Regional Framework Design

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Overview

The Regional Framework performs the following steps:

  1. Years to start period are calculated
  2. All treatment units are loaded and initialized
  3. Treatment units are set aside for nature conservation
  4. Total area of all treatment units is calculated
  5. Treatment units are allocated to forest domains and then to control categories
  6. Treatment units are initialized again
  7. For each period:
    1. For each control category:
      1. Growth to next period is performed
      2. Restrictions are updated
      3. Treatments are executed
    2. Treatment units are allocated to new forest domains
  8. Results are saved

Years to start period

Number of years to start period is determined by the reference year and the start year given by the user. Start year cannot occur before reference year. If start year and reference year are the same, simulation will be started directly, and the results and settings for the first period will be for the reference year period. If reference year occurs after start year, two extra periods will be added to the simulation, and settings for period 1 and 2 will be used for those periods, while setting for period 3 will be for the reference year period. Similarly two extra periods will be added to the results.

Reference Year Start Year Period 0 Period 1 Period 2 Period 3
2006 2010 2006 2008 2010 2015
2010 2010 2010 2015 2020 2030

Initialization of treatment units

Initialization of treatment units is done twice. The first time the treatment unit is initialized with age, volume, growth, and height for all trees using the settings of the default control category, as these values might be required when assigning treatment units to forest domains.

The second time each treatment unit is assigned to a forest domain. Age, volume, growth, and height is assigned again (since another control category might be used this time), and growth to the start period is performed. Empty treatment units are also regenerated in this step.

Handling of nature conservation

Treatment units are set aside for nature conservation at start of the simulation. Treatment units that has been set aside are included in the normal forest domain handling and treatment handling, but they are never prioritized for treatments.

Execution of treatments

Execution of treatments follow a simple pattern:

  • Execution of treatments is done for a domain at a time
  • There is a treatment planner for each type of treatment that can be performed
  • Each treatment planner evaluates all treatment units in the domain, checks if each treatment unit can be treated by the treatment and sets a priority for it
  • Each treatment planner executes treatments for the priorized treatment units until the desired goal for the treatment as set in the domain has been reached

Treatments are executed in the following order:

  1. Cleaning
  2. Final felling
  3. Fertilization
  4. Regeneration
  5. Thinning
  6. Intensive fertilization

Several treatments in the same period is not allowed. This means if several treatments are possible for a treatment unit, the treatment with the highest priority is most likely to be performed.

Forest Domains

How it should work

A ForestDomain is a classification of treatment units. Each forest domain has two properties that are of interest for the regional framework:

ChangeForestDomainAllowed
Can treatment units assigned to the domain be moved to other domains
ChangeMaturityClass
At which maturity class can the change be done

A ControlCategory specifies how treatments are applied, e.g. a kind of management system. Each control category has the following property of interest here:

TargetArea
Percentage of the total area being analyzed that should be allocated to the control category

Each ForestDomain is connected to one or more ControlCategories. The same ControlCategory may be connected to more than one domain.

In the regional framework, it is evaluated for each period which treatment units belongs to which control category.

For example:

Say that there are three control categories:

  • Intensive management (10%)
  • Continous management (20%)
  • Even Aged Management (100%)

And three forest domains, assigned to categories:

Oak Forest
Continous Management , Even Aged Management
Spruce Forest
Intensive Management, Even Aged Management
Other Forest
Intensive Management, Continous Management, Even Aged Management

The regional framework will do as follows:

  1. If possible, allocated oak forest to continous management
  2. If the area of the oak forest is more than 10%, use even aged management for oak forest
  3. Similarly try to assign spruce forest to intensive management
  4. For other forest, use intensive management if possible (there was not enough spruce forest), if not try with continous management, if that not works even aged management will have to do

Implementation

  1. Total area of the analysis area is calculated
  2. For each period:
    1. If first period:
      1. All treatment units are added to a list of not assigned treatment units
    2. If not first period:
      1. Treatment units that are in a forest domain where change of forest domain is allowed, and has the maturity class of the forest domain, are added to a list of not assigned treatment units
    3. Remove all treatment units set aside from nature conservation from the list of not assigned treatment units, assign these to the default control category of their forest domain
    4. For each forest domain:
      1. For each control category in the domain:
        1. While the assigned area of the control category is less than the target area of the control category, and there are available treatment units:
          1. Pick a treatment unit with matching forest domain from the list of not assigned treatment units
          2. Add the treatment unit to the control category
          3. Increase the assigned area of the control category
    5. For each treatment units that not yet has been assigned:
      1. Add it to the default control category of its forest domain