166
THE ESSEX NATURALIST
marginal arable land has been flooded and most of the
pasture is water-logged, but the early months of 1951 have
been exceptionally wet.
Of the drained land, only the pasture has been considered
in detail, as the arable land is no longer in a natural state.
Oats were cropped from this land in 1950, and cereals are
usually grown in the area.
No chloride could be detected in the soil of the pasture-
land. Presumably, the excess salt present when the marshes
were inned 300 years ago has gradually been leached out
into the creeks. The soil of the pasture is only very slightly
acid, so that the land is very similar to neutral grass-land.
Lolium perenne is the most frequent species here, but
Alopecurus pratensis L. and Cynosurus cristatus L. also cover
a considerable percentage of the ground. Where the grazing
is most intense, the proportion of Sonchus oleraceus L.
increases and the general appearance of the grass-land is of
a fairly short turf with the frequent plants of Sonchus
oleraceus conspicuously tall. Averages of quadrats on the
pasture-land show the following percentage of the various
species :—
Species. Lightly grazed. Heavily grazed.
Lolium perenne ... 26.0% ... 30.0%
Alopecurus pratensis ... 20.0% ... 19.0%
Cynosurus cristatus ... 13.0% ... 14.0%
Sonchus oleraceus ... — ... 7.0%
Achillea millefolium ... 9.0% ... 10.0%
Hordeum pratense ... 6.0% ... 4.0%
Poa trivialis ...... 3.5% ... 9.0%
Ranunculus acris ... 6.0% ... 2.0%
Agrostis tenuis ... 6.0% ... —
Plantago lanceolata ... 1.0% ... —
Holcus lanatus ... 1.0% ... 3.0%
Vicia angustifolia ... 1.0% ... —
Trifolium campestre ... 1.0% ... 2.0%
Taraxacum officinale ... 1.0% ... —
Of the drainage ditches of the inned marshes, those
specially dug since the enclosure will be considered first.
These include the one which follows the sea wall from Site 1
westwards—which is referred to as Creek 4. Water taken