Heatmap to create interval break by genus or species

When you create classified breaks, whether by jenks or equal interval etc., you can see the number of genera per classified level. How do I make it so it classifies by number of species instead of number of genera? Or do I have it mixed up? Either way, I’d like to have the option to classify breaks by genus or species. I’m assuming I’d build another heatmap with the taxa column specified to the genus column if I wanted to sort by genus.

I’ve got a map of species diversity which has over 1200 species, but the largest classified break in the heatmap I’ve built says I’ve got at most 538 species. Perhaps I’m doing something wrong?

The breaks are using the number in whatever field (column, attribute - whatever you like to call it) you have selected to do the styling on. Presumably, in your case that is Richness. The richness column in an atlas table created with the BRT counts the number of unique taxa for which records were present in that square.

But the BRT doesn’t really know what a ‘taxon’ is, much less a species or genus, it is really just looking for unqiue values in the taxon. So when you specify a taxon column in the tool to create the atlas table, the BRT is just counting unique text values. So if you want species richness, either preprocess your input data to remove everything but species, or, on the taxa tab, only select taxa which are species - leave those recorded to genus or other ranks unticked. Only records with taxa that you have ticked will be included in the result.

So presumably if the column I have selected contains species names, e.g. Vulpes lagopus, Macrophyllum macrophyllum, Peromyscus leucopus, then I should have a map of species because it treats both the genus epithet and species epithet as a single clause and just looks for unique clauses. It doesn’t actually separate out genus and species because of the space in between the two words