What Should a Computer Program Provide?

It helps to know what you want. Forestry is such a small profession that a software vendor might not care too much what you want, but the usual situation is that they simply DO NOT KNOW what you want. So tell them.

You have spent a great deal of time gathering data, so get all the information that data is trying to tell you. Not only do you want the information for your cruise, but you want to keep some of that information for future planning. If you kept the CV of each of the cruises you do by stand age or species mix (and perhaps some other items), then maybe you would be able to see a trend that would help in planning your next cruise.

Most compilers give you the basics like total volume and percent by species, and perhaps by "sort". Most of them will provide a list of log sizes on a per acre basis. You should also be getting other information directly, or in a file you manipulate yourself. Often the computer program calculates this data, but never reports it or puts it into a file to deliver to you.

Here is a partial list. When you get a chance, ask for this kind of data. You might just get it.

For each tree measured in the cruise, you should get a file containing :

  • Plot Number.

  • DBH.

  • Height (total height, if possible, as well as what you entered).

  • Species.

  • Gross volume (cubic and in BF).

  • Net volume (cubic and in BF).

  • Tree value in dollars (from a list of grade values that you provide).

  • Percent of volume for each log grade in each tree.

  • Volume to Basal Area Ratio (Net and Gross).

  • Dollars to Basal Area Ratio.

  • Log volume and grade for each log in the tree.

You can create some of these items (like VBAR) from volume and tree basal area, but the program should be computing the statistics on these as well. You might as well get it done for you. We often concentrate on tree volume, but for variable plot cruise planning we are concerned about the variability of the VBARs, so it is nice to have these immediately available.

For the stand as a whole, you should have the statistics processed for you and automatically providing the CV and the Sampling Errors for:

  • Volume (Net and Gross)/acre.

  • Dollars / acre.

  • Basal Area / acre.

  • Species percentages (by volume and basal area)

By individual species you should have statistics for:

  • Volume to Basal Area Ratio

  • Number of trees/acre

  • Dollars to Basal Area Ratio

If you are dealing with 3P sampling, you should get the ratio of each tree measurement compared to the KPI (estimated value). Along with this you should get any information which might tell you why the estimate was not consistent, such as species, who estimated it, and so on.

This is the kind of data you need to plan better cruising designs, reduce costs and increase the flexibility for your sampling methods. In some cases, it might be there for the asking. Make sure you show some appreciation when you do get help obtaining this data, or help might not be available the next time.

Some of you might have further suggestions for data that should be available as a file or as a report from your cruise. If so, email us at : johnbell@proaxis.com

Originally published April 2003

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