by Andrew Edwards, Bushfires Council of the NT
from Savanna Burning — Understanding and Using Fire in
Northern Australia, Tropical Savannas CRC, 2001
Cypress pine (Callitris intratropica ) is a long-lived
tree that occurs across northern Australia in a range of habitats
with free-draining soils. High-intensity fires will kill or scar
mature cypress trees but the termite-resistant stems remain
standing for many years. Low-intensity fires may kill juvenile
trees but will not generally affect mature trees.
The condition of cypress stands are therefore a guide to the
severity of the fire regime — dead cypress stems
indicate there have been high-intensity fires.
Aerial transects over western Arnhem Land for counting living and
In recent years, ground-based cypress surveys over many parts of
northern Australia have counted living and dead pine trees to
determine their current condition and former range. Both living and
dead cypress are highly visible in the savanna landscape, and
aerial surveys can also be used.
An aerial survey in October 2000 showed that the condition of
cypress pine stands in western Arnhem Land varied considerably.
There were more living trees than dead stems in areas protected
from frequent fire — in the rocky areas in the dissected
sandstone and the escarpment country.
Counting rings and measuring stem diameter at 1.3 m
On the open sand sheets and savanna lowland woodlands, the dead
stems far outnumbered the living, indicating that fire severity has
increased in recent times.
The diameters of dead trees are measured, sections cut and the
growth rings counted to determine a relationship between tree
diameter and age.
Fire threatens North's own Christmas Tree
Cypress pine ( Callitrus intratropica ) – the northern Christmas tree Photo: Mandy Trueman THE northern cypress pine the native Christmas tree of northern Australia is being wiped out by bushfires that have… [read more...