Sampling Frequency: annually
Leaves that drop during the season are collected in 0.8 m by 1.2 m wooden litter trap frames in the poplar plots (frames were designed to fit between the poplar rows) and 0.5 m by 0.95 m in the DF, CF, and SF (added in 2008) plots. Two traps are installed in each plot of the poplar and 5 traps in the forest treatments prior to leaf fall in August or September. Leaves within the traps are collected weekly throughout the season. Material is dried, weighed, ground, archived and subsampled for tissue analysis.