Oral Presentation Australian Society for Limnology Congress 2013

Root-zones of wetland plants - hot spots for nitrogen removal? (#4)

Mike Grace 1 , Dale Christensen 1 , Stephanie Robson 1 , Jennifer Tank 2 , Sarah Roley 2 , Perran Cook 1
  1. School of Biological Sciences, Monash University, Clayton, Victoria, Australia
  2. Notre Dame University, South Bend, Indiana, USA

Preliminary research has found that the root-zones of wetland plants can provide conditions conducive to the removal of excess nitrogen in sediments, which may otherwise result in eutrophication problems in wetlands and other aquatic ecosystems. It is believed that labile carbon exudates and dynamic oxic-anoxic switches over a 24 hour period surrounding the root-zones can stimulate both nitrification (ammonia to nitrate) and denitrification (nitrate to nitrogen gas). Questions remain about the effectiveness of this nitrogen removal and whether different plant species are more or less effective than others in N removal as nitrogen gas.

This talk will provide an introduction to the latest developments in the 'push-pull' methodology used in these experiments and present results from several common wetland plants including Typha, Phragmites and Cladium from the Ornamental Lake at the Royal Botanic Gardens, Melbourne.