A helicopter drops water on a massive wildfire in Tuen Mun. Firefighters extinguished the blaze yesterday after it had raged for 46 hours.

This week's mountain wildfire in Tuen Mun damaged the ecology enough that it could take a decade to recover, environmental specialists said after the fire was extinguished around noon yesterday.

The three-alarm fire on Po Lo Shan mountain lasted 46 hours and burned across 500 hectares of land, making it one of the worst wildfires in recent years.

"The fire has caused huge damage to the vegetation on Po Lo Shan," said C Y Jim, the chair professor of geography at the University of Hong Kong. "It will take eight to 10 years for the land to recover and accumulate nutrients" for shrubbery regrowth.

Firefighters got the blaze under control Wednesday evening after it had been burning for more than a day.

No one was reported injured in the fire, but many were threatened.

On Wednesday, more than 200 residents from Leung King estate, as well as monks from the Tsing Shan Monastery had to be evacuated. The fire also got as close as 100 meters to a village and recycling factory in Lung Kwu Tan, but no one there had to leave.

With the fire out, sights turn to the damage left behind. And Jim said serious erosion of the granite hills, thin soil and the area's low fertility make recovering vegetation even more difficult.

He guessed the fire was caused by careless people who either left behind a kindling flame or who had been playing with fire.

He noted that dry leaves and cold weather are catalysts for fire to spread easily.

With the existing soil erosion and cold weather, he believes reforestation won't be able to begin until the spring.

Peter Li Siu-man, campaign manager of The Conservancy Association, also stressed that Po Lo Shan will not be an easy area for vegetation to regrow.

"Soil loses nutrients from frequent fires, and the land will be difficult to restore to its original status," he said.

Ecology in Siu Lam Shui and Lung Kwu Tan was also affected. They are wintering sites for butterflies and other insects.

Lau Shu-lam, chief fire officer in the New Territories, said the fire had mostly burned wild grass, but precious woods were unaffected.

"Dry weather and the steep landscape made it difficult for us to put out the fire," he said.

More than a hundred firefighters fought the fire, while Government Flying Service helicopters dropped water on the flames, Lau said.

He added that firemen and fire engines would stay and watch the mountain to prevent the fire from reigniting.

(China Daily January 4, 2008)