Cardiff Bay Barrage is a monument to concrete, 135,000 square metres of concrete – in fact, it received an award from The Concrete Society soon after it was completed. And lichens love having so much concrete to colonise!
According to that same Concrete Society, ‘As the concrete ages, the surface alkalinity is reduced by carbonation and the action of rainfall, thus providing a more suitable environment for biological growth.’ And, as lichens are sensitive to air pollution, the almost constant blasting of fresh air aids their lush growth, as you can see from these photos, taken during one of last week’s exercise walks.
Just one old fencepost, wood species unknown, but look at the number of lichen species it’s home to, as well as the lichen-loving Springtails. It’s a multifarious microcosm of the wider environment, a miniature landscape of vibrant colour and diverse shapes. Old fenceposts are usually worth a closer look.
These stopped me in my tracks!
I’d enjoyed a nice amble around a local park and was on my way home when I spotted these incredible galls and just had to stop for some photos. The galls are caused by tiny mites that spend the cool winter months huddling in cracks on the tree’s bark, then head out on to the leaves when they sprout in the springtime.
The mites are leaf-sap suckers, and their sap sucking causes a chemical reaction in the leaf, which in turn prompts the leaf to produce these small, conical, hollow growths. The mites are incredibly tiny – less than 0.2mm long apparently – so they’re almost never seen, whereas their cosy gall homes can grow to 8mm long and, when they’re as bright as these ones were, are very obvious on the leaves.
I’m not sure which mites these are as I’m not sure which tree species this is. One mite species, Eriophyes tiliae, is the gall causer on Large-leaved lime trees (Tilia platyphyllos), Common limes (Tilia x europaea) and some hybrid Lime species, and another mite, Eriophyes lateannulatus, causes very similar galls on Small-leaved Limes (Tilia cordata) and hybrid Limes.
Amidst all the greys and browns and dull greens of the wintertime natural world, there are still wonderful wee spots and splashes of colour to be found. These are some I found during today’s stomp around Cosmeston, a rather rapid stomp trying, unsuccessfully, to avoid the rain showers.
I’m not good at identifying lichens but I do love their fresh, bright yellow-greens, especially on the twigs and small branches that have recently blown down from the tree tops.
The tiny bursts of lollipop pink are Illosporiopsis christiansenii, a lichenicolous fungus (that’s a fungus which is parasitic on lichens, usually on Physcia tenella and sometimes on Xanthoria parietina).
And the pretty pops of orange, found on several fence posts, are Common Jellyspot fungus, Dacrymyces stillatus.
One of the Cladonia lichen species is the food of Reindeer but I doubt this is it, though I don’t actually know which Cladonia species this is. As you can perhaps guess from the snippet of sign showing in my photo, the lichen was growing well on a signpost at the Wildlife Trust reserve I visited today. The brownish blobs on the tops of some cups are where the spores of these attractive lichen develop.
‘There is a low mist in the woods—It is a good day to study lichens. The view so confined—it compels your attention to near objects—& the white background reveals the disks of the lichens distinctly—They appear more loose-flowing—expanded—flattened out—the colors brighter—for the damp—The round yellowish green lichens on the white pines loom through the mist (or are seen dimly) like shields—whose devices you would fain read.’ ~ Henry David Thoreau, A Year in Thoreau’s Journal 1851, Penguin, New York, 1993
In this case, though, my rose is not a rose but a lichen that I thought looked a lot like the outline of a rose – my warped imagination perhaps, but pretty nonetheless. I spotted this on a gravestone during a wander around the graveyard that surrounds St Augustine’s Church here in Penarth. I presume it’s one of the Caloplaca species of lichen, possibly Caloplaca decipiens, but many of this species seem to look alike and I am not at all skilled in identifying lichens.
Much to the amazement – or perhaps the amusement – of Cosmeston’s dogwalkers, I spent rather a lot of time closely studying the tops of fence posts today. The variety of lichen to be found on them is really quite astonishing but I wasn’t only admiring the lichen. There were even more interesting things sitting on those fence posts …