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FAQ

Please submit questions to Robert Scheller (rmschell AT pdx.edu)

Is LANDIS-II compatible with older LANDIS version?

   Yes and no.  Although LANDIS-II can operate under the same principles and assumptions as older LANDIS versions by using the Age-only Succession extension, there are differences.  First, the file input formats (how the data are entered) have been simplified.  Second, the seed dispersal algorithm has been improved (see the related document in the documentation tab).  Third, numerous bugs, large and small, have been corrected.  

Is LANDIS-II linked to PnET?

  No.  Although PnET is often used to derive growth rates for the biomass succession extension, the user can estimate or generate growth rates any way they choose.  For example, in the Sierra Nevada, FVS is currently being used.  Likewise, although LINKAGES has often been used to estimate the probability of establishment, how these are estimated is entirely up to the user.

How should I cite LANDIS-II?  

  Scheller, R.M., J.B. Domingo, B.R. Sturtevant, J.S. Williams, A. Rudy, D.J. Mladenoff, E.J. Gustafson.  Introducing LANDIS-II:  design and development of a collaborative landscape simulation model with flexible spatial and temporal scales.  Ecological Modelling 201 (3-4): 409-419.

Where is the command prompt? 

 A good question! You can find the command prompt in the Start menu, under Accessories. Once you've opened the command prompt, remember to navigate to your LANDIS-II working directory before you start working with the model (use the command 'cd' or 'change directory').  More information on getting started with LANDIS-II and DOS can be found in the LANDIS-II Getting Started presentation on the Documentation page of the website.

How do I know which extensions are installed on my computer?

  At a command prompt, type 'landis-extensions'.  

How do I view ERDAS 7.4 *.gis files

  ArcMap can be used to view *.gis files.  However, some manipulation may be necessary to be viewed correctly.

  Add the .gis file of interest to ArcMap.  It may only be drawn entirely in black.  Right-click on the data layer, and select Properties.  Click on the Symbology tab.  In the left-hand field, select Unique Values.  A window will appear asking if you want to build an attribute table.  Click yes.  The .gis file now has an attribute table, and you can now visually differentiate between the values of the file.

  The LANDISViewer, available from the users/tools section can also display *.gis files.  Finally, GDAL can display *.gis files or export them to a format that can be read by many different mapping programs. 

How do I create multiple scenarios that use the same initialization files?
  
  The easiest way to create multiple scenarios is to use sub-directories.  For example, if your input files reside in c:\my landis files\, create a sub-folder for each scenario.  

 Example:  c:\my landis files\scenario a\

  Next, copy or move a scenario file (scenario.txt) into the sub-folder.  Within the scenario file, make sure the input files are properly referenced.  There are two ways to reference input files, absolute and relative.  Here are two examples for indicating the species file within scenario.txt:

  **Absolute:**  Species "c:\my landis files\species.txt"

  **Relative:**  Species ..\species.txt 

  The ..\ tells Landis to look in the next highest folder for the indicated file.

  These changes need to be made for ALL the input files in scenario.txt.  Output files will automatically be routed to the proper sub-folder.

How do I run multiple scenarios in a DOS batch file?

  To create a DOS batch file, open a text editor and save the document with a .bat extension (e.g., runMyScenario.bat).  

  Within the batch file, direct the command prompt to the proper directory:

  c:

  cd\my landis files\scenario a\

  Next, execute your scenario(s).  Precede the **landis-ii** command with **call**, e.g., 

  call landis-ii scenario1.txt

  cd\my landis files\scenario b\

  call landis-ii scenario2.txt

  And so forth.  To execute the batch file, simply select it in your file browser and hit Enter.  To edit a batch file, right-click and select **Edit**.

My output maps are displaying strange lines or other weird visual artifacts

  Double check that ALL of your inputs maps - to the scenario and to all extensions have the EXACT same number of rows and columns.  In ArcMap:  Open the input file.  Right-click -> Properties.  In the Source tab:  Columns and Rows.
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