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THE MICROSCOPIC LIFE OF THE "LEAF-
CARPET" OF WOODS AND FORESTS.
By D. J. SCOURFIELD, I.S.O., F.L.S., F.Z.S.
(With One Plate.)
[Read 5th March, 1938.]
IN calling attention to the various forms of microscopic life
which are to be found in the leaf-carpet of our woods and
forests it may be well first of all to explain exactly what is
intended by this term. In its most fully developed and typical
form the leaf-carpet may be defined as the permanent layer of
dead leaves which covers the ground in rather dense woods and
forests, consisting, on the top, of th more or less loose leaves of
the last fall and lower down of matted leaves showing more and
more signs of decay until merging into a pure leaf-mould with
but little trace of the original leaf structure. Lower still, of
course, the leaf-mould becomes intimately mixed with the
inorganic surface soil and all trace of leaf structure disappears,
but this layer is not included in the leaf-carpet, as it is rather
to be regarded as belonging to the soil more properly so called.
As thus defined, the leaf-carpet practically corresponds to the
upper part of the two main divisions into which forest soils are
divided by writers on soil science (7, 12, etc.*), the lower division
being that part which consists of the entirely disintegrated
organic material mixed with inorganic surface soil. For these
two main divisions, P. E. Muller, one of the earliest writers on
forest soils (4), introduced the terms "mor" and "mull"
respectively. Many other terms have been used by later writers
for the upper main division of forest soils, the most frequently
used perhaps being "raw humus," but the recent tendency seems
to be to use the simpler term "mor" for this division (7, 12 and
13). A number of subdivisions of the "mor" have been proposed
and are clearly to be recognised in certain cases, but it is not
necessary to refer to them here. We may assume, then, that
the leaf-carpet practically corresponds to the "mor."
Such a leaf-carpet may cover wide areas to a depth of several
inches, preventing all growth of grass or moss. It often happens.
* For List of References see p. 245.
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