GeneticGains

About

Simulation.Model.GeneticGains represents a collection of tree size and growth modifier rules that can be introduced by the user with the Add command. Rules are applied during stand load and/or during simulation. Genetic gain modifiers are declared by species or species groups, and optionally by tree Origin (Seed, Coppice, Plant) as well.

Immediate tree size increases during load

If the tree list you want to apply growth gains to was sampled from an unimproved (i.e., woods-run) plantation, then tree DBH and height measures in the tree list may need an immediate increase before the simulation begins to account for expected increases in tree sizes from time of plantation establishment to time of survey for the genetic gain scenario. We can accomplish this with the Add command.

Growth increases during simulation

During each simulation growth cycle, tree DBH and height growth gains are applied after Variant DBH and height growth estimates are set for each tree, and after any scheduled modifications from Action Amend statements, See the order of OSM cycle operations here. Because of this order, gains to DBH will not influence Variant height growth estimates, and vice versa. Again, the Add command is used to set DBH and height growth modifiers.

Commands

SIMULATION

MODEL

GeneticGains

Add {origin} {species} {dbhFactor} {htFactor} {dbhiFactor} {htiFactor}

Clear

Add

SIMULATION.MODEL.GeneticGains.Add {arguments}

Add Command Arguments

Argument	Type	Optional	Description
Origin	String	Yes	Tree origin code (Unknown; Seed; Coppice; Plant) this rule should be restricted to. If ‘Unknown’ then the rule will not be constrained by origin. If you want to constrain gains to trees with an Origin code of ‘Plant’ then state ‘Plant’. Default = ‘Unknown’. Origin codes for individual trees are set by the user in the OSM tree list.
Species	String	No	Tree Plant Code, Variant Key, or Species Group this rule should apply to
dbhFactor	Float	No	Tree DBH size scale factor; 1.05 = 5% increase to DBH on load.
htFactor	Float	No	Tree height size scale factor; 1.05 = 5% increase to tree height on load.
dbhiFactor	Float	Yes	Tree DBH increment scale factor; 1.05 = 5% DBH increment gain
htiFactor	Float	Yes	Tree height increment scale factor; 1.05 = 5% height increment gain

Add Command Overloads

There are four ways of stating required and optional arguments for the Add command, as shown and described below:

1. SIMULATION.MODEL.GeneticGains.Add {species} {dbhFactor} {htFactor}

· Origin assumed here to equal ‘Unknown’; i.e., not restricted by origin.

· dbhiFactor set equal to dbhFactor

· htiFactor set equal to htFactor

2. SIMULATION.MODEL.GeneticGains.Add {species} {dbhFactor} {htFactor} {dbhiFactor} {htiFactor}

· Origin assumed here to equal ‘Unknown’; i.e., not restricted by origin.

3. SIMULATION.MODEL.GeneticGains.Add {origin} {species} {dbhFactor} {htFactor}

· dbhiFactor set equal to dbhFactor

· htiFactor set equal to htFactor

4. SIMULATION.MODEL.GeneticGains.Add {origin} {species} {dbhFactor} {htFactor} {dbhiFactor} {htiFactor}

You can change a species multiplier values by calling Add again for that species or species, origin combination. The new rules for that species will overwrite the old.

Clear

Gain rules are not cleared (reset) between simulations unless ‘Clear’ is called. If you want to continue to use existing rules for the next simulation, then do not call this method between simulations. If you do want to clear the rules and state new rules for the next simulation, you will need to call this method.

SIMULATION.MODEL.GeneticGains.Clear

Examples

The following commands will increase the DBH and height of white spruce (PIGL) in the user’s tree list before the simulation begins by 6% and 9%, respectively. During simulation, DBH growth and height growth will be increased by the same respective proportions. After simulation, the genetic gain rules will be cleared from memory.

SIMULATION.MODEL.GeneticGains.Add PIGL 1.06 1.09

SIMULATE

SIMULATION.MODEL.GeneticGains.Clear

In this case, we further restrict the gain rules to planted white spruce. Any white spruce that have regenerated naturally in the field survey or that will regenerate naturally during simulation will not have these gains applied.

SIMULATION.MODEL.GeneticGains.Add PLANT PIGL 1.06 1.09

SIMULATE

SIMULATION.MODEL.GeneticGains.Clear

In this case, no increase to tree size occurs on load, but growth gain is applied.

SIMULATION.MODEL.GeneticGains.Add PLANT PIGL 1 1 1.06 1.09

SIMULATE

SIMULATION.MODEL.GeneticGains.Clear