Subject: Volume Updates
Name: R. Havis
Date: September 29, 2011
Variants affected: AK

Description: The modules used to evaluate profile models were updated to prevent
             potential numerical errors. The algorithms used to evaluate volumes using
             the Demars and Curtis profile models were changed for trees having
             DBH greater than or equal to 9.0 inches and height greater than or
             equal to 40 ft. Changes were made to the fwinit.f routine, but they 
             do not affect FVS
             
Impact on users: In the Tongass NF (Forests 1002, 1003, 1005) and the British Columbia / 
                 Makah Indian Reservation (Forest 701) the red alder volumes are
                 affected for diameters greater than or equal to 9 in DBH and heights
                 greater than or equal to 40 feet. Merch. board feet volumes are now
                 available for red alder. In the Chugach NF (Forest 1004), volumes for 
                 white spruce, western redcedar, Pacific silver fir, mountain hemlock,
                 western hemlock, Alaska-cedar, lodgepole pine, Sitka spruce, subalpine
                 fir, red alder, black cottonwood, other hardwoods, and other softwoods
                 are affected for trees having diameters greater than or equal to 9.0
                 inches DBH and heights greater than or equal to 40 feet. In addition
                 Merch. board feet volumes are now available for red alder.

Files:
./ak/src/varvol.f - modified logic to call PROFILE except when using Demars or Curtis equations
                    and trees are less than 9.0 in DBH or less than 40 feet height. In these cases
                    the R10VOL module is called.
./an/src/varvol.f - modified logic to call PROFILE except when using Demars or Curtis equations
                    and trees are less than 9.0 in DBH or less than 40 feet height. In these cases
                    the R10VOL module is called.
./volume/src/fwinit.f