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Scientists are trying to find out if native trees are adding to New Zealand's carbon emissions.
Two projects investigating native trees and carbon emissions are under way at Ensis, a joint venture between Crown Research Institute Scion in Rotorua and Australia's CSIRO.
Ensis senior scientist Dr Peter Beets is leading a programme looking at developing tools to predict native tree carbon emissions.
"Our aim is to work out the amount of carbon that is being absorbed by living trees and the amount of carbon that is being released when trees die and decay," Dr Beets said.
"We hope to find out if native trees actually reduce the country's overall emissions at all, or if the emissions the trees make just cancels any benefit."
Estimates of carbon emissions for New Zealand's indigenous and exotic forests must be reported to the United Nations because the country has signed the Kyoto Protocol.
Dr Beets aims to find out how quickly various species of native trees - including matai, rimu, red beech, silver beech, and tawa - decay.
Some species can take 30 or more years to rot, while others less than 10.
"It is difficult to work out decay rates because it can take decades to get data on trees that have only fallen down today. So instead we are going into areas where a known event has happened - for example Cyclone Bernie - and using those trees to come up with data from the last 20 or so years."
Cyclone Bernie swept through the central North Island in April 1982, damaging 6300ha of forest.
A closely linked project is looking at fungi that cause decay in native trees, which leads to carbon release.
Dr Beets said models for tree decay and carbon emissions had already been developed for forest plantations, and this research aimed to do the same for indigenous forests.
"The idea is that we don't want vast amounts of money spent on trying to measure forest sinks and emissions, so instead we are coming up with tools that make an accurate prediction."
- NZPA
