LONDON.- You walk by them everyday, but do you know their names? Trees may be a familiar part of your environment, but do you really know a chestnut from a fir or an ash from an elder?

Well here is your chance to find out and help scientists at the Natural History Museum with one of the biggest ever urban tree surveys in the UK.

Trees are essential in urban landscapes, helping to reduce noise and air pollution. But relatively little is known about them. A lot more is known about trees in the British countryside.

So, scientists want to find out what types of trees you have in your gardens and neighbourhoods across the UK, and here's how you can help.

Identify the trees in your area. There are guides and keys for 80 of the most common urban trees on the website www.nhm.ac.uk/trees. Scientists then want you to record the tree types you find in the online map of Britain.

‘Trees are more than just scenery,’ says Bob Press, Museum's Associate Keeper of Botany, ‘they are essential to the world in which we live.

‘The loss of trees to our ever-expanding towns and cities is balanced by a new range of trees planted in streets and gardens.

‘We need to know more about these trees, so we’re asking people to get outside to try to identify and map where every urban tree is in this UK-wide census of trees.’

Museum's Head of Interactive Media Ailsa Barry explains more. 'The urban tree survey is part of the Museum’s ongoing citizen science programme, which aims to increase public understanding and engagement with the natural world.

'A recent Museum survey carried out by Ipsos-MORI showed that less that 24% of adults in Britain were able to identify the sycamore, one of Britain’s most common trees, while more than 60% of adults expressed some level of interest in wildlife.

'This shows that many people have an avid interest in nature and are looking for ways to develop this, and we hope to harness this enthusiasm.’

Ancient tree cover
Scientists will also be finding out if there have been changes in tree distributions and populations. They can find out how woodland has changed in the past, even going back 10,000 years to the last ice age. They do this by studying ancient fossilised tree pollen and also by looking at historic documents like Anglo-Saxon charters and the Domesday Book. This data also reveals what species are native to the UK.

The results of the Urban tree survey will help scientists get a much clearer and more detailed picture of the urban tree landscape of today as well as how it has changed over time. And the data will help other researchers find out if climate change is affecting tree flowering and fruiting times.

Identification key
So, find out if that’s an ash or an elder in your garden. The Urban tree survey identification key will guide you through, looking at the shape and arrangement of the leaves, type of bark and fruits, and size of the tree. With lots of helpful photos too, you’ll soon be a tree expert, in your own garden at least!