Friday, 5 September 2008

The Stump

There's an old deciduous stump in Drumboe that demands that I photograph it on each visit. It's covered in lichens and mosses, with visits from occasional fungi, including the wonderful 'Jelly Tooth' that I might see there again soon. Here is a small (15cm.) fragment:

It's the kind of environment that draws you right into it. "You have to get down to its level", as a good friend told me (you know who you are).

I made another image, so that I can point out the various species:

1) and 4) Polytrichum commune - one of the 'Hair Cap' mosses.

2) Cladonia fimbriata - a lichen.

3) Pleurozium schreberi - a moss.

5) Cladonia portentosa - a 'Reindeer Lichen'.

6) A Birch seedling.

There will be more that I can't make out from the pictures.

Here's a close-up of the Cladonia portentosa:

Incidentally, this is a perfect example of lichens getting on with their work. The stump started off as clean dead wood and lichens (not Cladonias: they come later) colonised it, converting the wood into poor, thin, soil. The mosses need hardly any soil, so they come in after the lichens and then they, too die off and leave more organic material behind them. Eventually the soil is sufficient for a tree to take root above the old stump. I don't know how old the stump is (perhaps 20 years?), but the sequence of events is classic: Lichens are the pioneers, lower plants follow in and higher-order plants arrive last. Without lichens there is nothing. The same process takes place on rocks (and gravestones) but the process takes slightly longer.


Gill said...

Lovely - I like the idea of labelling the pic like that.

What is the pan-scrubber lichen (and if that's the Cladonia what's the cup-on-a-stalk one?).

Wish we had tree stump communities like that...

Leif said...

Hi Stuart,

Number 1 and 4 is not Polytrichum commune (not a 'Hair Cap' moss at all, actually) it's a Dicranum species.
Number 3 is not Pleurozium schreberi, it's Rhytidiadelphus loreus.
(I have no idea about the lilchens.)