The MTR Corporation chopped down 340 trees while extending Diamond Hill station as part of its Sha Tin to Central link project, while 22, including two Chinese banyans, were transplanted to a site nearby. Richard Kwan Kin-yan, the MTR's environment manager, said the operation required careful planning to ensure there were no delays to construction. Kwan said the original plan was to build a depot on the site, but this would have resulted in the loss of all the trees. So the company changed its mind to minimise the impact, and as a result 120 trees were saved. He said the shape and condition of the two banyans, between 20 and 40 years old, were so outstanding that its engineers believed they must be protected before construction could start. Engineers spent more than a year planning the transplants, some of the biggest in the Sha Tin to Central project. As the banyans were up to 16 metres tall and 20 metres wide, their roots branched out up to 10 metres. "Workers used shovels rather than machines in digging the earth while looking for the root systems," Kwan said, adding that if the roots were not preserved as much as possible, it could affect their health after the transplant. The operation was conducted in four phases, each lasting 90 days. The younger banyan was moved in December 2013, while the older one was moved in August last year, 75 and 100 metres south of their original positions. Ken So Kwok-yin, chief executive of the Conservancy Association, said it was too early to say if the transplants were successful. "Problems will not surface until a decade later. We have seen cases where the roots were infected and had decomposed," So said, adding it was important to observe whether roots continued to grow after they were cut. A tree protection zone has been set up to make sure the trees can rest with minimum disturbance, and 550 new trees would be planted at the site, the MTR said.