Subject: PV Code / PV Reference Code Crosswalk Update
Name: R. Havis
Date: May 14, 12009
Variants affected: CA, NC and WC

Description: 

1) PV Reference Code / PV Code combinations read in input data (FSveg Data) are
   cross-walked to FVS Habitat codes for processing (please see FVS Update
   Bulletin No. 672). These cross-walks were updated for the Region 6 forests
   of the CA, and NC variants and for the WC variant by Tom DeMeo,
   R6 Regional Ecologist and NRIS Coordinator, and his staff. Some comments
   from their work are that there are no models available
   for tanoak, but I wonder if we should try to fit something, since this is
   an important part of this ecoregion. The CA cross-walk is identical to the
   NC crosswalk.  This does not mean the two variants have identical plant
   associations.  For example, CA has white oak, ponderosa pine, and mtn
   hemlock associations that NC does not (according to Pat's work). The
   reason they are identical is that they both have the same set of FVS
   models available.  For example, I chose not to match anything to the
   oak series because no oak models are available.  It is too much of a
   stretch to match a Doug fir model to an oak model, for example.     

2) The forest code is an important input variable identifying the geographic
   location of the stand and is used to set some of the cefficients in growth
   equations. If a forest code is not provided in the input data, a defaut
   forest code will be set by the FVS variant. In some variants using the
   data base extension to input data, if the forest code was not specified,
   the defaut forest code was not beeing set in the proper sequence to
   avoid runtime errors. This problem was experienced in the AK, CA, NC, and
   SO variants for some stands, and could potentially occure in other variants.
   The problem has been corrected, but users are advised to carefully set
   appropriate location codes for their simulations.

Impact on users: Users should obtain new executables.

Files:
ca/src/pvref6.f     - updated arrays
nc/src/pvref6.f
wc/src/pvref6.f
dbs/dbsstandin.f     - added call to FORKOD if KODFOR is zero