West Cork Palaeoecology - the natural world around us, from past to present

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Introduction to the Blog Pages

These webpages are a series of blog posts that refer principally to my work on the palaeoecology of West Cork. As time progresses my focus of study will move to various sites across West Cork.

Palaeoecology is the ecology of the past, generally the distant past, as in ancient.

In reality of course it all connects seamlessly in a long unbroken timeline, so what we see today, is yesterday’s future and tomorrow’s past.

It is the traces that environments leave that can be used to get some understanding of what environments existed and what life was in them at any particular time, and if we can extract a whole series of these traces through time, then we can maybe see how landscapes and populations interact and change, and maybe understand why.

This photo shows a beach on the shore of Bantry Bay in which we can see the traces of at least 4 different environments, from different times, all lying together. The enormous 30m mound of boulder clay deposited under the 300m thick ice sheet from maybe 18,000 years ago; a woodland floor that grew in the valley after the ice but before the sea levels reached their present state (right inset), todays beach, and the sediments of interspersed grey mud and yellow silt from 300 million years ago when this area was an arid plain being washed by periodic floods (left inset).

Beach beach on Bantry Bay south shore

Ecology deals with the living systems, organisms and the environment they inhabit, and the chemical and energy flows into and out of the system. Ecologists study these systems in the here and now, and sometimes over a period of time, but what is lacking is a long term picture of how the system behaves over a long period.

Palaeoecology can give just that, a long term picture of the ecosystem over long periods of time - hundreds or even thousands of years. Even, using geological remains, hundreds of millions of years. But palaeoecology generally lacks the facility to understand all the organisms and all aspects of the environments, because not all of these are preserved.

Thus the methods and principles of both ecology and palaeoecology are complementary, and each can be used to expand the scope of the other.

By combining knowledge and understanding of present day ecology, with the information gleaned from the sediments and fossil remains from the past, we can put together a picture of the environment at that place at a particular time. This can be combined with knowledge of more wide reaching situations, like global climate, changes in atmospheric constituents and so on, to fill in some details and build a more complete picture.

My personal interest is in discovering what was alive at those various periods, and what the environment was like at different times, with a focus on appreciating the variety and diversity of organisms.

When I see something in the landscape, I ask myself, and want to know, what it is, why is it there, how did it come to be, how long has it been there, what was there before it. I want to create a picture of that thing, place, or feature, as it was before. A large scale background picture can be created, either through research or examination or enquiry, based on clues and discoveries. Then using knowledge, appreciation, and understanding of the natural world, we can go a long way to filling in the details.

What is Palaeoecology?

Palaeoecology, as I have already said, is the ecology of the past; most usually the distant past. But palaeoecology can involve investigation into the ecology of some geological period long gone, hundreds of millions of years ago; or it may involve investigating the relatively recent, historic past. Like the remains of a pond from the early 1900’s.

The most direct way to delve into the ecology of the past is by examining sediment, and anything deposited in that sediment, for clues left by living organisms or events. Clues left by the action of the climate on the rocks, by living things living, and dying, and clues left in the sediment themselves as to how they formed, what from, and why.

The sediments most suited to such enquiries are those rich in organic matter, and in Ireland there are plenty of those. Bogs, mires, and lakes.

A lot of palaeoecological studies have been undertaken in areas of uplands, largely because those areas have been assumed to have been interfered with least by human action in the more recent past. Which is reasonable - fewer housing developments, less intensive agriculture, and little industry has traditionally been found in upland areas. They are generally harder to get to, more exposed to the elements, the ground is less fertile and so on. But of course, they are upland areas, and what are uplands now, have been uplands for a long time, certainly for as long as most palaeoecological studies will extend back. And we all know that the climate, flora, and fauna are all different up there. So to get a picture of what life and the environment was like down here, where humans have mostly lived for most of history, in the lowlands, we need to study the palaeoecology of lowland bogs, mires, and lakes.

So, why bogs, mires, and lakes? And what is the difference between a bog and a mire?

Bogs mires and lakes are all wet places, and if sediments remain wet oxygen is largely excluded which makes the sediment anoxic, i.e. deprived of oxygen. This reduces bacterial and microbial activity and so decomposition is reduced to a minimum. There is therefore a better chance of more organic remains being preserved. Additionally, because of this anoxic state, the sediments are high in organic matter, which makes them well suited to radiocarbon dating. So lakes, mires, and bogs contain lots of macro fossils, big enough to see, potentially of both plants and animals, and also microfossils of all sorts.

These environments, as well as being wet, are often acidic, which also reduces microbial action. Siliceous rocks, high in silica, like we have in West Cork,can also give rise to acidic mires. Limestone areas are generally more alkaline, and an added complication with limestone is the effect that the carbonate can have on radiocarbon dating - but we do not have to worry about that here in West Cork.

A bog is generally considered to be both largely populated by sphagnum mosses, and the water comes mostly from the atmosphere, as rain. Mires have a somewhat different flora, not based on sphagnum moss, and the water comes from the ground as well. This means there is more of a mineral component, which affects the nutritional value of the sediment. But of course there are extremes in both cases, and there are all the possibilities in between. A raised bog is a vast community of sphagnum moss that has grown upon itself, above the water table, retaining its own water and taking nutrient and moisture only from the atmosphere, whereas a minerogenic mire is best shown by a river swamp that expands out into a large flat wet area, ground water flowing in all the time and washing in minerals. So really the difference between a bog and a mire is that a bog is low in nutrients, lacking in mineral sediments and largely populated by moss; a mire is high in mineral nutrients, lower in mosses and based on, and interspersed with, influxes of mineral sediment.

Palaeoecology in West Cork

Ireland is a country that is well suited to palaeoecology.

In West Cork we have some lovely uplands, but we also have a lot of lowlands, and there are still a lot of small bogs and lakes. In a lot of cases the bogs and mires were too small to be commercially developed and so in most cases retain their sediments. They haven’t been dug for peat or turf.

In West Cork the geology is almost entirely siliceous, that is, made up from silica based rock, and so is potentially slightly acidic; as opposed to lime based rock, like limestone, containing lime (calcium carbonate), that would be alkali. Some rocks in West Cork have a slight calcareous element to them, but really there is only one small part of West Cork that has true limestone. An added complication with limestone is the effect that the carbonate can have on radiocarbon dating. Carbon from the limestone, released as the lime reacts with the slightly acidic rainwater, can alter the proportions of isotopes that are included by living organisms in their structure. In these cases the ratios of the different carbon isotopes do not reflect the atmospheric ratios, and although minute, this can affect the calculation and calibration of dates. But we do not have to worry about that here in West Cork.

Being a rural area the effects of past glacial action can still be quite easily seen. Indeed it can in most parts of Ireland, but again West Cork is special in that there was - it is thought - a separate ice sheet covering Cork and Kerry, which means a lot of the effects of glacial erosion and deposition are quite local. And also still quite fresh and visible.

(We need to be careful with the term glacial. It gives images of glaciers, rivers of ice moving ponderously down a valley. But a more realistic image should be of an ice sheet, a layer of ice maybe 200 or 300 or even 1000 metres thick, lying on top of, and moving across, the landscape, sometimes, but not always, following the topography. Also bear in mind that the sea level was quite a bit lower, 100m or more, so most of what we know as the coast now was five or even ten miles inland then.)

As mentioned in the introduction, palaeoecological analysis can also be employed on rocks, and this has been done for the sedimentary rocks that make up the foundation of West Cork. Geologists studying the area over the past 100 years have combined knowledge of similar rocks of similar ages at other locations, and the fossils they contain. The results do not seem to be widely known - and they should be.

The geological palaeoecology of West Cork is a fascinating subject, and deserving of a separate blog entry (see here).

Algae - possibly the most important set of organisms on the planet

Most of us are familiar with the concept of algae, principally as a green growth on puddles, lakes and ponds, on a damp wall, an abandoned car, damp rock or wood. Anywhere damp really. And that is exactly right. Algae prefers to live either where it is wet or where it is damp.

Algae used to be thought of as a member of the plant kingdom, but that has been revised now, for various reasons. Once we start looking in detail at the various types of algae, we can start to understand why that is.

There are several different types, or classes, of algae, and they are an important consideration in palaeoecology. Some, the diatoms, have skeletons, or frameworks, that persist through time and endure as fossils. Some will only live under certain very specific environmental conditions. And most of them are the basis of the interlinking foodweb by which most natural organisms are sustained. Most algae are autotrophic, that is to say they produce their own food in a similar way to plants, by photosynthesis. They use the energy from the light of the sun to manufacture sugar, which is an energy store, from water and carbon dioxide, producing oxygen as a waste product.

When we combine this fact of carbon fixation, oxygen production and sugar manufacture with the almost complete global distribution of algae anywhere where it is wet or damp across the globe, the fundamental importance of these organisms to life itself becomes more understandable. It is often quoted - because it is true - that the largest single organ of the human body is the skin. This is exactly paralleled by the covering of algae across the globe, making it the most important organism which is also fundamental to life.

Because algae requires light to photosynthesise, it is found where light can penetrate. Surfaces of wet and damp areas, including the soil, bogs and mires; the surfaces of the sediment lying at the bottom of lakes, ponds, rivers, streams, and the ocean, at depths where light can reach. Other damp areas such as damp rock faces, walls, tree trunks, leaves; even on ice, snow, animal fur, and birds feathers.

Algae are generally small individuals, microscopic, measured in hundredths of a millimetre, sometimes reaching some tenths of a millimetre in size, occaisionally larger. They reproduce both asexually and sexually, over quite short time periods. Some of them can move, either with a smooth gliding motion, or by the use of whip like tails, or brush like cilia. But no matter where they are, from the tropics to the poles, from the ocean to a mountain top, they are fixing carbon from the atmosphere, producing oxygen and making sugar.

Some of the algae encountered in palaeoecology are extremely important and widely used, like diatoms, single celled photosynthesising algae with frameworks made of silica; some less so, like the dual celled desmids; and some rarely occur in the fossil record except by very subtle signs, such as the green algae.

So whenever you think of biodiversity, make sure you put the algae, those microscopically small green producers upon which most of life exists, at the very top of the list. As is so often the case in nature, it is the things we know little about, or can’t see, or even don’t know exist, that are so very important.

Algae are just one constiuent of phytoplankton, the vegetative microscopic organisms that form the basis of the oceanic food web globally. See here for a short film that demonstrates how widepread and vital such microscopic organisms are.

Desmid Algae - immortal cells, or dual aged?

Desmids are a type of algae. The Desmidiales. It reminds me of a song - but that aside, these present us, with our narrow restricted view of life forms and the way that things should be, with another interesting conundrum.

Desmids can be recognised by the fact that these single celled organisms are generally formed of two symmetrical halves, connected in the middle.

Each half is known as a semicell, and each semicell contains a very large chloroplast by which it photosynthesises. The two semicells are joined in the middle by a very narrow isthmus where the cell's nucleus is to be found. Because the chloroplasts in the semicells are so large, the general appearance of a desmid is bright green. They stand out quite prominently when seen under the microscope. Indeed, they colour the waters of ponds and puddles, water tanks, drinking trucks, and lakes.

Desmids photosynthesise and are a lovely bright green. They are also beautiful shapes with a high degree of symmetry. They used to be regarded as part of the plant kingdom. And yet some of them are capable of movement, by either the use of cilia, hair like projections that enable a sort of swimming motion; or by flagellae, one or two long whips by which they ‘whip’ their way through the water. Hardly the behaviour of a typical plant.

A montage of various desmids from Three Lakes in West CorkA montage of various desmids from Three Lakes in West Cork. Note the two parts to each of them. The eye shaped ones are the same as the triangles, just seen from a different angle. Spot the diatom that sneaked into the picture.

When the desmid wishes to reproduce, the two semicells split, each taking a small replicated nucleus with it. So one desmid formed of two semicells joined by a nucleus, becomes two separated single semicells each with a small nucleus. Once separated, the second semicell grows anew.

What this means is that each desmid is made up of two semicells - of different ages. So how do we determine the age of the single celled desmids? One half is older than the other, and yet a semicell is not a complete desmid. Or is it?

And if reproduction continues in this fashion, one semicell continues on down through the generations. Does that make it immortal? Well, longlived anyway, until it dies.

Brook, A. J. 1958. Desmids from the plankton of some Irish loughs. Proc.R.Irish Acad.,B.59, 71-91.

West, G. S., and Carter. N. 1923 British Desmidiaceae. V. London, Royal Society.

West, W., and West, G. S. 1905 British Desmidiaceae. II. London, Royal Society.

West, W., and West, G. S. 1906 A comparative study of the plankton of some Irish Lakes. Trans. Royal Irish Acad., 33, B,77.

West, W., and West, G. S. 1908 British Desmidiaceae. III. London, Royal Society.

Jobs, with no one to fill them. That’s loss of biodiversity

In Ireland today - and probably all across Western Europe as well - there are problem situations in the job market. There are jobs that it seems no one wants to do. Farmers are crying out for milkers, for drivers, and it seems that any job that requires hard work, long hours, and getting dirty, is not popular. People have got the idea that staying indoors, in the warm and dry and in a nice clean environment, is preferable. A better way to earn a living.

Let us hope this doesn’t get worse, and also that this doesn’t continue. Because if these businesses can’t get employees to do the work, the businesses could collapse. And if too many businesses collapse, the economy collapses. And if we take the whole idea to an extreme, that bodes very ill for all of us, whether involved in the job market, living in central Dublin, or rural West Cork.

This is a perfect parallel example of the need for high levels of biodiversity. Think of each ecological niche as a job opportunity, specifically a job for a certain set of special skills. And think of each organism as possessing a certain set of unique skills.

With high biodiversity, every job is filled by a skilled worker, and the whole system - the ‘economy’ - prospers. If the odd job, or odd set of workers fail, die out, get disrupted, the effect on the economy is slight and the hiccup is taken up by the rest of the workforce.

But the fewer skilled labourers there are, the more jobs there are that remain unfilled, and so holes appear in the job market, unfilled positions, businesses that cannot operate, functions that cannot be filled, services that cannot be provided.

At a certain point, the gaps become a serious problem, and the whole economy starts to suffer. And then if there is some slight disruption to the market, like a war in some distant country affecting the flow of produce, there are few workers who can step into the gap, make up the shortfall, fix the problem; or if temperatures rise or water supply drops, there are fewer organisms that can cope with the change, and fewer that can fill the gaps that arise. Eventually we are looking at the collapse of the system, with an inability to sustain itself to a degree that is even near useful.

High biodiversity, like a population of skilled, willing and variously experienced workers, gives a highly resilient and productive system. Resilience to change and disruption, and an ability to survive and continue.

Loss of biodiversity is like a population of unwilling, uncooperative, unskilled workers - it is vulnerable at best, disruptive at worst.

So for High Biodiversity - think Resilience - think Productive - think Survival.

I don’t think that is too strong a comparison.

Next time you think about getting the weedkiller, insecticide, fungicide, or mosskiller out - think of the labour market and what you are going to do to the economy. You are about to make some vacancies that cannot be filled.

It’s all Greek and Latin

Epitheca and hypotheca, the two parts of the diatom frustule, can be remembered by the fact that the epitheca, epi meaning above or upper (think epidermis, the upper layer of the skin), sits above and over the hypotheca - hypo meaning lower or below (as in hypodermic, below the skin). These two parts fit together like a box, with the epitheca acting as an overlapping lid that sits upon the hypotheca. The water in the surface layers of a lake are called the epilimnion, the deepest layers the hypolimnion. Limnic refers to lakes - see the entry below about Three Lakes.

The use of Greek or Latin words, the classical languages, in science has been cause for complaint by many people, most often students who find the new language terms a hurdle. But it is also seen as a barrier to the non-academics, a barrier that prevents them from even trying to understand what is being said or what has been written.

This is a great shame, and a failing of our school education system. These terms are not difficult, and in fact they are very logical. Indeed there are a lot of them that are incorporated into our everyday language and which we use without a second thought.

Maybe that is the secret. We should think more about the words we use.

But why do the sciences use so many of these Latin and Greek terms? The simple answer, and the most practical answer, is because they work so well at being additive, and embrace whole concepts in one single compound word. Things that in English - and possibly in other languages too, though I know German often incorporates nice long words that convey a whole sentence of meaning - but in English certainly, a sentence is instead required. As an example think about the word palaeoecology. Palaeo has the sense of past, mostly the ancient past, as in palaeolithic (including lithos which means rock or stone - so old stone age), palaeontology (incorporating onto meaning living being or creature, and logos meaning knowledge of - the study of ancient living things). Ecology incoporates the logos element as well as eco which is from the Greek for home, oikos - the study of our home, or the natural home of living things. Thus palaeoecology is the study of the natural home of living things in ancient times.

In addition to just extracting what the words mean, when added together they take on a specific and more complex meaning. Thus ecology is widely understood and is in reality a far more complex idea than just the study of the natural home of living things - it incorporates an understanding of the flows of energy and materials, the interactions between the environment and the living organisms, between the different organisms and relationships and fluctuations of all the populations. In fact the whole ecology of an area, however small, is so complex that it defies full understanding in all aspects.

The most basic Greek and Latin terms that are widely used in the sciences are not difficult. They have to be learned, but since so many are already incorporated into words in everyday use, the task is not that great.

There is the historical fact that Latin, and to a lesser extent Greek, was the language used by scholars and therefore enabled people from different cultures and languages to be able to communicate. It is still used in some cases in scientific papers particularly in cultures that use different letter systems - Chinese or Cyrillic for example.

Knowledge of these classical language terms would expand the vocabulary of modern English that is in use, and would also improve the ability to understand so much more. In fact it would also make the romance languages of French, Spanish and Italian less alien to English speakers.

A Floral Survey, Amoebae,and Bacteria

With palaeoecology being a study of past ecology, we have to decide at what point the past becomes the present. Or do we? In the case of the study at Three Lakes, I decided that the present is just the most recent part of the long timeline, and since I am looking at the fossil pollen and spores in the sediment, and using these to determine the vegetation at the many different times over the past 16,000 years, the vegetation at Three Lakes now is just the latest in that line.

So we undertook a floral survey (Fig 1).

Fig 1 - Surveying the lake margin floraFig 1 - Surveying the lake margin flora

The first one was done in June, on midsummer’s day in fact. But because different plants flower, seed, live, and die at different times throughout the year, we will probably do a similar survey every month of the year. Added to which there are so many habitat types it just isn’t possible to cover the area without an army of people. A small army. More about the floral survey will be forthcoming later.

I am also taking monthly diatom samples for the same reason - diatom populations rise and fall at different times of the year, and to compare my samples of fossils, that represent what got left behind and preserved, I need a full representative sample from today.

I was surprised, when I paddled in my canoe around to the south eastern wing of the lake, to find blobs of black slime floating like little black jelly icebergs, hanging down in the water. There was an accompanying petrol like sheen and a vile sulphurous smell (Fig 2). The water was warm to the touch following a very warm spring.

Fig 2 - Nasty stinky black effluentFig 2 - Nasty stinky black effluent

Under the microscope this black slime was not, as I had hoped, a diatom bloom, and all I found were a large number of large amoebae, between 50 and 800 microns across, which it seems are of the genus Pelomyxa (Fig 3) Also see here. Was it these amoebae causing some sort of anaerobic respiration? After contacting two experts in their fields, Wim van Egmond and Ferry Siemensma, both in Holland it seems that this phenomenon is not uncommon in freshwater lakes and ditches of the Netherlands. It was suggested by Ferry that a bloom of cyanobacteria (blue-green algae - but actually bacteria) on the bottom of the lake, amongst the low oxygen environment that Pelomyxa prefers, caused a generation of ?sulphurous? gas that caused rafts of sediment to float to the top; carrying poor oldPelomyxa with it.

Fig 3 - A selection of Pelomyxa amoebaeFig 3 - A selection of Pelomyxa amoebae

But after a couple of days, when I looked at the sample again, it was infused by hundreds if not thousands of spirochaete bacteria, all wiggling like little corkscrews (Fig 3). At least, that is what I think they are. But they may be Spirilla bacteria, which are ‘helically curved rod-shaped cells’ (Brock Biology of Microorganisms 16th edition). I do not have the time to go down the bacteria route.

Fig 4 - ?Spirochaete bacteria?Fig 4 - ?Spirochaete bacteria? Scale bar is 10 microns

Just to top it all off, it was just that part of the lake where I took a sample the previous month (May) of some shoreline sediment. Amongst the diatom community I found some strangely shaped diatoms that defied identification. Experts at the diatom group forum suggested they were teratological forms, that is, diatoms that have grown in deformed shapes (Fig 4). They are most likely of the genus Eunotia. Interestingly, what makes them deformed is likely some condition within the environment that results in aberrant growth. Might this be the action of blue-green algae proliferating? Or was the bloom caused by the same condition that caused Eunotia to deform?

Fig 5 - Various Teratological forms of EunotiaFig 5 - Various Teratological forms of Eunotia

We are inclined to immediately think of human causes for this 'pollution', but it might equally well be natural causes. There is only one inlet stream to the lake, running through a small number of pasture fields, as well as an inflowing connection from the western lake. These lakes are high up in the watershed and surrounded by either forestry with minimal disturbance, or non-intensively managed pasture. Natural events can have similar effects to human pollution, but it generally fits in with the ecology of the area. An example is just these anoxic and sulphic conditions that occur when large amounts of organic matter accumulate in a wet environment. In extreme, this is known as a euxinic environment, taking the name from the Black Sea, where such an environment occurs at depth, resulting in black mud rich in iron and sulphur. Temperature plays a big part as well, and interestingly when I visited 8 days later, after the weather had turned cool and it had rained, the black slimy rafts had all gone.

A lifetime of study on the occurrence of iron sulphide, also known, when crystalline, as pyrites, has been the work of David Rickard and his book “Pyrite: A Natural History of Fool's Gold” is full of surprises. Not least the fact that pyrites occurs almost everywhere where anoxic and sulphic respiration occurs, resulting in it being one of the most widely occurring minerals, albeit in microscopically small grains, on the planet - and often created by organic action.

Finally, a very in-depth study which yielded fascinating results was undertaken on Lake Vechten in Holland. The resulting paper detailed the variation in 10 different environmental parameters at different depths throughout a full year; temperature, pH, dissolved oxygen, dissolved organic carbon, sulphides, nitrates, sulphates, phosphates, ammonium, and chlorophyll A. The lack of inflow into Lake Vechten is similar to the Middle Lake which has only a small stream flowing in, but Vechten is up to 10m depth, whereas Middle Lake appears to be a constant 2.5 to 3m depth, so possibly the waters of Middle Lake do not get stratified to the same degree. There is room here for some fascinating studies.

See Diao M, Sinnige R, Kalbitz K, Huisman J and Muyzer G (2017) Succession of Bacterial Communities in a Seasonally Stratified Lake with an Anoxic and Sulfidic Hypolimnion. Frontiers in Microbiology. 8:2511. doi: 10.3389/fmicb.2017.02511

The Floral Survey at Three Lakes

Wet Willow Woodland with Royal FernsA very special lakeside wet willow woodland habitat with Royal fern understorey

The reasons for taking a floral survey as part of a palaeoecological study are three fold.

At the present time there are major concerns, world wide, but also specifically in Ireland, that biodiversity is being lost. This is happening at an alarming rate, and as described in other posts, there are several reasons for this. But a major part of understanding what has been, and is being, lost, is to find out what is there now, so biodiversity surveys are all the rage at the moment. Ireland has a specific organisation and website for understanding this - The National Biodiversity Data Centre - and data is being accepted from any genuine source - citizen science is coming into it’s own at last. The floral survey at Three Lakes will add in to this.

As a postscript to that first point there is also a scheme to register habitats across Ireland, and the original habitats defined by Fossitt (see here - pdf file) have since been replaced by a national vegetation classification ( see here - NBDC) which is managed by the National Biodiversity Data Centre. As well as determining the degree of biodiversity by surveying the vegetation, we will also be able to help define specific habitat types as we find them, and any variations that may be found.

Small selection of special plantsA small selection of plants from the various habitats within the Three lakes area

More specifically related to palaeoecology is the fact that having determined the vegetation that exists at this place today, we can make use of this to understand the vegetation of the past.

We shall be examining the pollen record from the top layers of the core, and we can make the assumption that the vegetation growing today is not so very different - because we believe the habitat types have not changed - from what grew here a hundred or two hundred years ago. So we can then relate the pollen preserved in the bog or lake sediment with the vegetation that was producing the pollen. Not all plants produce the same amount of pollen, and not all pollen is preserved, so looking at pollen does not give a complete picture. But maybe we can fill in the gaps by understanding what plants grow together, so finding pollen of one plant can indicate that another set of plants were probably also present. This will help to interpret the fossil record and build a picture of the vegetation from that time. An added implication of this aspect is that we shall also have to survey the vegetation of the surrounding area, the valley sides, back west towards the watershed, and eastward into the gorge. That way we can gain an understanding of how pollen from further afield ends up in the sediment we are examining.

The third use of the vegetation survey is simply to provide a final stage in the historical record of the changing plant communities over time. At Three Lakes the sediment covers the last 16,000 years, approximately, providing a record that goes back to the end of the Ice Age. In the intervening time the vegetation communities have built up through various changes in climate - a warming after the ice, a severe cooling for a thousand years or more at the Nahanagan Stadial (otherwise known as the Younger Dryas), and then, in the Holocene, a warming to above what used to be normal, then slight cooling. And of course we are now going into a rapidly warming period.

The record will continue into the future and we can assume there will be some quite severe changes. The past record may help us to understand these changes, not because they have happened before, but as part of a continuing process.

Floral Surveys, Mobile Phones and the Internet

While we are on the subject of floral or vegetation surveys, it might be worth mentioning the method that was used. Technology has many benefits, some of which are stunningly simple in concept - if not in implementation - like Google Maps and the facility whereby we can never get lost any more…

A central database of plant images - leaves, flowers, seeds and fruits, bark, and so on, for each species, along with botanical and local names as identifiers, is accessible via a smart phone. This application is called PlantNet, and is freely downloadable. By taking a photograph of the particular part of the particular plant the app checks the image taken with those on the database and suggests possible matches. Not only that but the GPS location of the particular point where the photo was taken is also recorded. Once a satisfactory identification has been made it can be shared onto the database, with the rest of the PlantNet community, where it will be checked and either verified or rejected.

PlantNet does not do all the work - the onus is on the user to verify the plant identification given the likely options that PlantNet offers. A book is still essential, and for Ireland Webbs Irish Flora is irreplaceable; or for a well illustrated book Collins Guide to the Wild Flowers of Britain and Ireland.

The location used by PlantNet appears to be based on mobile phone masts, and in Ireland this can mean the locations are a bit inaccurate. So it is not a bad idea to run another application while recording flora. A good one is the modern version of MyTracks, which is quite different to the original - and somewhat better. This app can run in the background and record every place the plant spotter goes.

Back at the office, or home, or lab, PlantNet can be accessed online and the identifications verified, and the dataset, complete with locations, downloaded in a format that can be imported to a mapping software.

Likewise, the route tracked by MyTracks and saved whilst out in the field can be downloaded from the phone, and also loaded into the mapping software.

You now have a graphically mapped set of data that shows the route taken and the plants identified.


Human Achievement

It does seem at times that the human race gets a bit of a bashing for all the doom laden destruction, industrialisation, money making schemes and greed that is going on.

We must not lose sight of the fact that so much that is not damaging, nor destructive, nor fuelled by greed or hatred, has been created by humans. It just seems right to acknowledge this occasionally.

The greatest achievement of the human race is artistic, and I have to mention this particular piece. A pinnacle of musical composition and orchestration. This performance is superb, showing the joy and companionship that can be generated by people playing great music, beautifully, together.

In addition, this piece demostrates the amazing technological simplicity achieved by the designers, creators, and builders of the violin family.

It all comes together in this performance. Even if the music is not to your taste, such incredible achievement cannot be denied.

Watch, listen, marvel

Spatial Analysis of Raths - or - Why Are They Where They Are?

One of the benefits of digital mapping is the ability to analyse the geographical distribution of features. This can apply to the combining of different layers in the maps, such as topography, geology and sediments, to get an idea of how they are related. And it can be used to great effect on man made features. In this regard an analysis of archaeological monuments in the countryside might throw up some interesting and otherwise hard to detect relationships. Such an exercise is being undertaken for the Raths in West Cork. The results will be presented on the Ringforts page of the WestCorkPalaeo website.

Raths on Drumlins south of Bantry BayA screen grab from a digital map of raths on drumlins on the southern shore of Bantry Bay

Analysis of elevation, aspect (which way the hillslope they are on is facing), and angle of the slope can all be quite simply considered. Also the distribution of Raths within townlands, the size of the townlands and the number of raths in them, and the intervisibility of the raths. All of these aspects can only make use of the information we have, so in the case of intervisibility - which rath is within view of which other raths - this will be on the basis of topography. Whether forestry or hedgerows at some time obstructed the view we cannot know. We also cannot know what degree of visibility, if indeed any, was required. In assessing intervisibility we have to make assumptions about the height of the observer (you can see further standing up that you can sitting down) and also the height of the feature being observed (how high was a rath? well, it wasn’t flat). A column of smoke will make a rath visible by rising 20 , 30, 40 metres into the sky above - is this a relevant consideration to hold?

We also do not know, and can only guess, at the considerations that are given to where raths were sited. Was the nearness of water a factor? Or the closeness to a relative in their rath? Did the quality of the ground - deep soil for the souterrain underneath the rath, rocky subcrops for a firm and non muddy base - make a difference? There are many possible factors.

So there are obvious problems in making these assessments, and many pitfalls that could be fallen into, all of which need to be borne in mind when undertaking spatial analyses. Giving consideration to raths of West Cork requires validation as well. The county boundary probably wasn’t in existence at the time, so when looking at regional groupings of raths, we need to try to understand the geographical groupings. Was it by peninsula, different ranges of hills and valleys, specific river drainage areas, areas of rock type or sediment type - like the difference between limestone and sandstone, or boulder clay and peat? There is an assumption that townlands probably date from the same period as raths, so is it relevant to assess the number of raths in each townland? We know that some townlands have been split, or newly created, as a result of relatively recent changes in land ownership, certainly long since the rath period.

Digital mapping does at least allow the examination of the landscape and it’s features to a level of detail not normally afforded by conventional maps, with the possibility of including calculated layers (such as an intervisibility network), and layers of data of disparate sources - geology, archaeology, environment, hydrology etc. Various ways of portraying the topography can be explored, such as contours at various intervals, and hillshading. The image above shows a group of raths on the southern shore of Bantry Bay just south of Whiddy Island. This is an area of drumlin hills - two drumlins can be seen ‘sliced open’ by coastal erosion on this part of the shore, at the western facing beaches. The red dots are raths, the white are souterrains (within the raths); red lines are roads and tracks, black lines are townland boundaries, contours are at 1m intervals. The yellow lines are the rath’s intervisibility network - by which one rath has line of sight to another, or not, according to the topography. Black patches are rock outcrops. An image of a larger area at smaller scale, with 5m contours, is shown below.

Raths on Drumlins south of Bantry BayA smaller scale screen grab from a digital map of raths on drumlins on the southern shore of Bantry Bay

Seeing this representation can raise all sorts of questions - why were the raths built on these drumlins? Why so close together? Did they therefore have smaller parcels of land? Were they even farmsteads?

I have yet to visit these raths to see them in the flesh which is, of course, the best and ultimate way to understand a feature within the context of the landscape.

Finally, while experimenting with visibility networks, what was visible from these raths situated on the drumlin tops? This third image shows the viewsheds of the drumlin raths; these raths are red, all other raths are purple. The shades of green signify visibility - to all intents and purposes we can say that the dark green areas are those that were not visible from our raths on the drumlin tops, all other shades are areas that were (and presumably still are) visible. The yellow lines are the lines of vision between raths, from the drumlin raths outwards. Visibility range has been extended to 10km.

Raths on Drumlins south of Bantry BayThe areas of visibility of the drumlin raths on the southern shore of Bantry Bay

Visualising the The Tree of Life

Whilst talking about the wonders of Human Achievement in the arts and in technology, we do well to consider that so much that has been achieved is of such vastness in concept it is hard to visualise. Biodiversity is a very big thing to take in, despite the fact that the word is bandied around in the media these days with such freedom. I have tried to engender an appreciation of what biodiversity loss actually means to the world, and to us in the blog  Jobs, with no one to fill them. That’s loss of biodiversity. But what is biodiversity? How diverse is biodiversity? How deep does it go, how far, how complex is the web that life encompasses?

It is only now, within the last ten or fifteen years that we are really starting to appreciate how all-encompassing the concept is, and although some of the older generation were deeply worried at the levels of pollution, destruction and blindness that was being practised across the globe - from our own streets and hedgerows, to forests and fields, plains and deserts across the globe - that was damaging the very life that we rely on to keep the nature that we evolved with running smoothly, nobody listened and nothing was fixed. So now, in the wake of the climate crisis, these concerns are, at last, being brought to the fore, even though they often detract from the focus and urgency of the climate crisis itself and the immediate main causes. The fact remains that these are issues that should have been sorted decades ago. But it is only now they are being considered seriously. We could say better late than never...

Consider the achievements of such figures as Darwin and Wallace, swimming against the tide of religious belief, stepping outside the accepted norms of scientific thinking, and embracing concepts that were so vast in extent. They must have been truly staggered when the realisation hit them of what later became the theories of evolution and natural selection and the vastness of time that was represented, the vastness and breadth of the development of species. Not just those in existence today, but all of those that evolved, developed, specialised, flourished, receded and then died out along the way. The ones that only remain to us as fossils, often as dismembered pieces of the whole organisms, sometimes microscopic remains petrified inside rocks.

Thankfully technology can help us grasp some of these concepts in their depth, breadth, extent, and age. Consider a journey, starting from the very base - or top - of the evolutionary tree, the tree that we have constructed to help us see the interrelationships between organisms. How one developed from another, or how one evolved alongside another; how some developed down a side branch that became more predominant than the main branch it came from. It was not a simple linear process, and there were and are lots of dead ends. But think of the journey from the basic start to the eventual emergence of a complex organism like.... a dandelion. Do you have any idea how that journey would proceed?

Well, go to this website and in the search box type 'dandelion' and select the top one that is shown Tree of Life (opens in a separate tab). Notice that every leaf you pass is a separate species alive today (the vastness of extinct organisms is only just beginning to get incorporated into this software). Branches are where development, evolution, caused a split down two different routes.

When you arrive at your destination, you are looking down into the vastness of the diversity of dandelions. Just dandelions. Not all flowers, not just daisy types. Just dandelions. The global spread of dandelions.

Now type into the search box 'Taraxacum borovezum', select the one listed, and watch. The rest of this journey is through the many dandelions that have diversified to fill the many environmental niches they have encountered, and adjusted to, evolved to cope with, across the globe. When you get to the end, breathlessly, scroll back, retrace your steps, and see where the route took you, which plants, proto plants and prior organisms you visited along the way. Alternatively click on the compass icon in the bottom left, the top icon. You will be shown a list of the main classifications, and you can click on each one, and go there. If you do this, notice how the occurrence of 'Land Plants', 'Vascular Plants', 'Seed Plants' and 'Flowering Plants' occur close to each other. These were evolutionary developments that occurred relatively close together in time, and resulted in the spread of plants across the land which changed just about everything in the world at that time. From then on the diversification of green, vascular, seed plants on the land has been enormous. Just look at how many branches, twigs, shoots and finally, leaves, you pass through from 'Flowering Plants' onward. This is biodiversity.

Try some other species - try a moss, a non vascular plant, like Ectropothecium ichnotocladum. Yes. It doesn't roll off the tongue. Then come back to 'True Mosses' using the compass icon. About 17 thousand species, which hardly compares with the 400 thousand of flowering plants. Ferns (Polypodiopsida) and Clubmosses (Lycopodiopsida) likewise. And yet ferns and mosses, of primitive types, dominated the world until the vascular plants, the plants we are familiar with around us, evolved explosively. Then the world changed, And it is only for the good fortune that they did evolve, that we can live today. I will explore what that meant in my next blog - it is crucial to understanding how West Cork developed.

OneZoom is a fantastic piece of software for visualisation. Play with it. But remember. This was created by voluntary work, so there are some out there who wish to disseminate knowledge and understanding without the need for monetary payment in return. This is just an example of how technology can be of such enormous use and facility.