(1) COMPUTE TREE CHARACTERS; 

 PHLOEM THICKNESS PO(I) 

 SURFACE AREA ^ 6 INCHES DOB - SURF(I) - f, (TOTAL VOLUME. SURFACE. LENGTH) 

 ATTACK PROBABILITY ATPU) - f, (TREES/ ACRE. ELEVATION. PCTILE) 

 BARK THICKNESS BT(I) - (DBH. HT) 

 ATTACK DENSITY OTD(I) - 1^ (BARK THICKNESS) 



START OF ANNUAL LOOP 



NO 



(3) COMPUTE INITIAL POPULATION EMERGING 

 FROM TREE f OUND AT (21 (STP) 



(4) COMPUTE POTENTIAL FOR STAND TO ABSORB BEETLES - POP • Z (ATTACK PROBABILITY) 

 •(ATTACK L/cuoi 1 r iMSunrMuc MncMClNUMbtM (JF TREES) 



(5) SCALE ATTACK PROBABILITY TO USE ALL AVAILABLE BEETLES 

 ATP(I) - ATP(l)«STP/POP 



(6) ACCUMULATE BEETLE-KILLED TREES. WK(I) - (TREES/ACRE)«ATP(1) 

 REDUCE TREES/ACRE BY WK(I) 



(7) COMPUTE NUMBER OF EMERGING FEMALES PER SO. FT EMEH - (PHLOEM DEPTH. 

 SEX RATIO. ATTACK DENSITY. ELEVATION) 



(8) ACCUMULATE TOTAL NUMBER OF FEMALES: STP - S EMER.SURF(I).WK(I) 



NO 



(10) REDUCE POPULATION FOR FLIGHT MORTALITY 



(13) COMPUTE NORMAL MORTALITY RATE FOR ALL 

 TREE RECORDS USING REDUCED STAND PARAMETERS 



RETURN TO STAND PROGNOSIS MODEL 



Figure 3. — Logic ftcn} of subroutine for mountain pine beetle inrpaat. 



18 



