Twenty-two plots were established in a Eucalyptus nitens plantation and measured over three years to investigate the effects of naturally regenerated Acacia dealbata weeds on productivity. Under favorable moisture conditions, A. dealbata grew at a rate close to (and sometimes exceeding) that of E. nitens, bringing about canopy closure by two years of age where A. dealbata stem densities were high. Competition peaked at age 2-6 years before declining as the A. dealbata canopy was suppressed, in part by intra-specific Acacia competition. E. nitens basal area was a highly significant inverse correlate of A. dealbata stem density from ages 2-8 years. However, a simple correlation between E. nitens and A. dealbata basal areas was significant only in young stands (age 2-4 years). The effects of early-age competition by A. dealbata on E. nitens productivity were substantial, reducing standing volume compared to Acacia-free plots by almost 25% by age eight years. Soil nitrogen status was positively correlated with A. dealbata presence at both ages sampled (four and eight years) and negatively correlated with E. nitens basal area. A. dealbata was, therefore, considered to be a net contributor of nitrogen during this period, but competition for other resources negated any positive effect of this contribution.

Item Type:	Refereed Article
Research Division:	Agricultural, Veterinary and Food Sciences
Research Group:	Forestry sciences
Research Field:	Forestry management and environment
Objective Division:	Plant Production and Plant Primary Products
Objective Group:	Forestry
Objective Field:	Hardwood plantations
UTAS Author:	Hunt, MA (Professor Mark Hunt)
UTAS Author:	Unwin, GL (Dr Greg Unwin)
UTAS Author:	Beadle, CL (Dr Christopher Beadle)
ID Code:	17710
Year Published:	1999
Web of Science® Times Cited:	20
Deposited By:	Applied Science
Deposited On:	1999-08-01
Last Modified:	2011-08-05
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