Natural Shortleaf Pine
Average dominant tree height is estimated based on stand age and site index (base age 50 years). Projected basal area per acre is based on current basal area, current age, and projected age. Survival of trees per acre from one period to the next is based on current trees per acre, current and projected average heights, and current and projected basal areas.These growth relationships for the shortleaf pine simulator are based on the following work:
Schumacher, F.X., and T.S. Coile. 1960. Growth and yields of natural stands of the southern pines. T.S. Coile, Inc., Durham, NC. 115 p.
The amount of sawtimber basal area per acre is based on a ratio of the merchantable basal area per acre. Total cubic feet per acre, pulpwood cubic feet per acre, sawtimber cubic feet per acre, and board feet per acre for the various log rules (International 1/4, Scribner, Doyle) are estimated using site index, age, and basal area relationships derived from the work noted below. Weight per acre is based on the estimate of total cubic foot volume per acre.
Murphy, P.A., and R.C. Beltz. 1981. Growth and yield of shortleaf pine in the West Gulf region. U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station, New Orleans, LA. Research Paper SO-169. 15 p.