Fig. 4. UV-B transmittance measured by biodosimeter packets (_bio) and a Vital radiometer (_rad) at soil level in eight tall fescue canopies: (A) correlation between the methods; (B) relationship of transmittance values to leaf area index (LAI) in each canopy. In A and B, each value is a mean of 20 measurements taken along a 1-m-long track at 5-cm intervals. In A, error bars denote standard deviation. In B, vertical bars indicate the range of measurements, and data are offset on the X scale for clarity.