sevenTeenTh-CenTury environmenTs: farmland^49remains debated.^44 They certainly provide a prime habitat in their own right
for bird species like dunnock, yellowhammer and common whitethroat.
The importance of hedges for wildlife in the early modern landscape was
particularly great because, as already noted, most were planted with a range
of species. This provided a diverse structure, and thus a wide range of niches,
but also a variety of food sources: modern research has demonstrated that
the number of bird species and the number of individual birds present in a
hedge both rise as the variety of shrubs increases.^45 Regular management
also increased biodiversity for, as with woodland coppices, the changing
structure as the hedge re-grew provided a rapid succession of habitats.
In old-enclosed areas, moreover, hedges were commonly accompanied by
substantial banks and ditches which afforded cover for shrews, voles, mice
and other mammals. In addition, many hedges were considerably wider than
the majority surviving today, in part because species like blackthorn tended
to sucker sideways, especially where fields lay under pasture. Sir John Parnell,
writing in 1769, described how Hertfordshire hedges appeared ‘rather the
work of Nature than Plantations generally Extending 30 or 40 feet Broad
growing Irregularly in these stripes and giving the fields the air of being
Reclaim’d from a general tract of woodland’.^46 Indeed, in some ‘woodland’
districts, fields were often bordered by strips of coppiced woodland, like the
‘shaws’ of Kent.
The density of hedges in ‘woodland’ districts displayed much variation.
On larger holdings fields commonly covered 5, 10 or 20 hectares, but in
general they were between two and four hectares in area, and sometimes
considerably less, in part because of the importance of hedges as a source
of firewood. A ‘Particular of Mr Rodwell’s Farm’ in Diss in Norfolk, made
in 1771, describes 21 fields with an average size of less than three acres (1.2
hectares).^47 We should not, however, assume that such very densely hedged
landscapes were necessarily the best for wildlife. Research suggests that
the number of bird species present in hedges does not increase in a linear
manner with increasing density of hedges but instead peaks at around 7–11
kilometres of hedge per square kilometre, due to competition for food and
territory.^48
Hedgerow trees were usually abundant and provided important song-
posts for species like whitethroat, wren and robin: hedges with trees support
a significantly more diverse avifauna than those without. Free-standing
trees were also usually numerous in woodland landscapes, scattered across
pasture closes or grouped around the margins of fields in ‘rows’ two or
three deep; for even where land was under cultivation hedges were often
accompanied by ‘hedge greens’, unploughed strips similar in character to
modern ‘conservation headlands’, on which hay was cut or cattle tethered,
and which provided a convenient area on which ploughs could be turned.^49
Data from farms in Essex, Suffolk and Norfolk suggest an average of around
25 farmland trees per hectare in the seventeenth and eighteenth centuries.^50
But on some farms the figure was much higher, one at Denham in Suffolk