Frequency

The frequency module accommodates a variety of frequency sampling protocols including nested frequency. In particular, it eases the process of recording nested frequency by not requiring the user to enter the number or identity of the nested quadrat in which a species occurs.

The display panel for frequency more or less mimics the appearance of the main quadrat and nested quadrats in use. This is based on the settings for the frequency module as discussed below. In this example, there is one small quadrat nested in the corner of the main quadrat. When the frequency module is first activated for each placement of the quadrat frame, the smallest quadrat is set to be the active or current quadrat first since nested quadrats are always read in order from smallest to largest. To activate a different nested frame, simply click within the exclusive boundaries of the desired frame. The active quadrat frame is highlighted in a bright color. In this example, the main (largest) frame is active and ready to receive species inputs.

The data input panel associated with the frequency module is the Species Input panel. This panel will appear automatically whenever the frequency module is activated. When an unselected species is clicked, that species is entered into whichever nested quadrat is currently active and is highlighted as yellow within the Species Input panel. Clicking a species that is already highlighted (already exists in a nested quadrat in the frequency display panel) will remove that species from the display panel from whichever quadrat where it is located regardless of which size quadrat is currently active.

It is not possible to enter the same species-qualifier combination in more than one quadrat, therefore a species must be entered in the smallest nested quadrat in which it is found. VGS reports associated with frequency know that a species that occurs in a nested quadrat also occurs in all larger frames within which it is nested, and will correctly report a hit for each quadrat size.

The settings for the frequency module are shown below.

In addition to setting the transect and sample configuration, it is necessary to set the size and configuration of the main quadrat and any nested quadrats. In the example above, in addition to the main quadrat frame there are three nested quadrats starting with a small 10 x 10 cm quadrat. Nested quadrats should be listed in child-parent order (in order of size). The "Nest Orientation" setting tells VGS in which corner to set the smallest quadrat. This setting is for display purposes only (so that the display panel mimics the layout of the quadrat configuration in use) and has no effect on function.


© Arizona Cooperative Rangeland Monitoring Program, 2018 • Updated: 01/18/18