What is the best way to classify biological soil crusts?

Biological soil crusts are such a rich mix of diverse organisms, yet they are a unique form of life. I’ve been struggling with how to identify them. Most of the examples I’ve seen on iNaturalist are either left unknown, or classified as cyanobacteria. I understand the cyanobacteria, since that’s a dominate component, but it just doesn’t seem like enough of an identification to me. Neither designation (unknown or cyanobacteria) helps if you are trying to map them through iNaturalist, or just looking for examples. Is there a classification for soil crusts that I have missed? What’s the best way to label them?


Good question, though I don’t have a good answer. Really it seems based on my limited knowledge that they are more like a tiny natural community type (“northern hardwood forest”, “coastal sage scrub” etc) than any given organism. Have they been classified in that regard? It seems we know very little. Maybe for now a field similar to the ‘natural community’ field or one of its many variants on iNat.

Since the crusts are composed of almost every domain and kingdom of life (lichen, cyanobacteria, bryophytes, and algae), you’d have to go with “life”.


For mapping and re-finding them, it would be best to start a project. They might have to be added manually to the project, as they are a community of organisms and not a single taxon. here my first contribution: https://www.inaturalist.org/observations/28344314

There are some others about that a search with keywords (Description / Tags) such as cryptobiotic, cryptogamic, and soil crust bring up a few observations that would need further filtering for such a project.

Interesting that there are these complex communities of organisms that exist yet are easy to overlook by some of us (me) because we ( I) don’t know what to look for. This topic brought me back to looking at Lichen as a pioneer species and how certain complexes need to be in place in order for other organisms to exist. It also made me think about biofilms and how they exist to form syntrophic consortiums of microorganisms. All very important stuff to consider when trying to understand an environment.

This does not answer your question @beetle_mch but I think @mreith suggestion of a project would be best for purposes of keeping track. And, I think that @pfau_tarleton is correct in saying it is “Life” or pick a fitting sub-kingdom or phylum know that it will never reach species. It would be nice if there was an easy way to populate such a project that was not manual (like this (shameless plug)).

I have been using https://www.inaturalist.org/taxa/357075-Geodermatophilaceae for the crusts on rock found in shield country

Using the moniker: “Life” seems inadequate. I appreciate the rules of iNaturalist. ID only to the level of certainty based upon the information given in the observation and only one species per observation. Yet lichen can get an ID and they are not one species per observation. Since the moniker “Life” is also used for completely unidentified observations, I would think there could be a solution for something like soil crusts that are IDed to the level possible. Question: How are we going to use iNaturalist as a research tool for studying biological soil crusts, if culling the observations will require looking at every single observation listed as “life”?

1 Like

If they are collected into a traditional project or an observation field then it’s not too hard to filter them.

1 Like

You are right…once they are in the project. I’m not too hip on the auto populating of projects, is it possible / easy to set a search amongst all in the “life” observations to automatically cull the biological soil crust observations into the project?

The goal would be to include observations from folks minimally familiar. For example, folks who might know enough to say its a butterfly and rely upon the community for further ID and then auto inclusion into ‘monarchs and milkweed’ project once it reaches research grade monarch.

Not really. This isn’t something that can be sorted automatically because it doesn’t involve specific taxa, observation qualities, users, or annotations, so you’d have to do a traditional project and manually add observations.
You can filter for observations that are identified at the level “Life”, but that would probably have thousands of unrelated observations and wouldn’t be very practical. To start you could click on the links above in this thread and add appropriate observations from those, and then you could try searching for observations with things like “biological soil crust” or variations of that in the comments. After that it just takes advertizing the project so interested people will join and add their own observations.


This topic was automatically closed 60 days after the last reply. New replies are no longer allowed.

There is now a project to gather observations that in some way mention, represent, suggest, are consistent with, etc Cryptobiotic soil. Observation fitting within can be yes/maybe or no answer to an Observation Fields of Cryptobiotic soil. Because it is a traditional project observations need to be added manually. Observations can be be described as representing or found within biological soil crusts, biocrusts, cryptogamic, microbiotic, microphytic, or cryptobiotic soils.


This is just being fleshed out now but welcome are Curators and Managers for this project. Also welcome are a better description of the project contents. Just PM me.

And thanks to @upupa-epops I used your comments query to help the initial population of the project.