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List of Species Parameter

species parameter

Species parameter are defined for each species in the input database. The Name of the variables is the name of the columns in the database. The Short name is the abbreviation used on the wiki pages and iLand related papers. iLand uses a SQLite database for the species parameters. The parameters need to be provided in a table specified in the project file; each tree species occupies a row in that table. iLand loads all species that are in the table and are 'active' (see below).

NameShortDescriptionExample
General
shortName unique identifier for a speciespiab
name descriptive (longer) name of a speciesPicea Abies
displayColor color used for drawing trees. The color is defined as a 6-character hexadecimal color in the form 'rrggbb' (red, green, blue, without a # character).3E9C49
active flag that allows to disable a species. Disabled species are not loaded into iLand1=enabled, 0=disableld
LIPFile filename of the binary LIP (light influence pattern) file. See also Path, LightInfluencePatternpiab.bin
isConiferous 0 for broadleaved species, 1 for conifers1
isEvergreen 1 for wintergreen species0
Growth
specificLeafAreaSLAFactor to calculate LeafArea from Foliage Biomass (LA=FoliageMass*specificLeafArea)5
turnoverLeaf$\gamma_f$Senescence factor of foliage. The yearly senescence is Mass*turnover. See also allocation.0.2
turnoverRoot$\gamma_r$ senescence factor for fine roots. See also allocation.0.05
HDLowhdminexpression lower bound of height to diameter ratios (i.e., open-grown trees). typical HD-ratios: 50-150. See also stem growth.max(40,80-8*sqrt(d))
HDhighhdmaxexpression upper bound of height to diameter ratio (for trees under heavy competition for light). typical HD-ratios: 50-150. See also stem growth.max(80,120-12*sqrt(d))
woodDensityρdensity of the stemwood (kg/m3) (used for calculating the tree volume). See also stem growth.300
formFactorφtaper factor of the stem (-) (used for calculating the tree volume).See also stem growth.0.3
Biomass Compartments
bmWoody_akW1Parameter a of the allometric equation for stem wood biomass. 0.03
bmWoody_bkW2Parameter b of the allometric equation for stem wood biomass. 2.75
bmFoliage_akW3Parameter a of the allometric equation for foliage biomass.0.069
bmFoliage_bkW4Parameter b of the allometric equation for foliage biomass. 1.56
bmRoot_a Parameter a of the allometric equation for coarse root biomass. 0.004
bmRoot_b Parameter b of the allometric equation for coarse root biomass. 2.79
bmBranch_akW5Parameter a of the allometric equation for branch biomass.] 0.022
bmBranch_bkW6Parameter b of the allometric equation for branch biomass2.3
finerootFoliageRatioprto observe the functional balance of a tree, the size of the fine root pool is defined relative to the size of the foliage pool, i.e. fineRoots = poolsize foliage * finerootFoliageRatio.1
cnFoliageCNfolC/N ratio of foliage75
cnFinerootCNfrC/N ratio of fine roots40
cnWoodCNwC/N ratio of woody tissues (branches, stem, coarse roots)300
barkThickness factor to calculate thickness of the bark (cm): thickness = dbh * barkThickness (see wildfire ).0.065
Mortality
probIntrinsicpluckyprobability of a tree to survive "maximumAge" years. See base mortality. A value of 0.01 = 1%.0.01
probStressbsfactor b_s (see base mortality) that determines the probability of death based based on a stress index (use values >0).6
Aging
maximumAgeAmaxindicates a maximum age for a species. Note that trees can grow older than this value in the model - this parameter is only used to determine aging and mortality probability and is not a deterministic cutoff age. See base mortality and primary production600
maximumHeightHmaxindicates a maximum height for a species. Note that trees can grow taller than this value in the model - this parameter is only used to determine aging and mortality probability and is not a deterministic cutoff height. See base mortality and expression60
agingfa used to calculate the decline in production efficiency with "age" (pysiological and/ or based on max. height growth). See primary production1/(1+(x/0.9)^3)
Environmental Responses
lightResponseClasskSdetermines shade tolerance / efficiency to use low light levels, where 1=very light-demanding, and 5 is very shade tolerant. Floating point values are allowed. See the project file for the definition of the classes and the page on individual tree light availability.3.4
respVpdExponentkDexponent in the calculation of growth response to vapor pressure deficit (resp=exp(respVpdExponen*vpd)), see vapor pressure deficit response-0.5
respTempMinkT0Lower threshold temperature for tree growth. See temperature response-2
respTempMaxkT1 Optimum temperature for tree growth. See temperature response 17
respNitrogenClasskNNitrogen response class. Value must be >=1 and <=3. 3= highly nitrogen-demanding, 1= efficient with low available nitrogen. Response values are interpolated between classes (see project file for class definition and the page on nitrogen response).2.2
phenologyClass link to a phenology class. 0= evergreen coniferous, 1= deciduous broadleaved, 2= deciduous coniferous. See project file for details as well as the page on phenology.0
maxCanopyConductancegcmax maximum conductance of the canopy for water. Used in the calculation of transpiration (m/s)0.02
psiMin$\Psi_{min}$maximum soil water potential that a species can access (i.e. +/- a species' permanent wilting point), in MPa. See the page on soil water response-1.5
Seed production / dispersal
maturityYearsamatminimum age required for a trees to produce seeds (years)30
seedYearIntervalaseedInterval between seed years. Each year has a probability of 1/seedYearInterval that a year is a seed year. This is calculated once per species and year, and applies for the entire landscape (years).5
nonSeedYearFractionpnsyfraction of the seed production in non-seed-years.0.25
fecundity_m2 seedlings produced and surviving the first weeks per m² canopy cover (see also fecundity).100
seedKernel_as1kK1 dispersal kernel parameter, following Lischke et al. (2006), see dispersal.100
seedKernel_as2kK2 dispersal kernel parameter, following Lischke et al. (2006), see dispersal.0
seedKernel_ks0kK3 dispersal kernel parameter, following Lischke et al. (2006), see dispersal.0
serotinyFormula
serotinyFecundity
Establishment
estMinTempkEtminabsolute minimum temperature for seed survival (°C)-39
estChillRequirementkEchillnumber of required days since the end of the last vegetation period between -5°C and +5°C.56
estGDDMinkEGDDmin minimum threshold of growing degree days for seedling establishment (GDD must be >GDDMin and < GDDMax to allow establishment)177
estGDDMaxkEGDDmax maximum threshold of growing degree days for seedling establishment (GDD must be >GDDMin and < GDDMax to allow establishment)3261
estGDDBaseTempkEGDDbasebase temperature (°C) for GDD calculation. GDD is the running sum of (mean daily temp - GDDBaseTemp) for all days with mean temp > GDDBaseTemp.4.3
estBudBirstGDDkEGDDbbrequired GDD before bud burst. Calculation is similar to GDD described above, except that the counter is reset when mean daily temp is below 0°C255
estFrostFreeDayskEFFrequired number of days without frost (daily minimum temperature > 0°C) in the year65
estFrostTolerancekEFTfrost tolerance parameter for frost events after bud burst (kF in Eq.2 of establishment).0.5
estPsiMin$k\Psi_{r}$minimum soil water potential for establishment; establishment probability is reduced linearly between $k\Psi_{r}$ (p=0), and field capacity (p=1, no limitation). Null or 0 disables soil water limitation.0
Sapling growth
sapHeightGrowthPotential expression to calculate the maximum height of the sapling for the next timestep. see sapling growth and competition. The first variable is interpreted as "height" (m).40*(1-(1-(h/40)^(1/3))*exp(-0.1))^3
sapMaxStressYearskMra number of consecutive years a sapling can withstand stress. If stress exceeds this threshold, the sapling cohort dies.3
sapStressThresholdkMrs defines threshold for stress. If actual height increment / potential height increment is below sapStressThreshold, the sapling is stressed. The ratio equals therefore fenv,yr * flight0.1
sapHDSapling hdsap The dynamic variable in simulating sapling development is height growth. Saplings in iLand have a fixed height-diameter ratio, sapHDSapling, which is used to derive a diameter from sapling height80
sapReferenceRatio frefThe empirically parameterized sapling height growth model (see sapHeightGrowthPotential) uses the same physiological modifiers as calculated for adult trees in iLand. The ratio (fref) grants consistency between saplings and adult trees in iLand by specifying the physiological constraints for an optimal site (as specified in sapHeightGrowthPotential); This is used in calculation of fenv,yr.1
sapReinekesR SDIsapStem number of the regeneration cohorts are derived by means of an allometric relationship to diameter following Reinekes stem density index, with sapReinekesR being the maximum stem number for a dg of 25.4 cm. See sapling growth and competition1450.
sapSproutGrowth multiplier for accelerated height growth of resprouted tree cohorts in the regeneration layer. Resprouting is enabled, when the value of estSprouting is not empty and >0. See sprouts.
Snags and carbon dynamics
snagKSWkSWDsnag decomposition rate (10°C, optimal moisture content), (see snag dynamics ).0.015
snagHalfLifehlhalf life (years) used for calculation of transition probability from snag to downded woody debris as described in snag dynamics10
snagKYLklitterlitter decomposition rate (10°C, optimal moisture content), (for the labile soil pool)0.15
snagKYRkDWDdowned woody debris (dwd) decomposition rate (10°C, optimal moisture content), (for the refractory pool)0.0807
browsingProbability annual probability that saplings (up to 2m height) are browsed by game and ungulates. See browsing.0.1



Created by werner. Last Modification: Thursday 29 of June, 2017 11:59:39 CEST by werner.