S2SIMSAP and SlMTlM are computer programs that have been developed to simulate the stand growth and development of natural and treated even-aged northern hardwood stands. SIMSAP begins with species distributions by quality classes in sapling stands after regeneration. SIMTIM, the poletimber-sawtimber-harvest phase, uses stocking guides based on quadratic mean stand diameter, number of trees, and basal area per acre of trees in the main crown canopy. Using available data, the connecting phases of the models have been tebted to determine the effects of silvicultural treatments (or no treatment) on long-term stand response. The models are coded in FORTRAN 77 and are available on mainframe and IBM compatible microcomputers with a minimum of 256 K.S3.

In 1959 a study of crop-tree release and species cleaning was established in a 25-year-old northern hardwood stand growing on an above-average hardwood site that resulted from a silvicultural clearcut in the White Mountains of New Hampshire. Three treatmentslight crop-tree release, heavy release, and species cleaningwere randomly assigned to quarter-acre plots, five plots per treatment, including five untreated plots. The stand was followed for 5 years and based on the results, treatment effects were projected to a stand age of 45 years. These projections were subjected to a financial analysis. The treatment plots were tallied at stand ages 56 (1990) and 69 (2003) years. We summarize the results of the early crop-tree release and species cleaning and provide a long-term financial perspective based on the new tallies. Our goal was to repeat the financial analysis and re-examine the results and conclusions of the original study. We found that the return on investment at stand ages 56 and 69 years was not as good as originally reported. The least expensive treatment, a light crop-tree release, gave the greatest return on investment. An opportunity for a commercial thinning between stand age 45 and 56 was missed and most likely would have improved the financial outcome of the treatments. Approximately 400 crop trees per acre were selected for release in 1959 but 200 crop trees per acre would have been more than sufficient and would have improved the financial outcome of the treatments by lowering initial cost. On a similarly good hardwood site, with an equally well stocked young stand, and good markets for small diameter roundwood, we only can speculate that releasing 200 or preferably fewer dominant or codominant trees per acre at stand age 25 followed by a commercial thinning when feasible after stand age 45 could be a good investment for a landowner.