Since 2013 I have been visiting a small area of ‘Celtic rainforest’ I know in Co. Mayo in Western Ireland. It’s hard to find much ecologically significant woodland in Mayo, a place of vast peat bogs, wetlands and where the woodlands are largely low diversity plantations of spruce and larch. Nine years ago I found one woodland on the map and asked my parents if they wouldn’t mind dropping me off there. In March 2022 I had about 30 minutes to check in on this real gem of an oak woodland.
I don’t want to give the name of the woodland openly because it is incredibly sensitive and is already experiencing the impacts of anti-social behaviour (fires, litter, human waste… not that you would head straight there to mess it up!) but if you want to know the details you can contact me via email for info (email@example.com). It’s one of the special Western Atlantic oak woodlands which the western edges of Scotland, England, Wales and Ireland are known for. This woodland is rich in ancient woodland plantlife and is also good for fungi, as you might expect due to the long-term stability of ancient woodland species communities.
Upon entering I spotted the little red traffic light of a scarlet elf cup in among the moss. This is a species which thrives in damp and shady woodlands near water.
The woodland here is close to a large lough so it is never short on moisture.
I was astonished to find this naturally-occuring terrarium on the woodland floor. Someone had chucked a jar here and the mosses and other plantlife had colonised it.
Anyway, I was here to check for an uncommon lichen in the UK & Ireland – tree lungwort, Lobaria pulmonaria. It’s a massive lichen that can be found in these ‘Celtic rainforest‘ habitats. The Woodland Trust say it’s an incredibly rare habitat.
After a few minutes of searching where I had found it back in 2017, I saw this. It is a seriously impressive species.
I was so pleased to find the tree lungwort again. It’s unlike similar organisms we find in the UK. It makes far more of its fungal elements than other lichens through its size and spread. Remember: in lichens, fungi provide the physical structure and fruiting mechanism (usually a cup-style spore shooter), while the cyanobacteria or algae are able to photosynthesise and harvest energy from the sunlight.
The oak trees in Celtic rainforest provide habitat for plants as well as lichen. There are often modest ivy vines trailing the trunk, as well as other epiphytes such as ferns and mosses:
Another thing I noticed was oaks leafing on the 31st March. This may be the earliest I have ever seen oak come into leaf, but the race between ash and oak is certainly a contest. The old saying of “If the oak before the ash, then we’ll only have a splash, if the ash before the oak, then we’ll surely have a soak” doesn’t quite play out from my experience. The very warm March we’ve experienced in the British Isles has possibly more of a role to play in this than traditional benign weather or climate patterns might.
One thing I learned from observing the other communities of tree lungwort were that the lichen seemed to prefer younger trees. I didn’t observe any on more mature specimens of oak. There didn’t appear to be a lot of oak regenaration but then again there was no danger of overgrazing due to the quite isolated nature of the woodland, its lough-side location and livestock being nowhere near.
Another lichen I observed was one of the pixie cup lichens in the Cladonia group but I couldn’t tell you the exact species.
There were many candidates for #StickOfTheWeek, so much so that there wasn’t even much of a stick to look at!
Thanks for reading