Copyright Oxford University Press. This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Tree Physiology following peer review. The definitive publisher-authenticated version: Variations in relative stomatal and biochemical limitations to photosynthesis in a young blackbutt (Eucalyptus pilularis) plantation subjected to different weed control regimes, Tree Physiology, (2008) 28 (7): 997-1005 is available online at: 10.1093/treephys/28.7.997