TMBRCRUZ - a timber cruise computer program for foresters an MSDOS program for IBM-PC compatible computers written by Duane Bristow, consulting forester Albany, Kentucky 42602 This is a system to input raw field data collected by sampling methods or 100% cruise and to print out stand and stock tables as well as timber value tables by selected criteria of size, species, strata, or cut, leave, cull designations. The program does a statistical analysis of the collected data and calculates additional plots needed for a selected error range. I plan to expand this system to use growth models to project stand growth. This system was recently rewritten for IBM-PC systems and improved and had additional features added. It is based on a computer system that I have developed for practical use by a field forester cruising timber in the appalachian hardwoods of Kentucky over a 20 year period. Its essential features are versatility as regards sawlog volume estimation and accuracy as regards standing timber value estimations. It is designed to use statistical analysis methods to enable the forester to get the degree of accuracy that he feels is economically justified. Since the rough terrain of eastern Kentucky mountains makes access difficult it is much more expensive to actually get to a plot center than it is to gather data once there. Therefore this system allows a forester to gather a number of types of data and to record these on an individual tree basis in the field. These are then typed into a database file in the office. The program is able to analyze this database and produce reports in an almost infinite number of ways depending on a reports configuration file set up by the forester. It allows tree valuation based on sawlogs using either doyle, scribner, or international 1/4 inch log rules. It also evaluates trees by tree grades loosely based on U.S.F.S. tree grading rules of grading the butt log into one of three grades. The reports configuration file then allows input of logs delivered prices by grade and by groups of species selling for similar prices. It reduces these prices by an average logging cost input by the forester and by a percent risk factor based on his estimation of the risk of estimating standing tree volumes as opposed to measuring harvested log volumes. (For instance to account for interior defects or hollows which might be missed in a standing tree.) It is felt that it is very inaccurate to evaluate good quality standing hardwoods without taking these factors into account. The method of use I have developed based on my experience in cruising a timber stand over 25 to 50 acres is as follows: (for small tracts it is usually most economical to do a 100% cruise.) 1. Divide the number of acres in the tract by 40 to 60 depending on the forester's gut feel for the amount of variation in the stand expected. 2. Lay out a grid on a topo map with size of the rectangles of the grid determined by the results of step number 1. For a 160 acre tract, 160/40 = 4 or 40 square chains so lay out a grid of 4 X 10 chains. Cruise lines will be 10 chains apart and plots will be taken every 4 chains on the lines. Ratio of distance between cruise lines to distance between plots should not be more than 2.5 3. Collect at least dbh, log height, species, and tree grade on each tree selected on each plot. 4. Collect logs delivered prices and logging cost information from local markets by visits to 2 to 4 of the larger markets in the area. 5. In the office input data into the database, set up the configuration file, run a detailed report and use professional skills and judgement to analyse the data. 6. Return to the field to gather additional data, if necessary. 7. Update the database and rerun detailed reports several times changing the report parameters by use of the configuration file to determine best management of the tract. 8. Using selected data from the reports generated write a narrative timber report for the client. This system consists of a data file and a configuration file both created with a word processor and a reports module which analyses the database in various ways to produce a number of reports. The input consists of: An expansion factor which can be entered as 5 for 1/5 acre plots or BAF10 for Basal Area Factor 10 point sampling. For a 100% cruise the expansion factor is 1. Of course any fixed or BAF plot size is allowed. Number of acres which is used for reports involving whole stand analysis as opposed to per acre analysis. For 100% cruises this would not be applicable or would be 1. A description of the cruise to be printed at the top of all reports. Form class for each species code which is not 78. (the program uses a 3% variation in volume for each form class variation from 78.) And for each sampled tree: Plot number 1-999 2 letter species code dbh in 1/10 inches 4-99 merchantable height in 1/2 - 16' logs or in feet if greater than 8. grade of butt log 1-3 strata - a code referring to the stand type designation used in doing a stratified analysis. Can be any three characters. status - [L]eave, [H]arvest, or [C]ull form class - 60-99 crown class - D, C, I, S for each tree. vigor - 1 (vigorous), 2 (under stress), 3 (dying), 4 (dead) For each set of reports produced the following must be specified: Species codes in species groups 1-9. A species group is a set of species which can be considered nearly identical in market value. Species group 0 is reserved for all species not specifically assigned to another group. Logging cost per mbf. Percent risk allowed for error of cruise. This reduces stand value by this amount. Tree Scale - Cubic Feet, Doyle, Scribner, or International 1/4 inch. dbh range to be considered for report. grade range to be considered for report. Species codes to include in report or all. Strata to include in report or all. Vigor classes to include in report or all. Crown classes to include in report or all. Reports will give the number of plots by strata and list species. Reports will give the following by species group and total for cruise: (You may specify that the stand info will be number of trees or basal area.) Species group 1 BO RO SO Doyle tree scale thousand board feet Total Volume Total # trees dbh grade 3 grade 2 grade 1 total gr3 gr2 gr1 Total 10 .02 0.00 0.00 0.02 0 0 0 0 . . . 16 11.58 7.02 0.00 18.60 80 100 0 180 . . . 24 0.00 10.58 18.47 29.05 0 0 80 80 . . . Tot 27.80 63.03 59.56 320.23 140 260 320 720 $$ 1,626 7,942 18,224 27,792 $/m 58.50 126.00 306.00 86.79 For the statistical analysis specify the t value or % confidence expected. For example, for 90% confidence t=1.645. The statistical analysis is available for Volume, stocking and dollar value. Example statistical report: Statistical analysis of plot data for 47 plots. t=1.645 90% confidence. Mean volume per acre is 4276.28 Half confidence interval is 481.956 Allowable error is .112705 Coefficient of variation is .469705 This means you can be confident at the level you specified by choosing the t value above that the Mean volume per acre is 4,276.28 plus or minus 482 board feet Doyle rule. This is an error of 11%. The coefficient of variation is a measure of the variability of the stand. The user can specify an allowable error such as .10 meaning he would like to be within plus or minus 10% rather than 11% of the true mean. The program then calculates the number of additional plots he must sample to get this accuracy.