Ochre Archives: Local Big Trees

On Saturday Jacqui Mitton hosted Derek McIntosh (who runs the National Register of Big Trees) around the local area (with us being part of the group out of general interest) looking at local big trees identified through local knowledge and contacts during the planning for the day. In all we looked at and recorded 6 trees each of different species. All are within an area where Grenfell is considered to be the local town. Grenfell is within the NRBT's designated region of Central NSW.

'Biggest' trees and Points Allocation

The biggest trees of a particular species are given 'champion' status and this can be at Region, State and National levels. To enable consistent comparison between all trees regardless of species points are calculated based on the trunk circumference at 1.4 metres from ground level, tree height and average crown spread. The formula for determining total number of points for each tree is:

Trunk circumference (girth) at 1.4 metres from ground-level in metres multiplied by 39.37 PLUS
Tree height in metres multiplied by 3.28 PLUS
Average crown spread in metres multiplied by 0.82

The resultant total from the above process enables direct comparison with trees listed in both the Australian NRBT and the American Forests register. The calculation process gives primary weighting to the girth measurement, secondary weighting to height and tertiary weighting to crown spread.

Biggest Trees in Australia and the United States of America

To give perspective to the size of our local trees:

The largest tree presently listed on the Australian NRBT is a Mountain Ash (Eucalyptus regnans) located near Geeveston in Tasmania. Its total points are 1,087 calculated off the tree's circumference of 20.45 metres, height of 81 metres and crown of 20 metres
The largest tree on the American Forests register is a Giant Sequoia (Sequoiadendron giganteum) located in Sequoia National Park, California. Its total points are 1,321 calculated off the tree's circumference of 25.9 metres, height of 83.5 metres and crown of 32.6 metres.

Local Trees we Visited on Saturday 17 November 2012

All 6 of the trees we checked out on Saturday are listed below in the order seen. All are on private property and we were grateful to the owners for giving us permission to access their land to see, photograph and measure the trees. The names of the owners and their properties are not shown below in the interest of privacy.
The following is given for each tree:

Common and scientific name
Location listed by Parish, Locality and Shire
Photograph NB: The photographs unfortunately don't do real justice to seeing these trees 'live'
Measurements in metres: Circumference, height and crown
Points
Status in terms of the National Register of Big Trees