The heathlands of Brede High Wood
East Sussex

Introduction

The Brede High Wood complex (BHWC) lies to the north and east of a tributary of the river Brede within the East Sussex parishes of Brede, Ewhurst Green and Sedlescombe. The underlying strata are primarily Ashdown Beds with areas of Wadhurst Clay and Tunbridge Wells Sand. The valley was dammed in the 1930s to create the Powdermill Reservoir for which the Brede High Wood complex is the catchment area.

The northern side of the BHWC is a mixture of deciduous woodland and conifer or sweet chestnut plantation with a variety of small open spaces. Several of these open areas are heathland of the type that would have developed very widely in the past in wood pasture in southern England. Judging by the flora and fauna of some of these areas, they have been open heathland for a very long time and represent a link between the heaths on the coast in the Fairlight Country Park to the east of Hastings and the well-known sites of Chailey Common and Ashdown Forest in the High Weald to the west. They are a remnant of an East Sussex countryside that was probably once widespread but is now largely gone.

The significance of these heathland areas does not hitherto appear to have been recognised or recorded and part of the purpose of this paper is to raise awareness so that a debate can take place about their future.

The heathland areas

There are six areas of heath in the BHWC, each with a different character.

1. On the east side of Streetfield Wood at TQ789203 an area has been fenced against rabbits and planted with European larch Larix decidua now c. 2 metres tall. The dominant vegetation here is broom Cytisus scoparius which forms an almost solid mass with an understorey of dwarf gorse Ulex minor and a rapidly diminishing ground flora of grasses, heath bedstraw Galium saxatile and tormentil Potentilla erecta. Along the southern edge there are some open areas of rough grass and bramble while to the west, between the fence and the public footpath, there is a small quantity of heather Calluna vulgaris and a few plants of bell heather Erica cinerea.

   The character of this area has already been considerably altered by fencing and, if the larch is allowed to grow, the shrub and ground layers will be shaded out within the next few years.

2. Lying immediately to the east of 1. above at TQ790202 is an area much of which is still open deer/rabbit lawn, though broom, bracken and birch are encroaching and oak, now c.3 metres tall, has been planted throughout. The area is dry and sunny, but there is a damper, rushy section surrounded by birch scrub to the east.

   In my view all of this area has been heathland for a considerable period and it contains strong populations of greater broom-rape Orobanche rapum-genistae, Dodder Cuscuta epithymum (both rare in East Sussex) and dwarf gorse Ulex minor as well as many commoner heathland plants and the very scarce heath dog-violet Viola canina. Butterflies include the grizzled skipper Erynnis tages, the dingy skipper Pyrgus malvae and the green Hairstreak Callophrys rubi, the first two now uncommon in The Weald and the last rare.

   Greater broom-rape is one of the proposed target species for conservation listed in the 2nd edition (1995) of Biodiversity Challenge: an agenda for conservation in the UK. Formerly quite common where broom and gorse occur there are now only a handful of plants known in East and West Sussex apart from this heath in Sedlescombe where, in 1996 and 1997, there were about 30 flowering spikes. It is now uncommon and declining throughout the rest of its British range. As well as its general interest it is a very dramatic, orchid-like plant which grows to a height of half a metre or so in as little as two weeks in early June. There are a few very rare insects associated with it. The small fly Chyliza extenuata (Dipt: Psilidae), for example, lives in a gall in the roots and the Agromyzid fly Phytomyza orobanchia feeds in the seed heads and stems.

3. There is a small field in the southern section of Holman Wood at TQ795202 that appears to have been kept scrub-free for many years, though I have not yet been able to ascertain how, or by whom. In the winter of 1994/95 the field was scarified and planted with conifers, though the ground has recovered quickly. However, the area is now suffering from rapid birch invasion and overshading and its character, and rare species, will soon be lost unless the birch and other tall woody plants can be kept under control.

   Much of the field is dry, acid grassland, but there are extensive colonies of Calluna on the northern and southern boundaries and an area of sandy pits with broom scrub where deer often shelter in the north east corner. Slow-worms also occur in this area. On the western side there is some dwarf gorse Ulex minor and heath dog-violet Viola canina, some lousewort Pedicularis sylvatica in the south east corner and lesser skullcap Scutellaria minor on the western boundary. The open areas of the field support strong populations of dingy and grizzled skipper butterflies as well as the day-flying burnet companion moth Euclidia glyphica and the field tiger beetle Cicindela campestris.

   The western boundary is fringed with sallow, alder and other trees growing along the stream dividing Sedlescombe from Brede parish. There are beds of Sphagnum moss here with marsh violet Viola palustris, marsh pennywort Hydrocotyle vulgaris and the alien New Zealand pigmyweed Crassula helmsii.

   Over the years this field and some of the adjacent parts of Brede High Wood have been worked by coleopterists who have made some remarkable discoveries. These include the following 'red data' species: Badister anomalus (RDB1), Bembidion octomaculatum (Extinct category! ), Longitarsus longiseta (RDBK), Rhinoncus albicinctus (RDB1), Sitona puberulus (RDBK), Acilius canaliculatus (RDB3), Haliplus varius (RDBK) (P J Hodge, pers. Comm.) plus many Notable A, Notable B and Local species.

4. In the area of chestnut coppice from TQ800206 to TQ803206 there is much tall, leggy Calluna which extends into the pine plantations to the south. Several of the streams in this area have beds of Sphagnum, all now in deep shade.

   There is an old record of pale dog-violet Viola lactea, a now very rare heathland species, from this tetrad.

5. At TQ804201 on the western side of Coneyburrow Wood there is an area of marshy alder carr with underlying Sphagnum, bur-reed Sparganium spp. and a generally rich flora and fauna. The marsh lies under electricity transmission lines and regular coppicing to keep vegetation clear of these has helped to retain biodiversity. In spring brook lampreys Lampetra planeri ascend the stream into the marsh the water of which rises far from any pollution.

   On the eastern side of the marsh is an area opened up from deciduous woodland by the 1987 storm and subsequent coppicing where Calluna is regenerating strongly. There are some good patches of lesser skullcap here with the Scutellaria-feeding sawfly Athalia scutellariae abundant amongst the plants. Butterflies in this area include the pearl-bordered fritillary Boloria euphrosyne, and silver-washed fritillaries Argynnis paphia and white admirals Limenitis camilla from the woodlands regularly patrol beneath the transmission lines. Rarer moths like the large red-belted clearwing Synanthedon culiciformis and the broad-bordered bee-hawk Hemaris fuciformis also occur in this part of Brede High Woods. The golden-ringed dragonfly Cordulegaster boltonii has been recently recorded and possibly breeds here in what is one of its most easterly British stations.

6. In the heart of the Brede High Woods complex at TQ799199 on the north eastern side of the reservoir is a level, swampy area of secondary woodland with open dry ridges with extensive stands of tall heather. The whole area lies in the lee of a steep, intrusion-like cliff of Wadhurst Clay some 8 to 10 metres tall and in itself a most unusual geological feature. There are several wild service trees Sorbus torminalis on and near this cliff.

   The banks and ridges in the heathery area, and possibly the clay cliff, are perhaps the result of past human activity, though expert archaeological input would be required to establish the nature of this activity.

   Another unusual feature of this area is the strong colony (c. 200 spikes) of twayblade Listera ovata which thrives in woodlands and on heaths, though it is not common in the Sedlescombe/Brede area.

The future

All the heathland areas in the Brede High Wood complex are, to a greater or lesser extent, suffering from the steady encroachment by self-sown or planted indigenous trees or conifers. Some areas are kept open by deer or rabbit grazing, but there is no management regime in operation, other than occasional coppicing or tree felling, that is likely to ensure the survival of these small heaths which, as well as carrying interesting and characteristic flora and fauna are delightful sunny, sheltered places.

Lowland heathland is an important target habitat for conservation and the suggested aim in Biodiversity Conservation (Wynne et al., 1955) is to maintain and improve by management all exisiting lowland heathland in Britain. The Brede High Wood Heaths, and indeed many of the other habitats in this complex, have still been relatively poorly explored for fauna and flora and, no doubt, many more important and interesting species are living there. In 1996/97 the area, with the Hurst Wood complex on the south side of the reservoir, was given the status of a "Site of Nature Conservation Interest" (SNCI) by East Sussex County Council. This is a very welcome step, but the full character of Brede High Wood in general, and its heathlands in particular, can only be maintained under modern conditions by active conservation management of at least some areas and it is to be hoped that a way can be found to do this.

Reference

Wynne, G., Avery, M., Campbell, L., Gubbay, S., Hawkswell, S., Juniper, T., King, M., Newbery, P., Smart, J., Steel, C., Stones, T., Stubbs, A., Taylor, J., Tydeman, C., and Wynde, R. (1995) Biodiversity Challenge (second edition). RSPB, Sandy.

Dr Patrick Roper, FLS, MRES, South View, Sedlescombe, Battle, East Sussex TN33 0PE
Tel/fax: (01424) 870208
Email:patrick@prassociates.co.uk