This guide explains what Sub-sampling grouping is in Pantheon, how you use it, and what it gives you. This function is currently only available to Samples in the My Species Lists rather than the Samples written to the public database.
Your Samples should generally, and by survey design, achieve the highest resolution they can, be this the aggregated records from a pitfall trap grid, the records from a vane or moth trap, or from a defined area sweep net catch or timed catch. You should aim for this level of detail in your data is it gives it the maximum flexibility or “agility”, meaning that you and others can use it in a wider variety of ways than is ever possible from a single monolithic species list for the whole site. Sub-sample grouping gives you this flexibility.
Making your sample
After identification of your, say, vane trap catch, you would paste the names into Pantheon, remove duplicates using the duplicates button, and check through the name choices offered up to you. Before saving this you should pay attention to the naming convention. When using sub-sample grouping it is easier and safer, to start the name with the site so, in our example “Bredon Hill”, and then the finer resolution naming, so “vane trap Ash 199”, so that your full sample name reads “Bredon Hill vane trap ash 199.” In the sample description it is always wise to provide some context on the sample. This might include the sample year, whether it was part of a wider trap programme, or the fact that the tree tag number and tree species is shown in the name. If you had vane trapped tree 200, then this would have a comparable name.
At the end of each saved Sample entry you will find the “Add to sub-sample group” option, and pressing this gathers up your selected Sample and places it under the Sub-sample group tab at the page top. If you then select the next Sample you want to combine with the first one, then it will add that. You can convert both Samples (here considered “sub-samples” of the new Sample you are just about to make, hence the name!) into a new Sample which you can then name. It will show the sub-samples which compose it, hence the usefulness of giving all your Samples well considered names.
It removes duplicates by default, and allows you to analyse the new Sample under that tab, although when you name and save, it writes the new Sample into the Lists. You again should follow the naming protocol, so that all your site Samples are clustered together.
Data analysis with sub-sample grouping
In this way, you can easily and quickly combine your high resolution data. You might group all vane trap data together, or make a Sample of just ash tree vane trap data. If your survey work involved placement of a moth trap in one compartment out of three, you can make a Sample (with a bit of filtering of the base data) that excludes lepidoptera as well as includes lepidoptera, to even things up. The facility really is useful and powerful, and allows you to explore the data in new and interesting ways.
If you look at the distribution of assemblage scores or rarity values via sub-sample grouping you can try and see where the real strength of a Sample lies on a site. Add some sites in or leave them out and see what that does to the overall values. By extracting species lists out into spreadsheets for the assemblages or rarity value species, you can see what a particular Sample adds to the mix. This is useful in site assessments and considerations of where mitigation might fall, as well as looking at the spread of resources across a site.