many years does not necessarily mean it has become extinct. It might be that no-one has
looked for the species, the species has become rare and hard to find, or the species
might have natural cycles of abundance, and is only readily found when its population is
at a peak.
However, I feel it is a very worthwhile exercise to try and collate the species records for
a site, and especially for a nature reserve as interesting as Hatfield Forest, and a reserve
that is under increasing pressure from developments such as the proposed expansion of
Stansted Airport. We need to know about the diversity of wildlife present.
But where to start such a task? The National Trust has had two biological surveys carried
out by a team of inhouse experts in 1986 and 2000, and these highlighted a number of
significant species records. There were also a number of reports and letters with records
in the property files. The NT had also commissioned Tony Drane to survey the saproxylic
Coleoptera (beetles associated with old trees and decaying wood) in 1999-2000 and his
reports were rich in information. The bird records came courtesy of Hugh Coe and his
colleagues from Bishops Stortford, who have been regularly surveying four areas of the
Forest for more than 20 years and produce annual reports. These sources were the
starting point and many hours were spent typing these data into excel files. In addition,
several Recorders of the Essex Field Club have kindly provided lists of species records
on computer files, with details of locations, dates, observer and field notes. These were
a significant leap forward and I am extremely grateful for this help.
The most important records, for vascular plants, fungi, bees, wasps, hoverflies and many
other insects, came from those wonderful field naturalists, Charles and Shirley Watson.
It has been an absolute pleasure to talk to them, collate their records and in the process
learn so much more about the importance of the Forest. The Trust has been so fortunate
to have such good naturalists take a long-term interest in Hatfield Forest and we will
deeply miss Charles Watson's expert advice.
So, what do we now know about the species that live at Hatfield Forest? Total number of
records for the site now is more than 12,500 of 3,516 species. The data are held on
Excel spreadsheets and on the RECORDER database. Table 1 (overleaf) shows the
breakdown of the species data into major taxonomic groups. Immediately notable are
the high numbers of species of plants, fungi, beetles (Coleoptera), moths and flies
(Diptera).
Taxa for which little or no species information is known: Algae, Earthworms, Nematodes,
Parasitic Hymenoptera (eg Ichneumonidae), Copepods, Cladocera (water fleas),
Ostracods, Rotifers, Collembola, Hemiptera-Homoptera (aphids, leafhoppers), and
several Families of Diptera (flies) such as Mosquitoes, Chironomids (Midges).
12
Essex Field Club Newsletter No. 50, May 2006