Success with mosses

mmm a Riccia liverwort. image by Show_ryu

It was extremely gratifying to see three keen new bryologists in the lab yesterday. They managed to concentrate for virtually four hours solid; it was a superb effort. They even let slip that they were enjoying themselves.

Between them they probably identified about half a dozen species, which is just excellent going for anyone, let alone a first-time attempt. There is certainly no shortage of specimens on campus to try. We examined specimens from lawns, on walls, and on trees - different habitats = different species.

We were using a combination of the BBS field key and 'Watson'. You're supposed to be able to use the field key just with a hand lens. But it's so much more interesting to be able to put the mosses and liverworts under a dissecting microscope. Sometimes the key did let us down a bit (perhaps due to our interpretation of the couplets, to be charitable). But sometimes with bryophytes you do have to admit defeat, at least temporarily.

So if you think this could be your thing, do come in and try. Or you can start off anywhere with a downloaded field key and a lens.

This is one of yesterday's discoveries - Syntrichia ruralis - with its hyaline (colourless) hair points and starry shape.

CC image by HermannSchachner

 Some very keen and thorough people at CEH/CCW compiled this document to list the attributes of British and Irish mosses, liverworts and hornworts. 'BRYOATT' has an enormous table describing the species' status, life history, habitat preferences and other traits. Here's the entry for S. ruralis.

It looks a tad overwhelming, but if you know what the codes stand for, you might be able to make some useful remarks about the species you've found. In the top right corner there are 'Ellenberg values' for L, F, R, N and S. These refer to the moss's preferred habitat: L (light) is 8 (on a scale of 0 to 9) - so this species definitely prefers well lit areas. The F value refers to how dry or damp it is where it grows: this is only 3 (on a scale from 1 to 12) and so it's an indicator of dry sites. 'R' is a measure of the acidity/alkality of its preferred substrate: at 7 (on a scale of 1 to 9) S. ruralis definitely prefers strongly basic conditions. N is 4, right in the middle of the scale from 1 to 7  which shows you how fertile (in terms of nitrogen) the site must be. And S is for salt tolerance: with a value of 0 this species is not going to be found near the coast (species on saltmarshes score a maximum of 5). HM is for heavy metals: some bryophytes are confined to spots that have high concentrations of these, believe it or not. But our species scores 0 (like almost 90% of others) because it can't tolerate such conditions.

I think it's rather interesting - and if you visit different habitats you'll see if your mosses are particularly indicative of those conditions.  Just a little thing if you fancy something extra for your notebook.