Post
by Steve » Thu Dec 31, 2015 11:28 am
Hi Ken,
I quite agree - lichens are neglected, but you can find them all year round, go back to check something a month later, take nice photos, do microscopy and some chemistry (I don't do "P" reagent), and they are reappearing after a couple of hundred years of sulphur poisoning. I studied them a lot 30 years ago, and am very rusty now.
I looked at a description of lichens in the Peak District in the 1960's yesterday:
“Most upland regions throughout Great Britain are notable for the richness of their lichen flora, but in this reepect the Peak District is somewhat disappointing. The relatively limited range of species and lack of growth in many cases is perhaps due in large measure to the atmospheric pollution from nearby indudtrial centres and from the quarrying and lime-burning both within and on the borders of the National Park. Lichens are probably more susceptible to the effect of smoke and fumes than any other type of plant and soon become impoverished and tend to die when the air becomes in any way impure.
The limitations of the Peakland lichen flora are most evident when one studies those which grow upon the bark of trees, for coticolous species are particularly scarce on the oak, which is the dominant tree on siliceous soils, and the ash which occurs in the limestone dales. Though not abundant, such plants as Evernia prunastri and Parmelia physodes are characteristic of these habitats” (In the New Naturalist “Peak District” (1962) K.C. Edwards).
Over the past half century we'v seen a miraculous re-colonisation of impressive growths of shrubby lichens such as Ramalina and Usnea after presumably hundreds of years of absence – especially on veteran oaks as in Longshaw. In the early 1980’s I discovered, at the same time as Joan Egan, Usnea lichen growing in the deep cracks of ancient willow trees just 4 miles west of Sheffield Town Hall. Oliver Gilbert was a top lichen expert at that time, and he surmised that the lichen probably colonised from propagules blown by westerly winds from Wales. Our survey has revealed some trees in Longshaw which look just like trees in west Wales. So this is a fantastic time to revisit lichens - after struggling with the stunted, infertile and sad-looking ones in the 70's and 80's, when you had to go to the Lakes, Cornwall, Wales or Scotland to see how they ought to be.
Looking forward to studying Cladonia in 2016 - there are only about 60 kinds I think. I was going to look closely at Galerina but I think it might be a waste of time - I identified almost nothing with confidence this year.
Have a great New Year - Slainte mhath!
Steve
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- Lichen-covered sycamore at Longshaw - mostly Ramalina farinacea and Evernia prunastri
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- Usnea subfloridana at Longshaw - recorded 9 times in 2 years. There are similar species but stripping the new growths to check wouldn't be right.