management

iLand includes two sub-systems that handle forest management:

• the “base” [management] is a rather simple, but still versatile approach which allows a wide range of altering the forest in the model (extracting of trees, planting of trees, …).
• iLand includes also the Agent Based management Engine (ABE), which is a powerful module that allows to simulate multiple management agents on a landscape. Agents can react to changes in the environment by changing management plans and can apply a variety of different management activities in a dynamically scheduled manner. The setup and application of ABE, however, is somewhat complex.

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

• Use “base” management by setting enabled to true and abeEnabled to false in the #management|management section.
• to use only ABE, set enabled to false and abeEnabled to true in the #management|management section (it is technically possible to use both mechanisms at the same time).

The management approach in iLand relies on using Javascript as the “scripting language”. The model exposes a set of objects and functions allowing a management script to interact with the model.

For the base management, good starting points are the [Object Management] and [Object Globals] API documentation as well as available demo examples (like this or that).

In base management, a single javascript file is defined in the Project file and loaded during startup of the model. Every year the function manage() is called by iLand. The example shows a very simple and not particularly useful management routine:

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

The user needs to provide his or her own way of dispatching events over time. Examples of how this can be done are shown in the examples: [management example: parallel management] or [management example: HJA fire history].

Note: the management happens quite early in a year.