Invertebrate survey at Gunpowder Park,
the former Royal Ordnance Site in the Lee Valley
PETER HARVEY1 AND TIM HILL2
132 Lodge Lane, Grays, Essex RM16 2YP
2 Nature Conservation Officer, Lee Valley Regional Park Authority,
Myddleton House, Bulls Cross, Enfield EN2 9HG
Abstract
Invertebrate survey was undertaken at the former Royal Ordnance Site in the Lea Valley at the end of the
2002 season and during 2003. Atotal of 769 invertebrate taxa were recorded, including a number of Red
Data Book species, Nationally Scarce (Notable) species and species new to Essex. One parasitic fly
Clytiomya continua, found on two occasions, was the second and third British record.
By far the most significant invertebrate communities in terms of the numbers of species recorded,
their rarity and conservation significance were associated with habitats remaining from before the
site's decontamination: the open parts of the Osier Marsh, an area of old pulverized fuel ash (PFA)
that was once open and supported marsh orchids (Hill 2000) but now mostly wet woodland, together
with surviving old flower-rich grassland areas.
Much of the site consists of new developing grasslands, and these already support species of
interest, and there is little doubt that with sympathetic management these grasslands will develop
greater significance as populations move in and colonize. Periodic management to retain disturbed
and open ground is considered to be especially important in this respect.
Background to Gunpowder Park
Moving east from the ancient habitats of Epping Forest, one encounters the valley of the River Lea
where the old River Lea and the Lee Navigation form the basis for the Lee Valley Regional Park. The
River itself has played an important part in the development of London, providing a major transport
route for both people and goods into and out of the city. Urban spread followed the course of the river
north, with some industries such as furniture making becoming established on the river. During the 20th
century sand and gravel has been extracted from large areas of the lower Lea Valley. Following extraction
the holes in the ground were either filled with waste materials or allowed to fill naturally with ground
water. At Chingford and Walthamstow huge reservoirs were constructed and north of Waltham Abbey a
thriving greenhouse industry developed on the rich alluvial soils of the valley sides.
By the 1960s the Lea Valley had changed beyond recognition. Lying on the boundary of the riparian
boroughs and county councils it had become London's backyard - a dumping ground used by all
and eared for by none. This may have been the ease today had it not been for the vision of Sir
Patrick Abercrombie who in 1944, in his Greater London Plan, proposed that the Lea Valley should
be managed as a ".. .great regional reservation". The idea lay dormant in the post war years until
1963 when resurrected by local authorities who commissioned the Civic Trust to prepare an appraisal
Essex Naturalist (New Series) 21 (2004)
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