Hanworth Park Management Plan - Hounslow.info

Appendix 4 - Conservation at Hanworth Park
London Borough of Hounslow
Much of the grassland within Hanworth Park is surprisingly diverse, and shows
characters of acid grassland. Sweet vernal-grass (Anthoxanthum odoratum) and red
fescue (Festuca rubra) are abundant in the sward, and pignut (Conopodium majus),
an uncommon plant associated with acid grassland, is frequent, along with
commoner wild flowers. The grassland holds wintering skylarks and meadow pipits,
and a good range of invertebrates, including a good population of the small heath
butterfly, and the conspicuous wasp spider (Argiope bruennichi). A bee bank has
been established in the southwestern corner of the site for mining bees and wasps.
A small area of wet woodland on the eastern edge of the park is dominated by
various willows (Salix spp.), with a ground flora including false fox-sedge (Carex
otrubae), pendulous sedge (C. pendula) and yellow iris (Iris pseudacorus). This area is
important for invertebrates and amphibians, and grass snakes have been recorded.
Large numbers of soprano pipistrelle bats forage around the edges of the woodland
surrounding Hanworth House.
The Longford River runs through the park, though it is in a culvert for part of this, and
continues for about a kilometre east to the borough boundary. The channel contains
unbranched bur-reed (Sparganium emersum), while a few plants of water dock
(Rumex hydrolapathum) and other marginals cling to the steep banks. Sandwiched
between Feltham Marshalling Yards and Hanworth Park, De Brome Playing Fields is a
mixture of acid grassland, neutral grassland and scrub. In winter the site is used by
skylark and meadow pipit and the site holds many of the invertebrates present on
Hanworth Park including good populations of the small heath butterfly.
The grassland of Hanworth Park supports a rich and diverse wildlife and is by far the
largest continuous area of lowland dry acid grassland in the Borough. The park is
designated as a Site of Local Nature Conservation of Borough Importance (Grade II),
together with the Longford River that flows through and beneath the site.
A large proportion of the park (approx. 50ha) has potential as a site for lowland dry
acid grassland regeneration. Around Hanworth House, 12.5 hectares of the site is
currently actively managed as acid grassland meadow.
Lowland dry acid grassland is a declining habitat with less than 30,000 hectares now
present in Britain. It develops on nutrient poor, acidic sands and gravel. In London, it
is confined to a few remnants of the once large commons and heaths that dominated
the Thames Terrace gravels. Dry acid grassland habitats support fine-leaved grass
species such as fescues, which plays host to many invertebrates, in particular, bees,
wasps and ants that occur only in these habitats and are rare both locally and
nationally.
Wildlife that can be enjoyed or seen in the park includes birds such as skylarks,
kestrels, and meadow pipit, as well as small heath, small copper and meadow brown
butterflies.
In the Northern part of the site, there is, complete with an interpretation panel, a
habitat which supports a variety of bees.
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