WALTER WOODHAM COMMON
171
Crataegus monogyna 12
Betula spp. 5
Ilex aquifolium 4
Prunus spinosa 4
Sorbus aucuparia 4
Corylus avellana 2
Cornus sanguinea 1
Fraxinus excelsior 1
Malus sylvestris 1
Total 480
(The preponderance of oaks in the above table is not to be taken
as showing the true relative frequencies of these species in the Common
as a whole, since the transect line was chosen deliberately to pass
through the Quercetum. A random transect would show greater numbers
of the other species.)
The histograms in Figure 1 have been prepared from the field
records, by taking each entry as 5 per cent of the total number of trees in
the corresponding 100-ft. section of the line. Records other than those
for the oaks and hornbeam have been lumped together for convenience
as the table above indicates, this group is largely Betula alba. At the
bottom of the diagram is an exaggerated vertical profile of the transect
line, with the nature of the soil indicated. The horizontal scale is
divided into 100-ft. intervals to correspond with the 100-ft. sections of
the histograms.
The distribution of species is roughly as follows:
Quercus petraea. Dominant along most of the transect, but thinning
out at the North end and in the 1,400 to 1,900-ft. region, where its place
is taken by Betula alba and Carpinus betulus respectively.
Quercus robur. Very sparse, but more frequent at 400 to 600-ft.
where the soil is sandy.
Quercus hybrids. Distributed nearly uniformly along the transect,
with a greater frequency round the 1,500-ft. mark where the soil is a
little more moist.
Carpinus betulus. Almost confined to the clay, especially in the
damper parts.
Other species. Apart from Betula alba, which is dominant over parts
of the sandy areas, the other species are uniformly distributed as
casuals along the transect.