I am working with a dataset that used a BACI design in R. The data was collected in 4 sub-watersheds (Subwatershed) and 5 hillslope positions that were nested in each sub-watershed (Position). I have created daily averages (WC_15cm_daily_avg) for each Date value (yyyy-mm-dd). I also have a column called Period (Cal or Trt) and one called Treatment (0 or 1) to indicate which period it was (Calibration or Treatment) and which treatment it was (Control or Thinned). I want to see if the harvest had an effect, which would show up in a significant interaction between Treatment and Period.