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THE USE OF MODELED ATMOSPHERIC WIND TRAJECTORIES TO DETERMINE POTENTIAL DOWNWIND GENE FLOW; A CASE STUDY USING GM-BENTGRASS
Citation:
Watrud, L S., P. K. Van de Water, C. A. Burdick, AND E H. Lee. THE USE OF MODELED ATMOSPHERIC WIND TRAJECTORIES TO DETERMINE POTENTIAL DOWNWIND GENE FLOW; A CASE STUDY USING GM-BENTGRASS. Presented at Ecological Society of America meetings, Portland, OR, August 1-6, 2004.
Description:
The down-wind dispersal of pollen and the airborne spread of seed are affected by the size, shape and weight of the particles and by the strength, buoyancy and direction of surface winds. An atmospheric model (HYSPLIT model: www.arl.noaa.gov\ready.html) was used to reconstruct wind trajectories starting at 10 m above two point sources within an 11,000 acre control area north of Madras, OR, designated by the Oregon Department of Agriculture for growth of genetically modified (GM) bentgrass. Wind trajectories during the summer of 2003, the first year that approximately 400 acres of GM herbicide tolerant bentgrass flowered in the control area, show a general pattern of northwest to southeast air movement. However, about 30% of the winds traveled toward the southwest, northwest or northeast. Analysis of each trajectory's travel distance, calculated for 11:00 am and 2:00 pm during the pollination season (June 15th to July 15th), shows that after the first hour, air moved a maximum distance of more than 10 miles from the control area border. After 2 and 3 hours, maximum travel distances increased to 25 and 40 miles, respectively. Assuming a 2-3 hour period of pollen viability, wind trajectory analyses can be used to model potential dispersal of viable GM bentgrass pollen to compatible recipients in surrounding agronomic and non-agronomic areas. Similar calculations are being used to predict patterns for airborne seed dispersal at other times of the year, e.g., at planting and harvest times.