Whole Stand Yield and Density Equations for the Basswood Forest Type in the Lake States

Whole stand yield models serve forest managers by providing projections of useful stand metrics such as height and volume. Climate shifts are currently being observed in the Lake States, including changes in forest composition and species’ ranges. Basswood (Tilia americana L.) has potential to become a climate winner but lacks whole stand yield model parameters to adequately predict forest conditions. This paper aims to extend the utility of an existing whole stand yield model to basswood dominated stands in the Lake States to enable adaptation to shifting climatic conditions. Basal area, quadratic mean diameter, trees per acre, volume, and height models were fit using nonlinear least squares estimation. Models were validated with cross-validation, independent stand inventory data collected from a local forest management area, and national forest inventory data from more southerly states to evaluate model performance under climate conditions the Lake States could see in the future. Fit statistics for these models were consistent with other modeling efforts in the region, and validation statistics showed applicability of the models to broad basswood ranges and potential stability under changing climates. Forest managers can now utilize these new yield models to improve current and future management of the increasingly important basswood forest type.