66 The Essex Naturalist
The loss of biodiversity in Essex
The massive changes in our countryside associated with agricultural
improvements and developments have decimated wildlife habitats, particularly
in the south-east of England and in Essex few substantial areas of semi-natural
habitat remain intact. Combined with existing geographical and climatic
isolation of populations the effect has been dramatic on much of our wildlife and
the populations of many species have become more and more isolated.
Changes this century in farming practices have left much of the county as
arable land and almost all remaining grasslands have been improved or re-
seeded, although some significant areas of old grazing marshes remain. Many
ancient woodlands were coniferised by the Forestry Commission after the war
and are isolated by arable deserts. Some of these coniferised woodlands seem
very resilient and are now showing a remarkable ability to recover when areas of
conifer are clear-felled and managed for a return to deciduous woodland.
Most commons and heathlands have either become secondary woodland
through neglect or have long since been ploughed. Very few heathland
remnants remain but there are plans to restore heathland in the county through
the Biodiversity Action Plans.
Changing attitudes to nature conservation can be seen by reference in
Hoskins & Stamp, 1963 to the large fen-commons of Bulphan and Orsett Fens.
Here it is stated "Some low-lying areas were so ill-drained as to constitute fen or
marsh of little value or interest. So there are the two large fen-commons of
Bulphan Fen (228 acres) and Orsett Fen (237 acres), which as commons have
little appeal aesthetically and are of little use for recreation, but which could by
drainage be converted into good agricultural land". These commons were
subsequently ploughed and little wildlife interest remains. Today it seems
probable that a quite remarkable wealth must have been destroyed.
The characteristic cycle of development which follows the construction of
new motorways and by-pass roads is particularly prevalent in Essex at the present
time. Thurrock and the East Thames Corridor in South Essex have massive
housing and retail developments like "Chafford Hundred" and "Lakeside" which
have followed on from the completion of the M25. Great Dunmow, Braintree
and Maldon are just three examples in the county where large scale housing and
retail developments have rapidly filled in the green open space enclosed by the
new by-pass roads and extended beyond. Extensive development is taking place
around Colchester, Bishops Stortford and Haverhill and the post-industrial or
"Brown Field" sites in particular are under enormous threat.
There are the common species that are able to take advantage of a wide
variety of habitats and the pioneer species which can rapidly move into newly
created ruderal habitats but which gradually disappear as succession takes place.
However many of the scarcer and more restricted invertebrate populations do
not seem to be able to move from one site to another easily. These species