On the Ecology of Mountainous Forests in a Changing Climate: A ...

230 Appendix
uLitt[roots] := littR*conv; littR := 0.0;
END LitterInitialization;
(**********************************)
(* Procedure TreeDeathAndGrowth *)
(**********************************)
PROCEDURE TreeDeathAndGrowth( VAR firstSp: SpeciesPtr; VAR cumLA: ARRAY OF REAL;
gLAI: REAL );
VAR sp: SpeciesPtr;
cohort, prevCohort: CohortPtr;
gAL, gL1, gL9, slope, DIncMax, gF: REAL;
iHT, i, cohortTrees: INTEGER;
PROCEDURE CalculateLitterProduction( VAR sp: SpeciesPtr; VAR c: CohortPtr;
nDead: REAL );
(* calculates litter production of a tree cohort, including litter production
if nTrees have died *)
CONST
pi4 = 3.141593/4.0;
VAR
nAlive: REAL;
BEGIN
nAlive := FLOAT( c^.nrTrees );
(* normal annual litter production from living trees: *)
(* foliage litter depends on foliage quality and foliage retention time *)
littF[sp^.p.kLQ] := littF[sp^.p.kLQ] + c^.gFolW * nAlive/ kFRT[sp^.specType]*kAFW;
(* twig litter is calculated from basal area according to Christensen (1977) *)
littT := littT + pi4 * c^.D * c^.D * kTwig * nAlive * kAFW;
(* root litter is calculated from foliage litter *)
littR := littR + kRSR * c^.gFolW * nAlive/kFRT[sp^.specType] * kAFW;
(* litter from the n dead trees *)
IF nDead > 0.0 THEN
(* foliage litter *)
littF[sp^.p.kLQ] := littF[sp^.p.kLQ] + c^.gFolW*nDead*kAFW;
(* twig litter *)
littT := littT + pi4 * c^.D * c^.D * kTwig * nDead * kAFW;
(* root litter *)
littR := littR + kRSR * c^.gFolW * nDead * kAFW;
(* woody litter *)
littW := littW + c^.gSBio * nDead * kAFW;
END;
END CalculateLitterProduction;
BEGIN
sp := firstSp;
WHILE sp NIL DO
WITH sp^ DO
prevCohort := NIL;
cohort := sp^.firstCohort;
WHILE cohort NIL DO
WITH cohort^ DO
cohortTrees := nrTrees;
FOR i:= 1 TO cohortTrees DO (* mortality according to Shugart (1984) *)
IF ( U() = kSlowGrYrs) AND (U()