Extract number of species within subset of diversity heat map

I created a diversity heat map of points using the FSC BRT, and then I subsetted the points I made into a set that only overlaps with a polygon, thereby reducing the number of species I originally had plotted. How can I determine the species that are left in this new set of points? I can tell the amount of species just by looking in the styling panel under the “Classes” tab in the “Graduated” color scheme and seeing the final color and the associated value, but I want to know the specific taxa I have left without having to go through the attribute table and count the unique values myself. The attribute table contains rows on the order of millions so counting by hand is out of the question

Can you post an image of the attribute table of the layer in question? ie select you layer in the layers panel and then clcik the ‘Open attribute table’ button (or hit F6) and get a screen shot of the attribute table.

Here are pictures of what I’ve done visually, the attribute table of the modified subset of points, and the attribute table of the original GBIF dataset. Perhaps I can extract them from the attribute table .dbf file or .shp file somehow? Under the taxa column in the attribute table I get concatenations of the genus taxa with pound signs and other species, presumably because it is referencing each grid cell atlas point which is sometimes made up of many species which occur at the same grid cell

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I sort of figured it out. I right clicked on the subsetted heat map layer and exported it as an excel document. However there are a lot of rows in the excel document with the whole speciesx#speciesy#speciesz type of notation, and not just a simple list of individual taxa. I can go through the document and cut out the extra rows but it would be nicer if I could just export them without all the “x#y#z” notation to begin with

I think I’ve finally figured it out, and it doesn’t have anything to do with the FSC BRT. I just need to subset the data using the original point data and get the number of species from that, rather than subset the already-created heatmap and attempt to get the number of species from the heat map

I think you have it now. Download your GBIF data, do any selection stuff that you need to do to get the records you want to work with, e.g. spatial select or other filtering, and then use the BRT to create the atlas map. Use the original filtered data with other QGIS tools to get stats on the taxa you’re working with.

Note the ‘taxa’ column on BRT altas layers contains a hash separated list of all the taxa that had points within the cell represented by that line in the attribute table. If genus appears separately from species, that means there are records in the source data that were only recorded to genus and some recorded to species level. Often this is not what you want. If you need to exclude records recorded only to genus you need to do some filtering on the source data first to remove them (or simply not select them on the ‘taxa’ tab in the BRT.

Also there is a text column length restriction of 254 characters, so if the concatenated list of taxa in a cell exceeds 254 characters, it gets truncated. This column is really useful when there are jist a couple - or at most a handful - of taxa being dealt with. It allows you to style each cell based on whether what taxa occurred. E.g. imagine a map of grey and red sqirrels. By styling the atlas map on the taxa column, you could have different colours for squares (or circles) that had either greys or reds, or both greys and reds.