INCA Users' Guide:
The INventory to CACTOS Conversion Program

by Walter J. Meerschaert, Ralph J. Warbington, and Lee C. Wensel
Abstract

INCA is designed to produce stand description files for the CACTOS 
system using data collected in the U.S.F.S. Region 5 inventories.  The 
program runs on PC-compatible micro-computers and the Forest Service 
Data General series mini-computers.  The necessary coefficients and 
conversion factors are provided, though they may change with experience.




	INCA is an interface between the standard USFS Region 5 
inventory analysis system and the CACTOS system (Wensel, et. al., 1986). 
The function of INCA is to reformat the inventory data, estimate the 
average CACTOS site index, and construct the necessary tree records to 
form CACTOS stand description files.   Site index is averaged over 
either cluster plots or stands, as selected by the user at runtime.  Tree 
records are processed  the same way regardless of the method of site 
index averaging.  More detail on the processing of site index and tree 
records follows.

	The sequential process for producing CACTOS stand description 
files from standard USFS Region 5 inventory files is illustrated in 
Figure 1.  Field data recorded on inventory form R5-2400-207 (see 
appendix) is run through either FIA-EDIT (in development), or CONVERT 
(step 5) in order to validate and sort the data.  The output files are 
then run through INCA to produce data files suitable for running through 
STAG, the STAnd Generator for CACTOS (Biging and Meerschaert, 1987). STAG 
will fill in any missing data and produce stand  description files suitable 
for running through CACTOS.


Site index
CACTOS requires a separate site index for each species in the stand, to 
account for different productivity levels (Biging and Wensel, 1987).  INCA 
determines site index for each species from either (1) the average 
calculated site index of site trees (trees less than 100 years old with 
crown ratios greater than 0.30 for dominant trees and greater than 0.40 for 
codominant trees) for that species; (2) referenced from the calculated 
average site index of one or more of the 5 major species (ponderosa pine, 
Jeffery pine, white fir, red fir, and Douglas-fir) using the adjustment 
factors in Table 1; or (3) referenced from R5 site class default CACTOS site 
given below.
	
Table 1.  Species adjustment factors for site index conversions.

CACTOS SPECIES CODE	ADJUSTMENT FACTOR
		1	Ponderosa Pine		1.00
		2	Sugar Pine1		0.90
		3	Incense Cedar2		0.76
		4	Douglas-fir		1.00
		5	White Fir		1.00
		6	Red Fir			1.00
		7	Lodgepole Pine2		0.82
		8	Western White Pine2	0.90
		9	Jeffery Pine		1.00
		10	Misc. Conifers		1.00
		11	Chinquapin3		0.54
		12	Black Oak4		0.57
		13	Tan Oak5		0.54
		14	Other Hardwoods6	0.52
________________________________________________
1	Dunning and Reineke,1933
2	Calculated from California National Forest inventory data
3	Assumed to be the same as Tanoak
4	Powers, 1972
5	MacDonald, 1983
6	Madrone factor from MacDonald, 1983

	The R5 site classes are given in The R-5 Timber Management Plan 
Inventory Handbook (R-5 FSH 2409.21b).   The conversion between the R5 site 
classes and the CACTOS site indicies is based upon ages (adjusted to breast 
height) and total heights found in the Inventory Handbook.  These conversions 
are shown in Table 2.

Table 2.  Site Index Conversion Table

	R5 site class	CACTOS site index
		0		          110
		1		           95
		2		           80
		3		           60
		4		           50
		5		           40


	There are two alternate methods by which INCA process the site index 
data: by cluster plot within a stratum or by stand.  The cluster plot option 
summarizes the site information for all site trees of each species and computes 
the average for each cluster plot.  The stand option does the same for each 
stand.  The format for the input data is the same for the two methods as shown 
in TableÊ3.  

Table 3.  INCA input data format.

COLUMNS	FORMAT	DATA IN COLUMNS
1	A1	Tree ID
19	I1	Site Class
23-26	A4	Stratum
33-34	I2	ElevationÖ100
35-38	I4	Stand Number
39-41	I3	Plot Number
42-43	I2	Point Number
46-50	F5.0	Basal Area Factor/Plot Size Class
51-52	I2	R5 Species Code
53-54	I2	DBH GROUP
55	A1	Crown Position
56	I1	Crown Ratio PercentÖ10
64-67	F4.1	DBH (inches)
68-70	F3.0	Height (feet)
71-73	F3.0	Total  Age

	The user has the option of manually checking the results of the site 
averaging process.  If this option is chosen, INCA will print out the species 
codes and their calculated site indices, along with a one letter code 
corresponding to how the site was determined ("c" if calculated average of 
that species site trees, "a" if referenced from average of major species site 
trees, "d" if referenced from R5 default CACTOS site class, or "u" if given 
by the user).   The user can then change any of the site indicies that seem 
unreasonable.  The program will also prompt the user for the elevation of the 
plot or stand if it is missing, the elevation being required in STAG.

	Tree records
	INCA processes individual tree records from the input file the same way 
regardless of the method of site index averaging.  Individual tree dimensions 
of diameter, height, and crown ratio are either used directly or converted from 
the class data, if available.  

	Species codes are converted directly from the R5 species codes as 
shown in Table 4.  Diameters for individual trees are used directly, if 
avaliable, or are obtained for the DBH group using the midpoint DBH shown in 
Table 5.  

	Total height is only placed in the output if it was available in the 
input file; if missing, a zero is placed in that field.  STAG will fill in 
any missing total heights.  Crown ratio is always present in R5 inventory data 
so it is used directly. 


Table 4.  R5 to CACTOS species code conversions.

		USFS Region 5		CACTOS

	Code	Species	Code	 	Species
  	1	Douglas-fir	  	4	Douglas-fir
  	2	Bigcone Douglas-fir	10	Misc. Conifer
  	5	Redwood			10	Misc. Conifer
 	 6	Giant Sequoia		10	Misc. Conifer
	11	Ponderosa Pine	 	1	Ponderosa Pine
	12	Jeffery Pine		9	Jeffery Pine
	13	Sugar Pine		2	Sugar Pine
	14	W.White Pine		8	White Pine
	15	Lodgepole Pine	 	7	Lodgepole Pine
	21	Coulter Pine		10	Misc. Conifer
	23	Digger Pine		10	Misc. Conifer
	24	Knobcone Pine		10	Misc. Conifer
	25	Bishop Pine		10	Misc. Conifer
	26	Whitebark Pine		10	Misc. Conifer
	27	Singleleaf Pinyon Pine	10	Misc. Conifer
	21	White Fir	  	5	White Fir
	32	Red Fir	  		6	Red Fir
	33	Grand Fir		10	Misc. Conifer
	46	Brewer Spruce		10	Misc. Conifer
	47	Mountain Hemlock	10	Misc. Conifer
	48	Western Hemlock		10	Misc. Conifer
	51	Incense Cedar	  	3	Incense Cedar
	53	Port-Orford-cedar	10	Misc. Conifer
	54	Western Redcedar	10	Misc. Conifer
	61	California-nutmeg	10	Misc. Conifer
	62	Pacific Yew		10	Misc. Conifer
	63	Western Juniper		10	Misc. Conifer
	64	Cypress			10	Misc. Conifer
	71	Red Alder		14	Misc. Hardwood
	72	Ash			14	Misc. Hardwood
	73	Aspen			14	Misc. Hardwood
	75	Black Cottonwood	14	Misc. Hardwood
	76	Bigleaf Maple		14	Misc. Hardwood
	81	California Black Oak	12	Black Oak
	82-86, 88Other Oak		14	Misc. Hardwood
	87	Tanoak			13	Tan Oak
	91	California Laurel	14	Misc. Hardwood
	93	Giant Chinquapin	11	Chinquapin
	94-96,98Other Hardwoods		14	Misc. Hardwood


	Table 5. Midpoint DBH's from R5 DBH group
		
		DBH group	  Midpoint DBH
		   	2		4.2
			8		8.8
			14		14.9
			21		21.2
			27		27.1
	    		35		35.2
			40		45.0

  
	The tree expansion factor (number of trees per acre) is calculated as 
follows: 
		Plot type            	Expansion factor              
		fixed area	43,560 Ö plot size
		variable radius 	BAF Ö basal area of tree
where BAF is the Basal Area Factor of the prism.  (Note: seedling tree records 
are ignored in INCA)  Species codes are converted from Region 5 codes to 
CACTOS codes as shown in Table 2. 


	The requirements given for selecting a tree to apply Dunning's site 
index classification system are as follwos:	
(1)	Tree position must be predominant or dominant and have grown freely 
        all of it's life.
(2)	The tree must be at least 50 years old.
(3)	Tree species must be either Douglas-fir; white or red fir; or 
        ponderosa, Jeffrey, or sugar pine
(4)	The tree must be of a suitable form class so that it is representative.
        (For example, a rough cull does not qualify as a site tree.)
(5)	The tree must have its orignial top.
Tree heights by age are show in table 6 for each of the R5 site classes.

	Organization of the Output
	There are two options for organization of the output, by stratum or 
by stand.  The output from INCA will be in as many different CACTOS stand 
description files as there are distinct strata or stands in the input data.  
These files will be named using the identifier from the input file (stratum 
label or stand number) followd by the ending ".sd" (for "stand description").
        INCA will also produce the CACTOS batch mode filename files that are 
necessary to run multiple stands through  CACTOS.  Operation of INCA is 
illustrated in the annotated sample runstream in the Appendix.