Surrey's Habitats : Woodland
Surrey is the most heavily wooded county in England and boasts a diverse selection of woodland types. Across the county can be found examples of ancient, pasture and commercial woodland as well as coppice, beech hangers,oak and pine woods. Although many acres have been lost over the years, Surrey retains many interesting woodlands.
Surrey is proportionally the most wooded county in England with 22% or 36,816 hectares of the land under woodland cover. It is unevenly spread across the county with only 1% cover in the northern borough of Spelthorne contrasting with 30% in Waverley down in the south-west. The Surrey Hills, which stretch across the North Downs, comprise the most wooded Area of Outstanding Natural Beauty in the country.
The term woodland is generally used to define vegetation dominated by trees more than five metres high when mature, forming a distinct though sometimes open leafy ‘canopy’. Below this is the ‘understorey’ - a layer of shorter or younger trees and shrubs. Underneath this is the ‘field’ or ‘ground’ layer made up of small herbaceous plants and grasses. A wood that contains vegetation of different heights and ages, and has gaps in the canopy that allow sunlight to reach the ground, supports a much greater range of plants and animals than an even-aged tree structure without the gaps.
The damp and often nutrient-rich soils developed from Surrey’s Weald Clay support a rich woodland flora in those areas that have remained relatively free from agricultural change. English oak is the characteristic tree of these woodlands with an understorey of hazel or hornbeam. These two species are often present as coppice, a reminder of past use of these woods in which pole timber was taken from species that would then resprout new growth and provide another crop after a period of 10-20 years. Indeed, many woods were replated in the early 19th century with sweet chestnut which provides a hard and durable coppice timber. Usually the replacement by this canopy species has not altered the ground flora appreciably, and where coppicing is still practised the show of springtime flowers can be spectacular, with carpets of bluebells and violets, celandines and anemone.
Sunny, sheltered rides, glades and clearings are very valuable, especially if managed rotationally to provide vegetation in all stages of growth from bare ground, through a flower-rich herb layer, to scrub and young trees.
Woods that have been unmodified by replanting show an attractive complexity both in the number of plant species present and the structure of the wood in terms of canopy, shrub layer and ground flora species. In addition to the dominant oak, there may be ash, birch, field maple, wild cherry, wych elm, wild service tree and small-leaved lime. The last three species are characteristic of ancient woodlands. Beneath the canopy, there may be holly, blackthorn and hawthorn, and, in the wetter areas, guelder rose, alder, buckthorn and willow.
The herbaceous plants of the woodland floor can also provide clues as to the age of the wood. Many species are unable to compete with the more vigorous plants of open habitats and often have very low rates of dispersal. So, depending on the distance from the founder colony, it can take centuries for some woodland plants to colonise new habitats. Species associated with ancient woodlands, and well represented in the Wealden woods, include wood anemone, wood sorrel, yellow archangel, yellow pimpernel, lily-of-the-valley, woodruff, oxlip, primrose and the grass, wood millet. The rare wild daffodil is restricted, in Surrey, to woods on the Weald Clay. Other species such as bluebell, dog’s mercury, greater stitchwort, goldilocks buttercup, pignut and violets are also typical and indicative of long-shaded conditions.
The variety of plants and micro-habitats within mature woodland are factors contributing to a high diversity of insect species. A number of butterflies are dependent on woodland plants as a larval food source. The fritillaries lay their eggs on violets, the white admiral on honeysuckle, purple emperor on willow, purple hairstreak on oak, the brown hairstreak on blackthorn. In addition to needing an abundance of their food plant, many butterfly species are highly dependent on the structure of the habitat. Some species need sunny glades and a source of young foodplants; other species are able to tolerate more shaded conditions.
Dead wood is an important part of any woodland. Up to a third of woodland insects, including a number of rare species, are dependent on dead wood, and it is used by more than 200 species of fly and some 760 species of beetle. Dead wood also provides valuable nesting sites for birds. One third of all woodland birds nest in holes or cavities in dead trees.
In the distant past, open spaces within woodland were created by tree falls as a result of disease, decay, storms, fires and animal activity. Grazing and browsing by deer and wild cattle delayed colonisation by trees and shrubs and kept the gaps open. When man began to use timber and to manage woodland through coppicing, more open conditions were created. This coppice-with-standards regime replicated the naturally occurring gaps, making ideal conditions for many species for centuries. This continuity of management ensured that the species-richness of woodlands was maintained. The widespread cessation of management during the 20th century has led to the decline and loss of a number of species that required the diverse structure and gappy, open conditions of actively managed coppice woodland.
Woodland Habitat Action Plan
Reserves with this habitatAshtead Park
Milford Green & Coxhill Green
Milton Heath & The Nower
Broadstreet & Backside Commons (inc. Rydes Hill Common)
Burners Heath & Swallows Pond
Fir Tree Copse
Graeme Hendrey Wood
Hill Park Estate
Vann Lake including Candy's Copse