TWO 120-year-old banyan trees dug up and rolled aside in a million-dollar move to accommodate the Happy Valley racecourse extension are alive but their growth appears to have halted, a tree specialist said. Dr Jim Chi-yung of the Hong Kong University Department of Geography and Geology said the last time he saw the trees, about four weeks ago, they looked healthy after they were re-located a few metres away in late March. 'In the short-term, the trees should be fine but the last time I saw them there were no new branches or leaves because any time you cut branches from trees it is not good,' Dr Jim said. 'Although the crowns have been cut back severely, the trees looked all right but the soil needs to be filled in by the trees and the road fixed,' he said. The professor said it would take time before monitoring revealed whether the trees were adapting to their new environment after the $1 million re-location. 'It is very hard to tell, these are living organisms and they have been subjected to a drastic measure, like major surgery,' he said. 'In the long run, can the patients recover, with their age, it is difficult to say but the banyan tree is tough.' He also said he had been unable to get to the banyans because of the fence surrounding the construction site and he could only look at the trees from a distance. The trees were excavated, secured in pots and rolled a short distance to their new site, in a week-long operation designed to minimise stress. Gerald Farque, production manager at Dragages et Travaux Publics (HK) Ltd, the company behind the trees' move, said the trees were cared for and monitored daily. 'There are two ways of ensuring the trees' health - an active and a passive way. The passive way consists of providing an artificial water table under the trees in order to 'attract' the newly grown roots down. A root enhancer in the soil used for backfilling the trees' surroundings 'attracts' the new roots horizontally,' he said. 'The active way consists of providing, through the canopy and aerial roots a sprinkler system and through the roots a dripping system, the required amount of water and fertiliser.' He said the irrigation system was a pump system that reacted to signals from a moisture sensor located in the trees' pots and delivered the appropriate amount of moisture when required. Dragages' tree specialist, James Green, said: 'Occasionally we dig into the soil to see if the roots are all right and they are now about one foot outside of the old container.'