WestPro: a computer program for simulating uneven-aged Douglas-fir stand growth and yield in the Pacific Northwest.
WestPro is an add-in program designed to work with Microsoft Excel to simulate the growth of uneven-aged Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Pacific Northwest region of the United States. Given the initial stand state, defined as the number of softwood and hardwood trees per acre by diameter class, WestPro predicts the future stand state for each year of a predetermined time horizon. Management regimes are defined by a target stand distribution and a cutting cycle. Performance indicators include diversity of tree size and species, timber yield, and net present value of harvest over the given horizon. This paper contains background information on the WestPro program and instructions and suggestions for its application. By working the examples found in the text, the user will learn how to simulate the growth of a given initial stand and to predict how different management regimes may affect stand structure, yield, and diversity. Limitations of the model also are discussed.