ControlTable Production Model

The production model control table contains settings that affect forest development, such as tree growth and mortality.

Growth and yield

Growth model settings

Growth Model Whole-Stand

None implies that no basal area development, as the sum for all trees at the plot-level, will be used in growth calculations.

Elfving2009: the model by Elfving (2009) will be used in calculation of basal area development at the plot-level (the prediction unit).

Growth Model Individual-Tree

Elfving: the single tree model by Elfving (2004) will be used in calculation of each trees' diameter development at the plot-level (the prediction unit).

Soderberg: implies that the model by Söderberg (1986) will be used in calculation of each trees' diameter development at the plot-level (the prediction unit).

Low Production Nyström: implies that the model by Nyström will be used in calculation of each trees' diameter development at the plot-level (the prediction unit). Intended for use on non-productive forest land only.

BIOMASS

BARK

Growth: Include Thinning Response

True if thinning response function should be applied, false otherwise. Only applied to even-aged stands.

Growth and Mortality Adjustment Factors

Adjustment factors for basal area and height growth, as well as mortality, in established forest. Default = 1, i.e. no adjustment. From version 2.21, factors are set per period and species' group. If data entry for a period is missing, closest previous period's value will be used. If data entry for a species is missing the user specified default value is used. Should normally not be changed, intended for research purposes.

Volume Function

Selected volume function.

Height Development Model

ErikssonElfving implies that the model by Eriksson and Elving will be used in calculation of height development.

SoderbergWithTreeAge implies that the model by Söderberg including single tree ages will be used in calculation of height development.

SoderbergWithStandAge implies that the model by Söderberg including average stand ages will be used in calculation of height development.

Low Production Nyström: implies that the model by Nyström will be used in calculation of height development. Intended for use on non-productive forest land only.

Height: Initial Height Function

SoderbergWithTreeAge implies that the model by Söderberg including single tree ages will be used in calculation of initial tree heights.

SoderbergWithStandAge implies that the model by Söderberg including average stand ages will be used in calculation of initial tree heights.

Height:Initial Height Source

UseFunction implies that the model selected in InitialHeightModel (above) will be used.

FromDatabase implies that initial tree heights will be obtained from the input database.

Height Calibration

True means that tree heights will be calibrated, False do not. Calibration factors are calculated using sample tree data.

Mortality Implementation

Deterministic will apply deterministic components in the mortality model (recommended).

Stochastic will apply stochastic components in the mortality model

Mortality Model

Selected mortality model. Default value for parameter "Calibrate Bengtsson" will depend on what mortality model is selected.

Mortality Factor Established Forest

Adjustment factor for mortailty in established forest (mean height > about 7 m). Default = 1, i.e. no adjustment.

Calibrate Bengtsson

Set to True if mortality rates according to Göte Bengtsson should be applied (for small basal areas), independent of selected Mortality Model. This means the mortality model is only responible for distributing mortality over trees.

Calibrate Söderberg

Set to True if the self thinning limit (for large basal areas) according to Söderberg (1986) should be applied. This means the mortality model is only responible for distributing mortality over trees.

Mortality for Retained Trees 1-5

Mortality rate for retained trees during the first 5-year period, defined per each species group.

Mortality for Retained Trees 6-10

Mortality rate for retained trees during the second 5-year period, defined per each species group.

Adjust Mortality for Retention Patches

Set to FixedMortality to let mortality in a retention patch depend (i.e. increase) if and when the main stand is clear cut. If FixedMortality is selected, mortality is set in Mortality in Retention Patches. These parameters are hidden if NoAdjustment is chosen, meaning that the mortality is not affected by a clear cut of the main stand.

Note! To have effect, parameter Retention Patches as Dependent must be set to true in the Nature Conservation control table.

Mortality in Retention Patches year 1-5 and 6-10

These parameters has the same functionality as Mortality for Retention Trees, but applies to all trees in retentions patches and edge zones if Adjust Mortality for Retention Patches = Fixed Mortality.

Site Index Adjustment

Adjustment factor for site index. Default value = 1. Intended for research purposes.

Height Threshold Young/Mature

Defines the arithmetic mean tree height at which a "sapling" stand is considered a "mature" "tree" plot. Calculated for each plot. When at least 90% (?) of the plots are no longer sapling plots, then the stand is classified as a mature stand and not young.

Age settings

Allows you to control how different types of ages, at tree-level, should be handled in the simulations.

Year to Breast Height Model

Elfving implies that the model by Elfving will be used in calculation of the age of a tree when it reach breast height (1.3 m).

Tax implies that the model from the Swedish NFI will be used in calculation of the age of a tree when it reach breast height (1.3 m).

Calibrate Age To Register Value, Established Stands

True implies that tree ages will be calibrated so that the mean age will be as close as possible to the mean age according to the input data. False do not. Calibration is not applied if the mean age according to Heureka differs by more than 30 % to the input data.

Calibrate Age To Register Value, Young Stands

True implies that sapling ages will be calibrated. True if computed mean age of main saplings in young stands should equal the mean age according to the input data.

Initial Age Source

UseFunction: The built-in function will be used to assign initial ages.

FromDatabase If the database contains tree ages, these will be used as intial tree ages.

Regeneration

Allows you to control how the forest regeneration, the establishment of new trees, should be handled in the simulations.

Deterministic Simulation

If True, a deterministic approach will be applied when simulating establishment of new stands (stem density and height distribution), and when simulating mortality and damages in young stands. This mean that the results will reflect an "average" regeneration, and for example mortality probabilities will be handled as frequencies, by adjusting the tree weight factors for the tree objects. If False, a stochastic approach will be applied. The default is determinstic.

Ingrowth Model

Deterministic applies deterministic ingrowth model components, where ingrowth is defined as the establishment of other seedlings than those planted.

Stochastic applies stochastic ingrowth model components, where ingrowth is defined as the establishment of other seedlings than those planted.

None applies no ingrowth/establishment of other seedlings than those planted.

Min Mean Age Invoke Ingrowth

Minimum mean age before invoking ingrowth function. When a young stand enters the established phase, part of the tree population may be truncated. Originally, the idea in Heureka was that trees smaller thatn 4 cm, should not be transferred to the established phase but instead represented by the new trees generated by the ingrowth functions. This has been modified, so that with diameter ≥ 2 cm are transferred. Running the ingrowth function immediately after the established phase is started, would overstimate the number of samll trees. It has been found resonable that at a stand age of 50 years, no trees that come from the young phase are less than 4 cm, allowing us to activate the ingrowth function at that age.

This means that the value of this parameter should depend on the minium diameter you set. If set to 4 cm, set this parameter to 0.

Ingrowth Species

Allows you to deactivate the ingroth function for selected species.

Max Age Ingrown Trees

Age limit for ingrown trees (brh). The minimum of this and the age calculated with the tree age function will be used (in the first period the ingrown trees occurs).

Sapling Diameter Model

Model for assigning sapling diameter (based on height-diameter relation)

Elfving implies that the model by Elfving will be used in calculation of the saplings' diameter.

NystromSoderberg implies that the model by Nyström and Söderberg will be used in calculation of the saplings' diameter.

Skip Ingrowth Step One

True means that the first step in the ingrowth model (Wikberg P-E), is skipped in the first 5-yr period and replaced with the actual number of small trees. This requires that your input data has information on the number of small trees in an established stand (for example NFI data). False if this step should be included (default).

Sapling Damage Factor

Weight factor for the mortality rate and occurrence of damages on young trees. The larger the weight, the larger the mortality and number of damaged trees. With 0 weight, no mortality and damages occur. Default value = 1.