Management module
The SVD management module simulates management actions on 100 m resolution (the SVD base resolution). Management is performed as clear cut of the grid cell. Management happens for stands above minHeight and whose annual height increment is below a (state-specific) threshold. The later mimics the tree growth & yield principle trees are harvested after growth has culminated (and is declining). Further, management probabilities are calculated externally and given to SVD with the transitionFile. In order to prevent large scale clearcuts in year 1, there is a burn-in period that can be defined via an expression.
Management actions
Management is triggered when:
height growth increment is below the state-specific threshold, and height is above
minHeightregionally managed area has not yet reached the maximum in the current year (management cap)
with a probability of state-specific probability * burn-in factor (
pManagement*burnInProbability)
| Column | Description |
|---|---|
| stateId | SVD state |
| heightIncrementThreshold | externaly defined threshold; management only if recent height increment (m/year) is below that threshold |
| pManagement | probability of management after crossing the heightIncrementThreshold |
Configuration
The module is configured in the project file. In addition to the enabled and type setting, the management module has the following settings:
transitionFile (filepath)
The file containing a transition matrix (see matrix module) for post management states (see above).
stateFile (filepath)
Data file with additional state-specific variables that specify per-state damage probabilities.
minHeight (numeric)
Height after which management becomes possible (meters)
burnInProbability (expression)
If not empty, the expression is used to scale the management actions that would happen in the first year to several years afterwards. Example: polygon(yr, 0, 0, 1, 0, 1, 0.5, 10, 1); from year 0 to 1 the probability of management is 0. From year 1 to year 10 the management probability increases from 0.5 to 1.
managementCapGrid (filepath)
Spatial grid (with user-defined resolution, e.g. 100x100km) that provides an upper limit to area managed (in hectares) per year and grid cell.
managementCapModifier (numeric)
Multiplicative factor that modifies the value provided in managementCapGrid. For example, consider a 10x10km grid and a value in the grid of 1000, and managementCapModifier of 1.2. This would result in a maximum of forest management per year on the cell (100km2) of 1200 ha / year.
Variables
The management module provides the following variables that can be used in expressions:
| Variable | Description |
|---|---|
| height | stand topheight (m) |
| heightIncrement | lower bound of height increment (based on current state & history) in m/yr |
| lastYear | simulation year of last management on cell (0 if never managed) |
Output
The module can provide tabular and gridded output.