Subject: BAL modifier for height growth
Name: Gary Dixon
Date: 02/23/04
Variants affected: NE, LS, CS

Description: Small hardwood trees growing under an overstory would grow
unrestricted in height, but not in diameter. The DG equations have a BAL
modifier function. I took the BAL modifier function out of DGF 
and made it into its own subroutine BALMOD and put calls to this routine
in DGF, HTGF, and RGNTHW. I also put a lower limit on the BAL modifier.
I modified the POTBAG calculation in DGF, inserted some debug write 
statements, and changed/added some comments.

Impact on users: Small hardwood height growth is now commensurate with
small hardwood diameter growth. The large tree height growth now is 
commensurate with large tree diameter growth. The overstory effect on
small hardwood trees is now more realistic.

Files: BALMOD, DGF, HTGF, RGNTHW
