(b) Hatfield Forest, Bishops Stortford
The large lake in Hatfield Forest was the subject of careful recording by D. A. Ashwell
between 1935 and 1945. During that period, eighteen species were recorded, some
sixteen or seventeen of which were probably breeding there. Apart from Lestes dryas, an
unusual record for a site of this character, the most remarkable species on Ashwell's list
was Cordulia aenea. This is the only fully authentic historical report of a breeding colony
of the species outside Epping Forest but recent observations suggest that C. aenea no
longer occurs at Hatfield Forest. J. Fielding, myself and others have recorded the
dragonflies of the Forest in recent years, producing a total list of thirteen species. The
main lake is subject to intense public pressure and has also had its water level raised in
recent years. The habitat for Odonata here is poor, but the marsh at the north end of this
lake, which is managed as a reserve of The Essex Naturalists' Trust, is subject to much
less disturbance and supports at least five damselfly species, including Erythromma
najas, Pyrrhosoma nymphula and Coenagrion puella.
A separate 'limb' of the main lake situated just to the south of it is used for angling, but
also supports a diverse marginal and floating-leaved flora, including the Broad-leaved
Pondweed. There is a strong colony of Erythromma najas on this lake and Orthetrum
cancellatum makes use of bankside areas which have been trampled bare of vegetation.
Other noteworthy species include Anax imperator. Libellula quadrimaculata and L
depressa. Though undoubtedly less rich than in Ashwell's day, Hatfield Forest remains
an important dragonfly site.
(c) Thorndon Park North, Brentwood
Significant wetland habitat in this Essex County Council country park is restricted to
a small marsh and two ponds in the nature reserve area on the southern tip of the park.
Though the dragonfly fauna has not yet been very thoroughly studied, nine species have
been recorded during the survey period. The rather local Sympetrum sanguineum is well
represented at both ponds, and Erythromma najas was recorded from the park in
1970.
(d) Wanstead Park
This southern outpost of Epping Forest is a good illustration of how, with appropriate
management, even an urban park with considerable public pressure can still sustain a
valuable dragonfly population. There are three main areas of water in the park: the
Shoulder of Mutton Pond, which is spring-fed, and of considerable antiquity; the
Heronry Pond, a narrow strip of water adjacent to the site of the old Roman villa; and
the 'Ornamental Waters', situated close to the course of the River Roding, on the eastern
boundary of the park. The Heronry Pond and the Ornamental Waters were created in
the seventeenth century. Despite its artificial bed and banks, the Heronry Pond has
developed a rich aquatic and marginal flora, and supports at least six species of
dragonfly. Nymphs of both Aeshna mixta and Sympetrum sanguineum have been
collected from the pond, and Orthetrum cancellatum has recently been observed there.
Despite their visual suitability, the dragonfly fauna of the other two ponds appears to be
rather poor.
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