Geoscience Reference
In-Depth Information
Regrowth of the vegetation from roots and seeds was rapid, and by the end of
May 1981 almost complete cover was re-established. After a couple more seasons
with light grazing by cattle, the site, indeed, looked like a long-established meadow.
Regular monitoring of the vegetation up to 1986 showed that all but one or two of the
original 85 species had survived. This successful outcome demonstrated the unique
nature of the topsoil as a living community, and its dependence, in this instance, on
precise hydrological conditions. The secret of success lay in the ability to measure
and re-create water tables and drainage appropriate to the different communities. The
site received a reclamation award from the Sand and Gravel Association in 1988.
Whether or not such transposed communities can be considered natural or not is
debatable. The purist will often accept the results of slow natural succession on an-
cient earthworks and mineral workings but not the deliberate manipulation of phys-
ical conditions to re-create communities lost through human impact. It seems that we
take special delight in the surprise of Nature, rather than in the works of man. Cer-
tainly, such techniques are a two-edged sword. Can mineral extraction be opposed in
areas of natural beauty if the landform and vegetation can be restored?
Each case must be judged on its merits in the light of existing ecological criteria
and technological know-how. In any event, the restoration of a community is not a
once-for-all process: suitable and sustained management is essential or else the habit-
at will change markedly. In general, we have much poorer knowledge of the soil fauna
and how long this would take to re-establish itself. We can be pretty sure, though, that
the rebuilding of ant-hills, for instance, would take decades, and some species that
are dependent on ants might not be able to survive the intervening period. Clearly, we
should not destroy rich habitats without very good cause even if we can re-create fac-
similes. Nor, perhaps, should we sweep away or bury all the newer spoil heaps and
quarries resulting from our industrial activities. These must increase the range of po-
tential soil types, and could, in another 50 years, provide unique communities for us
to study and enjoy.
