Silvah 5.5 - Silviculture for Allegheny Hardwoods and Oak

Software Tips

Peter D. Knopp, Northeastern Research Station

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Welcome to Silvah 5.5, the latest version Silvah.  This page provides a summary of our most recent developments, along with tips on how to use the software.  Until we have a Help system for Silvah, look to this page to provide help on essential program features.  


Until the summer of 2001, Silvah was being developed and maintained with Fortran77 – a programming language that came out in the mid-to-late 1970s.  While it was critical to upgrade our development tools we also wanted to move forward with the development of oak ecology and silviculture in Silvah.  Silvah’s analysis and prescription software (Silvah) relied on a relatively simple interface, which meant we could retain the software in it's traditional form.  Essentially, the analysis and prescription portion of Silvah remains just as it always has, with fixes and enhancements for silviculture of oak ecosystems.

Portions of Silvah’s data-entry/edit software (SilvEd) relied on DOS technology that required work-arounds to run on modern Windows PCs, and many of these features plainly were no longer supported by modern development tools.  With Silvah 5.5, SilvEd has been completely rewritten as a Windows program.  Most, if not all of the original functionality has been maintained.  What has drastically changed is not so much what the program does, but how you interact with it.  The bulk of the tips provided here mainly deal with the Windows replacement of SilvEd.

From the above, one can see that Silvah is still comprised of two separate programs.  However, with the new Windows replacement of SilvEd, now you can perform all of your tasks from one place.  Here is a list of the major features available:

** Silvah 5.5 does NOT yet offer prescriptions for oak ecosystems.  Oak prescriptions are currently under development.  Prescriptions for Allegheny/Northern Hardwoods are still available.

Microsoft Access Database Files

The new version allows you to save your data to a Microsoft Access database.  You don't need to have Access to run Silvah 5.5, but if you are using a pre-Windows 2000 machine and you don't have Access, extra steps (not covered here) are required in the setup process.  Feel free to contact us if you think you require these extra steps or if you aren't sure.

All of your inventory data and defaults settings can be saved to an Access database file by selecting File Save from the top-level menu or toolbar.  If you choose to save your data as an Access database, you can always open it later and continue modifying as necessary.  If you have Access on your computer, you can open the database in Access but it won't mean much.  It could be handy, for example, if you wanted to copy data into Excel for additional statistical analyses, and so on, but we don't recommend opening the file in Access and trying to do modify data.  It's better to launch the Silvah Windows program and then open the Access files from there.

Do you have to save your data to an Access (.mdb) file?  Currently the answer is no.  You don't really have to save your work to Access. But if you choose NOT to save your work, then you MUST save your work to a .SIL file, and if you modified the defaults, to a .DEF file as well. Otherwise you will lose all of your data!

Silvah still requires the original .SIL and .DEF file formats.  At some point, if you want to run Silvah on your data, you must choose to save your data as a .SIL file and, if appropriate, to a .DEF file. Eventually (way down the road) the .SIL and .DEF files might go away and we will only have Access files.  It's too soon to predict when, but our idea was to start with Access and build on it as we progressed in our development.  That's why it's currently optional to save to Access since we are still maintaining the original file types.  

Creating Data (.SIL) Files

Given that you have entered or imported data, you must first create an .SIL data file if you want Silvah to analyze your data.  You can do this by clicking on "Save to Silvah File" in the lower left corner of the screen, in the Inventory Data section.   When you click this button, you can browse to a folder and specify a file name.  

Importing and Converting Files

Silvah 5.5 can import older files, dating back to Silvah version 4.04.  During importing, Silvah converts the data into the current version/format.  Conversion may not always be perfect in cases when data items have been dropped or when inventory procedures have changed.  When in doubt, Silvah applies conservative values to avoid erroneous conclusions that might lead to recommended treatments with potentially irreversible results.  

To import data (.sil) files:  In the Inventory Data section, in the lower left corner of the screen, click on "Read from Silvah File".    When you click this button, browse to a folder and select a file to import.  

To import a defaults (.def) file:  In the Defaults section, near the left center of the screen, click on "Read from SILVAH def file".  When you click this button, browse to a folder and select a file to import.  NOTE:  From the Plant Species section, you may also have an option to save to/read from defaults files, this is just for convenience. Defaults and plant species information are both stored in .def files.

During analysis and prescription, Silvah no longer converts files on the fly.  Instead, you must follow the above steps to import the file, and then select "Save to Silvah File".  We recommend that you select a new name for the file, to preserve the contents of the original file.  

File Naming

When creating new data (.sil) files and/or defaults (.def) files, you are no longer restricted to short file names less than nine characters long.  Instead, you are limited to 70 characters which includes the full path information.  

It is okay to use spaces in file names.  For example, when specifying a name for a Silvah data file, you could enter "my favorite stand".  Just remember that the file name plus the full data path must not exceed 70 characters.

Entering Tree Data

When entering data from scratch, a fundamental rule of thumb is that you must establish overstory plots before you add tree observations.  One way to do this, then, goes as follows:  Create or add a plot, and keep adding as many plots as desired.  When you are ready to enter tree data, jump to the trees module.  To add a tree observation, click "Add tree" and select which plot it must belong to.  Repeat this step for each tree observation, changing only the plot where the tree may belong.

Alternatively, you can avoid creating plots at first, and simply click "Add tree" from the beginning.  This will automatically create a tree observation in Plot 1, regardless of whether or not you want to start in this plot.  From this point on, each time you are ready to add a tree to the next plot, select "Add tree to new plot" from the Add tree dialog.

There are some shortcuts to speed things along.  For instance, you do not have to click "Add tree" for every single observation in a plot -- just the FIRST tree in each plot.  Once you have added a tree to a plot following either of the procedures above, you can press "Ctrl - Enter" (hold down the control key and then press Enter) from any cell in the tree row and the program will add a new observation BELOW the current row.  In this way, you could add a bunch of rows ahead of time, and then go back and enter data by row or by column.

Keep in mind that Silvah requires a minimum of three pieces of information for each tree:  species, dbh, and quality.

If you any trouble with installation, questions, or comments,  feel free to call our office at 814-563-1040, or call Pete Knopp at 740-368-0075 for assistance.

This page was last updated on 10/30/2003

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