Ptyxis Ecology - Our Botany Blog

Saturday, 9 February 2008

Epiphytes in a Northumberland wood

A couple of weeks ago I went out hunting bryophytes with Doug McCutcheon and Ian Craft. We were trying to relocate a rare moss that Doug had found a few years ago in the woods between Bellingham and Hareshaw Linn waterfall. The woods were fairly ordinary at first with mainly the usual common species present. When we got about half way up we started to find more interesting species. The epiphyte communities were especially interesting, particularly close to the stream where the athomosphere was most humid.

As a rule in Britain, the further west you go, the more diverse the epiphytes. There are many species that have an extreme western distribution in Britain. So unsurprisingly the best places to find these species in Northumberland are probably in the extreme west of the county. The valleys of the South Tyne and Irthing are probably well worth exploring.

But the woods at Bellingham had some very nice uncommon species. Ian took all of the photos below. The first one is a nice shot of Frullania dilatata which is a common enough species but very noticable and attractive when it is this dark red colour. There is a tiny bit of Radula complanata (the pale green one) poking in at the top of the photo. This is also reasonably common but usually grows in fairly good quality habitat for epiphytes.
This little cushion-forming moss growing on the twig is Ulota drummondii. Most Ulota species nearly always grow on twigs. This is a fairly uncommon species in Britain and in England it is very uncommon and now more or less confined to Northumberland and nearby bits of Cumbria and Durham. I had never seen it before but Doug has found it several times in Northumberland and was able to point out its distinguishing features to me. The lower parts of the shoots have a reddish tinge and the peristome teeth are white and stick out.
By the stream on several trees there were lots of patches of this Metzgeria (a small thalloid liverwort). Unlike the very common Metzgeria furcata, this species has attenuate (narrowed to the tip) branches that stick out and are covered with tiny green gemmae (vegetative propagules). Doug and I both brought some home to check which species it was. Doug's plant was Metzgeria fruticulosa but mine looked more like Metzgeria temperata. I've sent this away to be checked by the BBS referee for Metzgeria. If it is right then its only the 2nd record for Northumberland for this species, the first one was only last year from a tree next to the South Tyne.

There are two epiphytic lichens (which Doug identified) in this shot. The one on the right with the light brown/reddish bits at the end of the thalli is Peltigera praetextata. Clinging closer to the tree and occupying most of the rest of the photo is Protopannaria pezizoides. This was a stiking species forming big patches, the red bits looked a bit redder in real life. Doug was very excited to find this as it is fairly rare, mainly occuring in north and west Scotland and had not been recorded from this wood since 1897! There was at least one other epiphytic lichen that we saw in the wood which is a good indicator of long ecological continuity in woodland.

Britain probably has more variety in its epiphytic communities than any other country in Europe (maybe apart from Norway and Ireland), but they get virtually zero attention in the conservation world. One of my 'big ideas' is to some day do a detailed study of epiphyte communities accross the country. As far as I know the type of comprehensive study I have in mind has only been done once before by JJ Barkman in Holland. But before I can embark on something so ambitious I really need to develop my ID skills more. After putting a lot of time in over 5 years I'm starting to feel like I'm getting there with bryophytes, but while I'm still learning them I just don't have enough room in my brain to cope with lichens also.

However, watch out for my tome on British Epiphyte communities in about 40 years time!

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