Computer Corner Forester's Yield Curve Designer Software David A. MacLean,Kevin B. Porter, Canadian Forest Service,Atlantic Forestry Centre, P.O. Box 4000, Fredericton, N.B., E3B 5P7, Canada, and Jeff Kerr, Forest ProtectionLimited, Compartment 5, Site 24, RR#1, Fredericton, N.B., E3B 4X2, Canada. ABSTRACT. TheForester's YieldCurve Designer (FYCD) software isaimed at helping forest management planners andfield foresters in thedevelopment and validation of timber volume yieldcurves. It uses a mouse- driven graphical user interface that facilitates the import and display of results from stand growth models, the comparison ofpotential curves with permanent sample plot data,and thecreation of new curves bydrawing, adjusting, andcombining curves. FYCD addresses the p roblem ofgetting management plan volume yield curve information out to field foresters fo r validation against available data andexperience, and facilitating feedback from the forester to theplanner. FYCD also increases the usability of valuabledatafrom permanent and temporary sample plotsby allowing easy access and display. This paper describes the primary functionality ofFYCD, the data formats used, andhow toobtain this free software from theCanadian Forest Service. North. J. Appl. For. 15(1):23-27. A major part offorest management planning involves estimating andpredicting volume-over-age yield curves for eachclass of stands. These sets of curves form an input to timber supply models thatoptimize management actions and calculate sustainable harvest levels. Yield curve sets often specify volumes byspecies and product (e.g., pulpwood, stud wood,logs)for a largenumber of classes of stands, typically 80-100+ classes in easternCanadian forest management units. The Forester's Yield Curve Designer(FYCD) software was designed to address two separate uses relatedto yield curve formulation: (i) to assist in thedevelopment of volume yield curves from stand growthmodeloutput andplot data; and (2) to allow field foresters to access, use, and help validate the complex yield curve data sets used in manage- mentplans. FYCD therefore is aimedat two very different types of users; one is the management planner who is con- structing the yield curvedatabases, andthe otheris the field forester who wants to use the management plan or plot informationin making decisions. Non•: David A. MacLeanis corresponding author andcan be reached at (506)452-3580; Fax: (506)452-3525; E-mail: dmaclean@fcmr.forestry.ca. This project wassupported by funding from the Canadian Forest Service, Fundy Model Forest, and the Canada Green Plan "Partners in Sustainable Development" program, with cost-sharing by the Integrated ForestPest Management and Decision-Support Systems initiatives. The authors thank Y.S. Park, E. Swift, and C. Frame for providing review comments ona draft of the paper. FYCD uses a mouse-driven graphical user interface (GUI) and was developedusing the Visual Basic programming language. It runs on a PC andrequires Microsoft Windows 3.x or Windows95, a mouse, at least 2 megabytes of free disk space, and 2 megabytes of memory. This paper describes the primary functionality of FYCD, the dataformats used, and how to obtain this free software from the Canadian Forest Service. Overview of FYCD FYCD provides a graphical environment to allow the use of stand growth model results and empirical data in building volume per unit area versus age yield curves. The main portion of the FYCD screen (Figure 1) consists of a yield versus age graph, upon which selected data sets are displayed as colored curves, curve segments that join repeated plot measurements, or points thatrepresent single plot measure- ments. Built-in functions and use of a mouse allow the selection and manipulation of any displayeddata. FYCD facilitates validation of yield curves by comparison with sample plot data.The usercan also createnew curves by drawing, adjusting, or combining curves. Age-based curves of volume per unit area,volume per tree,or stems per unit area can be used.The y-axis of the FYCD graph can be completely customized by theuser withrespect to variables, labels, and scale, so it is easyto use cords or board feet per acreinstead of m3/ha. NJAF 15(1) 1998 23 Downloaded from https://academic.oup.com/njaf/article/15/1/23/4788399 by guest on 23 April 2021