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Tuesday, 6 December 2016

Every Breath You Take

I thought that as we walk down the next part of the gully we’d have a look at air – there’s some, look, right in front of your nose. You can’t see, smell, taste or touch it so what exactly is it? Mainly it’s a mixture of two elements (not a compound – they don’t combine together). The two elements are Nitrogen (78%) and Oxygen (21%). The other 1% contains other elements, primarily Argon.

Rosularia serrata
Every breath you take (don’t worry – I’m not going to start singing again) is for the most part Nitrogen, a vital element for us but the problem is; we can’t use it directly. We need plants to do a bit of work for us like this Rosularia serrata here. It can’t use Nitrogen from the air either, it needs help from special bacteria in the soil that use enzymes to convert the nitrogen into organic compounds that it takes up through its roots. We, and other animals, can then take the nitrogen that we need to produce things like essential amino acids from the plants that we eat. When it, and we, die we pass the nitrogen back into the soil for reprocessing by bacteria. 


Ferns and Mosses
Air hasn’t always been air as we know it today and if we go grubbing about down there in the dark and damp bits we should find a couple of the major players in the events that led to the breathable stuff that we enjoy today. About four hundred million years ago, when these ferns and later these mosses, were the pioneering land plants oxygen was only running at about 15% but plants, as we know, give off oxygen as a by-product of photosynthesis and over the next hundred million years levels built up to about 35%, an abundance that gave rise to giant dragonflies and things. The rise of oxygen breathing animal life brought the levels back down to a range which we’ve evolved to function in which is about 19-24%. 

Darkling and Rosemary Beetles
We seem to have come out into the open air as it were and it looks as if we’re at the head of the oleander highway (see Into The Woods) so we should be able to find some nice insect life in there. We have beetles in abundance. This beefy, black job is the brother of the one we found a couple of weeks back up the valley. That one was Raiboscelis coelestinus with the blue sheen and this one is Raiboscelis corvinus. The other two are Rosemary Beetles, Chrysolina Americana, and they seem to be thinking about expending a bit of energy to make more Rosemary beetles. Which brings me back to oxygen. The reason why it so important to us and all other animals is that we need it to convert glucose into energy in a complex process called catabolism[1]. Simply put, we couldn’t move a muscle without it.

Ant nursery
Apart from the composition of air there are two other aspects of it that are important and those are its temperature and humidity, a delightful illustration of which you can see by looking under this rock that I’ve just turned over. The little white cocoons that the ants are fussing over are the larvae.  These, along with the eggs, they constantly move from one place to another within and just outside of the nest to regulate their conditions as the temperature and humidity fluctuate throughout the day and night. They really are the most dedicated of nursemaids. But now it seems we have reached a defile through which we cannot pass, not without ropes and crampons anyway. I suggest that we walk back over the hill, down through the village of Agios Ioannis and pick up our route again a couple of hundred feet lower down.

Cumulus and Cirrus clouds
Just look at that wonderful cloudscape above us. The large, fluffy one is a cumulus cloud (from Latin, meaning heap) while the streaky ones above are cirrus (from Latin, meaning a ringlet of hair). There are sixteen major cloud types in total, all of which contain water vapour in varying amounts evaporated from the Earth’s surface. You may be wondering; if air is 78% nitrogen and 21% oxygen how come your hygrometer says that its 60% water? Firstly it’s because those percentages are for perfectly dry air and secondly that your hygrometer is measuring relative humidity; the partial pressure of water in the air compared to what it could be if it was fully saturated, and not the actual amount of water in the air. Which is a good indicator of whether it is likely to rain or not and thus of far more practical use as a measurement.

So that’s air, in a nutshell. Meanwhile I think I can see the village below us so we’ll explore that next week.

The Extra Bit

Last week’s marmalade recipe seems to have gone down well so I may well do another in the New Year. Meanwhile if you want to know more about how we convert the sugars in the marmalade into energy then you can read all about it here: [1] https://en.wikipedia.org/wiki/Catabolism

I've just started a magazine called The Nature of Crete on Flipboard. Eventually it will not only contain links to the latest blog but other articles and blog posts about the flora and fauna of the island. If you'd like to read it and maybe even contribute a link then this is the web address: The Nature of Crete 


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LINKS:
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The Nature of Crete  (Flipboard Magazine)

Tuesday, 29 November 2016

The Snail That Built A Mountain


Forgive me if I break into song as we commence our walk into this gully but it’s such a beautiful morning – Sweet painted lady, seems it’s always been the same, getting paid for being laid, guess that’s the name of the game - that’s better; nothing like a bit of Elton John to start the day. OK that was not a bit like Elton John. 
Painted Lady, Vanessa cardui  and Red Admiral, Vanessa atalanta
The reason for this sudden burst of exuberance is the orange and brown butterflies that are accompanying us, Painted Ladies, which we saw a couple of weeks back pollinating the ivy (Life in the Uplands). The red and black butterflies that are also joining us are Red Admirals and the two are closely related. The Painted Lady is Vanessa cardui and the Red Admiral is Vanessa atalanta. I find it intriguing that one should be named after a lady of the night and the other after a high ranking naval officer, a sort of lepidopteran equivalent of the actress and the bishop I suppose.

Italian Vipers Bugloss, Echium italicum




Last week we were chatting about Iron and how it travels from the rocks to our blood but this week I want to have a little look at another chemical element, Calcium. Take this knee high plant down here for instance called Pale Bugloss which looks a bit like an artificial Christmas tree. If you look closely at the stiff hairs on the leaves and stem (a characteristic of the borage family to which it belongs) then you are looking at calcium in action, the element which gives life its hard bits. In our case that means bones and teeth and it gives plants the ability to stand erect.





Snails of the Helicidae family

Snails of course, such as these of the Helicidae family which I’ve assembled on this bit of limestone, use it for shell building. This is recycling in its purest form as limestone, which is primarily calcium carbonate (calcium + carbon + oxygen), is formed from the shells of marine molluscs. When the sea bed was lifted to form these mountains, about 26 million ago, the calcium in the sea shells formed these rocks and the land snails are now taking it back by rasping away at the algae on the rocks and munching the plants that grow on them to make their own shells. And so the elements go round. There are 94 naturally occurring elements in all and nature re-uses most, if not all, of them in continuous cycles.



Lichens
Come on, I’ve spotted a cave, or leastways a medium sized hole in the rocks, I suppose one could call it a cavelet. Let’s explore it. Ooh, lichens. Look at this doughnut shaped one up here. Lichens grow very slowly from the middle out. This one is so old that the original ancestor has died and we’re looking at the succeeding generations. And this one at the back here seems to be almost glowing green. Unlike plants, lichens have no waxy cuticles or pores that they can close to keep out unwanted substances so they are very useful for monitoring air pollution. If you take a piece of lichen, dissolve it in acid and analyse the resultant liquid you can determine the types and amounts of elements that shouldn’t be there. In 2015 for instance the discovery of heavy metals in the lichens of Washington State in the US was traced to a zinc and lead smelter across the border in Canada. [1]

Jumping Spider of the Salticidae family
Ever get the feeling that you are being watched? There’s a little jumping spider on that rock down there and I think that he’s got his eye on us, or to be more precise, at least six of his eight eyes on us. Why so many? Recent research has found that the front pair are for sharp, colour vision including ultra violet. The next pair, the anterior lateral eyes, are detailed motion sensors. If you cover only the main eyes the spider will back away from an approaching object but if you only cover the anterior lateral eyes it won’t. The other eyes are thought to be less detailed motion sensors giving the spider a wider field of awareness but research continues on that score.[2]

This seems a nice place to stop and admire the scenery so we’ll continue on down the gully next week and see what else we can find.

The Extra Bit

It’s that time of year again when the oranges are ripening and it’s time to make some marmalade. When I mentioned this last year so many people asked me for a recipe that this year I’ve decided to publish a supplementary blog post complete with recipe card and a cut out label for your jars. So if you’d like to follow me to the kitchen I’ll show you a simple way to make delicious marmalade that keeps for a couple of years (if you haven’t eaten it all by then)…Steve's Simple Marmalade

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Tuesday, 22 November 2016

How To Get Blood Out Of A Stone

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.[1]

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)



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Tuesday, 15 November 2016

Descent Into The Milonas Valley

Now that we’ve made it all the way up here we’ve got to get all the way back again but this time we’ll come down the Milonas (or Miller’s) Valley. So first we must descend that evil looking slope .


Autumn Crocus, Colchicum pusillum
A quick look at the flowers before we start our descent, most of which we met on the way up, such as the little yellow Sternbergia but there are also these delicate little Autumn Crocuses. Pretty little things that those of you with long memories may remember we met once before when we visited The Waterfall of Milonas a couple of years back and I told you the story of a famous murderer. On the plus side though, it was the original source of the drug colchicine which has a number of uses including treatment of Familial Mediterranean Fever. This is a rather nasty human disease caused by a genetic mutation specific to people of Eastern Mediterranean origin.  Like nettles and dock leaves the problem and solution are to be found in the same place. 

Raven, Corvus corax
I see that our friends the ravens are keeping an eye on us from above. One of these days I’ll get a decent photograph but it’s difficult to hold the camera steady whilst spinning on a scree slope as you may have noticed. You may be forgiven for thinking that a raven is a raven is a raven but apparently not so. According to an analysis of  DNA taken from 72 birds across the northern hemisphere they are all the same apart from those in California which are genetically different.[1]  (I can’t help feeling that this may explain a lot about Californians in general). Incidentally I’ve seen a lot more ravens about this year and at lower altitudes. I wonder why?

Seed Bug, Lygaeus pandurus
Watch your step coming down here, it really is quite treacherous underfoot. I usually find that using the plants as stepping stones rather than trying to step between them gives you a better purchase. I see we have a couple of seed bugs down here, one adult and one nymph. Both the same species as far as I can see; Pistachio Red Bugs. A bit of a misnomer really as they’ll sup sap from a multitude of plants. They’re very hardy little bugs, as happy up in the mountains as they are down on the coast, so you can’t help admiring them.  Talking of the coast, you can just about see it from here (the sea at any rate). 

Darkling Beetle, Raiboscelis coelestinus
We’re aiming for that track below us but first, a fallen pine tree to investigate. Let’s sit down here a while and poke about among the decaying branches and see who’s home. What have you got there? A smashing little Darkling Beetle, no bigger than my thumbnail.  These are cosmopolitan beetles that you can find from the driest deserts to the wettest rainforests and are omnivores, like ourselves. If you want to live all over the world then it pays not to be too fussy. If you look closely you can see that this one has a blueish sheen and that, along with the pattern of dimples on his back helps us to identify him. He goes under the name of Raiboscelis coelestinus if you’re taking notes.

And here we are back on the track that leads to the church. Next week we’ll see what’s lurking in that gully but first – let’s rock. A couple of weeks ago we were looking at minerals and now I’d like to draw your attention to some of the rocks that are lying around, of which I’ve collected a few on the way down. So what’s the difference between a rock and a mineral? To illustrate: the church is sat upon a limestone outcrop. Limestone is a rock which consists primarily of two minerals: calcite and aragonite. Both of these minerals contain the same elements: calcium, carbon and oxygen but they’re put together in a different way. Simply, elements make minerals make rocks. We too are a collection of elements put together in different ways which we get, via plants and other animals, from rocks. So on our way down the Milonas valley we’ll have a little look at the chemistry of life as we go and see how we’re all bound together with the planet on which we live.

The Extra Bit

Black Redstart, Phoenicurus ochruros
The first Black Redstarts of the autumn have arrived on the south east coast. I spotted this female on the way up and there was a male on my gate post as I left home this morning. These birds usually appear in November and overwinter here. They form a part of our ongoing phenological study (see Phenomenal Phenology).




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Tuesday, 8 November 2016

The Final Ascent





Just before we begin our push for the summit there are a couple of other little things in this cave that I’d like to draw to your attention. This apparently dead spider up here for instance. As a spider grows it gets too big for its skin but unlike us its skin is its skeleton and although it is flexible enough to allow the spider to move it doesn’t grow like our bones do. Periodically then a spider needs a new skeleton. How it does this is to start absorbing the inner layers of its existing skeleton and use that to start growing a new skeleton inside. It also produces a fluid to keep the old and new skeletons apart. There is an obvious flaw in this arrangement in that the new skeleton must necessarily be smaller than the old one (like Russian dolls) which obviously defeats the object. Undeterred by this drawback, the spider reabsorbs the separating fluid so that the new skeleton is loose within the old one, pumps itself up until the old skeleton cracks and then bursts out. This new skeleton however is extremely soft and flexible and also folded to some extent. The spider then undergoes a growth spurt to inflate the new skeleton to its maximum before it hardens. Result; one new, bigger spider and one discarded skeleton like this one here.



 

The other things are these curious looking objects growing in this crevice. If I just cut a bit of the surface off with my penknife…ooh, look, it’s like Turkish Delight inside. My guess is that it’s one of the Pannariaceae family of lichens. We’ve discussed lichens before of course in A Kingdom In The Pine Woods but I don’t think I mentioned that they come in eight different forms. The commonest are foliose which have a leafy appearance, crustose which are crusty, and fruticose which are branched in a fluffy, thready sort of way.  This one has flat, overlapping scales if you look at it under the hand lens, see, which is one of the less common, squamulose types. Lovely word isn’t it? The other four types?  Placodioid, leprose, filamentous and those with no visible thallus. Well, you did ask.




I’m sure we haven’t exhausted the possibilities of this little cave but we’d better get on or we’ll never reach the top. Last week we were discussing how the rocks and minerals help to define the character of an ecosystem.  What we’re trundling up now is known as karst and it’s formed when rain dissolves the limestone. All rain is slightly acidic as water reacts with the carbon dioxide in the atmosphere to produce a weak solution of carbonic acid. The more CO2 there is in the atmosphere the more acid the rainwater becomes. Add in a few industrial pollutants such as sulphur dioxide and various nitrogen oxides and you have the problem known as acid rain which has an adverse effect on virtually everything you can think of. Some plants, like this heather (Erica manipuliflora) for example, positively thrive on acidic soils which is why there’s so much of it around. I’ve just thought of something: the girl’s names Heather and Erica mean the same, it’s just that Erica is the posh version and Heather is common. Moving on. There’s a little grasshopper in that patch there, see if you can catch it. Too slow. Still, he’s more used to bouncing around at this altitude than we are so you’re excused.



Whilst we’re on the subject of rain have you noticed what’s heading towards us? That’s thick, black nimbostratus cloud to the north whereas if you look over your shoulder to the south, that’s fluffy, white cumulus cloud. The wind is picking up too as you’ve doubtless noticed and it’s blowing north to south. This is obviously not unusual up here as you can see by the shape of the trees; they’re growing practically horizontally and pointing very decisively due south. I reckon we’ve just about got time to get round these rocks to our left, breast the crest, and then it will be time to get off the mountain. Weather plays a big part in what lives and dies up here and we don’t want to be among the latter.

We’ve made it. All the way from the sea at Agia Fotia right up into the heights of the Thriptis mountains overlooking the village of Monistriaki. The other white rectangular blobs you can see down there are greenhouses. Agriculturally, Crete is a very productive island; not just the olives and olive oil for which it is justly famous but tomatoes, peppers, cucumbers and aubergines are all being grown for the tables of Europe in those unsightly edifices. At these heights we’re very much in vulture territory and that one wheeling about up there is a Griffon Vulture. Massive birds with wings that could cover any one of us laid out on the floor. They were in decline in the nineteenth and twentieth centuries, mainly through eating poisoned bait, but this century, thanks to conservation efforts, they seem to be bouncing back which is good news. It’s getting a bit chilly up here now. Thankfully the rain seems to have held off but we’d better not push our luck – we’ve got a long walk back.

The Extra Bit

Told you it was going to rain didn’t I? Ok, so I didn’t predict a hurricane but technically we didn’t have one; we had a medicane which is a horrible portmanteu word (Mediterranean + Hurriccane). They are rare events but predicted to get less frequent if more intense as the climate warms. We didn’t have it too severe down here in the south east but the normally dry gullies of Ierapetra had a thorough clean out. Wikipedia has a whole page devoted to them: https://en.wikipedia.org/wiki/Mediterranean_tropical-like_cyclone


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