Table 1.
Values and units for model parameters.
| Variable | Value | Units | Interpretation (with reference if available) |
|---|---|---|---|
| t | 5000 | Day | Number of iterations |
| NE | 50 | Number of enzymes in community | |
| NS | 12 | Number of substrates | |
| NU | 14 | Number of uptake transporters | |
| NB | 100 | Number of taxa | |
| Ea | 35 | kJ mol−1 | Activation energy for uptake |
| EaK | 20 | kJ mol−1 | Activation energy for Km (German et al., 2012) |
| KmESlope | 10 | mg enzyme day cm−3 | Slope for Km – VE relationship |
| KmEInt | 0 | mg cm−3 | Intercept for enzyme Km – VE relationship |
| KmUSlope | 0.2 | mg biomass day cm−3 | Slope for Km – VU relationship |
| KmUInt | 0 | mg cm−3 | Intercept for uptake Km – VU relationship |
| VE | 100 | mg substrate mg−1 enzyme day−1 | Vmax for enzymes |
| VU | 5 | mg substrate mg−1 biomass day−1 | Vmax for uptake |
| λSlope | −0.8 | Fractional change in cellulose decay per unit lignocellulose index | |
| ES | 1 | Minimum number of enzymes capable of degrading each substrate | |
| UM | 1 | Minimum number of uptake transporters capable of taking up each monomer | |
| Emax | 40 | Maximum number of enzymes a taxon may produce | |
| θ | 1 | Coefficient determining strength of specificity-efficiency tradeoff | |
| ε0 | 0.5 | mg mg−1 | Intercept for C use efficiency function (Thiet et al., 2006) |
| mT | −0.016 | mg mg−1°C−1 | C use efficiency temperature sensitivity (Allison et al., 2010) |
| mE | −0.1, −0.2 | mg mg−1 | C use efficiency change with enzyme investment |
| mU | −0.1, −0.2 | mg mg−1 | C use efficiency change with uptake investment |
| ZEC | 5×10−5 | mg mg−1 | Per enzyme C cost as a fraction of uptake rate |
| βEC | 5×10−5 | mg mg−1 day−1 | Per enzyme C cost as a fraction of biomass |
| ZEN | 0.3 | mg mg−1 | Per enzyme N cost as a fraction of C cost (Sterner and Elser, 2002) |
| L | 0.1 | day−1 | Leaching rate |
| τE | 0.04 | day−1 | Enzyme turnover rate (Allison, 2006) |
| τB | 0.02 | day−1 | Bacterial turnover rate (Schimel and Weintraub, 2003) |
| τF | 0.01 | day−1 | Fungal turnover rate (Rousk and Bååth, 2007) |
| FMS | 0.045 | mg mg−1 | Initial monomer present as a fraction of initial substrate |
| DB | 0.1 | Initial bacterial cell density per lattice point | |
| DF | 0.004 | Initial fungal cell density per lattice point | |
| CB | 0.825 | mg mg−1 | Bacterial C fraction (Sterner and Elser, 2002) |
| NB | 0.160 | mg mg−1 | Bacterial N fraction (Sterner and Elser, 2002) |
| PB | 0.015 | mg mg−1 | Bacterial P fraction (Sterner and Elser, 2002) |
| CF | 0.900 | mg mg−1 | Fungal C fraction (Sterner and Elser, 2002) |
| NF | 0.090 | mg mg−1 | Fungal N fraction (Sterner and Elser, 2002) |
| PF | 0.010 | mg mg−1 | Fungal P fraction (Sterner and Elser, 2002) |
| Cl | 0.090 | mg mg−1 | Tolerance on C fraction |
| Nl | 0.040 | mg mg−1 | Tolerance on N fraction |
| Pl | 0.005 | mg mg−1 | Tolerance on P fraction |
| Cmin | 0.086 | mg cm−3 | Threshold C concentration for cell death |
| Nmin | 0.012 | mg cm−3 | Threshold N concentration for cell death |
| Pmin | 0.002 | mg cm−3 | Threshold P concentration for cell death |
| CBmax | 2 | mg cm−3 | C concentration threshold for bacterial reproduction |
| CFmax | 50 | mg cm−3 | C concentration threshold for fungal reproduction |
| FB | 0.5 | Initial biomass fraction of fungi | |
| ρy | 0.05 | Probability of fungi dispersing in y direction | |
| δ | 1 | lattice point | Maximum dispersal distance |
| T | 15, 20 | °C | Temperature |
| x | 100 | Lattice length | |
| y | 100 | Lattice width |