Hedgerows

 

The weather forecast had promised a sunny morning so I set my alarm to 5am to take a walk at first light along my local boreen. This particular boreen is not as the name implies a small country road, it’s rather a glorified path that gives access to a number of fields. The gravel that had once covered the surface is long gone, disappeared between dirt and grass. The deepest of the potholes have been filled in with rough stones and after heavy rain the boreen tends to flood and become unpassable in places.

The forecast turned out to be correct and I arrived at my destination just when the sun was sending its first rays of light over the fields. The southern side of my boreen is marked by old stone walls which are periodically interrupted by metal gates that lead into the adjoining fields. In parts the stone walls have completely disappeared under an array of grasses, ferns and various wildflowers that provide ever changing colours throughout spring and summer. In some parts however the old west Clare walls show through. These are not made of the big chunks one will find in Connemara or the Burren, these are small stones, pebbles almost, dug out of the soil and then painstakingly stacked up to a height of about a meter. Most of the stones are covered in lichen, shades of brown and white that form intricate patterns. In the narrow crevices between the stones ferns and mosses have found the sheltered dampness they like.

It is impossible to determine what the northern boundary of the boreen was originally made of. Whether it was another stone wall or an earthen bank, it has completely disappeared under a mix of grasses, bracken, heather and bramble. In parts this green wall reaches up to 2 meters in height and here live the feathered individuals I was hoping to photograph this morning. The wren was the first of the resident birds to appear, chanting its characteristic and for a bird this minute size very loud song. But this was not the bird I was looking for. A few meters in the boreen becomes a different world. It feels pristine and wild, not at all like the domesticated landscape this is and only the mooing from the other side of the stone wall and the sound of a distant tractor brings a touch of reality. There I heard the song I was waiting for, the sound of pebbles being banged together, the voice of the stonechat. At least two couples of this bird are breeding in the thickets of the boreen and spring is the best time to photograph them. At this time of the year they are extremely protective of their territory and any intruder will be approached and called out which was exactly what happened. The female sat down on a protruding bramble runner, eying me suspiciously, while the colourful male perched a bit further away continuing his warning song.

I spent the better part of the morning in my boreen bubble, discovered the unrolling fonds of the heart’s tongue fern, the blue flowers of dog’s violet and the crimson carpets of the English stonecrop that later in the year will produce precious white flowers. The stone chats stayed with me for a good while, keeping an eye on me and keeping everybody else informed about my doings.

 

An aerial view of Ireland reveals the characteristic checkerboard landscape this island is so famous for. Small fields are coloured in various shades of green and are separated by rows of shrubs and trees or overgrown embankments and stone walls. Over the centuries and especially over the past few decades these dividers of the agricultural landscape have become one of the most important habitats in Ireland. While fields and pastures are no longer able to support a wide variety of species due to the ever intensifying monocultures  that come with modern farming practises, hedgerows are now islands of biodiversity in a sea of a bleak farming landscape.

The origins of Ireland’s checkerboard landscape date back to the Neolithic. The oldest known farming landscape in Ireland sits on a gentle slope overlooking the Atlantic Ocean on the north Mayo coast just west of Ballycastle. The Ceide Fields were discovered by a local school teacher while he was cutting his turf for the winter and subsequent excavations revealed a vast network of fields separated by stone walls, several dwelling houses and megalithic tombs, all that remained of a Neolithic farming community.

The tradition to use stone walls as a border between fields has lived on until present day. The west of Ireland in particular is hard to imagine without the endless lines of dry stone walls. The use of these structures as a field divider has very likely been born out of necessity. Soils along the west coast are generally poor and the first action that had to be taken to create a usable pasture was removing the stones lodged in the dirt. These stones were then used to build the walls around the small fields in order to keep livestock in and to keep the ever present wind from removing too much of the little arable soil there was.

Building these walls has become a craft, even an art form, in certain areas. In the limestone landscape of the Burren and the Aran Islands as well as in parts of Connemara this craft has reached an unmatched sophistication and in these places the walls are being kept in pristine condition. While these walls themselves rarely host more than lichen and bryophytes, the base of the wall, the narrow strip of land between the structure and the field proper is often the last place of refuge for the original flora of the area. In other parts of the country stone walls fell in disuse and were fully or in parts claimed back by nature. Those abandoned walls have become a habitat in their own right. Soil that has accumulated in the crevices between the stones is hosting ferns and wildflowers like navelwort, English stonecrop or ivy-leaved toadflax. The stones themselves are almost always overgrown with lichen and bryophytes and the nooks and crevices give shelter to field mouse, the common lizard and other small animals.

In other parts of the country, predominantly the midlands and the east, hedgerows replace the stone walls. When this well-known  feature of the Irish landscape became first established is not entirely clear but it is likely that hedgerows also date back to the early days of farming. In some places there is a considerable similarity between the composition of species that make up the hedgerow and nearby woodlands. The question however if these hedgerows were left standing deliberately or by chance or if they have been planted later using local species will probably never be answered for sure. What is known for certain is that building field enclosures was common practice by the early years of the last millennium. Texts from the 7th and 8th century  describe temporary solutions like movable panels made of wattle but also earth walls topped with blackthorn and it is not unlikely that some of these blackthorn cuttings did take root and other flora might have invaded subsequently.

Despite its mostly sinister reputation in Irish folklore the blackthorn is to date one of the most common and characteristic plants in the Irish landscape. It is easy to distinguish from other shrubs because it is the first to come into bloom, sometime as early as March, and the only shrub that carries flowers before it produces leaves. The delicate white flowers that can make the shrub look like a giant snowball in spring turn into perfectly round, succulent berries, known as sloes, that shimmer in a dark blue colour in the autumn sunlight and are traditionally being used to make gin.

The arrival of the Anglo-Normans in the 12th century brought major changes to Ireland including new ways of farming and the deliberate planting and laying of hedgerows was part of this new regime. A second wave of hedge planting happened in the 18th century as a consequence of the Enclosure Act, a re-mapping and re-distribution of farmland all over the United Kingdom and Ireland. By medieval times the hedgerow had become much more than just a fence to mark field boundaries and separate pastureland from tillage and livestock from crops. The hedgerow itself had become part of the farm yield, a source of food as well as timber which was used for fuel and as building material. In addition to the primary hedging plant which was mainly hawthorn, other plants like crab apple, wild plum, wild cherry and hazel had been deliberately introduced. Hazel was particularly popular for its versatility. It not only provided high energy food in the form of nuts, its stems were used to make wattle and baskets and were favoured by water diviners and popular among pilgrims as a walking stick.  

Today some 830.000 kilometres of hedgerow criss-cross the Irish landscape and these checkerboard lines have become a refuge for flora and fauna and at present are more important for biodiversity than any other habitat. More than 60 different species of plants and animals can be part of a hedgerow, but the composition of species varies considerably and is dependent on location, soil type and how, if at all, the hedge is being managed. The basic building block of a hedgerow was and still is the hawthorn. This shrub can tolerate a variety of soil types and grows quickly and is therefore the perfect candidate to establish a new hedge. Hawthorn produces distinctive clusters of white flowers in May and June which on closer inspection reveal delicate filaments topped by anthers that turn from a bright pinkish red to dark brown. These flowers, together with the young leaves were once a popular snack known as butter and cheese. Over the summer the flowers transform into small, crimson berries which can be made into a wonderful jam or jelly. Together with the blackthorn the hawthorn is considered to be one of the magic trees of Ireland. Known as a fairy tree it is being held in high esteem even today and free standing individuals can often be found near holy wells where they function as a wishing tree or rag tree.

Over time the hawthorn and other deliberately planted hedging plants would be joined by wild species: Spindle tree and guelder rose are common in lime rich soils of sheltered lowland sites. Despite their delicate clusters of small, white flowers these two shrubs appear rather understated throughout spring and summer. Spindle tree and guelder rose wait for autumn to show off and from September onwards display striking tones of pink, red, orange, yellow and brown with both their foliage and fruit.

On the poorer soils of the uplands and exposed coastal sites blackthorn and gorse, also known as furze or whin, are dominating. The gorse is without a doubt one of the most striking plants in Ireland. It not only appears in hedgerows but can blanket vast areas where it forms an impenetrable thicket. The leaves of the gorse have been transformed into spines to reduce water evaporation and as a defence against grazing animals. For most of the year this shrub is nothing much to look at and wears a dull green coat. In spring however and in some places again in autumn the gorse bursts into bloom and produces countless yellow flowers that exude an overpowering coconut aroma. The flowering of the gorse is one of the major events in spring and is seeing hedgerows, mountainsides and coastal slopes transformed and brightened up by a sea of the bright yellow flowers. Today this shrub is often seen as a nuisance but only a century ago gorse was used as protective fencing, for harrowing fields, as a chimney brush and as fuel. Bakers in particularly appreciated gorse wood due to its high oil content which allowed for a long and hot burning flame. This characteristic unfortunately makes gorse also susceptible for wildfires. Another well known, almost iconic shrub of Ireland’s hedges is the fuchsia with its uniquely bell-shaped and red and blue coloured flowers. The plant is particularly associated with the west coast but can be found all over the country. Unlike the plants described so far fuchsia, which was named after the German botanist Leonhart Fuchs, isn’t a native but has been introduced from South America as a garden plant and eventually escaped into the wild.

Once a hedge was established and had reached a proper height the climbers would arrive. The most common of those, which is especially ubiquitous in the west of of Ireland, is the bramble. This hardy species comes in more than 80 microspecies which often appear together in the same hedge. The difference between these microspecies is almost impossible to tell for most of the year but becomes somewhat apparent in autumn when the blackberries ripen. Botanically speaking the blackberry is not a berry but an aggregate fruit, consisting of multiple drupelets, each of which contains a seed. Some “berries” are made up of only a few, loosely arranged drupelets, others consist of many, tightly packed ones. Some berries are small and hard, others are big and juicy, some are ready to eat in August, others need until early October before they have turned from green to red and finally to the characteristic deep, dark blue. All these represent a different microspecies but what benefit these variations bring to the individual plant is unknown.

Where brambles thrive honeysuckle isn’t often far away. The flowers of this plant are unlike any other, all parts from the petals to the style are slender, graceful and coloured in soft, creamy colours. The British poet Lord Alfred Tennyson was one of many enchanted by the honeysuckle and wrote in 1859: '...how sweetly smells the honeysuckle in the hush'd night....' The enticing scent Tennyson was so enchanted with is aimed at bees and moths who are the main pollinators of the plant, the bumblebees during the day and the hawkmoths at night. Locally ivy and members of the rose family - dog rose and field rose - can also be part of the hedgerow. The members of the rose family are known to hybridize and one of these hybrids is the almost legendary wild Irish rose. This plant was discovered in Holywood, County Wicklow in1795 but soon after disappeared and hasn’t been found in the wild ever since. Ivy plays a very special and often underestimated part in the yearly cycle. Unlike other members of the hedgerow plant community ivy is not only an evergreen plant it also starts to bloom when all the others start to retire for winter. Ivy produces its flowers from September and is therefore an important food source for insects. A few months later in January and February the dark blue berries help birds get over the worst part of the winter.

Some hedgerows also feature proper trees like rowan, sycamore, elder, beech or oak in addition to the various shrubs and climbers. These trees were either planted to fortify the hedge or they invaded the hedge naturally as it would happen during the development of a new woodland. Sometimes this procedure also happened backwards: Trees planted as an alley along roadsides or a driveway were invaded by shrubs and other plants to eventually form a hedgerow.

A hedgerow rarely stands on its own. Often a ditch runs parallel to the hedge which is particularly common along roadsides. This ditch often become a habitat of its own with a completely different flora to the adjoining hedge and field. In extreme cases these ditches can display plant communities similar to those along lakes and rivers with reeds growing at the edges and water cress, marsh cinquefoil, water mint and other lovers of a damp or wet environment flowering in and around the trench. In drier surroundings the ground flora that grows on both sides of the hedgerow, known as the herbaceous strip, very much resembles that of a deciduous forest: Tutsan, woody nightshade, lords and ladies, ground ivy, herb Robert, primrose, cowslip, wood anemone, dog violet, buttercups, goldilocks and bush vetch are just some of the flowers that can be found here. The herbaceous strip along roadsides is often especially rich in species and is playing a bigger and bigger role in maintaining Ireland’s biodiversity. This space between a hedgerow or stone wall and the road, especially old country roads, often measures less than one meter but in many locations contains the last survivors of the original flora of the area. The either flat verges or raised banks alongside newly build roads can also present some wonderful surprises. The disturbed ground can contain dormant seeds and acts like a blank canvas that gives these seeds a chance to germinate and grow without having to fight an already established flora. Rare species like common poppy, blue fleabane, bee orchid or common knapweed can pop up in this way and transform a roadside into an unlikely wildflower ark. This wide variety of flowering plants along our road network supports a multitude of other wildlife, starting with pollinating insects which in turn sustain birds and other animals.

Because hedgerows resemble woodland edges it is no surprise that the fauna is also similar to those of woodlands. Ireland’s smallest mammal, the pygmy shrew that reaches a length of only 5 centimetres, the field mouse and the hedgehog are locally common. The latter can be found noisily foraging the damp soil under the branches for worms and other delicacies, a habit that gave the animal its name. Stoat, fox and badger are also regular inhabitants of hedgerows and use them for both shelter and raising their offspring.

Of particular importance are the hedgerows however for birds. In many areas the hedgerow provides the only suitable place for finches, thrushes, tits, flycatchers and the tiny wren to build a nest and rear chicks. Surveys have shown that around 50% of all recorded countryside birds use hedgerows more or less exclusively as their home and that the majority of these birds prefer hedges of a certain size. A height of over 1 meter and a similar width seems to hit the sweet spot between accessibility and shelter from ground and aerial predators. One of those predators is the barn owl. This bird of prey is a typical hunter if the woodland edge and needs trees or shrubs to perch and seek out the next meal and the open space of the adjoining field to silently swoop down for the attack. The barn owl, like all owls, are night hunters. Despite their big eyes the birds don’t rely on eyesight to locate and target their prey, instead they hunt by sound. A barn owl’s ear openings are enormous in relation to the size of the head. In addition one ear sits slightly higher up than the other and they are also out of line in the vertical plane which allows the animal to pinpoint the source of a sound with greater accuracy. The secret weapon however is the characteristic shape of the owls face. The flat facial disc together with a ring of special feathers around it acts like a satellite dish and captures even the slightest movement on the ground beneath the perch. Unfortunately the barn owl is a sad example of a species on the brink of extinction due to habitat loss and the bird is evaluated to be declining not only in Ireland but the whole of Europe.

For many animals the hedgerow is not only a place to live, it  is also a road network. Traveling over open ground always poses danger and the hedgerow provides much needed protection while getting from one place to another. Insects in particular depend on the relative safety and the food supply these green highways provide.

In addition to being a sanctuary, shelter and  travel network for plants and animals hedgerows carry out a wide variety of other functions in the landscape. They control the water saturation of the ground and can so avert flooding. The root system prevents erosion and the foliage can cool down air temperature through evaporation and so influence local climate.

Unfortunately hedgerows and stone walls don’t go well with modern farming practises. The trend is for bigger farms and bigger herds which need bigger fields and bigger pastures. Where partitions are needed wire fences are easier to install and maintain. This disappearance of the old hedgerows is a sign of the times we are living in. The loss of those old structures is not only a loss for and subsequently of nature, it is also a loss of heritage and local identity and transforms the countryside into an ever more uniform and sterile place. The diverse farming landscape of old is becoming an empty factory floor.

 

Carsten Krieger, September 2020

All content © 2020 by Carsten Krieger - no reproduction without written permission

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