Sawtimber yield tables for Pennsylvania forest management planning

Models to predict gross and net sawtimber volume per acre for even-aged stands were calibrated for Pennsylvania forests as part of a continuing forest management planning project for Pennsylvania's 2.1 million acres of state forestland. Because of the requirements of the models and limitations of the planning data, the main variable driving the yield models was age. Binary variables were used to shift the sawtimber volume predictions up or down to differentiate yields for 3 site classes, 2 stocking classes, 7 forest types, and 10 ecological regions within the state. The models were fitted using plot-level observations from a continuous forest inventory that has been carried out by the Pennsylvania Department of Conservation and Natural Resources Bureau of Forestry since the 1960s. To apportion the total volume into species groups, proportions were derived of the total sawtimber volume per acre for seven different species groups by forest type and site class for four macro-regions aggregated from the ecological regions within Pennsylvania.