Category: Lichen

Caz Walker and I like Umbilicaria spp and other montane lichens, so looking for the only English record of U. hyperborea on Cross Fell in the Pennines was a challenge we couldn’t resist. Two problems: (1) there were no accurate grid references and (2) it is a long walk in so there might not be much time available for searching.  OK and (3) the weather: the species up there are called arctic-alpine for good reason.

The British Lichen Society database has just one entry for Cumbria for Umbilicaria hyperborea, dated 27/7/1979  on a BLS field trip, with a hectad grid reference NY63 giving us 10km x 10km to search! The record gives the location as “Cross Fell” with the notes saying “on tops of several boulders in sheltered enclave on the N side; an area of late snow-lie”.  Narrows it down a bit.  This was echoed in the field trip report in the Lichenologist: “In a slightly sheltered enclave on the N side where the snow often lies into June, U. hyperborea was seen in its only English locality, on tops of several boulders.”  It also references an earlier article by Rod Corner announcing the original discovery on 6/7/77 where it was “Seen in at least two areas of discontinuous scree”, adding that “Cetrariella commixta , a rare montane species in England, was an associated species.”

On our previous trip, we’d slogged up from the Eden valley to Little Dun Fell: a long walk in and out. We got permission from Natural England to reduce the walk in from the Great Dun Fell side – whew!

The day we chose to go, it was due to clear up at lunch time.  It was August, but we set off in the cloud with virtually all our winter gear on amid occasional showers driven by a strong wind. At the top of Great Dun Fell, it was still very misty so we couldn’t see the big golf ball when we walked past 25m away!

Despite poor visibility, we soon found nice lichens on Great Dun Fell in the low heath near the track of the Pennine Way including several small patches of Cetraria islandica. These were not seen on Little Dun Fell, though we knew from our previous trip that the rocks just north of the summit held some great saxicolous species.

When we got onto the Cross Fell plateau Cetraria islandica appeared again, along with Fuscidea lygaea and Myriospora smaragdula on rocks. The weather started to clear as we hunkered down out of the wind at the summit shelter for a first lunch and a hot drink.  We headed over to The Screes on the north side of the plateau and saw a dauntingly huge area of large boulders stretching into the distance, many with an orange covering of algae.

We started looking for vague recesses where snow might lie.  Things started to hot up: we started finding some Umbilicaria spp including quite a green looking U. deusta. And then Caz hit the jackpot, finding what looked like U. hyperborea. There were two thalli on one boulder and I soon spotted another couple on another boulder nearby.

Umbilicaria species are often identified on morphological features, rather than chemical tests or spores, and are usually found in prominent sites on top of boulders or outcrops.  They all have a central holdfast on each thallus. Looking at the upper and lower surface carefully is required, noting whether there are marginal fibrils.  In this case, there were quite a few gyrose fruit but no idisia, soredia, granules or fibrils. The dark brown upper surface had small sinuous folds except at the edges, with one or two new lobes appearing less lumpy. The margins were lacerate. Wetting the lobes we carefully looked underneath: it was uniformly brown with no rhizinomorphs and no thalloconidia.  It looked spot on!  Success!  We took a very small sample in case any confirmation is needed.  According to the ViewRanger app on my phone we were at just under 850m above sea level.

The alternative candidates include U. cylindrica which has abundant marginal fibrils.  U. proboscidea has ridges around the centre of the upper surface, not small folds; it’s not lacerate at the margin.  U. torrefacta has a lower surface with fibrous strands (trabeculae/lamellae).  The rarer U. nylanderiana has a black lower surface with single-celled thalloconidia present.

On the same boulders were a few Melanelia hepatizon and several Cetrariella commixta – splendid. Soon afterwards, Caz found another arctic-alpine specialist Allantoparmelia alpicola along with Parmeliopsis ambigua which we’d seen on Little Dun Fell.  There was also the bobbly version of Stereocaulon vesuvianum ie var. nodulosum.  We also spotted a bright yellow Rhizocarpon – it would be great if this were montane specialist R. alpicola. However later dissection showed it to be R. lecanorinum.  R. alpicola has 1-septate spores, while in R. lecanorinum they are muriform. The literature describes the spores as brown; ours were clearly green as found in other photos online.

We also found Ionaspis lacustris on some exposed rocks, not near water, where it is usually found. We’re guessing that the atmosphere is usually very damp here; indeed quite a few lichens were very swollen.  On the way back we saw Ochrolechia frigida on Cross Fell and Lichenomphalia umbellifera on Little and Great Dun Fell.

We were lucky: we only scratched the surface of the Cross Fell scree area. There’s a huge number more boulders to explore.  We didn’t find Frutidella caesioatra which was described as being on Cross Fell at “the same site, found on a sheltered ledge formed by the juxtaposition of two boulders”. This’ll be much harder to spot – fancy joining us to have a look? 

Chris Cant

1. Coppins & Gilbert (1981). Field Meeting near Penrith. Lichenologist 13(2): p193
2. Corner (1978). Umbilicaria hyperborea discovered in England. Lichenologist 10: p134

2020 was a difficult year. Covid disrupted the usual routines; courses and face-to-face meetings were cancelled; injury affected lots of things too. Thank goodness for lichens! Shortly before the first lockdown began, Chris Cant produced maps of lichen records in Cumbria, including the number of records for each square. So many squares had no records…

… and even in my relatively well-surveyed home 10km square (NY30- Ambleside area) nearly half the monads seemed unvisited. Shortly beforehand, I had started sending in lichen records to Janet Simkin at the British Lichen Society (BLS). So it seemed like a challenge was being laid down: I’d try to record from all the 1km squares in my home hectad.

Needless to say, I failed in my attempt to visit all the squares in 2020: recurrent injury put paid to that. But by summer 2021 the project was complete. There’s over 3000 records on the BLS database and I can safely say that local square recording is a great way to explore an area’s lichens and habitats. I have moved out of the woods and spend more time looking at rocks and walls and buildings. And that desire to get to grips with what I can find locally has significantly improved my identification skills.

Partly because of this, comparisons of the numbers of species found in different squares (and so on) don’t really bear scrutiny: I made no attempt to make visits comparative. But a quick glance at the records shows the only lichen found in every square was Parmelia saxatilis, though Rhizocarpon geographicum (91 records) wasn’t far behind. I was fairly pleased by the “rarity” of Xanthoria parietina (53 squares): maybe nitrogen pollution isn’t quite as overwhelming as I sometimes fear. I found Normandina pulchella in a perhaps surprising 74 squares. That can’t just be because it’s very recognisable: there must be a lot of suitable habitat for it.

Along the way I found lots of interesting lichens: a new site for Sticta fuliginosa s.l. (in a quarry used by outdoor activity centres); the first Bunodophoron melanocarpum and Micarea alabastrites in the South Lakes, the first Gyalecta derivata in Westmorland. And “just outside the square” were a new crag with Umbilicaria crustulosa and a new site for Lobaria virens in Langdale. But more importantly I have learnt a great deal about the lichens of the area and their habitats. I might not have found any “new” woods overflowing with Lobarion, but I’ve discovered hitherto unsuspected basic crags in acid-rocked valleys, and developed an interest in old barns. Peltigera leucophlebia turns out (to my surprise) to be not uncommon on the fells; once I got my eye in Anisomeridium polypori is often to be found on older trees.

There have also, of course, been memorable human interactions: the potential Samaritan who saw me lying by a rock and stopped their car in the middle of a usually busy road to check I was Ok; the young man from Wuhan touring Britain in the midst of the first lockdown (!); the man who was delighted when I showed him Stenocybe septata on an old holly and taught me the Gaelic word “Eolas”, knowledge gained by experience. An apt word for lichen hunting?

As an obsessive walker, cyclist and explorer I thought after nearly 20 years that I knew my local area pretty well. But the need to visit each square kilometre has had me visiting paths and tributary valleys I never knew existed; exploring the little grove of oaks I can see from my window that has never been on the way to anywhere (a nice patch of Sphaerophorus globosus since you ask). And then there’s what I call the lichen by-catch: the first wood warbler of 2020, migrating whooper swans crossing the fells and purple hairstreaks in Langdale.

Questions have been thrown up: whilst so many woodlands have Hypotrachyna laevigata, why is it often on just the one tree? Why is Physcia adscendens so relatively (only 5 squares) rare here? And realisations have been made made: the lichens of basic rocks are pretty widespread thanks to lime mortar creating suitable little “cliffs”. How woodland rocks must have been a vital refuge over the centuries of coppicing and clear felling: Ochrolechia androgyna, Sphaerophorus globosus and Mycoblastus sanguinarius (amongst others) could survive on boulders and cliffs when there were no trees.

So what’s the next project? Shall I go south to SD39, or south east to SD49? Or maybe I should follow the example of peak baggers and do another round? For if the year and a bit of monad recording has taught me one thing, it’s that there is an almost limitless scope for getting out and exploring the many and varied habitats of my local area, learning about its species and trying to understand their ecology. And how a relatively small area, albeit a very varied one, can hold my interest.

Continuing my theme of upland lichens, Caz Walker and I visited Little Dun Fell in the Pennines on 7/6/21 hoping to acquaint ourselves with the arctic-alpine species that have been found there, as well as to see how they are doing. We approached from a friends’ house in Eden valley fellside, so quite a trek with 11 miles total and 600m of ascent!  We saw a ring-tail hen harrier on the way up, along with a couple of curlews and golden plover, though perhaps there should have been more. There weren’t very many flowers but a red admiral butterfly perched on the rocks at the summit of Little Dun Fell (which is just inside the Moor House NNR). The boulders also hid several bits of flotsam including two fluorescent rucksack waterproof covers and that not so rare species Plastic pepsicola.

Little Dun Fell, Great Dun Fell and Cross Fell are on the Pennine Way in Cumbria with tops at over 840m: a layer of hard acidic gritstone, interbedded with other sedimentary rocks, showing as outcrops on the sides of Cross Fell and a boulder field just to the north of the summit of Little Dun Fell.  Great Dun Fell sports a “golf ball” radar station – a landmark visible from afar on the west, and looks like a modern art installation close up.

The altitude and geology of these windswept tops provides a suitable home for various arctic-alpine lichen species that are more usually found on the tops of Scottish hills. Most of the lichen records are from some time ago, though Allan Pentecost visited Cross Fell summit in 2016.  The last lichen records for Little Dun Fell in the British Lichen Society database are from 1979 at a BLS field trip which spent a week in the Penrith area (1). Some notable records have a 6 figure grid reference while others just have a hectad reference.  

Caz had seen a few of the target species on trips in Scotland with the BLS montane group. We should also recognise other montane specialists that we’ve seen in the Lake District fells.  We made a good list of species, re-finding some of the rarities and adding one more.  However, Umbilicaria proboscidea was missing, having been described as locally frequent at Little Dun Fell in 1979. We also didn’t see Arctoparmelia incurva which had been present then, but we could have missed it this time.

We re-found nationally scarce Allantoparmelia alpicola on quite a few boulders – tiny contorted and convex lobes.  In addition we found two small appressed species that look a bit like Cetrarias.  Cetrariella commixta was there previously, but Melanelia hepatizon is new for this top, though found west of Cross Fell in 1990 by Simon Davey.  The M. hepatizon had pseudocyphellae on the lobe margins and the surface of the thallus; not present on the upper cortex of the C. commixta. More definitively, in M. hepatizon the white medulla is K+ yellow while in C. commixta it is K-. Note that the algal layer will turn greeny yellow during the test.

We also found Parmeliopsis ambigua on a boulder. This is mainly on acid barked trees, but it was found here in 1979 and there are a few other saxicolous records for Cumbria, with some of these on headstones in graveyards. It is yellow grey with globose soralia testing yellow with K.  We wanted this to be Arctoparmelia incurva but that is KC+ pink and has different shaped lobes.

Schaereria cinereorufa was also present, with the uniseriate globose spores confirming it later.

In the turf, slightly surprisingly, was good old Bilimbia sabuletorum which we wouldn’t expect in an acid environment. However there is basic rock in the area.

Fifty metres closer to the actual summit there are two fenced exclosures, erected in 1954.  The 1979 BLS trip report says that these had taller vegetation inside, with Cetraria islandica and Cladonia arbuscula having increased their cover to form large cushions. The exclosures are still there with intact fences, but we saw neither of those species in a quick look, though we did see Cladonia ciliata.  The inside vegetation is indeed slightly taller, but not a lot, so the extremes of weather do stop dominant species even with no grazing or trampling. I don’t think the two lost species were present outside of the exclosures in 1979, presumably due to grazing or historic burning. But any chance of recolonisation now seems to have gone. Update: We did see Cetraria islandica on a later visit to nearby Great Dun Fell and Cross Fell.

There’s a similar old exclosure at Cow Green Reservoir (also in Moor House NNR) that we visited on 29/7/20. The growth there was similarly slightly higher inside, and had bushy C. islandica along with Common twayblade and Cloudberry.  So, it feels like the Little Dun Fell exclosures aren’t doing very well, even with grazers excluded.  A long term study of the Moor House vegetation plots, 2015 (3), says that “during the period that Moor House has been protected as a nature reserve the vegetation quality has declined in spite of reductions in grazing pressure.”  The study reports Little Dun Fell as having the highest numbers of sheep (at 5.8 per hectare average between 1954 -1998) but says that “overall, removal of sheep grazing had few positive effects and many negative ones”. It doesn’t reach any definitive conclusion as to what’s going on but speculates that “it is possible that this reflects a continuing late-twentieth century impact of  atmospheric pollution”. Increased temperatures from climate change won’t help. 

That report also says, “What is of particular concern are the reductions in the probability of occurrence of liverworts and lichens.”  “Biotic homogenisation has now been detected in Great Britain at the countrywide-scale (Smart et al. 2006) and within alpine communities (Britton et al. 2009 (4)), and it is possible that this reflects a continuing late-twentieth century impact of atmospheric pollution”. A paper from Mitchell in 2017 (6) echoes these findings: less specialist species are invading the highest refuges for alpine species of various taxa. The combination of warming and nutrient loads in most uplands is therefore reducing biodiversity.

It would be good to check out more of these Pennine tops to get a better overview of the situation, so, as usual, a repeat visit is required, ideally with less of a walk-in.  In particular it would be lovely to check the only English record of Umbilicaria hyperborea on Cross Fell, in the database for 1979 following its finding by Rod Corner in 1977 (2).

Re-finding existing records is great to build up your knowledge – and check the state of play on the ground. The distribution lichen maps for Cumbria are online here, and I can provide full records –  and the BLS records officer is happy to provide database snapshots for other parts of the country. It’s also good to visit new areas – and thinking about the geology and vegetation can suggest where to look.

Chris Cant

1. Coppins & Gilbert (1981). Field Meeting near Penrith. Lichenologist 13(2): p193
2. Corner (1978). Umbilicaria hyperborea discovered in England. Lichenologist 10: p134
3. Milligan, Rose & Marrs (2015). Winners and losers in a long-term study of vegetation change at Moor House NNR: Effects of sheep grazing and its removal on British upland vegetation.
   https://core.ac.uk/download/pdf/82709587.pdf
4. Britton et al (2009) Biological Conservation 142/8 p1728-1739
   Biodiversity gains and losses: Evidence for homogenisation of Scottish alpine vegetation
   https://www.sciencedirect.com/science/article/abs/pii/S0006320709001451
5. Britton et al (2016)
   Climate, pollution and grazing drive long-term change in moorland habitats
   https://onlinelibrary.wiley.com/doi/abs/10.1111/avsc.12260
6. Mitchell et al (2017). Biological Conservation 212 p327-336
   Forty years of change in Scottish grassland vegetation: Increased richness, decreased diversity and increased dominance
   https://www.sciencedirect.com/science/article/abs/pii/S0006320716310722