The Oak (Duir)
The oak, in this case Quercus robur, is the dominant tree in these woods, though in places it is replaced
by beech, when the soil favours the latter. You may also see a sprinkling of yew and ash trees in these
woods.

The oak was sacred to the ancient Druids who considered it to be the King of Trees. Indeed the word
'Druid' probably stems from the old name for the oak of 'Duir'. When the Roman invaders crushed British
resistance they destroyed the great sacred oaks at the centre of the chief Druid sacred site in Anglesey. It
seems unlikely that the Druids actually worshipped trees, for they had a pantheon of deities, but perhaps
like the ancient Greeks they saw Nature as the image of the divine. To the ancients the tree always
symbolised harmony, for in order to grow it needs a balance of all the elements - fire (light), earth, water
and air and it unites the underworld to the skies above. Furthermore, the greater trees became symbolic of
immortality for their great longevity. The oak can frequently live a thousand years.

Trees are the givers of life - in Britain, the oak supports more species of organism than any other tree.
Many creatures live on its bark, in the hollows of its bough and branches and among its roots, as well as
the multitude of creatures that feed off its leaves, acorns and other tissues. More creatures feed off its
dead parts - off its rotting wood and leaves. You will see some of these creatures in these woods.

Click a link below to learn more about oak trees or take a
closer look at what is living on the bark of the oak.
Learn more about the biology of the oak tree...
Oak sprouting branchlets
Other dominant trees in these woods include the beech (Fagus sylvatica), ash (Fraxinus excelsior), the
yew (
Taxus baccata), the hornbeam (Carpinus betulus), the small-leaved lime, and the occasional
chestnut tree (e.g. sweet chestnut (
Castanea sativa) and horse chestnut (Aesculus hippocastanum) )
and maple including sycamore (
Acer). Silver birch (Betula pendula) and the quacking aspen (Populus
tremula
) also belong here. Alder (Alnus glutinosa) and willow (Salix) dominate in some of the wettest
parts of these woods. Smaller trees like hazel (
Corylus avellana), hawthorn (Crataegus), holly (Ilex
aquifolium
), wild cherry (Prunus avium), crab apple (Malus sylvestris) and rowan (Sorbus aucuparia) are
also common here, but these are not dominant as they are too short generally to reach the highest
canopy and form part of the shrub layer. The English elm (
Ulmus procera) was also once a dominant
tree here, until all mature specimens were destroyed by Dutch elm disease.

Most of these woodlands are mixed woodlands of mostly oak and hazel, which grow well on the clay
alluvial soils here. Different trees dominant under different physical conditions, such as on different soil
types:

  • Ash prefers limestone soils.
  • Beech prefers calcareous chalk and limestone soils.
  • Yew prefers well-drained chalk and limestone soils, but can grow on acid soils under milder
    conditions.

  • Silver birch prefers acid soils where it's nitrogen-fixing root nodules allow it to thrive where
    nitrogen is poor, such as at high altitudes and high latitudes.
  • Cherry prefers chalky soils, but will grow on acidic plateaux in milder conditions.

  • Alder prefers damp soils along riversides, in fens or wet woods.

In Britain there are two species of native oak - the pedunculate or English oak (
Quercus robur) with
leaves on short stalks and acorn cups on long stalks and the sessile or durmast oak (
Quercus petraea)
with long-stalked leaves and stalkless acorn cups. The pedunculate oak is more rugged and found
throughout the lowlands with more basic, nutrient-rich wetter and heavier soils, such as alluvial clays.
The sessile oak prefers high rainfall and is found more along the West coast of the British Isles and
prefers higher ground with more acid, well-drained sandy or gravelly soils. Many woods contain
populations of both species and many hybrid forms exist.

Both native oaks have similar timber properties, but the sessile oak makes a better timber tree since it
tends to have a straighter, single stem and straighter branches. The pedunculate oak tends to be
broader with a broader and more rounded crown and the stem tends to branch not far above the ground
and the branches have a sinuous or wavy appearance. The sapwood is whitish and the heartwood
golden-brown. The timber has had many uses, from shipbuilding to fences to furniture and buildings. For
shipbuilding purposes, trees used to have their branches staked for several years to encourage them to
grow to the required curvature. (In contrast the Florida oak tends to form the right shape naturally). The
bark can be used as a source of tannins for tanning leather. Oak mast (acorns) and beech nuts used to
be used as pannage for pigs.
Acorns were a major food source for many ancient cultures. However, if large quantities are consumed
then it is necessary to soak them in water for a time to remove much of the tannins. The acorns of
Quercus robur are pale brown with olive-green longitudinal stripes when mature and fresh. The acorns
of
Quercus petraea are dark brown, lack stripes, and are usually smaller and rounder. In Quercus robur
the acorns are usually born on longer stalks (2-9 cm).

Wood: both
Quercus robur and Quercus petraea have ring-porous wood with both multiseriate rays
(made up of more than one row of cells) 0.3-0.55 mm wide and 2.5 cm deep and uniseriate rays (one
cell thick).

Leaves: the leaves of
Quercus robur have 3-6 lobes on each side and are borne on very small petioles
(2-7 mm) and have auricles and largely hairless (except for a few inconspicuous hairs on the
underside). The leaves of
Quercus petraea have 5-8 lobes on each side and longer petioles (13-25
mm) and have much less obvious auricles and are often quite hairy and are larger.

Habit: in
Quercus robur, the main trunk tends to disappear in the crown and branching is irregular with
wide branching angles with abrupt decreases in diameter between successive orders of branch. The
foliage and twigs are clustered, resulting in an open crown. In
Quercus petraea, the main trunk tends to
persist through the crown, is straighter and branches in a more regular manner with gradual decreases
in diameter between branch orders. The branching angles are narrower and the uniform foliage gives a
dense crown.

Good web sites with pictures of some of the largest oak trees: