Nature, Culture, and Conservation in the Anthropocene - Biodiversity Conservation and Environmental Change - page 151

flexuosa, , Festuca ovina , and Nardus stricta , and mire or bog communities where sedges,
sphagnum moss, and small shrubs are common (Holden et al. 2007). Most moorlands
depend on continued management for their existence; burning regenerates heather and
reduces the risk of wildfire by breaking up the fuel base into a heterogeneous patchwork
through which fire is less likely to spread. Too much grazing or burning, however, can lead
to the spread of aggressive, unpalatable grasses, erosion and gullying. Burning prevents tree
regeneration and can encroach on woodland areas. It may also convert blanket bogs to
heather moorlands (Reed et al. 2009).
To plan a sustainable future for the uplands, it is necessary to understand their origins and
history. Once covered by extensive forest cover (Figure 7.4b), upland management probably
began in Mesolithic times when hunter-gatherers cleared small areas of woodland to facili-
tate hunting of wild herbivores, such as deer and wild boar. From the mid-Holocene, humans
cleared woodland to create pasture, and from about 3000 bce, Iron Age farmers began more
extensive clearance (Simmons 2002, Reed et al. 2009). Grazing and fires kept pastures free of
encroaching trees, and over the centuries, deep layers of peat developed, creating soil condi-
tions unique to the moorlands. The uplands became a mosaic habitat of woodlands and
moorlands whose extent varied in response to climatic, social, and economic drivers (Holden
et al. 2007).
Over time, a system of transhumant pastoralism developed, in which cattle and sheep
were moved between winter and summer grazing areas, allowing lowland pastures to rest in
the summer months. Records of this system date back to the eleventh century ce, but it was
probably established much earlier than this. Valley farms provided shelter in the winter, as
well as fertile areas in which crops and feed plants like turnips and sown grasses could be cul-
tivated. Cattle and goats were also kept for milk and cheese. Townships grew up around the
summer grazing areas, and the annual migration was an important part of pastoral society
and ecology (Reed et al. 2009). Trees still remained an important component of the upland
landscape, and summer wood-pastures—known as shielings in Scotland—contained an
open canopy of trees, sometimes pollarded, that would have provided shade, shelter and
building materials, food for animals, as well as seed sources that provided connectivity with
remaining woodland fragments (Figure 7.3c) (Holl and Smith 2007). Veteran pine and oak
trees can still be found on abandoned shielings, themselves now highly valued as the endur-
ing sentinels of a lost way of life.
Woodland clearing intensified in medieval times; from the twelfth to the fourteenth cen-
turies, monasteries introduced extensive sheep grazing in the uplands to produce wool. In
the highlands of Scotland, it is estimated that by 1500, only 20% of tree cover was left, falling to
only 5% by the 1750s (Dodgshon and Olsson 2006). Cultivation, overgrazing, burning, har-
vesting of wood for construction, and bark stripping for use in the leather industry were also
contributing factors to ongoing woodland clearance. Continued grazing, managed burning
to rejuvenate heather plants, as well as soil erosion and acidification prevented the forests
from recovering.
In the eighteenth and nineteenth centuries, market forces and changes in farming practices
led to the formation of enclosures in place of communally managed grazing areas, associated