Summary of average light level (expressed as a percentage of full light) in upper and lower crown positions.

Measurements were conducted between 11:30–16:00 hours in mid-summer. Mean percentage of light saturated photosynthesis was estimated from light response curves ([Landhäusser and Lieffers 2001]) and PAR estimates determined from light reduction imposed by shading treatments. Treatment codes are as follows: NS = non-shaded, AS-L = asymmetric-light shaded, AS-H = asymmetric-heavy shaded and US = uniform-shaded. Values in brackets represent the range of measurements observed. Light was measured with multiple readings around the crown position with an Acupar Ceptometer.