English Oak

Perhaps our most iconic tree the English Oak (Quercus Robur) has assumed the status of a national emblem and is the most common and easily recognised tree species in the UK. In Birmingham, there is even an area called Selly Oak, named, in part, after a prominent Oak tree that formerly stood at the crossroads of the Bristol Road and Oak Tree Lane/Harborne Lane. As a timber tree, its wood was once highly prized for building ships and houses, and making furniture. Its autumnal acorns are also highly prized by both people and wildlife - the former use them for fodder for pigs and the latter often store them for the long winter ahead.

In Birmingham, there is even an area called Selly Oak, named, in part, after a prominent Oak tree that formerly stood at the crossroads of the Bristol Road and Oak Tree Lane/Harborne Lane.

As a timber tree, its wood was once highly prized for building ships and houses, and making furniture. Its autumnal acorns are also highly prized by both people and wildlife - the former use them for fodder for pigs and the latter often store them for the long winter ahead.

Identification

Leaves
Growing up to 10cm long the leaves are easily recognised by their lobed leaf shape and smooth edges

Flowers and Seeds
The fruits, commonly known as acorns, are not produced until the tree is at least 40 years old. They are 2-2.5cm long, borne on lengthy stalks (peduncles) and held tightly by cupules (the cup-shaped base of the acorn). As it ripens the green acorn takes on a more autumnal, browner colour, loosens from the cupule and falls to the canopy below. Most acorns will never get the chance to germinate as they are a rich food source, eaten by many wild creatures. Following a successful germination, a new sapling will appear the following spring.

The English Oak can be distinguished from the Sessile Oak by its broader shape and by the presence of stalks (peduncles) on its acorns.

Bark
Bark is smooth and silvery brown becoming rugged and deeply fissured with age.  As common oaks mature they form a broad and spreading crown with sturdy branches beneath. Their open canopy enables light to penetrate through to the woodland floor, allowing bluebells and primroses to grow below.

Age and height
A large deciduous tree growing up to 20-40m tall and can live for a 1000 years or more.  Oak tree growth is particularly rapid in youth but gradually slows at around 120 years. Oaks even shorten with age in order to extend their lifespan.

Distribution
It is the most common tree in Britain especially in southern and central British deciduous woods. It prefers heavy and moist, nutrient rich soils and can tolerate some waterlogging provided such soils do not dry out in summer. Its ability to root in to heavier soils is ecologically valuable for its structure-improving and drainage effects.

Woodland Ecology
Oak forests provide a habitat rich in biodiversity; they support more life forms than any other native trees. They host hundreds of species of insect, supplying many British birds with an important food source. In autumn mammals such as badgers and deer take advantage of the falling acorns.

The soft leaves of English oaks breakdown with ease in autumn and form a rich leaf mould beneath the tree, supporting invertebrates and numerous fungi. Holes and crevices in the tree bark are perfect nesting spots. Several British bat species may also roost in old woodpecker holes or under loose bark, as well as feeding on the rich supply of insects in the tree canopy.