A Tracer Investigation of Pheromone Dispersion in Lodgepole and Ponderosa Pine Forest Canopies

  • Holly G. Peterson Environmental Engineering Department, Montana Tech of the University of Montana, Butte, Montana 59701
  • Mark E. Peterson Mine Waste Technology Program, Montana Tech of the University of Montana, Butte, Montana 59701
  • Harold W. Thistle USDA Forest Service, 180 Canfield St., Morgantown, West Virginia 26505
  • Brian K. Lamb Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, Washington 99164-2910
  • Gene Allwine Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, Washington 99164-2910
  • Tara Strand Laboratory for Atmospheric Research, Department of Civil and Environmental Engineering, Washington State University, Pullman, Washington 99164-2910
Keywords: average plume spread, bark beetles, Dendroctonus, dispersion coefficients, forest canopy, mountain pine beetle, pheromones, tracer experiments

Abstract

Tracer experiments were conducted in 2000 and 2001 to study spread of insect pheromone plumes in forest canopies. The field sites consisted of lodgepole pine (Pinus contorta) and ponderosa pine (P. ponderosa) canopies in 2000 and 2001, respectively. Ranges of temperature, wind speed, and turbulence conditions were similar in the two campaigns, and field data showed comparable variability on near-instantaneous time scales of wind speed, wind direction, and plume behavior. We developed simple empirical equations to estimate average horizontal and vertical plume spread as functions of standard turbulence statistics, downwind distance from the source, and wind speed. For horizontal plume spread, predicted dispersion coefficients were within a factor of 3, or better, for 97 percent of the observed values in the combined dataset from 2000 and 2001. Likewise, 99 percent of the predicted vertical dispersion coefficients were within a factor of 3 of the observed data.
Published
2010-12-31
Section
Environmental Sciences and Engineering [Articles]