Just to get everybody up to speed, I'm on holiday on the Isle Of Lewis in the outer Hebrides at the moment and am keeping my eye open for anything interesting. We'd already spotted porpoises, jellyfish and a dead monkfish before we'd even got there and, on arrival, we were not disappointed!
The western Isles, which are a very remote, wet and windswept place are renowned for their machair, or beds of wildflowers. This is from the gaelic for 'fertile plane' and represents a flat bit of coastal land, stuck at a fairly neutral pH level between the alkaline sea and the acid bog of the inland.
To expand briefly on that, all soil is either acid, neutral or alkaline. Soils such as chalk, which is the predominant soil type down where I live on the south coast, are alkaline while "good" soils tend towards either neutral or very slightly acid. It's one of those things you get a lot in ecology, where a healthy soil helps maintain a healthy soil. Plants die and are eaten by various critters, down to and including microbes, which creates a rich hummus that is ideal soil for plants to grow in.
It's one of those weird, chicken and egg type situations, where perfect harmony is perpetuated somehow. However, in some places, heavy and persistent rain will wash all these nutrients out of the soil. The western isles are all about heavy and persistent rain. And wind. This makes the soil very acid indeed and, as we know acid and microbes do not get along very well. The rain washes nutrients from the soil, making the soil more acidic, which inhibits microbial life in the soil and microbial life is basically the bottom of the pyramid that all life rests on. Without it, nothing happens.
Last time I was up here, it was February 2015 and I was moving stones around amongst other things. Down south, even in February, when you moved a stone, lots of little critters like woodlouse and centipedes would scurry out of your sight but here... nothing. Not even worms. It was one of the best illustrations of a line in a text book that I'd ever seen. Without microbes, stuff does not rot and so you get great, springy, squishy matts of peat building up over the centuries. Remove a core from these bad boys and you can bring up seeds going bucket just after the last ice age.
So, just to recap, rain washes out nutrients, creating a highly acidic soil. This creates a difficult environment for most plants - the interior of the Isle of Lewis is not thick with fields of wheat, for example - however, this makes it a just fantastic habitat for plenty of rare plants. Orchids, for example.
The four pictured are in the driveway of the place where we are staying. Just to confirm that: in the place where we are staying, there are at least four wild orchids IN THE DRIVEWAY. The one in the picture above is a good foot high. According to my research, it's a northern marsh orchid, on account of the fact that it looks like one, it's in the north (we're about 20 miles south of the most northerly point in the British isles) and it's on a marsh. Dactylorhiza praetermissa to give a species name, though be warned I am not an expert, just a bloke with a book on wild flowers.
This one was probably a common spotted orchid, although according to this same book, they tend to grow on lime soils, which this very much is not. But putting all that aside, isn't it pretty? And they're all over the place. Literally: you look in a roadside verge and think 'oh, another orchid'. Back home, I got quite excited when I saw a few on a roadside verge that had specifically been planted for wildlife. Here... they just grow.
Anyway, just to wrap up, this is not the machair that I described above. That is mostly buttercups and daisy as far as I can tell. This is on the acid bog that covers most of the island. More to follow... stay tuned.
