trees and shrubs

Trees are the tallest and oldest living things in our area, with specimens of coppiced small-leaved limes in the Lune Valley believed to be over 1,000 years old. Trees in England can grow to over 40 metres tall and the oldest trees in the UK are believed to be yews, aged over 6,000 years!

Trees are plants just as wildflowers and grasses are, but whilst grasses all belong to a single Family called Gramineae, trees occur scattered throughout Families, Orders and both Classes.

Gymnosperms are vascular plants that reproduce by seeds that are not enclosed within an ovary. Gymnosperm is from the Greek gymnospermos, meaning "naked seed".

Angiosperms (or flowering plants) are vascular plants whose ovules, or young seeds, are enclosed within an ovary. The Angiosperms can be divided into Dicotyledons, which have two embryonic seed leaves or cotyledons that usually appear at germination and the Monocotyledons, which have a single cotyledon in the seed, such as orchids, grasses and lilies.

Strictly speaking a tree is defined as "A woody plant that commonly achieves a height of six metres (20 feet) on a single stem" (Mitchell 1978). There are nearly 50 trees that meet this definition, which are native to Great Britain, and of these less than 40 are considered native to Lancashire. Woody plants that are shorter or only reach a height of six metres as a multi-stemmed plant are called shrubs and include blackthorn, elderberry and Rhododendron (I).

Trees have long been used to make houses (including roof timbers, internal supports, floorboards, doors and windows), beds, seating, kitchen units, spoons, bowls, chopping boards, rolling pins etc. The "wattle" in "wattle and daub" that was previously plastered over to make walls was made of interwoven hazel sticks.

In the past, wood was the primary source of fuel for cooking and heating and is still a major source of fuel today in open fires, wood burning stoves, ranges (such as Aga and Rayburn) and barbecues (charcoal is wood burnt in the absence of oxygen).

Timber is still used to make yachts and canal barges but in the past all ships, including cargo and war ships, were made primarily of wood, especially oak. Timber was also used inside the old style railway carriages and even made it into some cars such as the Morris Minor with its distinctive wooden framework.

Wood has been used for footwear, with clogs being a local example in Lancashire, and other clothing such as buttons and jewellery.

Trees, and other plants, are considered native if they survived the last ice-age or made their way to the British Isles by natural means following the retreat of the last ice-age that ended about 10,000 years ago. Many species recolonised across the land "bridge" that connected Britain to mainland Europe before the sea levels rose and formed the English Channel, giving rise to the British Isles as we know them. Plants and animals have colonised, and continue to colonise, the British Isles in more recent times by natural means such as being carried by the sea, carried by birds or even blown over in very strong winds.

Many of the trees that are common in the UK have been introduced from other countries/continents and are not native, e.g. sycamore, horse chestnut, larch, spruce, all pines except Scots pine, and many fruit trees. The Romans are believed to be responsible for the introduction of sycamore, horse chestnut and poplar into the UK, but the majority of the introductions have occurred more recently, in the 1700's and 1800's through the Victorian plant collectors and by foresters for timber.

Some trees that are native to the UK didn't naturally occur in the original wildwood that existed throughout most of the northwest but were confined to southern England and have, at some time in the past, been deliberately planted in the northwest, such as beech, hornbeam and wild service tree.

Trees produce flowers in a huge variety of colour, size, shape and visibility. Plants, including trees, which produce petals do so because they are pollinated by animals; mainly insects but also birds and mammals, e.g. fruit bats which pollinate banana trees. The plants produce petals to advertise themselves and nectar is produced by the plants to tempt the animals to feed on the nectar, during the course of which they pick up pollen and may deposit it on the ripe receptacle of a female flower of another plant of the same species and result in successful fertilisation. Examples of insect-pollinated trees include hawthorn, apple, cherry, sloe, pear, elder and rowan.

Trees that don't produce petals are pollinated by the wind (as are grasses and many other plants such as plantain, docks etc) hence have no need to produce petals to attract insects. Examples of wind-pollinated trees include hazel, beech, oak, alder, birch, poplar/aspen and elm.

The native species of trees and shrubs, in particular oaks, willows and birch, support many more species of insects than introduced trees, as the insects tend not to be introduced with the trees and are adapted to survive in different climates than the UK.

(*) = trees introduced to the British Isles