Site characterization
Photosynthetically active radiation (PAR: 400–700 nm wavelengths)
was measured within each shelterwood and midstory
planting block and in an adjacent full-sun clearing. PAR was
measured 1 m above the ground using a quantum sensor (LICOR
191SA line quantum sensor, Lincoln NE) between 10:00 and
14:00 h on cloud-free days on three growing season dates (June–
August) per site. At each planting site, PAR was measured at 3-m
intervals along seven parallel transects in each planting block.
Percent of full sunlight was calculated from PAR measured in
planting sites and adjacent full-sun openings; full-sun PAR was
averaged from measurements collected