Table 4 3-PGmix parameter descriptions, their names, symbols, units, values, and sources: Default (D) values from the 3-PGmix model/modelled values Fitted (F) to observed data/Literature (L) related to teak from Indian conditions/Observed (O) data from the field used in this study
Parameter’s description | Name | Symbol | Unit | Value | Source |
|---|---|---|---|---|---|
Biomass partitioning and turnover | |||||
Foliage: stem partitioning ratio (DBH = 2 cm) | pFS2 | p2 | - | 0.33 | F |
Foliage: stem partitioning ratio (DBH = 20 cm) | pFS20 | P20 | - | 0.12 | F |
Constant in the stem biomass and DBH relationship | aWS | \({a}_{S}\) | - | 0.13 | F |
Power in the stem biomass and DBH relationship | nWS | \({n}_{S}\) | - | 2.01 | F |
Maximum fraction of NPP to root | pRx | \({\eta }_{Rx}\) | - | 0.6 | F |
Minimum fraction of NPP to roots | pRn | \({\eta }_{Rn}\) | - | 0.2 | F |
Litterfall and root turnover | |||||
Maximum litterfall rate | gammaF1 | γFx | mn−1 | 0.03 | D |
Litterfall rate when age = 0 | gammaF0 | γF0 | mn−1 | 0.001 | D |
Age at which litterfall rate has a median value | tgammaF | tγF | months | 12 | D |
Average monthly root turnover rate | gammaR | γR | mn−1 | 0.015 | D |
If deciduous, leaves are produced at end of this month | leafgrow | leafP | month | 4 | O |
If deciduous, leaves all fall at start of this month | leaffall | leafL | month | 11 | O |
Temperature modifier \(\left({f}_{T}\right)\) | |||||
Parameter’s description | Name | Symbol | Unit | Value | Source |
Minimum temperature, optimum, and maximum temperature | Tmin, Topt, Tmax | \({T}_{\mathrm{min}}\), \({T}_{\mathrm{opt},}\) \({T}_{\mathrm{max}}\) | ˚C | 13, 25, 43 | Pandey and Brown (2000) |
Frost modifier \(\left({f}_{\mathrm{frost}}\right)\) | |||||
Days production lost per frost day | kF | \({k}_{F}\) | days | 0 | O |
Soil water modifier \(\left({f}_{\mathrm{ASW}}\right)\) | |||||
Moisture ratio deficit for soil water content = 50% | SWconst | \({c}_{\theta }\) | - | 0.5 | D |
Power of moisture ratio deficit | SWpower | \({n}_{\theta }\) | - | 5 | D |
Atmospheric CO2 modifier | |||||
Assimilation enhancement factor at 700 ppm | fCalpha700 | fCα700 | - | 1.4 | D |
Canopy conductance enhancement factor at 700 ppm | fCg700 | fCg700 | - | 0.3 | D |
Fertility effects (fN) | |||||
Value of m when FR = 0 | m0 | m0 | - | 0.01 | D |
Value of fN when FR = 0 | fN0 | fN0 | - | 0.6 | F |
Power of (1-FR) in fN | fNn | \({n}_{fN}\) | - | 0.6 | F |
Age modifier (fage) | |||||
Maximum stand age used in age modifier | MaxAge | tx | yrs | 120 | Gangopadhyay (2005) |
Power of relative age in function for fage | nAge | \({n}_{\mathrm{age}}\) | - | 4 | D |
Relative age to give fage = 0.5 | rAge | \({r}_{\mathrm{age}}\) | - | 0.95 | D |
Stem mortality and self-thinning | |||||
The mortality rate for large age | gammaN1 | γN1 | yr−1 | 0.005 | Behera et al. (2019) |
Seedling mortality rate at age = 0 | gammaN0 | γN0 | yr−1 | 0 | D |
Age at which mortality rate has a median value | tgammaN | \({t}_{\gamma N}\) | yrs | 2 | D |
Shape of mortality response | ngammaN | \({n}_{\gamma N}\) | - | 1 | D |
Max. Stem mass per tree at 1000 trees ha−1 | wSx1000 | \({w}_{Sx1000}\) | kg trees−1 | 300 | D |
Power in self-thinning rule | thinPower | \({n}_{N}\) | - | 1.5 | D |
The fraction of mean single-tree for foliage, root, and stem biomass lost per dead tree | mF, mR, mS | \({m}_{F,} {m}_{R},\) ms | - | 0.01, 0.1, 0.04 | D |
Specific leaf area | |||||
Specific leaf area at age 0 | SLA0 | σ0 | m2kg−1 | 10.68 | Mehta et al. (2012) |
Specific leaf area for mature leaves | SLA1 | σ1 | m2kg−1 | 22.7 | Gopalakrishnan et al. (2011) |
Age at which specific leaf area = (σ0 + σ1)/2 | tSLA | \({t}_{\sigma }\) | yrs | 3 | D |
Light interception | |||||
Extinction coefficient for absorption of PAR | k | \(k\) | - | 0.47 | D |
Age at canopy cover | fullCanAge | \({t}_{c}\) | yrs | 10 | F |
Canopy quantum efficiency | alphaCx | \({\alpha }_{Cx}\) | molC/molPAR | 0.055 | D |
Rainfall interception | |||||
Maximum proportion of rainfall intercepted | MaxIntcptn | \({i}_{Rx}\) | - | 0.15 | D |
LAI for maximum rainfall interception | LAImaxIntcptn | \({L}_{ix}\) | m2m−2 | 3.79 | Behera et al. (2017) |
LAI for 50% reduction of VPD in canopy | cVPD | \({L}_{50D}\) | - | 5 | D |
Production and respiration | |||||
Ratio NPP/GPP | Y | \(Y\) | ̵ | 0.47 | D |
Conductance | |||||
Parameter’s description | Name | Symbol | Unit | Value | Source |
Minimum canopy conductance | MinCond | gSx | ms−1 | 0.013 | D |
Maximum canopy conductance | MaxCond | \({g}_{Cx}\) | ms−1 | 0.08 | F |
LAI for maximum canopy conductance | LAIgcx | \({L}_{Cx}\) | m2m−2 | 3.33 | D |
Defines stomatal response to VPD | CoeffCond | kD | MBar−1 | 0.04 | D |
Canopy boundary layer conductance | BLcond | \({g}_{B}\) | ms−1 | 0.01 | Behera et al. (2019) |
Branch and bark fraction \(\left({p}_{\mathrm{BB}}\right)\) | |||||
Branch and bark fraction at age = 0 | fracBB0 | \({p}_{\mathrm{BB}0}\) | - | 0.75 | Pontes (2011) |
Branch and bark fraction for mature stands | fracBB1 | \({p}_{\mathrm{BB}1}\) | - | 0.15 | Pontes (2011) |
Age at which \({p}_{\mathrm{BB}}\) = (\({p}_{\mathrm{BB}0}\) +\({p}_{\mathrm{BB}1}\))/2 | tBB | \({t}_{\mathrm{BB}}\) | yrs | 2 | Pontes (2011) |
Minimum basic density for young trees | rhoMin | \({\rho }_{0}\) | tm−3 | 0.45 | D |
Maximum basic density for older trees | rhoMax | \({\rho }_{1}\) | tm−3 | 0.45 | Pontes (2011) |
Age at which ρ = ½ density of old and young trees | tRho | \({t}_{\rho }\) | yrs | 4 | D |
Stem height | |||||
Constant in stem height relationship | aH | \({a}_{H}\) | - | 0.4501 | F |
Power of DBH in the stem height relationship | nHB | \({n}_{HB}\) | - | 1.0892 | F |
Power of stocking in the stem height relationship | nHC | \({n}_{HN}\) | - | 0.002 | F |