Aversley Wood - Sawtry
Site Description
Aversley Wood lies on a prominent flat topped ridge at the western edge of the Cambridgeshire fens, south-west of Sawtry and the A1 (M). The wood is one of the largest Ancient Semi-Natural woodlands in Cambridgeshire and forms an important landscape feature. It is surrounded on all sides by intensively farmed land-arable and grassland although there are some managed hedges abutting the wood. Archers wood (also owned by the Woodland Trust) is 0.5 km south of Aversley Wood.
The solid geology is Oxford Clay overlain by chalky glacial till, with a mixture of sand and loess in the topsoil. Both clays are calcareous, but made slightly acid by the sand and leaching. Soils are surface water gleys belonging to the Hanslope Series. These are ill drained and suffer from poaching from even moderate use in wet periods.
Approximately 20 ha of the southern end of the wood on well defined ridge and furrow lies (compartment 1). The ridges vary from 6-11 m wide by 130-300 m long. This is thought to date to from ~ 1350 when the Black Death reduced the population and the land was abandoned and reverted to woodland. The wood is bounded by a discontinuous wood bank. The present size and shape of the wood dates from 1768 and most of the internal ride system from 1887. There is some evidence of shallow mineral workings in the very SW corner. This lies adjacent to the ancient track way, the Bullock Road which was a major route until the 18th Century.
The whole wood is ancient coppice woodland. Large scale coppicing ceased ~1890. The typical structure is an upper storey of ash and oak with a second storey of ash and maple coppice and maidens, and an under storey of small coppice hazel, hawthorn and blackthorn. The wood is a typical W8 Ash/Maple/Dog’s Mercury woodland. Hazel would have been the dominant tree in the past but it is in decline due to shading and an increase in ash maidens on cessation of regular coppicing. Since this period management has been ad hoc with opportunistic felling of coppice and removal of mature timber trees. Prior to acquisition by WT the site was managed for sporting use resulting in wide mown rides and the clearance of the northern artificial pond. The wood is notable for its wild service trees, some of which exceed 60 cm diameter large for this species. The wood also contains small pockets of elm and aspen. The woodland ground flora is generally rich and contains a number of ancient woodland plants. The commonest dominant species is Bluebell, followed by Dewberry and Bramble. Dog’s mercury is also locally dominant in the original woodland. Much of the denser stands have few vascular plants, but a vigorous although species poor bryophyte layer. In the ridge and furrow area Bluebell and Enchanter’s nightshade predominate.
The rides are broad, ditched and levelled but are prone to water logging in places. The main rides support much of the wood’s present floral interest. The NCC 1972 survey recorded 130 species of vascular plants with rideside communities of particular importance. The wood also contains 12 species of butterfly and at least 37 species of bird. Of specific interest are black hairstreak butterfly, white admiral and white letter hairstreak.
The wood harbours a population of Muntjac deer that can quickly increase to levels that damages the natural regeneration of tree species and other ground flora if not effectively managed by controlling their numbers
Access to the wood is from Sawtry village in the east or Bullock Road public byway to the west. .A public footpath abuts the eastern boundary of the wood. There is a good path and ride network in the wood some of which is very muddy in the winter
