Response of Eucalyptus sideroxylon to release from competition in an irregular stand.  J. D. Kellas, J. V. Owen and R. O. Squire.  April 1981.  5 pp. (unpubl.)

SUMMARY

The effect on basal area increment (BAI) of various release treatments, involving the partial or complete removal of competing regrowth (DBHOB < 20 cm) and complete removal of overwood (DBHOB >20 cm) about selected overwood and regrowth stems of Eucalyptus sideroxylon A.Cunn. ex W.Woolls (red ironbark), was studied in an area of box-ironbark forest north of Costerfield. Competing stems were identified by the ‘zone count’ method, using a 9.2 m² ha^-1 optical wedge.

After a period of 8.25 years, BAI of regrowth stems was significantly greater in the absence of competing overwood. This response was further enhanced by the partial or complete removal of competing regrowth stems within the zone of influence.

The effects of regrowth and overwood competition on BAI of the overwood were inconclusive. However, as the level of competition between overwood stems was low in this study, any such responses were expected to be small.

Also published:

Kellas, J.D., Owen, J.V. and Squire, R.O. (1984)  Response of Eucalyptus sideroxylon to release from competition in an irregular stand.  For. Comm. Vic., For. Tech. Pap. 29: 33-6.