DFSIM (Douglas-fir Simulator) is a managed stand growth and yield simulator for coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii). It was developed in the 1980s from remeasured plot data contributed by many organizations in the Pacific Northwest. It is designed to project the development of stand with at least 80 percent basal area in Douglas-fir and produces yield tables for managed stands with include the effects of initial spacing, precommercial thinning, commercial thinning and fertilization. The DFSIM model also contains an economics option that allows users to estimate present net worth of the simulated regime.
A modified version of the DFSIM Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) growth and yield simulator, DFSIM WITH ECONOMICS, now has an economics option that allows users to estimate present net worth at the same time a silvicultural regime is simulated. If desired, the economics option will apply a volume adjustment multiplier in yields used in the analysis to reflect application of small-plot research results to average operating conditions or to account for genetics or other local conditions. It can also account for salvage of mortality. Prices can be entered as a table of values or as an equation that can vary with diameter. Logging costs can be entered as a table or can be generated internally for a short-span cable system. Logging costs can vary by diameter and volume harvested. Other harvest-related costs can be included on a per acre bases and also on a unit volume basis. Prices and costs can be trended using an annual percentage rate of change that is applied for a 50-year period.
To find out more about this github project, see https://github.com/hamannj/DFSIM/wiki
See http://www.fs.fed.us/pnw/software/DFSIM14/DFSIM.htm for more information.