Tuesday 24 July 2012

Lichen Workshop at Grassington Methodist Church

Although not a specifically church event, local Methodists Christine Bell and Judith Allinson made good use of Grassington Methodist Chapel and its schoolroom when Christine invited Judith to come and run a Lichens workshop for the Botany Group of Upper Wharfedale Field Society on 24th July.

 "How many lichens do you think there are in Britain?" asks Judith.
Answer "Almost 2000. And about 1000 in Yorkshire, as recorded by Prof Mark Seaward. A lichen is an association of a fungus and an alga. The fungus is always different for each lichen, but many lichens have the same alga. Algae contain a green pigment and make sugar for the lichen using the sun's energy."

Under a hand-lens lichens have beautiful shapes

After the morning session and lunch the group set of for Grass Wood.. but first we are sidetracked by the wall outside the church.

Passers-by stop to ask "What is going on?"
Judith lends a hand-lens for one to try. "Hold the lens close to your eye. Then move your finger nail until it is in focus and clear"

At last we reach the Yorkshire Wildlife Trust Reserve of Grass Wood.
We carry out a survey organised by OPAL  . We can learn much about the air quality from the lichen species. This survey  records species that are tolerant or sensitive to pollution by nitrogen oxides (from car fumes, and fertilizers)

We look at lichens on Willow and then on Oak. The wood is quite shaded and there are not too many species. (Which makes it easy for beginners...)
Then we move across the road to where the trees are more spread out so there is more light.
On the branches of an oak we are rewarded by finding the "fruticose" lichen Ramalina farinacea   sometimes called the Farinose Cartilage Lichen

Well, we did not see the 2000 UK lichens, nor the almost 1000 species as recorded by Mark Seaward in Yorkshire, nor even the 346 species on the Checklist for 5km radius of  nearby Malham Tarn (Seaward and Pentecost) .. (Of which about 48 may be extinct in the area) but we did name 15 different species.. A good start.. and I think most of the group will be happy if they go away remembering three.

To the Group "Which three can you remember?"

Latin Name English Name
Arthonia radiata
Aspicilia calcarea Calcareous rimmed lichen
Caloplaca flavescens
Cladonia pocillum Carpet Pixie-cup
Collema auriforme Jelly Lichen
Evernia prunastri Stags horn or Oakmoss
Hypogymnia physodes
Lecanora chlarotera
Lecidella elaeochroma
Lepraria incana Blue-grey Dust Lichen
Melanelixia fuliginosa - Parmelia glabratula Brown Parmelia
Parmelia saxatilis (Crottle, Stony rag)
Ramalina farinacea Dotted ramalina, The dotted line;
Farinose cartilage lichen
Verrucaria nigrescens Black Verrucaria
Xanthoria parietina Bird perch lichen

No comments: