The most species-rich and interesting part of a woodland is its edge; where one habitat meets another. This is partly because of the increased amount of sunlight available, but more important is the variety – it is two habitats in one – a transitional place which suits animals and plants from either side of the border. A hedgerow is essentially the edge of a wood without the wood attached, two edges placed together, this makes it an optimal home for all wildlife that usually thrives on a woodland edge.
At the very bottom of a hedge there is the sward; where wild flowers can grow just out of reach of the mower, shade-loving plants grow right under or within the hedge while sun-loving flowers grow tall further out. The base of a hedge is a perfect home for small rodents which will make their burrows and track-ways under the shrubs, beetles will also live in this cool and dense place and the odd bird may make its nest close-to or on the ground. Higher up in the middle of the hedge is where it is thickest; many birds will nest in here; protected from predators by the tangle of branches and thorns. Vines and other climbing plants such as nightshades, black and white bryony or traveler’s joy will add more layers to the hedge and provide berries and flowers. The main bulk of the hedge is made up of shrubs; there are many species and the more there are the older the hedge probably is. Hawthorn, Blackthorn, field maple, wild rose, Hazel and holly are common hedgerow species but look out for rarer shrubs such as spindle, small-leaved lime, Alder buckthorn or English Elm.
The top of the hedge is often the favoured place for birds to sing from; in the country birds such as Yellowhammer, Stonechat, finches, whitethroat and of course the thrushes perch and sing from branches atop the hedgerow. Many hedges have mature trees along their length which add to the biodiversity and extend the habitat, they may also indicate that the hedge was once part of a woodland that used to cover the area – rather than a more recent planted hedgerow.
The true extent of the importance of hedges as corridors for wildlife has only recently been realised – many bats will fly along hedges to-and-from roost sites and feeding grounds rather than just fly over open ground. Dormice are endangered in Britain and hedges are vital for them to be able to move from one wood to another and thus increase their range and chances of survival. The linear structure of hedges makes them ideal for animals to migrate out of and into surrounding habitat much quicker than naturally – especially if all other routes are open fields or urban sprawl. It is not just animals that move along hedges either – plants will often spread out from an area via hedges because their seeds will spread quickly (relatively) along them because they act as refuges from the sterile farmland around them.
The 19th Century was a good time to be a hedge – for the enclosures act was passed, meaning that the whole countryside was changed forever. The large open fields of the past were divided up into smaller sections – with hedges forming the barriers, this was good for wildlife at the time but since then farming practices have changed. The industrialisation of agriculture has meant that large fields are favoured again – this has led to the rapid and severe loss of many hedgerows across the country; bad for wildlife and ironically also bad for farming.
Hedges are man-made for our own purposes, but seeing as we have removed much of Britain’s natural woods many woodland species have been able to relocate to hedgerows because of the similarity of the habitat. Though they are by no means a substitute for woods, hedges act as important refuges and pathways for wildlife – so much so that many conservation organisations such as the RSPB utilise them in landscape-scale conservation in order to link up reserves and isolated habitats.