Monday, 23 April 2012

WA Flora being rescued from extinction by prior seed banks

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Grevillea batrachioides• The Mt Lesueur grevillea (Grevillea batrachioides) in Lesueur National Park is currently known from less than 65 plants. Image: Illawara Grevillea ParkA SEED conservation program is helping to save some of WA’s most threatened plant species from extinction.

Established in late 1992 by the Department of Environment of Conservation (DEC), the program was initially aimed at species affected by the root-rot pathogen Phytophthora cinnamomi (Phytophthora dieback).

Since then, seed collections have targeted species threatened by habitat fragmentation, salinity, weed invasion and, more recently, climate change.

Senior research scientist Anne Cochrane manages the DEC’s Threatened Flora Seed Centre, operating one of the largest and most comprehensive threatened flora translocation programs in Australia.

“Forty-six species are currently being recovered through this program using the seed resources from the centre,” she said.

“Species identified for translocation by DEC scientists have the required numbers of seeds germinated in the seed bank laboratory and the resultant seedlings are then given to the Kings Park-accredited nursery to grow before they are planted in existing or new translocation sites in the wild.

“Additional translocations are being conducted in WA using vegetatively propagated material.

“Since 1995, a total of 74 threatened flora translocations have been initiated in WA in order to support the survival of species in the wild.”

Seeds are collected across WA, primarily in the South West where flora is under the greatest pressure of decline and extinction—especially where human development and land use threaten native vegetation.

Once the seeds are collected, they are taken to the Threatened Flora Seed Centre where they cleaned and quantified, tested for viability and stored at -20C after drying, until required for use in translocation or research supporting conservation.

WA currently has 419 species listed as Declared Rare Flora, including 14 extinct and 148 critically endangered species. Some facing an extremely high risk of extinction in the wild include:

• The swamp starflower (Calytrix breviseta subsp. Breviseta) in Perth was first collected in 1901 and 1915, then presumed extinct until its recollection in 1990. Less than 1000 plants are currently found in the wild.

• The Mt Lesueur grevillea (Grevillea batrachioides) in Lesueur National Park is currently known from less than 65 plants.

• Jacksonia pungens is known from less than 300 individuals in the wild.

• Species such as Banksia brownii, Banksia anatona, Banksia montana and Lambertia fairallii in the Stirling Ranges are being severely impacted by Phytophthora dieback.

“Collections are generally prioritised on the level of threat those flora are experiencing in the wild,” Ms Cochrane said.

“They aim to capture the genetic diversity of each species targeted, so multiple collections across a species’ geographic range are made.”

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