Decoy Pit, Pools and Woods

Decoy Pit, Pools and Woods is a 20.27 hectare (50.08 acre) Site of Special Scientific Interest (SSSI) at Aldermaston Wharf in the civil parish of Aldermaston in the English county of Berkshire, notified in 1993.

Located at grid reference SU612632, the site comprises several habitats including woodland, heathland, grassland and small waterbodies. The site supports the greatest known number of breeding dragonfly and damselfly species in Berkshire, and includes alder woodland types which are nationally uncommon and a declining habitat. The presence of other nationally uncommon species of insect and bird adds to the value of the SSSI.^[1]

In the southern part of the site the land slopes gently within an eastward draining gully system, the head of the stream West End Brook flows through here. The north part of the site, a former gravel pit, now partially infilled and which was abandoned in the early 1980s. The former gravel pit surface has developed into a mosaic of shallow pools, a pond, heathland and scrub. The area supports many wetland plants including bulrush Typha latifolia, common spike-rush Eleocharis palustris, as well as a locally scarce species marsh speedwell Veronica scutellata. Drier areas are dominated by heather Calluna vulgaris and are being colonised by birch. Adjacent land is primarily secondary birch woodland with heathland, and a small valley bog where purple moor-grass Molinia caerulea is abundant.^[1]

Ancient semi-natural woodland occurs in the areas known locally as Brick kiln Gully, Roundwood Gully and Roundwood Copse. The low lying gullies here are permanently waterlogged and support alder woodland. The ground flora is diverse and includes greater tussock-sedge Carex paniculata and opposite-leaved goldensaxifrage Chrysosplenium oppositifolium.^[1]

The Brilliant Emerald dragonfly, Somatochlora metallica

Other more commonly occurring woodland types are represented within the SSSI, associated with the middle and upper slopes of the gullies. These areas contain species typical for semi-natural ancient woodland including hard shield-fern Polystichum aculeatum and Solomon's-seal Polygonatum multiflorum. A well vegitated pond is located on the north side of Best Gully.^[1]

Twenty-three species of dragonfly and damselfly breed within the site. The ponds, streams and shallow pools are used for breeding whilst valuable feeding habitat is provided in the adjacent woodland. Three nationally scarce species are present; the blue-tailed damselfly Ischnura pumilio, a species known to prefer shallow, newly created pools; the downy emerald Cordulia aenea and the brilliant emerald Somatochlora metallica.^[1]

The site is associated with a range of rare fauna, including woodlark and the silverstudded blue butterfly Plebejus argus, both of which breed in the heathland area. Another scarce species is the Devon carpet moth Lampropteryx otregiata, which is apparently restricted in Berkshire to this single colony. In winter snipe and jack snipe frequent the pools whilst siskins and redpolls are regularly recorded feeding in the alders.^[1]

References

1. ^ ^{a b c d e f} "English nature citation". English Nature. http://www.sssi.naturalengland.org.uk/citation/citation_photo/1006377.pdf. Retrieved 7 February 2011. 

Coordinates: 51°23′50″N 1°08′41″W / 51.39711°N 1.14470°W / 51.39711; -1.14470