Hawai’i volcano study could help rejuvenate mined land

Published 01 December 2008

ohelo.jpgA University of New England researcher based on the rift zone of an active volcano in Hawai’i is studying the way flowering plants colonise lava.

Professor Caroline Gross says the outcome could be applied to barren and mined landscapes around the world – including Australia – to help recolonise the land.

Professor Gross is working with colleagues from the University of Hawai’i and Virginia Tech as part of a Special Studies program.

Her main field site is on the north-east rift zone of Mauna Loa volcano, which stands 4,169 metres above sea level and descends another 13 km below sea level. To the north, she can see Mauna Kea, a now dormant yet statuesque volcano 4,205 metres above sea level.

The team is working with native cranberries – known locally as “Ohelo berries” – to understand how plants colonise and reproduce on barren, high-altitude lava fields.

“Ohelo plants are one of the few species growing on this lava at 2,440 metres altitude,” Professor Gross said. “Their flowers have ‘poricidal’ anthers (i.e., anthers with a pore at the top of them). This prevents pollen robbing and also promotes out-breeding, as only bees capable of buzz pollination can trip open the anthers.”

She explained that understanding the reproductive success of Ohelo plants on these lava fields – and the pollination ecology of Hawaiian plants – was crucial, as the islands were among the world’s most vulnerable ecosystems, with species prone to extinction.

The study could also see a change in the way mined landscapes rejuvenate, she said. “Getting plants with poricidal anthers back into the mined landscapes is very important, as these species nearly always have fleshy fruit, and this provides food for fruit-eating animals – such as birds – that disperse the seeds farther afield and help with recolonisation.”

Professor Gross will return to Armidale in January.

THE PHOTOGRAPH displayed here shows Ohelo plants that have colonised a crack in the lava on Mauna Loa volcano. Clicking on this image reveals a photograph of Professor Caroline Gross on the lava field.