It is relatively easy to identify the types of trees in Harmers Wood from their leaves, unless it is late autumn or winter. Before the Second World War, pine predominated the woodland until bombs jettisoned by Nazi planes following a raid on Liverpool, destroyed a swathe of trees across Helsby Hill and Harmers Wood. It is likely that Cholmondeley Estate who owned the land replanted with mainly silver birch but there are a small number of older oak trees that seemed to have survived (albeit with some fire damage).
In line with our 20 year management plan, agreed with Mersey forest, we will gradually replace the silver birch with new birch saplings and supplemented with other tree types such as oak, to improve the diversity of the woodland and create a natural, native, lowland broadleaf wood.
The north east corner of the wood did have a number of sycamore trees but on the advice of the Mersey forest were removed as they were not native to the type of woodland we need to create and sustain. Around the edge of the wood there are Crataegus monogyna or Hawthorn, Rosa canina or Dog Rose and Ulex europaeus or Gorse. We are hoping to introduce crab apple, wild cherry, hazel, blackthorn, elder and guelder rose to diversify the woodland whilst retaining 70% of the canopy as silver birch and oak. To do so, the bracken needs to be controlled which has taken over large parts of the field layer.
Betula pendula or Silver Birch, (right) currently makes up around 60% of the canopy in Harmers Wood. Most are around 50 to 70 years old and are starting to come to the end of their natural lives.
Silver birch can be used to improve soil quality for other plants to grow. Their deep roots bring otherwise inaccessible nutrients into the tree, which are then recycled onto the soil surface when the tree sheds its leaves.
Mature trees can grow up to 30m in height, forming a light canopy with elegant, drooping branches. The white bark ppeelsaway naturally like tissue paper and becomes black and rugged at the base. As the trees mature, the bark develops dark, diamond-shaped fissures and twigs are smooth and have small dark warts.
Silver birch is classed as 'monoecious', which means both male and female flowers (catkins) are found on the same tree, from April to May. Male catkins are long and yellow-brown in colour, and hang in groups of two to four at the tips of shoots, like lambs' tails. Female catkins are smaller, short, bright green and erect.
Quercus robur or English Oak (left) currently makes up less than 10% of the trees at the wood and we will be aiming to increase the number of oaks over the coming years.
A large specimen can grow up to 40m tall and as common oaks mature they form a broad and spreading crown with sturdy branches beneath. Their open canopy enables light to penetrate down tothe woodland floor, allowing bluebells and primroses to grow below. Their smooth and silvery brown bark becomes rugged and deeply fissured with age.
Oak tree growth is in younger years and starts to slow down at around 120 years. Oaks even shorten with age in order to extend their lifespan. The trees' flowers are long yellow hanging catkins which distribute pollen into the air. Its fruit, commonly known as acorns, are 2–2.5cm long, borne on lengthy stalks 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.
Oaks provide a rich habitat for over 400 insects and the acorns provide important food sources for squirrels, deer and badgers.
Llex aquifolium or Holly (right) are common throughout the wood. Mature trees can grow up to 15m and live for 300 years. The bark is smooth and thin with numerous small, brown 'warts', and the stems are dark brown.
Leaves: dark green, glossy and oval. Younger plants have spiky leaves, but the leaves of older trees are much more likely to be smooth. Holly is 'dioecious', meaning that male and female flowers occur on different trees. Once pollinated by insects, female flowers develop into scarlet berries.
Sorbus aucuparia known as Rowan or Mountain Ash (left), can live up to 200 years and grow to 15m in height.
Rowan is 'hermaphrodite', meaning each flower contains both male and female reproductive parts. Flowers are borne in dense clusters, each one bearing five creamy white petals.
After successful pollination by insects, they develop into scarlet fruits. The berries are edible but very sour but can be made into a delicious jelly. As usual, we advice woodland users not to pick the berries but rather leave them for the birds to enjoy!