Geoscience Reference
In-Depth Information
F
IG. 52
Increase in soil organic matter content in chalk grassland over a period of 130 years at Porton Down,
Wiltshire. (From T.C.E. Wells, J. Sheail, D.F. Ball & L.K. Ward 1976.)
One might expect that lowland grasslands would be most extensive on the chalk
downlands of southern England, but, even here, it is rare to find sites that have not
been ploughed and used for cereals in recent years. An important and virtually unique
area has been protected from this land use change by its inclusion within the Por-
ton Ranges of the Ministry of Defence in Wiltshire. Here, a multi-disciplinary project
was carried out by T.C.E.Wells and colleagues in the Nature Conservancy (later of
the Institute of Terrestrial Ecology). This study, already touched on in the section on
ants (
chapter 4
), explored the relationships between land use history, vegetation, soil
fauna, and soil properties.
Cultivation last occurred on different parts of the area at different periods. The
land had been in Government hands since 1916, and this date marked the end of any
substantial agricultural use, though range activities caused local ground disturbance
in some parts. The most recent, and very limited, cultivation had taken place about
