NATURAL INDICATORS A sign of clean air, Lobaria pulmonaria – also known as lungwort lichen, tree lungwort and oak lung – grows happily on the native broadleaf trees that populate the woods above Old Head, Louisburgh.
Non-natives are threatening to overtake one of Ireland’s only Atlantic-Oak forest that grows on the coast
Country Sights and Sounds
The woods above Old Head are part ancient and Irish and part planted. Old oak and great beech stand side by side; sycamore, birch and holly rub shoulders (or branches) with mountain ash and willow, creating a mosaic of colour and form with the promise of new things around every corner.
The best of this woodland is toward the top of the hill, the climb is steep, sometimes near a scramble, and the temptation to turn downward toward cliff, rocky seascape and the comfort of sand is hard to resist. Still, stick to the task and the rewards are great. Not only do we find some of the finest views of Clare Island and the coast from Mulranny to Achill, we also find ourselves in a Lilliputian woodland, where trees sculpted by stern Atlantic winds grow no higher than five or six feet from the ground and are more horizontal than vertical.
When I brought my botanist friend Ian here and showed him thick drifts of tree lungwort, he pulled a portable microscope from his backpack and spent a happy afternoon examining bryophytes, the variety of mosses, lichens and liverworts that thrive in the moist, maritime climate. He was totally absorbed.
“Clean air,” he said, without looking up.
“This here,” he shuffled his hand through a particularly healthy patch of flat-fingered lungwort before plucking a piece and holding it up to the sky. “Lobaria pulmonaria,” he squinted. “The only moisture it gets is rainwater, and if that is polluted the poor old Lobarai gets it in the neck, as it were. Unlike ourselves it has no way of expelling waste from its body, so once it gets exposed to any kind of toxin it’s as good as dead. Yet judging by the size of these they must be more than 50 years old!”
I feigned interest, which spurred him on. “And look, unlike most forms of symbiotic life, wherein two species support each other with mutual benefits, Lobaria here is comprised of three distinct organisms. The fungal body gives shelter to a type of algae, which is able to harness energy from the sun, to photosynthesise, and provide the fungi with the food it needs to survive. But then we’ve got a particular type of bacterium, a type of cyanobacteria, that lives within the cephalodia. The bacterium takes atmospheric nitrogen and changes it into a form that can be utilised… you’re not listening, are you?’
I confessed, I hadn’t found it easy to concentrate. I might be better off looking for mushrooms, I said, and wandered down the hill to where the trees were taller, to find a broad semi circle of hedgehog mushrooms and just a few chanterelle in the drain where they always grow. When I came to a thick growth of laurel something moved ahead of me. What could it be?
The lightest rustle drew me through the trees. Knowing that most wild things will move uphill if they feel threatened and that it’s a lot easier to follow that way as well, I made a wide circuit of the laurel and came at it from below. Every time I stopped the creature moved at a slightly different angle, making my path back up the hill rather longer than it would have been had I not been diverted. It went from thick evergreen into dead bracken and from there into a tangle of fallen wood where it lay tight and refused to budge.
I threw a stick and out it burst: a cock pheasant, its explosion into towering flight accompanied by strident calls. Up, up, up, it went, way above the trees until it turned with the breeze, set its wings and glided back the way we had come with its long tail streaming behind.
I think I never saw a pheasant here before, though the ground is perfect for them, with plenty of native trees providing a year-round banquet of insects and seeds.
There is one thing though. Where indigenous oak and birch have fallen, sycamore and beech, both non-native and more vigorous in growth, are filling available space. Neither of these species provides near the biodiversity value of oak, yet without vigorous intervention on our part these will overtake the oaks of Old Head over the coming decades.
Back at the top of the hill I found Ian examining a growth of tiny green scales on a low-hanging branch. ‘Look at this,’ he said excitedly. ‘I never saw this one before.’
Old Head. A place worth preserving. If we let it go we’ll never get it back.