Cambridge Green Belt Project - Species

Species

Species - Black Poplar (Populus Nigra Var. Betulifolia)

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We need your help to conserve this rare native species!

Also known as water poplar, this traditionally important tree is now Britain's rarest native timber species, with estimates of less than 7000 trees left in England and Wales. We have records of approximately 100 for the county of Cambridgeshire, but think there are more out there. We need your help to find these grand trees so we can conserve them for the future.

Recognition

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Large trees, up to 30m in height and 2m diameter.

Lower branches arch downwards and then sweep upwards at tips giving it a very distinct appearance.

The trunk leans and has large swellings/burrs on it. The bark is dark grey to deep brown and deeply fissured.

Leaves are triangular with tips elongated to an acute point and the leaf margins (edge) have rounded teeth. They can also have a lightly hairy underside.

Twigs are cylindrical and young growth is often hairy.

Winter buds are sticky and yellow/brown in colour., with the ends turning out from the twig.

Male catkins are red, appearing in March/April and female ones are lime green producing fluff in June.

We ran two Black Poplar identification training days on 1st and 4th April 2006.

Traditional Importance of Black Poplars

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Traditionally used to delineate parish and county boundaries because of its distinctive shape and the way it forms a dramatic feature in the landscape.

Timber properties and traditional uses:

Strong and fire resistance, therefore a good choice of timber forflooring, especially around fireplaces;
Shock absorbent, so used for wagon construction;
Lightweight and light in colour, often chosen for clogs and furniture.

There are also often important local folklore and legends surrounding these trees.

Threats

There are a number of causes for the decline in this magnificent tree:

Natural reproduction rarely occurs for a number of reasons:

Black poplar trees are either male or female and they need to be close to each other for natural reproduction to occur;
Very few female trees are left as they produce large amounts of fluffy seed, therefore male trees were favoured by landowners;
The seeds are only viable for a short time and need very specific conditions to germinate.

Black poplar trees are no longer planted, since introduced varieties grow faster and straighter, therefore their timber is more valued.

Destruction of wetlands, which is their main habitat is also a key reason for their decline.

How To Help

When you are out walking in the countryside, please keep a look out for this rare tree. If you see it then please let us know. We need the following details (Contact details will only be used by those involved with the project. Please let us know if you do not want your record to be used for Cambridgeshire and Peterborough Biological Records Centre work outside this project without your prior permission) and a photograph if possible:

Recorder name;
Contact details (tel no./email);
Tree photo number (if sending multiple records and photographs);
Date;
Village/town including nearest street and landmark;
Situation (e.g. riverside, roadside, hedgerow);
Grid ref (6-figure) Or sketch map;
Girth at 1.3m;
Tree sex;
Tree form (e.g. coppiced/pollarded);
Other Comments (e.g. tree health);

You send us the details in a number of ways. You can use our online Black Poplar wildife reporting form.

Or, you can email the details to christine.whinney@cpbrc.org.uk

Or, you can post them to:

Cambridgeshire and Peterborough Biological Records Centre,
The Manor House,
Broad Street,
Cambourne,
CB3 6DH

For more information please contact:

Christine Whinney
01954 713571
christine.whinney@cpbrc.org.uk

Find out about what's been seen on our sightings page, or take a look at details of some of the projects and sites that we work on.