Some of the trees might have stood at the same height as Nelson's Column
Computer images of a "ghost forest" art installation planned for Trafalgar Square show the vast scale of a project designed to highlight deforestation.
The artist's impressions were released as nine of the tropical tree stumps set to form the heart of the exhibit have been loaded on board a ship in Ghana.
The vessel is due to arrive at Tilbury in London on 17 October.
A tenth stump - the remains of a huge Denya tree - will be brought to the UK at a later date.
To meet trade controls, the stumps were cleaned by fire hose and then fumigated.
It is believed to be the first time that intact stumps of massive tropical trees - many with their roots still attached - have been brought to Britain.
The artwork will be in Trafalgar Square from November 16-22 before being shipped to Copenhagen in time for the UN climate conference where new measures on deforestation may be agreed.
The installation is the work of artist Angela Palmer who has made repeated visits to western Ghana to search for the stumps.
The stumps are hosed down as stipulated by trade controls
She told the BBC: "It's been an extraordinary journey getting this far - finding the trees, securing all the permissions, getting the stumps transported by road from the forest to the port and then getting them on board.
"But it's been a fantastic combined effort by the timber company John Bitar, the teams in the forest, the Ghanaian authorities, the shipping line Grimaldi and rainforest and engineering specialists from Oxford University."
The project has been supported by a number of Ghanaian experts, with the extraction, cataloguing and cleaning of the trees supervised by Ntim Gyakar, former curator of the Herbarium in the Ghanaian city of Kumasi.
Transporting the largest stump from Suhuma to the port at Takoradi was not straightforward. Two trucks broke down in the forest, local elders had to be called to perform traditional blessings and then the huge load snagged on overhead cables.
Ms Palmer hopes the artwork will carry an optimistic message
Angela Palmer's hope is to raise awareness of the tropical rainforests and the connection with climate change - about 20% of global emissions are the result of deforestation.
"For most visitors, the scale, beauty and diversity of the stumps will be unlike anything they have experienced before. Nelson's Column stands over 50 metres (169 feet) tall, the approximate height many of these trees would have stood at in the wild.
"It will be impossible not to imagine what a space like Trafalgar Square would look like if populated by such massive examples of nature's work alongside man's, and to think about the destruction the missing trees represent."
Angela Palmer says she also hopes the installation will carry a message of optimism because although Ghana has lost 90% of its virgin rainforest in the past 50 years it is now trying to retain its remaining forests through selective logging.
"As a result, the forest canopy is retained, the young saplings regenerate naturally, leading to a thicker forest, and the timber industry continues.
"In order to reflect this, the 'Ghost Forest' will feature two or three logged stumps, and the rest would be naturally fallen trees complete with their root systems - protruding like the nerve-endings of the planet."