A/Ci curve parameters and modeled carboxylation, electron transport, and triose-phosphate utilization efficiency rates from shoots clipped from low, mid, and the top of tall, shrub canopies dominated either by Salix pulchra or Betula nana species. Six shoots were harvested from each 1m x 1m plot, two from each level in the canopy. These plots were located near the LTER shrub plots at the Toolik Field Staion, AK for point frame measurements, and all measurements took place the summer of 2012.
Within-canopy PAR was measured with a Delta-T SunScan wand every 15 cm from the ground to above the canopy under both direct and diffuse light. The data includes all outputs from the SunScan wand: time of measurement, spread of PAR sensors, total irradiance, total diffuse light, and individual outputs of 64-PAR sensors on the SunScan wand. These measurements were taken for 1m x 1m chamber flux (n=14) and point frame (n=19) plots as well as sites four montitored remotely by PAR sensors located above, within, and below shrub canopies.