Patch Sub-Account Types

Once your model is loaded you will notice in the 'Targets' panel that Patchworks has created six sub-accounts for each of the patch size accounts you have defined. The following section describes each sub-account.

Table 2. Patch Sub-Account Types

Sub-Account TypeDescription
AreaThe patch area sub account is summing the total amount of area that falls within the patch size category for each period (in hectares).
SizeThe patch size sub accounts represent a percent of the total patch criteria that is within the size class. The maximum value of this account is 100%.

The shape sub account represents an average edge to area ratio for the size class category. This is the perimeter of the patch area divided by the perimeter of a circle with the same size. The range of values is therefore between 0 and 1 (1 being a more compact circle shape, 0 being more dendritic and dispersed).

Not a very effective tool because it is based on the average of all patches in that size category (meaning this is an account and not a block attribute).

Frequency and Percent Frequency The frequency sub-account represents the number of patches in the size class.

The attractor sub-account can be used to encourage the scheduler to allocate patches of the given size class. The account works to draw the average patch size of all patches (in all size classes) towards the range of the select category. Implementation of this feature provides a 'gravitational attraction' for the formation of large patch sizes.

It is important to activate only one attractor in the analysis so that they do not conflict with each other. An attractor sub-account is simply active or inactive and requires no values to be set. The values within the attractor sub-account target chart mimic those of the size sub-account.