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Never trust Australians; are Banksia and Acacia becoming a problem in New Zealand?. Gary Houliston, Peter Heenan Landcare Research, Lincoln, New Zealand. Lots of bad / unpleasant things come from Australia:. Plant Invasions in New Zealand. 29000 introduced plant species in New Zealand
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Never trust Australians; are Banksia and Acacia becoming a problem in New Zealand? Gary Houliston, Peter Heenan Landcare Research, Lincoln, New Zealand
Plant Invasions in New Zealand • 29000 introduced plant species in New Zealand • 700 new emerging weeds reported in the last 20 years (approx 1 every 10 days) • Border incursions are minor!
Genetics of plant invasions • Plants usually undergo a “lag-phase” between introduction and invasion • What causes plants to emerge from the “lag-phase” • Local adaptation • Propagule pressure
Two case studies: Acacia pravissima Banksia integrifolia
“Coastal Banksia” • Popular nursery plant! • Australian Dryland / coastal species • Sampling across Australian / New Zealand Ranges
Banksia integrifolia in NZ • Planted to stabilise sand dunes / ornamental • Naturalising in several regions • Fast growing, high seed output • Widespread coastal species in native range
Microsatellites developed for Banksia oblongifolia • Five reliable markers • 2- 8 alleles per locus • Initial analysis for 98 individuals (27 from NZ, 71 from Aust)
QLD N = 17 NZ N = 27 NSW, VIC N = 54
Principle Co-ordinate Analysis • Pco 1 = NSW / Vict, 2 = NZ, 3 = QLD
Why does it matter? • Variable populations are generally: • Healthier / more vigorous • Better able to resist control agents • More likely to match the local environment • Have full suite of reproductive types
Acknowledgements • Landcare Research FRST Capability Fund • Linda Broadhurst / Andrew Young CSIRO • Melbourne University Herbarium