Single Versus Multiple Sampler Comparisons

Experiments comparing spore concentrations obtained by a single versus multiple Rotorod samplers in a 2 m×2 m×2 m grid were conducted within similar ecological areas and environmental conditions. Mean spore concentrations obtained by samplers at the same height above ground level were not significantly different at the p=0.05 level in all tests. However, significant differences in spore concentrations were measured among samplers operating at different heights above ground level when wind velocities were greater than 5 m/sec and no free moisture was on the spore bearing tissue. Samplers operating near a spore source measured significant differences in spore concentrations at various heights above ground but not among samplers at the same height. A single volumetric sampler will adequately measure spore concentrations for powering simulation models, but care must be taken to determine the location of the sampling unit in relationship to spore source and ecological or environmental conditions.