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Ecophysiological responses of a young blue gum (Eucalyptus globulus) plantation to week control

Citation

Eyles, A and Worledge, D and Sands, P and Ottenschlaeger, ML and Paterson, SC and Mendham, D and O'Grady, AP, Ecophysiological responses of a young blue gum (Eucalyptus globulus) plantation to week control, Tree Physiology, 32, (8) pp. 1008-1020. ISSN 0829-318X (2012) [Refereed Article]

Copyright Statement

Copyright 2012 The Author

DOI: doi:10.1093/treephys/tps058

Abstract

Early weed control may improve the growth of forest plantations by influencing soil water and nutrient availability. To understand eucalypt growth responses to weed control, we examined the temporal responses of leaf gas-exchange, leaf nitrogen concentration (N) and water status of 7-month-old Eucalyptus globulus L. trees in a paired-plot field trial. In addition, we monitored the growth, leaf N and water status of the competing vegetation in the weed treatment. By the end of the 11-month experiment, complete weed control (WF treatment) of largely woody competitors increased the basal diameter of E. globulus by 14%. As indicated by pre-dawn water potentials of >− 0.05 MPa, interspecies competition for water resources was minimal at this site. In contrast, competition for N appeared to be the major factor limiting growth. Estimations of total plot leaf N (g m−2 ground) showed that competing vegetation accounted for up to 70% of the total leaf N at the start of the trial. This value fell to 15% by the end of the trial. Despite increased leaf Narea in WF trees 5 months after imposition of weed control, the photosynthetic capacity (A1500) of E. globulus was unaffected by treatment suggesting that the growth gains from weed control were largely unrelated to changes in leaf-level photosynthesis. Increased nutrient availability brought about by weed control enabled trees to increase investment into leaf-area production. Estimates of whole-tree carbon budget based on direct measurements of dark respiration and A1500 allowed us to clearly demonstrate the importance of leaf area driving greater productivity following early weed control in a nutrient-limited site.

Item Details

Item Type:Refereed Article
Keywords:competition, gas exchange, leaf area index, resource availability
Research Division:Agricultural and Veterinary Sciences
Research Group:Forestry Sciences
Research Field:Tree Nutrition and Physiology
Objective Division:Plant Production and Plant Primary Products
Objective Group:Forestry
Objective Field:Hardwood Plantations
Author:Eyles, A (Dr Alieta Eyles)
Author:Worledge, D (Mr Dale Worledge)
Author:Paterson, SC (Mr Stephen Paterson)
Author:Mendham, D (Mr Daniel Mendham)
Author:O'Grady, AP (Dr Anthony O'Grady)
ID Code:74624
Year Published:2012
Web of Science® Times Cited:11
Deposited By:Agricultural Science
Deposited On:2011-12-08
Last Modified:2013-05-13
Downloads:0

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