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:

Naturalists (the facebook page that accompanies this blog)

See detailed pictures at http://www.inaturalist.org/login  (search - people-stevedaniels-observations)

Cretan Flora

The Nature of Crete  (Flipboard Magazine)

Flowers of Crete;

BIRDS OF CRETE

Crete Birding

Greek Butterflies and Moths

Aquaworld Aquarium

Visit Greece (National Government Tourist Office)

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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LINKS:

Naturalists (the facebook page that accompanies this blog)

See detailed pictures at http://www.inaturalist.org/login  (search - people-stevedaniels-observations)

Cretan Flora

Flowers of Crete;

BIRDS OF CRETE

Crete Birding

Greek Butterflies and Moths

Aquaworld Aquarium

Visit Greece (National Government Tourist Office)