News from the CRC
Measuring trees and fire in the Top End
A team of researchers has been gathering data on how high severity fires in northern Australia can affect the health of trees.
Late last week CRC researchers Adj Prof Jeremy Russell-Smith, Dr Andrew Edwards, Dr Kamalijt Sangha and CRC PhD student Grigorijs Goldbergs (all Charles Darwin University), along with CRC Communications Officer Nathan Maddock, visited Mataranka Station in the Northern Territory to sample trees burnt by a high severity fire in November 2015.
The team spent a very long hot day gathering data on tree species, their diameter and height and the status of each tree.
This last aspect – tree status – was the most important, explained Dr Edwards.
“We need to know exactly how this type of fire affects the trees. Was the tree standing but dead, fallen over but dead or resprouting epicormically?” he said.
Following directions from the property caretaker, the team visited the areas burnt hottest by the fire. In two teams, the day was spent measuring trees by following transects of 100m in length in a triangle pattern, measuring each tree within 5m either side of the centre of the transect. Data were recorded on a PDA, including the GPS coordinates of each individual tree.
“We measured approximately 1000 stems for the day,” said Dr Edwards.
Preliminary indications show that this high severity fire killed around half the trees.
“Even by taking out the small size class of trees with a diameter of less than 10cm, which can get knocked out by a moderate severity fire, approximately 50% of the trees we measured were killed by this one high severity fire. This is the information we need to know,” explained Dr Edwards.
The data gathered will also feed into mapping tools and carbon sequestration information.
“The fire severity mapping uses satellite imagery across most of northern Australia,” Dr Edwards outlined.
“I will be able to extract fire severity information for Mataranka Station for the November 2015 high severity fire and calculate the proportion of the property that was affected. Aided by satellite mapping of the density of the trees, we can then estimate the tree loss on the station.”
“This helps us model the proportion of trees killed, and therefore the amount of carbon lost due to high severity fires in this type of landscape.”
“We want to measure in enough places to create an algorithm to model this across northern Australia, that when applied to the fire severity model, tells a very powerful story” said Dr Edwards.