Plume dispersion in four pine thinning scenarios: development of a simple pheromone dispersion model

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 l4-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 of32.l, 23.0, and 16.1 m2ha-l.ln 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 10m, respectively. In addition, the model was used to generate a field chart to predict optimum spacing in arrays of anti-aggregation pheromone dispensers.

Keywords

Pheromones, tracer experiments, forest canopy, stand density

Citation

Peterson, H.G.; Thistle, H.W.; Lamb, B.; Allwine, G.; Edburg, S.; Strom, B. 2010. Plume dispersion in four pine thinning scenarios: development of a simple pheromone dispersion model. Intermountain Journal of Sciences (16) 4:73-86.