Plume Dispersion in Four Pine Thinning Scenarios: Development of a Simple Pheromone Dispersion Model

  • Holly G. Peterson Environmental Engineering Department, Montana Tech of the University of Montana, Butte, Montana 59701
  • Harold W. Thistle USDA Forest Service, FHTET, 180 Canfield St., Morgantown, West Virginia 26505
  • Brian K. Lamb Department of Civil and Environmental Engineering, Washington State University, Pullman, Washington 99164-2910
  • Gene Allwine Department of Civil and Environmental Engineering, Washington State University, Pullman, Washington 99164-2910
  • Steve Edburg Department of Mechanical Engineering, Washington State University, Pullman, Washington 99164-3140
  • Brian Strom Research Entomologist, USDA Forest Service, Southern Research Station, Pineville, Louisiana 71360
Keywords: Pheromones, tracer experiments, forest canopy, stand density

Abstract

A unique field campaign was conducted in 2004 to examine how changes in stand density may affect dispersion of insect pheromones in forest canopies. Over a 14-day period, 126 tracer tests were performed, and conditions ranged from an unthinned loblolly pine (Pinus taeda) canopy through a series of thinning scenarios with basal areas of 32.1, 23.0, and 16.1 m2ha-1. In this paper, one case study was used to visualize the nature of winds and plume diffusion. Also, a simple empirical model was developed to estimate maximum average concentration as a function of downwind distance, travel time, wind speed, and turbulence statistics at the source location. Predicted concentrations from the model were within a factor of 3 for 82.1 percent and 88.1 percent of the observed concentrations at downwind distances of 5 and 10 m, respectively. In addition, the model was used to generate a field chart to predict optimum spacing in arrays of anti-aggregation pheromone dispensers.
Published
2010-12-31
Section
Environmental Sciences and Engineering [Articles]