The Scatterplot - multiple tool allows for the plotting of a taxa or species assemblage occurrence records across all pairs of selected environmental layers. This includes any environmental-type layers from prior analysis.
This tool provides a powerful way of identifying layers/variables that appear related in some way to species distributions. The user can then redo these Scatterplots individually to further investigate the relationships between the environments given by the two environmental axes of the Scatterplot, for each occurrence record.
The following variables are used when running multiple scatterplots:
- The area within which occurrences and environmental layers will be examined
- The species or taxon of primary importance
- The environmental layers for the various scatterplots
- A background taxon for comparison against the primary one - this is optional
In the following example, Victoria has been added to the map, prior to running the multiple scatterplots. For further information on adding areas see Areas (Add to Map).
From the menu option, select Tools, and then Scatterplot - Multiple
Select the area you wish to examine.
Note: the Define new area option will involve an extra step (please refer to Add Area for additional information). In this example the state of Victoria has been pre-defined and selected from the ASGS States and Territories contextual layer.
Select the primary species or taxa for the scatterplots
It would usually be wise to use only points for occurrences that are deemed spatially valid, unless this yields far too few records. The more comprehensive and consistent the occurrence records are, the better the results are likely to be.
Select environmental layers for scatterplots
There are many ways to select the environmental layers:
- You can take a quick look using the best five independent terrestrial layers.
- You can also use any previous layer selections
- You can search for layers
- You can paste in a set of layer names or select them individually in the list of environmental layers.
If you search for layers remember that you can also search on layer keywords, for example ‘marine’ or ’2030′. As mentioned above, test out various combinations of environmental layers and look out for patterns shown in the display of species points on the scatterplots.
Select a background species or taxon - Optional
The background taxa group is this case is the genus Eucalyptus. This gives us a good indication of what environments the genus covers and what portion of that environment is covered by E. mellidora. However, choosing a competing species or genus might also be very useful in identifying their (environmental) niche.
Scatterplots are produced for the variables chosen. The blue dots are occurrences of Eucalyptus Melliodora, the grey dots are the distributions for Eucalyptus in general.