ConClusion: naTure, hisTory and C onservaTion^187fen – became increasingly derelict, with a marked loss in botanical interest.
Woodland, too, was increasingly neglected. At the same time, the need for
large landowners to make up for falling rental incomes ensured a further
expansion of game shooting, and a further onslaught on perceived predators
of game birds, which continued on some scale into the inter-war years. Where
large estates were broken up, moreover, land fell into the hands of new
owners who, through necessity or cultural preference, viewed the land in
more purely agricultural terms, ensuring further losses of trees and hedges.
In the spreading suburbs, however, in areas of urban dereliction, and in the
new ‘edgelands’, novel habitats, often as rich as anything now to be found in
the countryside, were emerging, albeit characterized by increasing numbers
of alien plants and invertebrates.
Relatively few of the 100,000 or so species present in Britain as a whole
became extinct at a national level as a consequence of the changes described
in this book, or even as a result of the more dramatic developments of the
period after 1950: perhaps 21 species of flowering plant, around 16 mosses
and liverworts, 13 lichens and a single species of the larger fungi.^17 The
extinctions in England of the pine marten and polecat, and of birds of prey
like the hen harrier and red kite, have been reversed by recolonization or
reintroduction from Wales and Scotland during the later twentieth century.^18
But regional and local extinctions have been numerous, especially in the
suburbanized and intensively cultivated south and east of the country.^19 Since
1750, one species of flowering plant has been lost on average every 1.7 years
from Middlesex, and every 2 years from Cambridgeshire.^20 The country’s
native flora, and much of its fauna, has become more and more spatially
restricted and many species face an uncertain future even in national terms.
Forty per cent of our butterflies, for example, are currently under threat.^21
Over the period covered by this book losses have, on the whole, been heaviest
among ‘specialist’ species, those with the more exacting requirements, and
especially those plants and animals most closely associated with the kinds
of essentially artificial habitat (heaths, downs, woods, wetlands) created by
medieval and early post-medieval farming, but destroyed wholesale in the
course of the eighteenth, nineteenth and twentieth centuries. The traditional
‘wastes’ have been progressively reduced and fragmented, limiting the
opportunities for these specialized organisms to move from one remaining
‘island’ to the next.^22 Less adversely affected have been the generalists, the
flora and fauna associated with farmland, and which have often been able
to adapt to urban, or at least suburban, conditions. As Fox has noted in the
case of butterflies, ‘As is probably the case for many taxa, the massive decline
and extinction of specialist species are being masked by the colonisation of
generalists’.^23
Biodiversity, if correctly defined not as the total number of species in
any area but as the maintenance of healthy populations of a particular
district’s characteristic species, is thus closely associated with the fate of
what biologists often describe – perhaps incorrectly – as ‘semi-natural’