HEATHLAND fires in Dorset have more than halved over the past four years, says the county's fire chief.

But arson still remains the biggest cause of heath blazes, with more than three-quarters started deliberately.

Rising temperatures have also had a major impact on the number of fires, with warmer weather drying out vegetation and encouraging more people to cook in the open.

Firefighters in Dorset often face added headaches due to the threat to nearby homes.

In a report to Dorset Fire Authority's audit committee, Chief Fire Officer Darren Gunter says the number of heathland fires in the county dropped from 448 in 2003 to just 214 in 2006.

Nearly four fifths of these incidents involved just one fire pump but 16 major fires needed more than 20 appliances.

Last March saw more than 150 firefighters battling for three hours to bring a blaze on Canford Heath under control.

It tore through around 100 hectares of tinder-dry heathland, destroying rare flora and fauna and came within metres of houses.

CFO Gunter said heathland firefighting in Dorset presented the county's crews with some "unique problems".

"Most fire services will let such a fire burn at night, their strategy being to contain it and extinguish it in daylight," he said.

"This provides additional safety for crews and their equipment and vehicles working in hazardous environments on uneven ground.

"While large open areas of heath and moorland lend themselves to such tactics, they are rarely an option in Dorset due to the threat to people's homes and the habitat value of the heathland areas.

"Crews invariably have to make a stand early, often without the benefit of natural breaks and on occasion when they do not have sufficient resources, all because a fire is threatening to engulf houses."

Nine firefighters have suffered serious injuries over the last 10 years due to these firefighting tactics, he added.

Long spells of dry weather and windy conditions can also fan devastating fires. Over the past four years, the UK experienced two of the hottest periods on record, with highs in 2003 topping 100 degrees Fahrenheit.

Work is continuing on improving firefighting tactics at heath fires, with new compressed air foam systems fitted to two of the service's new pumps.