Savanna Explorer > Arnhem Land > Fire > Fire and Cypress Pine

Fire and Cypress pine

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 dead cypress
Aerial transects over western Arnhem Land for counting living and dead cypress 

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 height 

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.


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