| Parameter | Description | Units | Valid Values | Default Values | ||||||||||||||||||||||||||||||||||||||||||||||||||||
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| BASFC2 | (savanna only) A tree basal area factor used to calculate N availability for the grass/crop system. Increases (< 1.0) or decreases (> 1.0) the amount of N available to grasses relative to the size of the tree and SITPOT and mineral N amount. If not simulating a savanna, set to 1.0. | fractional factor | 0.1-2.0 | 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| BASFCT |
(savanna only) A constant used to calculate the tree basal area; it is equal
to (form factor * wood density * tree height). As used in the model, BASFCT = above ground wood biomass / basal area |
1 - 500 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| BTOLAI |
Biomass to leaf area index (LAI) conversion factor for trees. This is a biome-specific
parameter. Values used by CENTURY include:
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| CERFOR(1,1,E) | Minimum C/(N, P, S) ratio for leaves, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 200.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(1,2,E) | Minimum C/(N, P, S) ratio for fine roots, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 200.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(1,3,E) | Minimum C/(N, P, S) ratio for fine branches, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1000.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(1,4,E) | Minimum C/(N, P, S) ratio for large wood, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1500.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(1,5,E) | Minimum C/(N, P, S) ratio for coarse roots, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1500.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(2,1,E) | Maximum C/(N, P, S) ratio for leaves, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 200.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(2,2,E) | Maximum C/(N, P, S) ratio for fine roots, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 200.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(2,3,E) | Maximum C/(N, P, S) ratio for fine branches, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1000.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(2,4,E) | Maximum C/(N, P, S) ratio for large wood, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1500.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(2,5,E) | Maximum C/(N, P, S) ratio for coarse roots, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1500.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(3,1,E) | Initial C/(N, P, S) ratio for leaves, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 200.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(3,2,E) | Initial C/(N, P, S) ratio for fine roots, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 200.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(3,3,E) | Initial C/(N, P, S) ratio for fine branches, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1000.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(3,4,E) | Initial C/(N, P, S) ratio for large wood, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1500.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CERFOR(3,5,E) | Initial C/(N, P, S) ratio for coarse roots, where E = 1 for N, 2 for P, 3 for S. | 1.0 to 1500.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CO2ICE(2,1,E) | The effect on minimum C/(N, P, S) ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm, where E = 1 for N, 2 for P, 3 for S. A value of 1 will have no effect. A reduction will have a negative effect, and an increase will have a positive effect. | 0.5 to 1.5 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CO2ICE(2,2,E) | The effect on maximum C/(N, P, S)ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm, where E = 1 for N, 2 for P, 3 for S. A value of 1 will have no effect. A reduction will have a negative effect, and an increase will have a positive effect. | 0.5 to 1.5 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CO2IPR(2) | The effect on plant production of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect. | 0.5 to 1.5 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CO2IRS(2) | The effect on root-shoot ratio of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect. | 0.5 to 1.5 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| CO2ITR(2) | The effect on transpiration rate of doubling the atmospheric CO2 concentration from 350 ppm to 700 ppm. A value of 1 will have no effect. A reduction will have a negative effect. And an increase will have a positive effect. | 0.5 to 1.5 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DECID |
Flag for type of forest: 0 = continuous evergreen 1 = temperate deciduous 2 = drought-deciduous |
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| DECW1 | Decomposition rate for dead fine branch per year. | 0.0 to 5.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DECW2 | Decomposition rate for dead large wood per year. | 0.0 to 5.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DECW3 | Decomposition rate for dead coarse root per year. | 0.0 to 5.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| DEL13C | Delta 13C value for stable isotope labeling. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| FCFRAC(P,1) | C allocation fraction of new tree pools for juvenile forest. P = tree component index; P is tree part -- 1 = leaves, 2 = fine roots, 3 = fine branches, 4 = large wood, 5 = coarse roots. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| FCFRAC(P,2) | C allocation fraction of old tree pools for mature forest. P = tree component index; P is tree part -- 1 = leaves, 2 = fine roots, 3 = fine branches, 4 = large wood, 5 = coarse roots. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| FORRTF(E) | Fraction of (N, P, S) retranslocated from green forest leaves at death where E = 1 for N, 2 for P, 3 for S. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| FRFRAC(1:2) | DayCent5 only: Minimum (1) and maximum (2) possible allocation fraction to fine roots. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| KLAI | Large wood mass (g C m-2) at which half of the theoretical maximum leaf area ( MAXLAI) is achieved. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| KMRSP(2) | DayCent5 only: Fraction of production that goes to maintenance respiration storage. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| KMRSPMX(P) | DayCent5 only: Maximum live C fraction that goes to maintenance respiration storage; P is the tree part: 1 = leaves, 2 = fine roots, 3 = fine branches, 4 = large wood, 5 = coarse roots. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| LAITOP | Parameter determining relationship between LAI and forest production. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| LEAFDR(1..12) | Monthly death rate fraction for leaves for months 1 through 12. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MAXLAI | Theoretical maximum leaf area index achieved in mature forest. | 0.0 to 50.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| MAXLDR | Multiplier for effect of N availability on leaf death rates (continuously growing forest systems only); a ratio between death rate at unlimited vs. severely limited N status. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| NO3PREF | DayCent5 only: Fraction of N update that is NO3. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| PPDF(P) |
Parameterization of a Poisson Density Function curve to simulate temperature
effect on growth. P = index for parameter: 1 = Optimum temperature for production - the peak of the curve. 2 = Maximum temperature for production; larger values = broader bell shape, and production is less sensitive to soil temperature. 3 = Spread of the bell curve; smaller values = broader bell shape, and production is less sensitive to soil temperature. 4 = Left curve shape; smaller values = more production at lower temperatures. See the figure "Graphs_PPDF" to visualize the effects of these parameters. |
1: 10.0 to 40.0 2: 20.0 to 50.0 3: 0.5 to 5.0 4: 1.0 to 5.0 |
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| PRDX(2) | Gross monthly forest biomass potential production. To disable this value and use PRDX(3) instead, set this value to be very large (e.g, 10000). | g biomass m-2 month-1 | 0.0 to 9999.0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| PRDX(3) | Maximum monthly forest potential production excluding respiration, expressed as organic C. To disable this value and use PRDX(2) instead, set this value to be very large (e.g, 10000). | g C m-2 month-1 | 0.0 to 9999.0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||
| SAPK | Controls the ratio of sapwood to total stem wood, expressed as g C m-2; it is equal to both the large wood mass (RLWODC) at which half of large wood is sapwood, and the theoretical maximum sapwood mass achieved in mature forest. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
| SITPOT | (savanna only) Site potential for the N fraction to grass. A measure of the aboveground herbaceous layer production (kg ha-1 year-1) in the absence of trees. (SITPOT = 2400 * monthly N availability in g N m-2 year-1). A higher value results in more N given to grass production. | 1200.0 to 9600.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| SNFXMX(2) | Symbiotic N fixation maximum for forest in grams of nitrogen fixed per gram of carbon of new growth (g N fixed/g C new growth). | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| SWOLD | Year at which to switch from juvenile to mature forest carbon allocation fractions for tree production. | simulation year range | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| WDLIG(P) | Lignin fraction for production of tree components. P = tree component index; 1 = leaves, 2 = fine roots, 3 = fine branches, 4 = large wood, 5 = coarse roots. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| WOODDR(1) | Controls the proportion of leaves that drop during senescence month or at the end of the growing season when DECID = 1 or 2. This is especially useful for drought-deciduous systems where only a portion of the leaves drop. Also useful when you are attempting to simulate a deciduous/coniferous mixed system of forest. | 0.0 to 1.0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
| WOODDR(P) | Monthly death rate fraction for tree component. P = tree component index; 1 = leaves, 2 = fine roots, 3 = fine branches, 4 = large wood, 5 = coarse roots. | 0.0 to 1.0 |
