The value of hedges
The value of hedges is very complex. Hedges are essential parts of the landscape that provide shelter and habitat for animals; they also protect the soil from drying out, and keep wind and water erosion at bay. All woody plants, including shrubs in hedges, act as air-conditioning elements in hot temperatures and are important carbon stores. With their roots they stabilize slopes and banks, protect surface waters, condition the microclimate and help maintain the water balance within the soil. Birds and insects seek them out as hiding places and habitats: due to this, shrubs play an important role in biological pest control. They also deliver various essential functions in maintaining an ecological equilibrium and serve as important point features in the landscape - bridging and linking habitats. In places where biotopes are located further apart, shrubs really do act as bridges and establish fundamental ecological relationships between the biotopes, such as species traffic and exchange, species distribution and propagation, as well as migration.
Hedges absorb carbon dioxide (CO2) from the atmosphere, by which they make it harmless to the climate. Organic carbon and nitrogen are stored in hedgerow soils. Hedges also have a cooling effect. Hot days are much easier to cope with in residential areas with lots of planted hedges. Likewise in dry periods, areas planted with hedges suffer less damage because as the green areas retain moisture in the soil longer than areas with bare surface.
Hedges are so-called “stepping stone biotopes” and “bridge builders”, which essentially means they enable ecological connections and relationships. They provide shelter and breeding space a wide variety of wildlife. Thanks to hedges, wildlife species can migrate and their populations have an opportunity to mingle, interbreed, and thus remain resilient and healthy. This is particularly important in urban areas, which represent barriers preventing traffic of many different species of wildlife. Hedges can also provide extra living space for wildlife, thus promoting biodiversity.
Animals and plants are able to find a very broad variety of conditions within the smallest of spaces. Wildlife species use hedges to find shelter, food, and to build their nests and burrows. This is why hedges are referred to as stepping stone biotopes and bridging or networking elements.
Typical residents of hedges:
- Tree layer: long-eared owl and kestrel· Trunk zone: green woodpecker
- Higher and middle shrub zone: fieldfare, red-backed shrike, common hedgehog, shrews and dormouse
- Lower shrub zone: whitethroat
- Old and dead wood: longhorn beetle and carpenter bee
- Ground and small structures within hedges: sand lizards, common toads, ermine, least weasel, stone marten, shrews and hedgehogs
- Herb zone and the litter layer: yellowhammer, butterflies, hares and rabbits, ants and ground beetles
Hedges make the landscape look more beautiful.
They break and divide it into smaller varied spaces, introduce a variety of colours, shapes, and textures, and form specific spatial structures that make us feel secure and cosy: this is why children love to play in them. To put it simply, hedges enhance the value and general experience from leisure and recreational areas, for all of us, big and small, young and old.
Hedges offer many ways of enriching our cuisines with their edible flowers, leaves, buds, fruits, and nuts. Planting and harvesting fruit-bearing trees is a valuable contribution to protecting the climate, as the fruits are local and do not need to be imported. In addition, hedges also enrich the senses with the scents of their blooms, and please the eye with their colour variety. Moreover, hedges can also provide firewood and timber, or alternatively the pruned branches can be shredded and used for mulching.
When used as privacy screens, hedges usually consist of just a single species. However, mixed hedges, which are more diverse in shape and structure, offer much more for wildlife and the plant world, and also for the human eye! These ecologically valuable mixed hedges also offer very good privacy protection and have an essentially higher value from the nature-conservation perspective.
Hedges have the ability to absorb fine dust and therefore act as filters binding CO2 from the air and producing oxygen. This comes as a very important strategy especially in towns, where shrubs and hedges help significantly improve the quality of air we breathe.
The greatest risk of losing fertile soil is through soil erosion. Erosion is caused by wind and water, and also in combination with the open landscape. This is becoming an ever increasing problem, not just in the landscape, but also in private gardens and in public green spaces, where erosion literally destroys and steals soil from open areas not protected with the cover of greenery, and also on embankments. Losing the fertile layer of the soil has not only ecological, but also economic impacts, as plants basically stop growing or grow very poorly. Absence of fertile soil means less space for the roots, the roots of young plants and seedlings become exposed, dry up and die. Once lost, fertile soil can only be brought back with a lot of effort. It takes many years for humus to build up again, naturally with intensive care and greening of the surface.
However, if a hedge consisting of suitable tree and shrub species is planted across the wind’s direction, it can act as a very good wind-break and protect soil from drying out and erosion.
Hedges act as wind barriers and shade the ground; due to this snow remains on the ground longer and the soil retains moisture for extended periods. This extra moisture ensures the essential supply of water to all plants close to the hedge, as their seeds germinate faster in the sheltered and more humid space. The living green surface reduces the impact force of the raindrops and protects the structure of the soil, which stays firm and does not become muddy. This is particularly important in private gardens and in public spaces.