Threats to our hedgerows
Although the rates of direct hedge removal have been reduced, we are still seeing the loss of hedges through mismanagement. With many farmland species now marginalised to hedgerows, we take a look at the issues that are threatening them.
Neglect from under management
The last Countryside Survey in 2007 saw a 9% increase in the number of hedges that had been lost to under management over the previous decade. Hedgerows require management in order to stop them developing into a line of trees. Over half our ‘priority species’ mammals make significant use of hedgerows for food and to travel through the landscape. A line of trees can eventually become gappy and lose all the low shrubby cover that wildlife need for shelter, food and as corridors to travel. Once a hedgerow has become a line of trees, it is very difficult to return it to a hedgerow structure. By this point, it will have lost many of its wildlife credentials. It is therefore essential to prevent this structural decline.
Inappropriate cutting from over management
On the opposite end of the spectrum, over management can also threaten hedges. Cutting a hedge too often and at the same height, reduces the value of the hedge to wildlife, and threatens the future of the hedge structure. This leads to gaps forming in the hedge which impacts their value as wildlife corridors. Cutting every year will also significantly reduce the number of flowers and fruits for wildlife to enjoy, as many of our native berry bearing species only flower on growth that is two years or older.
The timing of hedge cutting is also of huge importance to wildlife. No hedge should be cut in bird nesting season and ideally, we should wait until January where possible to trim, as this means the hedgerow berries can keep feeding our wildlife through the winter. 84% of our farmland birds rely on hedgerows for food and protection. For over half of these a hedge is their primary habitat.
Ploughing too near a hedge not only destroys the herbaceous vegetation that usually grows at the base of the hedge, but it can damage the roots of the shrubs and hedgerow trees that make up the structure of the hedge. This can kill the trees and lead to the loss of parts of the hedge as the root systems are no longer able to support them. This is especially true in times of drought.
Although the rates of direct removal have slowed in recent years, hedgerows can still be removed, with council permission, for agriculture or development. Any removal reduces how well connected the hedgerow network is. Birds, bats and butterflies all use hedges as foraging and commuting habitats.
Over 500 native plant species have been recorded as being supported by hedgerows. Herbicides sprayed too close to the hedge, or in windy conditions, can kill off plant diversity, especially at the base. Similarly, pesticides can cause a decline in the number and diversity of insects available. This can have a knock-on effect on the wildlife that they feed.
Over 1,500 different insect species have been found feeding on or living in hedgerows. In turn, they provide a huge food resource for our birds, bats and other mammals. Fertilizers can cause a change in the type of plants growing at the hedge base. Many wildflowers do not thrive in enriched soils. This is because enrichment causes the rapid growth of nutrient-loving plants such as nettles and docks, which then dominate the ground vegetation.
Health-check your hedgerows
The Healthy Hedgerows survey provides instant feedback about the health of the hedge and bespoke management advice. The data that you contribute helps us to understand the overall health of hedgerows at a national scale so that we are able to direct our conservation work. Learn more: