Black Poplar Trees



One of Britain’s most endangered trees is the native black poplar Populus nigra. Around the country there are a number of authorities with Biodiversity Action Plans to promote this species including in Greater London.

The plans promote actions which increase public awareness over the plight of the tree; create inventories of existing trees; and carry out additional planting of locally sourced cuttings. Some plans state the need to use planning policy and Tree Protection Orders to protect trees that might be threatened.

Others go as far as to remove flood-banks and create conditions suitable for floodplain woods exactly as those in Ham-between Ham Lands and the river Thames - where there are two fairly prostrate native black poplars.

An analysis of Norfolk BP tree locations showed they were often associated with kilns, farms, mills, smithies and malthouses indicating they had been planted rather than a product of natural seed dispersal. The wood was fire resistant, can resist paraffin and was used to make matches. Its branches grow in a curve so it was used for timber framed buildings.

One introduced hybrid is Populus x canadensis which is a cross between the American and European black poplar P. deltoides and P. nigra. There is one which suffers from numerous planning applications due to the siting of temporary Axis portacabins on the Cambridge Road Estate.

After the Daily Telegraph ran a national ‘Black Poplar Hunt’, 1994 it was realised that the trees are very rare with only 7,000 recorded of which 600 were females.

The benefit of fingerprinting to Black Poplar conservation activities first came to light in the late 1990’s and established that many of the trees in Britain had been established by vegetative propagation. Initial studies identified 17 clones in the 36 fingerprinted tree. Some of the clones were common and had a widespread distribution, while others were less widespread.

A collaborative project formerly known as EUROPOP has examined the black poplar on a European scale. In the course of this project microsatellite DNA markers were developed.

I had a DNA analysis of the native black poplar felled at Dickerage Road adventure playground earlier in the year and received an EXCEL spreadsheet with the results of the DNA fingerprinting with nine microsatellite markers. Poplars are diploid, so there are two alleles sizes per marker (one allele inherited from the mother and one from the father), giving a 18 data point fingerprint. 

The results indicated that the tree matched the fingerprint of the native black poplar male clone 28 in the National Register. This is the common clone that is often referred to as the ‘Manchester’ poplar and has been widely planted across six counties. Its tolerance to pollution made it a ‘popular’ choice for roadsides and cemeteries.

Any regrowth would have been from the original tree, as poplars are not grafted onto root-stock for vegetative propagation. Therefore, as long as the regrowth was attached to the original stump then it is a clone 28.

It is recommended that conservationists arrange for black poplars in their area to be tested prior to the establishment of rooting material for planting schemes. Material should be collected from a broad geographical area and should include females as well as males. Should we take cuttings from the stump regrowth of the Dickerage road tree as they have at Barnes Common (see photo).

 Read more here https://barnescommon.org.uk/tag/black-poplar/

and here (Jan 2021) https://barnescommon.org.uk/conservation/black-poplar-project/


 



 

Comments

Post a Comment

Please share your thoughts

Most viewed

Heritage Trees part 2: street trees.

Image
  Oaks and maples Cambridge Gardens 2019   Street trees can often be the most beautiful objects in our streets. They are important to their communities as well as having environmental benefits. They are a living history in our landscape and can have particular connections. They may be fragments of a previous landscape incorporated into a modern street scene, such as the oaks at Cambridge Gardens once  part of the Duke of Cambridge's estate.  A great read with information on how to research street trees is a  History of Street Trees by Dr. M. Johnston.  London plane trees CRE 1976 Beech tree, Chesterton Terrace 1976 Studies show that the difference in local tree cover can reflect the various socio-economic groups. In Victorian times middle class areas were planted with many street trees or had higher quality front gardens than working class districts; now referred to as 'green equity'. It can be demonstrated by looking at old photos of the seven roads that were
Read more

Fishing the Hogsmill

Image
Fly-fishing the Hogsmill   It is interesting to see the river from a different perspective: the Hogsmill is popular with anglers at this time of year; although it is unusual to see someone fly- fishing. A chub has just been caught on bread and it looks a good size. Trout are sometimes seen in the Hogsmill and can sit in the weir notch by the school. Our own Richard Jefferies in his book 'Nature Near London'  remarked on the Hogsmill trout as far up as Tolworth Hall Bridge (now the A240). chub    This fish was carefully unhooked and orientated in the swim where it soon finds it way - probably to the next father and son - sitting further upstream. These anglers have caught the 'ghost' koi within the last two weeks and appear to be the second successful pair to catch the pond-escapee in the last few days. Ghost koi are a British invention. They were produced by accident in the early 80’s when a farmer allowed a mirror carp and a koi to spawn together. The offspring
Read more

Seething Wells: they've done it again

Image
The last day of May, I went to see if I could find the black redstart that had been widely reported, no luck but it will turn up again on one of the old buildings. The lush vegetation was looking beautiful between the Filter Beds at Seething Wells. I made a note of the breeding birds: goldfinches twinkling away, blue tits gathering food, sand martins flying over the FB's (only two this year unfortunately) moorhens and some scruffy little coot chicks entangled in the algal blooms.   Proud parents were showing off their four Canada chicks; they can cover a lot of ground in a short space of time they were soon feeding on water pepper and bistort gleaned from  the ziggerat-sided basins. A song thrush sang from the wharf alongside greenfinches as well as the seasonal chiff chaff; although this year all numbers are down, reflecting not only the topsy-turvy Spring but also the continued tumble in insect numbers (even seed eating birds are dependent on insects to feed their young).
Read more