April 22, 2011 | 3
In 2009 six weeks of wildfires in Victoria, Australia, killed 173 people and injured hundreds more, but the fires may have also led to the resurrection of a rare tree that was previously on a path to extinction.
Only about 670 Buxton silver gum trees (Eucalyptus crenulata) were left in the wild before the devastating Black Sunday bushfires, and they weren’t healthy. After several years of drought at the beginning of the century, a 2005 survey of the trees found no new seedlings. Officials worried that the fires could have put the final nail in the coffin for the endangered trees.
But a survey at the end of 2010 revealed a different story. “The intense fire burnt a significant amount of the topsoil in the Buxton gum’s swampy habitat,” Parks Victoria Ranger in Charge Julie Flack said in a prepared statement. The fires revealed underground lignotubers, nutrient-rich stems that some trees use as a backup system to help them grow new shoots after losing their leaves during a fire. The trees had never been studied below the surface, so the existence of these lignotubers was a pleasant surprise.
In the two years since the fire, the lignotubers have sprouted seedlings, giving the silver gum trees their first real growth in a decade.
The seedlings got another boost in September when the Buxton Silver Gum Reserve, with 600 of the trees, flooded. The silver gum thrives in swampy conditions.
Flack told the Australian Associated Press that the parks service now knows the tree needs both fire and flood in order to survive.
Beyond survival, Flack said, helping the Buxton silver gum to thrive remains a priority. “Fire management over the next decade will be important to allow the new regrowth to mature” and produce seeds, she said. Parks Victoria has also built fences to block out grazing wombats, wallabies and rabbits as well as cut back parasitic dodder laurels (Cassytha melantha), which threatened to choke some of the new growth.
The trees will be surveyed again next month, and again five years from now as part of the ongoing national recovery plan (pdf) for the species.
Photo: Eucalyptus crenulata, by “Melbournian” via Wikimedia Commons under Creative Commons license