Identification of Ulmus as
a sub-fossil material depends on the recognition of wood,
charcoal and pollen. No macroscopic records occur earlier
than Flandrian zone 6, records have been found in the
Cromer
forest bed series. There also has been some fruit identification
from sub-stage 2 at Trafalgar square. Pollen is present
in all British interglacials form the Ludhamian onwards,
although only at low frequencies. During the Hoxnian,
Ipswichian and Flandrian, it played a mediocratic role
within mixed oak forest.
Pollen is present through all four Hoxnian sub-stages,
but most consistently in the two warm middle stages. However,
most frequencies are below 5% in the Hoxnian, and only
marginally higher in the Ipswichian (Godwin, 1975).
Radiocarbon dating conclusively indicates the Ulmus decline
is remarkably synchronous over wide regions of Europe,
at about 5000 radiocarbon years ago. The decline had such
a widespread and sudden effect that it is believed not
to have been caused primarily by the utilisation of Ulmus
by pre-historic man. Climate change and epidemic disease
may also have contributed and had considerable effect
(Godwin, 1975).
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