No one will argue that trees are filled with our collective memory, as well as our longing and belonging. People look up to them for making any concrete jungles like Hong Kong look more refreshing, natural and beautiful. To many of us, trees symbolize vitality and courage that stand the test of adversity and weather the harshest storm. Not until we saw how thousands of the city's trees were devastated by the cruel force of nature in Typhoon Vicente, did we realize how fragile and vulnerable they are - more than 4,700 trees were knocked down.

Needless to say the typhoon had exposed the long-standing problems with urban tree care and management. Up to now a month has gone by and there are still some damaged trees yet to be removed, the remnants having been shoved to car parks and cycling tracks. If some of them are infected trees, leaving them exposed could allow the fungal virus to spread out in the district infecting the others. As with the case of the spill of plastic pellets, carried on board a container ship during the typhoon, this is obviously due to the lack of coordination among various departments.

In the past before the Food and Environmental Hygiene Department contracted out its cleansing services in 2009, whenever there were storms, relevant departments including food and environmental hygiene, leisure and cultural services, housing, agricultural and fisheries, were all well-coordinated and efficient in their clean-up operations. But after the outsourcing exercise, what people see is the management chaos and a lack of an efficient clean-up in the aftermath of severe typhoons. In the end, the government may need to fork out an extra HK$3.4 million for planting trees to replace the fallen ones. But the loss of the trees' sentimental and aesthetic value is impossible to evaluate.

What is worse is that officers were too busy hacking and pruning the tree trunks and branches without bothering to inspect whether the fallen trees could still be saved. According to an expert, as long as the tree trunks and limbs remain intact with half of the tree roots covered by soil, they can be saved within 48 hours of recovery. Now because of the slow action of government departments as well as the Tree Management Office, they missed the best opportunity to recover the trees.

True, it is unrealistic to expect the Tree Management Office to prevent every tree from falling down or being damaged. However, these accidents could be minimized if the office had better urban tree management and precautions in place to care for the trees. According to some experts, half of the fallen trees might have had problems such as decay and diseases like brown root rot, an incurable tree cancer, before being hit by the typhoon. For example, an over 70-year-old banyan along Nathan Road that collapsed before the typhoon struck and injured five passers-by was infected with root rot. A heritage weeping fig in Chater Garden was also found with infectious brown root rot disease and blown over by the typhoon.

The crux of the matter is how the government cares for and inspects these infected trees, and prevents the spread of brown root rot before the force of nature comes to the fore. It was reported that the government only cut the tree and left the roots behind. But tree experts have criticized that approach, saying if the roots are left behind, the disease will spread and not be contained.

According to a green group, five of Hong Kong's heritage trees are in danger of death and collapse, with a banyan estimated to be over 400 years old in Kowloon Park having fungus on its branches and losing its bark under the government's care. It is a big question whether the government has taken the correct approach to caring for these trees and conducted sufficient checks on their health.

In addition, young trees are supposed to be resistant to strong winds and should not be easily brought down. Some experts attributed their collapse to the quality of saplings and insufficient underground space for roots to take hold. Very often saplings are shoved into pavement and street-side settings with inadequate space for their roots to spread and grow, resulting in decay and death.

Also, the quality of some imported saplings does not meet the standards adopted by developed countries. In other words, the government should nurture more local tree species instead of buying sub-standard saplings from outside, as well as to train more tree specialists to correct their planting methodology and conduct more regular checks on trees.

The destructive force of nature is always unpredictable, but with better precautions and getting the approach right, mishaps might be avoided.

The author is a current affairs commentator.

(HK Edition 08/24/2012 page3)