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Huge Australian bushfires
ignited rare plant growth
Rare plants are springing up in an Australian park ravaged by bushfires –
plants that had never been recorded there before the fire. The astonishing
revival is providing new insights into the way ecosystems recover from fire
damage.
Over 90 per cent of Kinglake National Park in Victoria was damaged by
bushfires in a February 2009 disaster that also claimed 173 lives. "Very few
areas were unaffected by the fire, leaving minimal refuge for flora and
fauna," says Richard Francis, a botanist at Abzeco, an ecological science
consultancy based in Melbourne, Australia.
Now Francis and colleagues have completed a two-year survey of the
330,000-hectare park and found that the fires not only stimulated dormant
seeds to grow but also attracted previously unknown plants to the region.
More than 60 plant species never before recorded in the park have
flourished since the fires, including blue-spike milkwort (Comesperma
calymega) and tufted lobelia (Lobelia rhombifolia).
In addition, plants that had been under threat before the bushfires are now
germinating prolifically. These include round-leaf pomaderris (Pomaderris
vaccinifolia), silky golden-tip (Goodia lotifolia var. pubescens) and swamp
bush-pea (Pultenaea glabra).
Francis says the seeds of these species were buried in the soil but could
not grow because mature plants such as rough tree ferns (Cyathia
australis) were outcompeting them. But when the fires decimated the
mature flora, exposing the ground beneath to heat, smoke and more light,
the underdogs were able to thrive. Seeds are thought to be stimulated by
chemicals in the smoke and ultraviolet light, he says.
The new plants also attracted several bird species that had rarely, if ever,
been recorded within the park. According to Karl Just, also of Abzeco, very
large congregations of white-browed woodswallows (Artamus
superciliosus) could be seen gliding through the sky for months after the
fire. The red-capped robin (Petroica goodenovii), which normally lives in
open scrub and low-density woodland, was also recorded in forested areas
for the first time.
But is this a long-term change? Probably not. "It's likely that these species
will be gradually outcompeted once more," says Francis. Already, some of
the rare plants that proliferated in the first year after the fire have begun
to retreat as ferns, trees and wet forest shrubs have started growing
back.
"These forests were portrayed as destroyed, but they weren't," says David
Lindenmayer, a fire ecologist at the Australian National University in
Canberra. "All the plants are there in the soil seed bank and will remain so
after the parent plants die."
Huge Australian bushfires ignited rare plant growth - environment - 19 September 2011 - New Scientist
ignited rare plant growth
Rare plants are springing up in an Australian park ravaged by bushfires –
plants that had never been recorded there before the fire. The astonishing
revival is providing new insights into the way ecosystems recover from fire
damage.
Over 90 per cent of Kinglake National Park in Victoria was damaged by
bushfires in a February 2009 disaster that also claimed 173 lives. "Very few
areas were unaffected by the fire, leaving minimal refuge for flora and
fauna," says Richard Francis, a botanist at Abzeco, an ecological science
consultancy based in Melbourne, Australia.
Now Francis and colleagues have completed a two-year survey of the
330,000-hectare park and found that the fires not only stimulated dormant
seeds to grow but also attracted previously unknown plants to the region.
More than 60 plant species never before recorded in the park have
flourished since the fires, including blue-spike milkwort (Comesperma
calymega) and tufted lobelia (Lobelia rhombifolia).
In addition, plants that had been under threat before the bushfires are now
germinating prolifically. These include round-leaf pomaderris (Pomaderris
vaccinifolia), silky golden-tip (Goodia lotifolia var. pubescens) and swamp
bush-pea (Pultenaea glabra).
Francis says the seeds of these species were buried in the soil but could
not grow because mature plants such as rough tree ferns (Cyathia
australis) were outcompeting them. But when the fires decimated the
mature flora, exposing the ground beneath to heat, smoke and more light,
the underdogs were able to thrive. Seeds are thought to be stimulated by
chemicals in the smoke and ultraviolet light, he says.
The new plants also attracted several bird species that had rarely, if ever,
been recorded within the park. According to Karl Just, also of Abzeco, very
large congregations of white-browed woodswallows (Artamus
superciliosus) could be seen gliding through the sky for months after the
fire. The red-capped robin (Petroica goodenovii), which normally lives in
open scrub and low-density woodland, was also recorded in forested areas
for the first time.
But is this a long-term change? Probably not. "It's likely that these species
will be gradually outcompeted once more," says Francis. Already, some of
the rare plants that proliferated in the first year after the fire have begun
to retreat as ferns, trees and wet forest shrubs have started growing
back.
"These forests were portrayed as destroyed, but they weren't," says David
Lindenmayer, a fire ecologist at the Australian National University in
Canberra. "All the plants are there in the soil seed bank and will remain so
after the parent plants die."
Huge Australian bushfires ignited rare plant growth - environment - 19 September 2011 - New Scientist