Our riverbanks and hedgerows are home to many essential plants and animals which all contribute to the health of our rivers. Did you know that most of our land is used for farming and we have very little natural forest left? Hedgerows are one of the few places where wildlife can live without being disturbed. This makes them an extremely important habitat.
Forests have many different plants and shrubs. They give homes and food to birds, insects, badgers, foxes, hedgehogs, bats, mice, and shrews. These, in turn, are important food sources for owls and other birds of prey. The existence and health of these species have a far-reaching impact on our ecosystem and underline the importance of preserving our hedgerows.
Most hedgerows were planted from the 18th century onwards, when landowners were required by law to enclose their land. A report from Teagasc in 2021 estimated that Ireland has about 689,000km of hedgerows. While this sounds like a lot, very few of these hedgerows are of high quality, with a wide diversity of plant species. Herbicide and run-off are the main culprits, along with the trend for very severe annual cutting which damages the hedges.
However, hedges can also benefit farming, providing shelter for livestock, preventing soil erosion and helping to prevent the spread of livestock disease. A well-managed hedge will also remain forever, unlike a fence which will have to be replaced periodically!
Plant and Wildlife Diversity in Hedgerows
The more diverse the plant species the better, with the most common species being whitethorn/hawthorn, blackthorn, holly, rowan, ash and hazel. Bramble, dog rose and honeysuckle are all common and important hedge plants.
A healthy hedge will be “alive inside” and home to a huge range of birds, insects like butterflies, moths, bees and other pollinators that depend on the flowering of hedge shrubs like whitethorn and all the smaller flowering plants that grow alongside the hedges such as dandelions, primrose and cow parsley. According to the National Biodiversity Data Centre, planting a diverse range of species is key for our pollinators and wildlife, as well as ensure good connectivity between hedgerows and other natural habitats such as rivers and woodland.
Hedgerows function as “wildlife corridors” that allow wildlife to move safely between habitats such as rivers and woodlands. As many birds and small mammals never venture more than a few metres from cover, populations would become isolated and vulnerable without hedges. According to the Heritage Council, nearly two-thirds of Ireland’s bird species nest in hedges.
Wild flowers and plants flourish in hedgerows, attracting insects and enhancing the diversity and beauty of the area. These natural reserves also offer nutritional benefits for humans, as highlighted in our recent River Ecology course. Herbalist Aurora discussed the use of plants such as nettles, goosegrass, and hawthorn in recipes. These plants can be used to make nettle soup and hawthorn tea, which can improve health.
Defence Against Flooding and Climate Change
Hedgerows and riverbanks play an undervalued role in flooding control, an ever more pressing issue in our changing climate. The root systems of hedgerows regulate water movement and help prevent flooding and also improve water quality by trapping silt and soil particles which clog up fish spawning grounds if they enter watercourses.
A gradual decline in the quality of our hedgerows over time means a loss of their flood control capacity and a loss of nutrient absorption because they can no longer function. There is a clear and pressing need to raise awareness of the importance of our native hedgerows, both from a climate change and flooding perspective and for the sake of our wildlife and biodiversity.