I think you’re gonna find one of the big issues with any geographically standardized Mycological study is the fact that we haven’t really standardized the methodology for collection and identification yet.

This paper has to do with marine fungi in particular, but a lot of the obstacles of geographic assessment are commented on in this paper; varied sampling methods, no standardized primer for the PCR reactions, no standardized ITS for decoding the eDNA, questions of eDNA versus transcriptome surveys.

https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1613&context=honors

It’s amazing we don’t have a baseline for some of the stuff already. Hard to tell how the world is changing if we don’t know the state that it’s in today, let alone the state it was in yesterday.