22
THE ESSEX NATURALIST
Woodham Walter Common
A Study in Plant Ecology
By W. E. MASEFIELD.
The distribution of vegetation on Woodham Walter Com-
mon affords an excellent illustration of the dependence
of plant life on the physical factors in the environment. The
following short account summarises some of the results of an
ecological survey of the Common, carried out recently by the
author, in collaboration with Mr. G. Clements, of Maldon and
Oxford.
Woodham Walter Common is an area of about 100 acres of
woodland, lying on the north-east slopes of Danbury Hill,
midway between Chelmsford and Maldon, in Essex. The main
features of the Common are shown in the map, Fig. 1. The
highest and lowest points are 300ft. and 160ft. respectively,
and the Common occupies two spurs lying between two small
streams which form its northern and southern boundaries.
Fig. 2 gives an impression of the lie of the land, showing the
general slope from SW to NE, and into the two valleys, and
the depression between these. The land formation gives two
contrasting habitat conditions : the higher regions to the SW
and along the ridges of the spurs are well drained and tend to
be dry, while the lower land in the valleys tends to be wet.
These tendencies are further increased by the distribution of
soil types.
Fig. 3 shows the distribution of soils of the area. During
the preparatory work of the survey, many soil samples were
taken, to a depth of nearly 2ft., in all parts of the Common.
Most of these samples were roughly assessed in the field by
examination and "feel", and were classified into two broad
groups—predominantly clay and predominantly sand. A more
subtle differentiation was not found to be necessary, since inter-
mediate types did not occur often, and when they did, they
marked only a rapid transition from a definitely clay soil to one
predominantly sandy. Therefore, on Fig. 3, the area is shaded
to show only the two groups.