Defining groups

Groups are defined in a simple CSV file that contains two fields: BLOCK and GROUP.


The value of the BLOCK field contains the block identification labels. The value of the GROUP field contains the group identification labels. Each record identifies the membership of a block in a group.

Groups can be defined for specific geographic areas (e.g. watersheds or landscape units) that divide the entire planning area, or for specific initial stand conditions (e.g. all blocks of a specific site type). Individual blocks may be members of more than one group. For example, a group might be defined to include upland site types (blocks 1 and 6 in the above example). The area could be sub-divided by management zones that have distinct geographic areas within the planning area. For example, the area could be divided into three zones (zoneA, zoneB, zoneC).

Let's illustrate the concept of accounts with a few examples. In these examples let us assume that we have a forest that is divided into three compartments: 'zoneA', 'zoneB', and 'zoneC'. Blocks must belong to one and only one of these zones. Each block also contains attributes for 'Conif' and 'Decid' yields, for both growing stock and harvest volumes. We will show the corresponding records that would be included in the accounts.csv file to represent several different summary accounts.

In the example below, all amounts of the harvest volume attribute 'product.Yield.managed.Conif' from blocks in 'zoneA' are assigned to account 'zoneA.product.Yield.managed.Conif'.


This allows you to set objectives for, and report on just the conifer harvest volume from zone A.

Account values are summed from the attribute values of all blocks in the chosen groups. In our example we stated that each block belongs to one of the compartments name 'zoneA', 'zoneB', or 'zoneC'. In this case the following records include all blocks in the forest.


The above lines would be equivalent to:



Watch out for "double accounting" in the following example: if a block is a member of groups '_ALL_' and 'zoneA', then all the 'Conif' yield attribute produced by this block will be added to the same account by both the first and second assignment. The result is that the values will be added to the account two times.


Patchworks will issue a warning when it detects this happening, because this is usually unintended.