//---------------------------------------------------------------------
private double UpdateDeadBiomass(ICohort cohort, double actualANPP, double totalMortality, ActiveSite site, double newBiomass)
{
ISpecies species = cohort.Species;
double leafLongevity = SpeciesData.LeafLongevity[species];
double cohortBiomass = newBiomass; // Mortality is for the current year's biomass.
double leafFraction = ComputeFractionANPPleaf(species);
// First, deposit the a portion of the leaf mass directly onto the forest floor.
// In this way, the actual amount of leaf biomass is added for the year.
// In addition, add the equivalent portion of fine roots to the surface layer.
// 0.8 was used to calibrate the model to steady-state Nitrogen. Without this reduction, total N
// increases by 0.038% each year.
// Remove jan 2020 to more closely match code with the current Biomass succession model
//double annualLeafANPP = actualANPP * leafFraction * 0.8;
double annualLeafANPP = actualANPP * leafFraction;
// --------------------------------------------------------------------------------
// The next section allocates mortality from standing (wood and leaf) biomass, i.e.,
// biomass that has accrued from previous years' growth.
// Subtract annual leaf growth as that was taken care of above.
totalMortality -= annualLeafANPP;
// Assume that standing foliage is equal to this years annualLeafANPP * leaf longevity
// minus this years leaf ANPP. This assumes that actual ANPP has been relatively constant
// over the past 2 or 3 years (if coniferous).
double standing_nonwood = (annualLeafANPP * leafLongevity) - annualLeafANPP;
double standing_wood = Math.Max(0, cohortBiomass - standing_nonwood);
double fractionStandingNonwood = standing_nonwood / cohortBiomass;
// Assume that the remaining mortality is divided proportionally
// between the woody mass and non-woody mass (Niklaus & Enquist,
// 2002). Do not include current years growth.
double mortality_nonwood = Math.Max(0.0, totalMortality * fractionStandingNonwood);
double mortality_wood = Math.Max(0.0, totalMortality - mortality_nonwood);
if (mortality_wood < 0 || mortality_nonwood < 0)
{
throw new ApplicationException("Error: Woody input is < 0");
}
// Total mortality not including annual leaf litter
M_noLeafLitter = (int)mortality_wood;
SiteVars.soilClass[site].CollectBiomassMortality(species, cohort.Age, mortality_wood, (mortality_nonwood + annualLeafANPP), 0);
//add root biomass information - now calculated based on both woody and non-woody biomass
Roots.CalculateRootTurnover(site, species, cohortBiomass);
SiteVars.soilClass[site].CollectBiomassMortality(species, cohort.Age, Roots.CoarseRootTurnover, Roots.FineRootTurnover, 1);
//if biomass is going down, then we need to capture a decrease in the roots as well.
if (cohortBiomass < cohort.Biomass)
{
double preMortRoots = Roots.CalculateRootBiomass(site, species, cohort.Biomass);
double preMortCoarse = Roots.CoarseRoot;
double preMortFine = Roots.FineRoot;
double TotRoots = Roots.CalculateRootBiomass(site, species, cohortBiomass);
if (preMortRoots > TotRoots) //if the root biomass went down, then we need to allocate that difference.
{ //We will allocate the total root decline to the different pools based on the relative proportions
//prior to the decline. (Note that we are not calculating actual declines for each type because
//sometimes if we are changing calculation methods, we may change the allocation and may cause a large
//decrease in one pool and an increase in the other.)
double diffFine = (preMortFine / preMortRoots) * (preMortRoots - TotRoots);
double diffCoarse = (preMortRoots - TotRoots) - diffFine;
SiteVars.soilClass[site].CollectBiomassMortality(species, cohort.Age, diffCoarse, diffFine, 1);
//write a note to the file if the allocation changes unexpectedly, but not during spin-up
if (((preMortCoarse - Roots.CoarseRoot) < 0 || (preMortFine - Roots.FineRoot) < 0) && PlugIn.ModelCore.CurrentTime > 0)
{
string strCombo = "from: " + preMortCoarse;
strCombo += " to: " + Roots.CoarseRoot;
string strCombo2 = "from: " + preMortFine;
strCombo2 += " to: " + Roots.FineRoot;
PlugIn.ModelCore.UI.WriteLine("Root Dynamics: Overall root biomass declined but note change in coarse root allocation " + strCombo + " and fine root allocation" + strCombo2);
}
}
else if (PlugIn.ModelCore.CurrentTime > 0)
{
//write a note to the file if the root biomass increases while abio decreases, but not during spin-up
string strCombo = "from: " + cohort.Biomass;
strCombo += " to: " + cohortBiomass;
string strCombo2 = "from: " + preMortRoots;
strCombo2 += " to: " + TotRoots;
PlugIn.ModelCore.UI.WriteLine("Root Dynamics: Note that aboveground biomass decreased " + strCombo + " but root biomass increased " + strCombo2);
}
}
if (PlugIn.ModelCore.CurrentTime == 0)
{
SiteVars.soilClass[site].CollectBiomassMortality(species, cohort.Age, standing_wood, standing_nonwood, 3);
Roots.CalculateRootTurnover(site, species, (standing_wood + standing_nonwood));
SiteVars.soilClass[site].CollectBiomassMortality(species, cohort.Age, Roots.CoarseRootTurnover, Roots.FineRootTurnover, 4);
}
return(annualLeafANPP + mortality_nonwood + mortality_wood);
}