Ok folks, our mission for today is to clamber down through these rocks and explore that gully down there. To make things more interesting our route is lined with plenty of spiky plants so our chances of getting to the bottom without being bloodied and bruised are remote to say the least. This lethal looking bush here for instance, which I can’t quite place, looks capable of causing serious injury. I see that it’s producing tiny red fruits and as we have our botanist friend Steve Lenton with us today (although he’s opted to take a more sedate route) we’ll collect a couple and pass them on to him for identification. After all, there’s no point in having a dog and barking yourself. Talking of which, you wouldn’t just like to put your hand in and grab a couple of berries would you? Thought not. Here goes then. Ouch, first blood to the flora.
|Red rocks contain iron|
That’s the difficult part over, all limbs etc. intact? Good. My arm really is bleeding quite profusely now and my hand will soon be as red as that rock down there. I’d ask you to keep an eye out for some woundwort but it only grows down by the coast. The fact that both my blood and this rock are red is no coincidence. The linking factor is iron. Blood contains haemoglobin which uses iron to bind with oxygen in order to carry it from the lungs to where it is needed. Similarly, that rock down there is composed primarily of iron oxides and the chemical bonds between iron and oxygen reflect red light. This is also why arterial blood which carries blood from the lungs and has more iron/oxygen bonds is redder than venous blood which carries blood back to the lungs for oxygen replenishment and thus has fewer bonds.
|Plants take up iron from the soil|
Now I don’t know about you but I don’t go around eating rocks for a pastime so the question is: how does the iron get from the rock to our blood? The answer of course lies in what we eat. Plants like spinach, as we all know from Popeye, are full of iron but in fact all green plants take up iron from the earth in order to photosynthesise. Which begs the question; if it’s all to do with iron why are plants green and not red? The answer is that although the main element in chlorophyll is magnesium, iron is used in its synthesis. Without iron the plant cannot make chlorophyll and the leaves become yellowish in a condition known as iron chlorosis. So all the plants that we see around us here, from the cropped grasses to the trees, are busy taking up iron.
|Herbivores take in iron from plants|
The story doesn’t end there of course. All of the herbivorous animals that we eat, from this garden snail down here to that goat up there, (“Who me?” “Yes, you”) are busily devouring plant material and passing the iron along through the system. Which is good news for us because with insufficient iron in our diet we can’t produce enough haemoglobin and we become anaemic. (The word itself means lack of haem, the iron molecule in haemoglobin). The iron also gets passed along to us in the milk (the goat’s not the snail’s) and although the mineral content of goat’s milk and cow’s milk is fairly similar the body processes iron and the other minerals more efficiently from goat’s milk so it’s a useful addition to your diet.
|Termites help take iron back to the soil|
That just about wraps up our story of how to get blood out of a stone but having got it out, how do we put it back again? Everything that lives must die, whether it be a blood cell, a tree or one of these here termites that are aiding the process of decay. As we go through life, the trees, the termites and us, we excrete waste products and return iron to the soil along the way and then, at the end of our lives, back it all goes to be taken up again or, over geological time, to be compacted, subducted, churned about in the mantle, eventually to re-emerge on the surface as a red rock.
What goes around, comes around as they say. Talking of which, here’s Steve.
“Any idea on these berries which I’ve taken from one of these horrendously thorny bushes, at great risk to life and limb, not to mention septicaemia, for your collection?”
“I’ll have to examine the whole bush and leaves to determine the species but I'm fairly certain it’s a Rhamnus.”
Ah, that would be a Buckthorn in plain English. Not content with trying to stab me to death it’s probably injected toxic berry juice into my fingers. The things I do for botanical research. Oh well, if I’m not dead by next week we’ll continue on down and see if we can reach the village of Agios Ioannes.
The Extra Bit
And now I think we’ve earned one of those beers that I spotted in the back box of Steve’s quad bike. A lovely warm November morning for a quiet drink on a mountainside in good company and you really can’t beat the scenery.
Meanwhile back at home the Hooded Crows have just started to congregate for their November conference. (see also Bramiana In Winter)
Naturalists (the facebook page that accompanies this blog)
See detailed pictures at http://www.inaturalist.org/login (search - people-stevedaniels-observations)