LAND managers on Mt Warrenheip have experimented with an ecological burn to try to stimulate growth after hundreds of trees died.Acting land manager Mathew Sobey said they had been trying over the past 15 years to find out why so many trees, predominantly peppermints, manna gums and stringy barks, had died.The Lal Lal Landcare Group and University of Ballarat were called in to investigate the deaths, and they decided to proceed with the burn yesterday."In the past three years we've worked with the local community to try and ascertain why the tress have been dying on Mt Warrenheip," Mr Sobey said."This trial fuel-reduction burn is another part of that monitoring program."It has been 70 years since there was a fire on the mount and there have been a lot of grasses and weed species introduced that we believe may be having an effect on native vegetation."We're trying to see if we can try to restimulate the vegetation and unearth some of the dormant seed banks that have been sitting there for a long time."The one-hectare trial burn was carried out yesterday by the Department of Sustainability and Environment (DSE) and Parks Victoria.The burn program for the Mount Warrenheip Flora Reserve will be staged over three years to enable Parks Victoria to monitor how the vegetation responds to burning.Mount Warrenheip is one of only two Victorian volcanos still covered by bushland and is a valuable flora reserve overlooking Ballarat. Meanwhile, DSE plans to carry out a 35-hectare forest fuel reduction burn adjacent to Mt Clear Secondary College some time this week.Smoke may be visible around Mt Clear, in particular along Old Geelong Road and Olympic Way.