeled. Because it can take decades or centuries to document in the field the effect of management on forests, the model will be a powerful decision making tool to predict the effect of various management activities on long-term vegetation structure.

Key words: burn interval, vital attributes modeling, woodland succession