Limestone Country: The Burren
The path, carved by countless feet into the shallow layer of dirt that covers the limestone, is barely visible. A thick blanket of fog cover the landscape and the path ahead. The damp air is swirling around me, at times lifting for the blink of an eye to allow a brief glance on wet limestone slabs. Suddenly the lake appears out of the white, its surface motionless, its extend hidden. I am gathering some idea on where I am and keep on walking, keeping the lakeshore to my left. It is winter solstice day and despite the fact that the day is already in double digits it still feels like early morning. The fog is the perfect cover for this mysterious landscape that extends around as well as below me. I am on my way to the summit of Mullagh More, the iconic, flat topped hill that sits in the heart of the Burren National Park. The stile in a dry stone wall shows me that I am on the right track; a small group of trees and shrubs, hazel and ash, just about visible to my left, are another landmark.
Soon after a number of natural steps in the limestone bring me onto the first plateau. Landmarks and way markers are hidden in the fog which is now thicker than ever. The well-trodden path has disappeared and the now bare limestone at my feet doesn’t keep any memories of other travelers. I am stranded and all I can do is sit and wait. The silence is eerie. After what feels like hours there is a hollow clock-clock, the unmistakable sound of limestone on limestone; feral goats navigating the winter fog maybe? After another couple of hours (?), minutes (?), seconds (?) a raven croaks close-by or at least it sounds near. In this impenetrable fog it is impossible to tell. Time goes by, I am alone with my thoughts in this ancient landscape, the cold and damp slowly making its way through layers of clothing. All of a sudden it seems to be getting brighter. I can see a bit further; the curtain is lifting enough to wander on.
Many steps later and three plateaus higher I am witness to the fog finally falling apart, holes appear in the soft sheet and a soft breeze rips further openings in the wall of droplets. Patches of blue appear in the sky above me and the mountainscape of the Burren is revealing itself all around me. Poulnalour and Slievenaglasha to my left, Slieve Roe and Knockanes ahead of me and the lowlands of County Clare and Galway to my right. Wafts of mist are still lingering but most of the limestone hills are now bathed in warm winter sunshine. The skeletons of the hazel scrubs glow in gentle brown and yellow tones, the wet limestone is glistening in the light and the only sound is the hushing of the wind. This is the Burren.
The northern part of County Clare, together with a small part of southern County Galway, is occupied by an unusual and very special landscape: The Burren. The first impression of this area is one of gloomy desolation. From a distance the first feature that catches the eye are teracced, raggy and seemingly bare hills. A closer look reveals polished rock pavements that are traversed by deep fissures and strewn with erratics of various sizes.
On dry, sunny days the rock presents itself in a bright, in the sunlight almost blinding, grey. After the common downpour the landscape appears in a dark grey, almost black, and glimmers with a blueish tint. And on those soft days, that are so typicall for Ireland, when a constant fine drizzle drenches the land, it is almost impossible to tell where the grey landscape of the Burren ends and the equally grey sky begins.
The name of this landscape derives from the Irish word Boireann which translates into large rock or rocky district and the English politician and military leader General Edmund Ludlow, while passing through the area on a military campaign in 1659, described the Burren like this:
It is a country where there is not enough water to drown a man, wood enough to hang one, nor earth enough to bury him. In the following centuries the Burren was being called a moonscape and has been portrayed as the fertile rock. Singer & songwriter Luka Bloom sang about the flowering desert and for botanist Charles Nelson the Burren is a limestone wilderness. Whatever you would like to call it the Burren is a landscape that is cherished and respected by its people and known to leave a deep impact on its visitors. The Burren seems to exist on another plane, disconnected from the real world, timeless in one way but also laden with the burden of history. There just is no other place like it.
The Burren is a limestone karst landscape. Its foundations were laid down during the lower carboniferous period some 350 Million years ago far away from its current location on the west coast of Ireland. Imagine a shallow ocean in a tropic climate just south of the equator. Some of the inhabitants of this ocean were the ancestors of our snails, mussels and corrals all of which shared one feature, a shell made of the minerals calcite and aragonite. After their inhabitants had met the end of their life the shells sank to the seafloor and there accumulated, layer after layer, over a period of some 20 Million years and hardened into limestone which eventually reached a thickness of up to 800 meter. Periodic outwashes of mud, sand and clay from adjacent river estuaries added bands of shale and other deposits that in places separated the limestone beds. During the upper carboniferous period these fluvial outwashes became more dominant and as a result shales and sandstones built up over the limestone and in time completely covered the older rock. These younger stones can today be found south of the Burren at the Cliffs of Moher and the Loop Head Peninsula.
Time passed, continents moved and Ireland took its current place on the map. The earth’s climate oscillated, cooling and warming in cycles. The cool periods saw vast glaciers advancing from the poles covering much of Europe including Ireland and the area of the future Burren. Once the temperatures started to rise the ice would retreat northward, for a while releasing the land from its icy grip. This process went on for thousands of years and the back and forth and back again movement of these immense masses of ice, several hundred meters thick and weighing many tons, was sculpting the landscape. In some places the glaciers cut deep valleys in the rock, in the Burren they completely removed the top layers of shale and sandstone, exposing some 250 square kilometers of the older limestone. The best place to see the transition from limestone to sandstone is to the south-east of Doolin Harbour. Here the limestone disappears under the sandstone cliffs that a bit further south rise to form the Cliffs of Moher.
The glaciers also carried vast amounts of material with them. Once the temperatures rose and the ice begun to melt these materials were dropped on the landscape. Drumlins, small elongated hills made of silt, gravel and rocks, are a common sight all over Ireland. In the Burren the drumlins mainly appear along the southern and eastern borders of the area. Erratics however, another glacial deposit, are very obvious all over the Burren from the coast to the mountaintops. Most of the erratics are made of limestone but sandstone and granite rocks that originated further north in Connemara and were transported by the glaciers to their current resting place can also be found.
The bleak landscape of the Burren as it is today is however not an entirely natural phenomenon. Cartographer and author Tim Robinson wrote in one of his books: “The Burren’s austere beauty is due to millennia of abuse.”
After the end of the last glaciation, about 10.000 years ago, the Burren didn’t look very much different than the rest of Ireland. After the ice had disappeared a tundra-like landscape developed, with a warming climate shrubs and trees established themselves and over time vast pine and oak forests took over the land. In the area known as Rock Forest, in an undisturbed corner sheltered by a stone wall stand today a few gnarled and stunted trees. Their shape bears little resemblance to the mighty scot’s pines that once made up Ireland’s forests but nevertheless pollen core record suggests that these trees are direct descendants of the old forest that once covered the Burren
It is possible that the limestone of the Burren area never had a very deep soil cover and was more susceptible to erosion than other areas. It is however clear that the first Burren farmers and the ones after sped the erosion process along by clearing land for crops and livestock. They also left their mark on the landscape in other ways. The Burren has one of the highest concentrations of ancient monuments dating back as far as the stone age. Cooking places known as fulachta fiadh, portal and wedge tombs, cairns, ring barrows and stone forts, early Christian monasteries, medieval tower-houses and the ubiquitous dry stone walls have all become part of the Burren landscape.
Another factor that had significant influence on the juvenile Burren even before the arrival of men was water. Limestone has one very prominent feature: It dissolves through a chemical process when it comes in contact with water. Rain water contains dissolved carbon dioxide which makes it slightly acidic. This acidic solution causes a chemical process when it comes in contact with the limestone which converts the calcite into calcium bicarbonate which then dissolves in the water and is being washed away.
It is this process that shaped and sculpted the Burren to its unique appearance: Smooth limestone blocks, known as clints, that are separated by deep fissures, known in Ireland as scailps (from the Irish word for fissure or cleft) and everywhere else as grykes , runnels and flutes, terraced hills, sinkholes and vast cave systems. To date some 60 kilometers of cave passages have been explored but the real extend of the Burren cave systems is believed to be a multitude of that. The exploration of the known caves brought with it glimpses of the Burren’s past. At Ailwee Cave, one of the two show caves of the Burren, the skeleton of a brown bear was found and dated to be 10.400 years old. A bear patella, discovered in another cave, shows parallel cut marks that were most likely caused by a stone knife and was dated to be 12.500 years old. The presence of a top predator like the brown bear and signs of it being hunted by men suggests that a diversified flora and fauna already existed in the Burren towards the end of the last glaciation before the complete disappearance of the ice.
The second show cave of the Burren, Poll-an-Ionain, today better known as the Doolin Cave, features the Great Stalactite. With a length of 7.3 meter this is the biggest free hanging stalactite in Europe. Considering that stalactites grow by less than 10 centimeters every 1000 years this means that this cave has existed well before the last ice age.
Many of the Burren’s cave systems have been formed by streams and rivers most of which run their complete course underground. This explains the lack of water courses above ground and the general lack of surface water in the Burren. The only stream that runs its complete course above ground is the Caher River which has its source beneath Slieve Elva and after a short run of 7 kilometers enters the sea at the beach in Fanore. The upper part of the Caher is a gentle affair through hazel scrub and meadows, one of the most beautiful spots in the Burren. In the early 1990s local man John MacNamara turned this area into a nature reserve. His goal was to let nature run its course and leave the plants and animals in this little kingdom undisturbed. I had the pleasure to know and work with John for a brief time but unfortunately our plans to put together a photographic record of the plants and animals at the Caher Valley Nature Reserve were cut short. John passed away after a short illness in 2004. His hopes for the reserve however came true. After his death the gates to the valley were closed and the plants and animals were left in peace. After leaving the Caher Valley Nature Reserve the river turns west and starts to descend. Trout can often be seen swimming in the clear water and it is not unusual to come across a dipper, otter or heron. On its last 2 kilometers before reaching the Atlantic Ocean the Caher drops 60 meters and completely changes his appearance. The gentle river becomes a mountain stream and after heavy rain turns into a raging torrent rushing around boulders and over cascades. Why the Caher River never wanders underground is not entirely clear but it is known that in parts of the Burren impervious layers of mainly clay but also chert and sandstone exist between the limestone. In most likelihood the Caher runs above one or more of these layers that prevent the water from going underground.
Most rivers in the Burren run their complete course underground, only a few make a sporadic appearance on the surface. One example of those is the Rathborney River. It emerges from under Gleninagh Mountain, runs down the Feenagh Valley only to disappear again under the limestone once it has reached Ballyvaughan Valley. Another is the Castletown River which flows through the Carron basin and is one of the sources for the Carron Turlough.
The only standing water bodies can be found in the eastern Burren. These fens, lakes and turloughs are known as the Burren wetlands and mark the eastern borders of the Burren area. Some of these lakes, the turloughs, are rather special and are also known as seasonal lakes. Their existence is very much dependent on the prevalent precipitation. Unlike proper lakes the turloughs are not fed by a constant water supply like a river or groundwater. They are however connected to the cave systems of the Burren. During times of consistent or high rainfall these underground passages flood and eventually overflow, filling the turloughs in the process. During dryer periods, mostly during spring and early summer, water levels fall and the lake disappears. The biggest of those is the beforementioned Carron Turlough that can fill the Carron basin and cover some 4 square kilometers.
Some of the lakes of the Burren wetlands are a combination of a lake and a turlough. This means they never disappear completely but will easily triple in size during times of high rainfall. The most interesting of those is Lough Gealain in the Burren National Park. The lake is fed through springs under the limestone but also features a number of swallow holes that connect to the underground cave system. During dry periods these swallow holes can easily be observed to the south of the main lake. In autumn and winter, when rainfall amounts are usually higher, Lough Gealain expands considerably and at times floods the nearby road. Lough Gealain is also special in other ways. The spring water that feeds the lake is rich in dissolved carbonate which makes the lake alkaline and so impossible for the water to dissolve the limestone. The carbonate is also present in the mud layer that forms the bottom of the lake. This mud, scientifically known as marl, does not only acts as a protective layer but also gives the lake its distinctive cerulean colour.
Lough Gealain sits in the heart of the Burren National Park, an area that hosts all of the various Burren’s habitats. Apart from the beforementioned fens, lakes and turloughs there are vast stretches of limestone pavement interspersed with patches of fertile soil, small woodlands and wildflower meadows. It is in these habitats where the flora, for which the Burren has acquired world-wide fame, can be found. This wonderworld of wildflowers is rather unexpected in a place that on first sight appears to be made of barren and desolate rock. The Burren however hosts 600 species of wildflowers and other plants which is 70% of all species known in Ireland. But it is not only the abundance of plant life that makes the Burren unique, it is especially the distribution of individual species and the composition of the plant communities that makes the Burren stand out.
The most famous of the Burren flowers and something of an emblem for the area is the spring gentian. This species with its deep blue flowers is an alpine species that usually flourishes in the high mountains. In the Burren it bursts into bloom around April and can be found not only at sea level but even right at the sea. The Ballyryan area north of Doolin is, together with the Burren National Park, one of the strongholds of this enigmatic plant. Each plant produces several hundred seeds which are shed in summer for germination the following spring. There is however one problem. In order to germinate, spring gentian seeds have to experience frost. Experiments have shown that seeds kept in warm soil will not germinate and will keep lying dormant, only frosted seeds will produce a new gentian plant. Although frost is not unknown in the Burren it is very rare and years can go by between one frost event and the next. In order to survive the Burren gentian came up with another solution. Mature plants produce underground stolons and these grow new rosettes and subsequently produce new gentian flowers. In its 8000 years of isolation the Burren gentian has not only developed an alternative reproduction method, it is also visually different from the populations on the continent. For now these differences are minutiae and are only of interest for the keen botanist. But give it another few thousand years and gentiana verna might develop into a completely new species.
The early purple orchid, a species more commonly at home in the Mediterranean, can often be found close to the spring gentian. Just a little bit later in the year the mountain avens, an arctic species, joins the mix and bursts into bloom beside other orchids like the fragrant orchid, the pyramidal orchid, the red helleborine or the twayblade to name a few of the 24 species of orchid that call the Burren their home. These orchids are without a doubt the stars of the Burren flora. Today it is the striking colours and intricate shapes that make these flowers attractive, until not so long ago however it was another alleged ability that made orchids very appealing. The word orchid comes from the Greek word όρχεις (“orcheis”) which means testicles. Orchids spend most of their life underground in the form of tubers and it can take years for a seed to produce leaves above ground not to mention developing flowers. These tubers very much resemble a particular male body part and it is very likely that the very particular shape of the tubers led to the belief that orchids have aphrodisiac properties and led to their name. Superstition aside orchids lead a very unusual and complicated life. Underground each orchid lives in a symbiotic relationship with a particular fungus. This relationship is still not fully understood but what is known is that the orchid seed needs a fungal partner to provide carbon in order to germinate, if you want you could describe the fungus as a kick starter for the orchid seed. Later in life it is thought that this seemingly one-sided relationship continues and the orchid keeps receiving carbon and other nutrients from the fungus. Above ground orchids make life also unnecessary complicated. For starters orchids produce flowers in rather irregular intervals. Years can go by without any flowers showing. Once they do the various orchid species have each specialized for one very particular pollinator which is reflected in some of the species names like fly orchid or bee orchid. Should this pollinator for one reason or another not appear the orchid won’t be pollinated and not produce seeds. In a worst case scenario many years can go by for an individual plant without producing any offspring. The perfect example for the orchid’s unpredictability is the story of the narrow leaved helleborine. One lonely specimen of this woodland plant was discovered in 1980, halfway up a mountain on open limestone. Over the following years the plant produced flowers every spring like clockwork. In the year 2000 it refused to appear above ground for the first time and despite intense looking and searching it hasn’t re-appeared since.
Another piece in the floral puzzle of the Burren is the presence of lime-loving (calcicoles) and lime-hating (calcifuges) plants often growing in close proximity. Giving the ubiquitous presence of limestone it would be logic to conclude that the soil cover would consist of weathered limestone rock and the remains of glacial drift, a soil type known as rendzina. Calcifuges however wouldn’t thrive on such a soil and the existence of other soil types in the Burren has been a bit of a mystery until microscopic examinations revealed the prevalence of an aeolian (wind deposited) soil known as loess. This loess most likely came from east Galway and Connemara and was deposited in various places all over the Burren during the Tundra period after the last glaciation. Another theory is that sandstone and granite erratics that originated further north disintegrated over time to form loess.
In addition to its strange plant communities the Burren also hosts a few unusual flowers and straight rarities. The O’Kelly’s Spotted Orchid is a rare white subspecies of the common spotted orchid which was named after Patrick O’Kelly from Ballyvaughan who first described the plant. A bit of an oddity is the pyramidal bugle, something of a stumped version of the very common bugle. This is one of Ireland’s rarest plants and only flourishes in a few localities along the Burren coast, the Aran Islands (which are geologically a part of the Burren) and it has also been reported in Connemara and on Rathlin Island off the Northern Ireland coast.
The question why the Burren hosts these unusual and rare plants and plant communities has never really been answered. It is thought that the alpine and artic species arrived shortly after the end of the last glaciation and were part of the early tundra-like landscape. After the climate had warmed enough other plants, including the beloved orchids, followed from the south and settled in the Burren right beside the existing flora which for whatever reason still feels very comfortable in the mild climate of Ireland’s west coast.
How much human activity and the Burren flora are connected and why the Burren is essentially men-made came to light in the final decades of the last century. Back then, in order to protect the delicate wildflowers, it was decided to restrict farming activity in the Burren and reduce the number of grazing animals considerably. Surprisingly this conservation effort had the exact opposite effect of what it was supposed to do. Because the fast growing grasses and shrubs, mainly hazel, blackthorn and hawthorn, were no longer kept in check many of the delicate wildflowers were pushed out of their habitat by these fast growing species.
Then, in the year 2010, the Burren Life project was founded. Goal of this project was not only to find a balance between farming and conservation but to actually use farming as a conservation tool. The farmers who signed up for this project took on a number of tasks to preserve the natural as well as the built heritage of the Burren. Among the actions taken was the re-building of dry stone walls, shrub removal and the re-introduction of the Winterage and other traditional farming methods like herding and goat husbandry. The century old tradition of Winterage sees livestock being brought to pastures in the uplands of the Burren where they spend the winter. The generally mild climate and the heat-storage capacity of the limestone make sure that grasses are growing almost all year round. This provides free, natural food for the animals which in turn keep the grasses down which benefits the wildflowers in the following spring. Over time the Winterage became a yearly community event and now every October the cattle are being accompanied by crowds of people on the way to their winter pastures.
Today the Burren Life project is one of the most important factors in the conservation of the Burren flora. Without grazing animals not only would the diversity of the this flora be greatly diminished, in the wake of the loss of flowering plants the insect population would suffer which again would impact the bird and mammal, especially the bat, community.
The Burren is an important stronghold for bats. All seven bat species known in Ireland have been reported in the Burren including the lesser horseshoe bat which has become extinct in many parts of Europe. The Burren provides plenty of food in the form of moths and other small insects as well as caves for overwintering. It is therefor no surprise that the Burren holds one of the biggest populations of this tiny night-flyer.
Moths and butterflies are also widespread in the Burren. There are 27 species of butterfly resident and half of all the 540 or so Irish moth species have been recorded here at one time or another. One of those and a true Burren speciality is the Burren Green. This moth had first been recorded in 1949 and put the Burren on the map for Lepidoptera fans. The Burren is the only place in Ireland and Great Britain where this emerald green beauty has ever been recorded. The Burren Green is however resident in other parts of Europe.
Other Burren wildlife worth mentioning are the pine marten, who feels very much at home in the hazel forests, the common lizard, which can often be found sunbathing on the warm limestone, and the common frog, who can look slightly out of place hoping across the limestone pavement. Finally there are the feral goats. These descendants of formerly domesticated goats roam the Burren and are not only very pretty to look at in their rugged and colourful appearance but they are pretty much the only animal that munch on the ever spreading shrubs and so play their part in the conservation of the Burren.
Unlike other landscapes and habitats in Ireland the future of the Burren karst and its famous flora is safe, for the moment at least. The combined efforts of farmers, communities and environmental groups make sure of this. The special case of the Burren however raises the more fundamental question of what conservation really means. Is it right to protect an admittedly unique but ultimately men-made piece of landscape or would it be proper to let nature reign which would transform the Burren into a very different landscape. First a hazel and ash woodland would establish itself, a process that can already be observed at the foot of Mullagh More and around Eagle’s Rock, and in time other trees, most likely oak and scots pine, would take over and revert the Burren to its origins of a mixed woodland. Parts of the current Burren flora would survive in this new habitat, others, first and foremost the arctic and alpine species, would probably disappear and be replaced by new species.
Ultimately the Burren as it is today will only exist for a glimpse in the vast reign of time. In another few thousand years all the limestone will be gone, washed away into the ocean, or the Burren will have been decimated to a few small limestone islands by rising sea levels. Whichever way it may turn out another of nature’s circles will have been completed.
Carsten Krieger, Spring 2019