Sunday 4 March 2012

Lichens of Malham Tarn House - 1

 "Malham Tarn House: Its building materials, their weathering - and colonisation by plants" is a paper written by Arthur Raistrick and Oliver Gilbert in 1963 in Field Studies, the Journal of the Field Studies Council.  You can read it online

1963 is 49 long years ago.

On 25 Feb 2012 Allan Pentecost led an introductory lichens day at Malham Tarn Field Centre, and we looked at the walls of the house. Will this blog post develop into a 50 year update?

Acarospora fuscata

Arthur Raistrick was a famous historian,  geologist, a Quaker and a conscientiousness objector. I was privileged to hear him give a talk in Littondale once when he was in his late eighties.  He had led excavations of archaelogical sites on Malham Moor, and wrote books on many topics. The room where students make their tea is now named in his honour.

When I lived at the Centre as Botany and Ecology Tutor, from 1979 to 1987  I used that paper many times to learn of the history of the house and I used to walk round the outside of the house peering up at the tall walls, working out which coloured blob was which lichen. I expect Mark Seaward who ran many lichens courses a the centre also showed it to people.

I met Oliver Gilbert when he came up to run a lichens course in the eighties.

Oliver Gilbert used to be a tutor at the Field Centre too. When I first met him, I regarded him in awe.. being tutor here, after Sinker, near the Beginning of Times. (The house may be old, but the FSC only started in 1947, and the Centre started in ....).  .

Oliver proudly showed me the boardwalk on the fen which he and his brother, Richard, had first built in the 1960s, with their bare hands. Before that access to the fen had been a black peaty squelchy path.The boards had been relayed several times since then - and now the National Trust  are putting plastic boards down which will last longer. Oliver told me me how very much he had enjoyed being tutor.

Now it was 25 February 2012  I  was at the Centre again, one of eight students attending a day course on lichens run by Allan Pentecost, sponsored by the British Lichen Society.

When we first went into the courtyard, I went to the coal house door, and chirped "Can I do this bit please?"

The wall to the (former) coal-house and other out-buildings is north facing and built of limestone but the wooden shutter of the coal-house opening is framed by sandstone building blocks. When I and Henry Disney had both taught here week after week, we always started our grand guided natural history walk of the estate with an examination of the lichens (and algae) on the building blocks round the coal-house door.

There is ecology under your nose, wherever you are.

Why did the powdery pale green lichen Lepraria incana grow where it grew.?

And why did the Orange Alga Trentepohlia (which looks like a lichen but isn't)  grow where it is growing?

Have a look if you visit the coal house door.

You might even see a slight depression in the sandstone block where I used to scratch away the sandstone and mix the grains produced with water - and add Universal Soil Indicator solution. A yellow orange colour was produced .. to show that water flowing over the sandstone had a pH of about 5.8 or 6.  The limestone rock is much harder and there is no tell-tale hole on the limestone block. - and the limestone powder added to distilled water and indicator produced a deep bluegreen colour - showing the water is pH 8.

New fact for me:
There are actually two species of Trentepohlia on that door. Both are filamentous algae, with ordinary green algae pigments, but they also have orange pigments.
 Allan showed us-
Trentepohlia aurea  link1-  a brighter, lighter more golden version of bright orange, a fluffier appearance
Trentepohlia umbrina a darker brick red colour (is umber a dark version of orange?), more adpressed to the rock.

I will take a photo of the coal-house door another day.

Meanwhile at the top of this blog post is a picture of Allan on the south side showing us Acarospora fuscata on the south side.

We actually started in detail on the East facing side which is sandstone.

Candelariella vitellina and Klebsormidium crenulatum (filamentous nuisance alga)

Candelariella vitellina.

The yellow-orange  lichen on sandstone is often Candelariella vitellina.

Well I've had enough writing now - and you've probably had enough reading.

In my next post I will write about the other twenty or so
 lichens (with pictures) that we found.

Since starting this blog post, I have just  learned of the death of Audrey Disney  two days ago on 1st March  Audrey is/was the above mentioned Henry Disney's wife - Henry was Director when I was here, and then he moved to Cambridge. Audrey was Secretary at Malham Tarn Field Centre for a while. The funeral will be in Cambridge on 12th March.
She had a lovely smile and happy nature.
I don't think lichens were her major interest - but she was helpeful to people who came to the centre, and would have met Oliver Gilbert and Arthur Raistrick who lived in the area, and Allan Penteost. I have a picture of her skiing on the lawn, with the house in the background which I will add when I have opportunity.

Other Lichens posts (see also the Lichens link in the menu in the right hand column):-

    1. Lichens of Malham Tarn House - 2    29 February 2012
    2. Lichens of Malham Tarn House - 1    29 February 2012
    3. Lichens of Malham Tarn Fen - with Allan Pentecost 29 February 2012
    4. Lichens flourescent in bonfire light  5 Nov 2011
    5. Opal Lichens Settle    CCG walk led by myself -  2 April 2011
    6. Algae (and Lichens) for Beginners - Malham Walk with Allan Pentecost August 2009
    7. Lichens Day at Giggleswick Churchyard with Mark Seaward 14 June 2009

1 comment:

Helen Ashton said...

Yes - very sad to hear about Audrey.