Forest Management

iLand includes two subsystems that handle forest management:

• “Base” management: A simple, versatile scripting approach that allows altering the forest directly through JavaScript (harvesting trees, planting, modifying soil carbon, etc.).
• Agent-Based Management Engine (ABE): A powerful module that simulates multiple management agents across a landscape. Agents can react to changes in the environment by adapting management plans and executing dynamically scheduled activities.

Choosing between these management approaches is handled by keys in the project file:

• To use base management: set model.management.enabled to true and model.management.abeEnabled to false in the management section.
• To use ABE: set model.management.enabled to false and model.management.abeEnabled to true in the management section (it is technically possible to enable both mechanisms at the same time).

Base Management Scripting

The management approach in iLand relies on JavaScript as the scripting language. The model exposes a rich set of objects and functions allowing a management script to interact directly with the forest:

• Good starting points in the API documentation are the Management API and Globals API.
• Additional core scripting objects include Map (for GIS raster stands) and CSVFile (for reading input data tables).

In base management, a single JavaScript file is defined in the Project file (setting model.management.file) and loaded during model startup. Every simulation year, the function manage() is called automatically by iLand:

function manage(year)
{
    print('management called in year ' + year);
}

The user provides their own logic for dispatching events over time. Several complete scripting examples demonstrate how this is done:

• Parallel Management: Demonstrates handling parallel, stand-level events over time.
• HJA Fire History: Shows how to reconstruct historical fire and harvest events across a landscape.
• Restoration Area (Modern JavaScript): Illustrates how to read custom tabular data files (such as CSVs), filter and manipulate data in memory, and dynamically execute operations (like planting) based on it.

Note

In the annual simulation sequence, management operations are executed early in the year, before growth, mortality, and disturbance modules run.