Boundaries such as hedgerows and stone walls are important features in the landscape. The first Enclosure Act passed in 1710 created today’s network of boundaries which are vital corridors for wildlife.
Hedgerows are an integral part of the countryside, ideally forming stock-proof barriers between fields. A valuable hedgerow has a variety of woody species such as hawthorn, blackthorn, dog rose and standard trees. This variety in turn supports bird species by providing homes and food such as haws and rose hips, particularly during the leaner winter months. Hedgerows can become lines of trees and gappy if left unmanaged. Gaps can also appear under standard trees and where livestock are allowed to graze right up to the base of the hedge.
Management of hedgerows
• New hedgerows should be as wide as possible; ideally, 5 whips per metre in a zigzag formation 0.5m apart. Saplings for hedgerow trees can be planted between the whips at irregular intervals 20-40m apart, but should be marked to make sure that they are not cut as part of the hedge. Fencing should be used temporarily to prevent livestock eating the base of the hedge, and rabbit guards may need to be used in the first few years until the hedgerow is established.
• ‘Gap-up’ hedgerows and mulch any new planting so that moisture is retained to help the whips establish and suppress any weed growth. A wide variety of shrub species should be used when planting and gapping up hedgerows. The new planting should complement the local character.
• When planting new sections of hedgerow the under-storey should also be considered and native plants such as primroses, sorrel, campion and common vetch could be planted. Using plugs of wild flowers helsp the plants to become established quickly.
• Lay established hedgerows in rotation to reinvigorate old growth. Hedgerows should be allowed to grow to a couple of metres in height and then their stems partially cut and laid along the hedge line. The trunks and stools sprout new growth and the hedgerow is rejuvenated.
• On a farm, the hedgerows should be cut at a variety of times and every other year trimming is recommended to encourage more flowering and fruiting. Cutting hedges in late winter can encourage sprouting. Hedges should not be cut between 1st March and 31st July as this is the bird nesting season. If hedges are cut in autumn, important bird food sources such as ripened berries may be lost.
• Buffer strips widen the corridor allowing species movement across arable fields and grassland. Agri-environment schemes offer incentives for the creation of buffer strips along boundary features.
Stone walls are not legally protected but are ecosystems in their own right, as well as providing connective corridors across the landscape. Walls are a particular feature of parts of the county such as the Mendip Hills and are generally constructed at altitudes more than 100m above sea level, particularly on poorer soils where hedgerows may have trouble growing. Walls were first built along parish boundaries in medieval times. Stone walls are an important habitat for wildlife, including mosses, ferns and animals like adders and small mammals.
Management of Stone Walls
• Undertake to repair stone walls rather than stripping them down to re-build. Stone from a nearby source should be used rather than new stone as some plants may already be present. If need be, take stone from walls that are not going to be re-built, but bear in mind that slumped and derelict walls are also an important habitat for wildlife. Carry out repairs to walls in the original style, for example using stone mortar if it was used in the original wall.
• If stones are accidentally knocked from a wall, put them back to maintain its integrity. Over time all walls will degrade due to natural processes such as water freezing and thawing in winter or damage by livestock. Fencing can protect walls from livestock damage.
• Re-build walls bearing in mind the wildlife that may be present. For example, adders may use holes in stone walls or bask on their tops. Stones with mosses should be replaced in a similar position facing the same direction to retain a matching environment. Remove woody growth such as young saplings, while small, to prevent their roots making the wall unstable.
• Buffer strips widen and diversify the corridor around a wall allowing species movement across arable fields and grassland. Agri-environment schemes offer incentives for the creation of buffer strips along boundary features.