WOODHAM WALTER COMMON
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hybrids) and Hornbeam (Carpinus betulus). Comparison of
this map with Fig. 3 will reveal that the oak occupies all the
sandy soils and part of the clay soils fringing the sand, and the
hornbeam is confined entirely to the clays of the valleys and in
Fig. 3. Distribution of soils.
between the two sand ridges. The deciding factor in the distri-
bution of the trees is not the nature of the soil, because the
oak occupies both sand and clay, but, rather, moisture. It is
probable that, in the absence of hornbeam, the oak would