mixing with lower layers, together with the
vegetation, suggested an acid soil.
(b) The soil under the deciduous woodland also
showed no apparent gleying at the sites exam-
ined. A more typical brown earth occurred
with a 12 cm organic mull layer merging into a
mixed layer some 15 cm deep, with a lower
horizon of heavy yellow/brown clay. Soil
organisms, including earthworms, were abundant
in the upper layers.
(c) In the marsh area there was no topsoil/
subsoil horizons apparent. The profile was
some 36 cm deep and throughout a homogenous
gleyed brown/grey clay occurred, with some
mottling apparent as the iron salts occurred in
the ferric and reduced ferrous forms as a
consequence of temporary water logging. (The
profile, dug in April, quickly filled with
water on this occasion.)
pH
Unfortunately soil acidity was not measured,
but generally the sites were mildly acid as
indicated by the species present. The pond
water was tested with indicator paper (the
reading was later checked) and was between 4
and 5 throughout the year. This represents a
high concentration of hydrogen ions and quite
an acidic environment. This may be one reason
why the number of plant and animal species has
been rather low.
Biotic Factors
The composition of the flora is also influenced