Attack of the mechanised symbionts?

There's not been much happening on the wildlife-watching front this weekend, as household chores took precedence and the upcoming festivities loom ever closer. But that doesn't mean I'm not thinking about Nature.

Perhaps it's an age thing, but as one grows older, is less active and possessed of duller senses, the sections of the biota that reflect these characteristics increase in attraction. I am thinking of the stuff that can't run or fly or swim away, which then becomes more apparent. At least when they come into focus. Trees, for instance, which are often so permanent in our landscape that we fail to notice them until they're gone, attacked by disease or the sharp edge of some implement. And then there's the life that grows on trees, and elsewhere, like mosses and lichens.

I well recall some of the lichens that we have found thriving in harsh environments, perhaps hanging from the branches of a stunted, wind-lashed oak tree on a Welsh hillside...

or clinging to a dry stone wall at the top of a storm beach in the Northern Isles...

These slow-growing lifeforms have been able to attain a size relative to their age, in no small part due to their undisturbed habitat and the unpolluted atmosphere in which they live.

I am not an expert on lichens, only being vaguely aware that they are symbiotic organisms, consisting of fungal bodies inhabited by photosynthesising algae. To be honest, I haven't even tried to identify the few species that I've photographed, especially since there's reputed to be in excess of 2000 species in the British Isles alone. For more official and knowledgeable information, please visit the British Lichen Society website.

Lichens can be excellent indicators of the state of the environment, certain species only thriving in sites free from air pollution. Many have evolved to inhabit small ecological niches, and coupled with poor colonising ability, this can be a good indication of the age of a habitat or its length of appropriate management.

All this comes as a shock to me, as the bit of lichen with which I'm most familiar is not found in the Elan Valley in Wales, nor at Bridesness on North Ronaldsay, but more weirdly on the back of my truck. It is one of the few ecologically-redeeming features of my diesel-burning 4x4 that the spare wheel cover is home to its own micro-habitat. This despite sitting in the prime spot for exposure to exhaust fumes, road spray, windscreen washing fluid and the occasional high pressure hosing at the local carwash.

Tucked away on the very top of the cover, somehow clinging to the stitching of the fabric, is a small colony of... something.

That life can exist in such an artificial, unhelpful and polluted place, does inspire hope for the future of the planet.