Saturday, 23 January 2016

Fire razes rare Albany banksias

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B. verticillata after the fire in the south-west. B. verticillata after the fire in the south-west. Sarah Barrett
  • Nearly one quarter of banksia populations torched by bushfire
  • Burned plants did not have time to reproduce after last fires
  • Rare banksia seeds backed up at Perth seed bank

CONSERVATIONISTS have taken stock of areas of the south-west hit by bushfires late last year and determined that fragile populations of one of WA’s most iconic plants has been significantly ravaged.

Four out of 19 populations of the critically endangered Banksia verticillata, commonly known as Albany or granite banksia, which are found along coastline between Walpole and Cheyne Beach, were burned.

The damage occurred during the bushfire that torched 616ha of Torndirrup National Park in November, an area roughly one-and-a-half times bigger than Kings Park.

About 50ha of that was critical habitat for B. verticillata, which has declined in recent years due to disease, Department of Parks and Wildlife Albany threatened flora officer Sarah Barrett says.

She estimates four fifths of about 2000 plants previously found at Jimmy Newell’s Harbour, Stony Hill, Salmon Holes and Peak Head were burned.

A survey to assess the fire’s impact suggests the species’ slow maturity rate could inhibit its recovery.

B. verticillata razed by the bushfires. Credit: Sarah Barrett.

 

B. verticillata typically takes at least 10 years to flower and produce cones and seed—twice as long as other banksias—making it vulnerable to fire.

“The worrying thing is there were fires in 1998 and 2005 that affected Stony Hill,” Dr Barrett says.

“I could see that all the plants that had regenerated after the 2005 fire didn’t have cones, so the ones that were killed never had a chance to reproduce.

“Fortunately, some older plants growing on the granite were not burnt and they have released their seed.

“Hopefully that will regenerate the population sufficiently, but we won’t know until next spring when we can check for seedlings.”

The plant’s recovery, which grows up to five metres tall and has golden flowers, is precarious, Dr Barrett says.

B. verticillata after the fire. Credit: Sarah Barrett.

 

“We are hoping we will get a reasonable rate of germination but we are not 100 per cent sure,” she says.

“We are not sure how well the populations that were in decline will regenerate.

“It’s really going to be a case of wait and see what comes back—we just have to hope they survive.”

As part of the surveys they collected B. verticillata seed to store at Perth’s seed banking facility for rare and threatened native species.

The Threatened Flora Seed Centre, established 23 years ago, offers a lifeline for conservation of the banksia and some 4000 other plants.

Sufficient genetic material has been preserved to ensure the species could be re-established if it fails to recover.

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