On the River Bank

The London plane trees in Bishop’s Park provide a shady walk along the Thames upstream of Putney Bridge. The oldest were planted in 1893.

Of course London planes are not rare; there are plenty in London Squares, Battersea Park and the Royal Hospital for example. A much rarer and long-living species grows on the river bank downstream of Hammersmith Bridge on the south bank and I’d never identified it although I often walk along that stretch. It took this notice to educate me.

”You are now entering a section of the Thames towpath that holds the most important population of Black Poplar trees in the UK!

Black Poplar trees are one of the rarest tree species across the country and are currently under threat from a range of factors. They usually grow in areas of wetter ground and are commonly found alongside rivers and in wet woodlands. Unfortunately, their ability to regenerate naturally has been almost completely lost due to human impact on natural habitats and processes.

This population of Black Poplar trees on the Thames is important as it is the only known surviving population in the UK. It consists of around 40 trees including many ancient trees and rare females, accounting for around 5% of all female trees nationally. However, the most important aspect of this population is their genetic diversity as most of the trees are genetically unique and once lost can never be replaced.

These trees have survived here despite all the odds against them of living in a highly developed and polluted capital city and even their proposed felling in 2009! Thankfully, through research and conservation efforts over the last 15 years, they have finally received the recognition and conservation they deserve. There are currently a range of activities being undertaken to safeguard their future, including the work you see on the Thames today.

The results of cutting down trees might look drastic , but this is a common tree conservation practice known as ‘haloing’. Younger trees which compete for resources such as light as water have a detrimental impact on more vulnerable ancient trees and reduce their longevity. Again, this may appear drastic, but it can actually increase the lifespan of a tree as well as creating more varied opportunities for tree associated wildlife.

Later in the season, a new generation of Black Poplars will be planted in the treeless areas along this stretch of the Thames. Over the past 3 years cuttings have been taken from trees with a unique identity and grown on to a size suitable for planting along the towpath. These trees will hopefully grow up to be the ancient trees of the future and complement the existing population and wider river habitat. Most importantly, the rare genetic diversity of the ancient Black Poplar trees will have been conserved in this current era of destruction and neglect of the natural world.” (Barnes Common, Black Poplar Project)