PS 17-122
The effects of diesel exhaust and particulate matter on plant ecophysiology, reproduction and growth
Living along traffic corridors and lacking voluntary locomotion, plants of economic and agricultural importance are constantly bombarded with vehicular exhaust and particulate matter (PM). Although there have been numerous studies detailing the effects of gaseous emissions from vehicles on plants, there is a gap in the understanding of the effects of PM on plants. I have been conducting an interdisciplinary study that combines environmental engineering methods with ecology to investigate and quantify the consequences of diesel exhaust, and especially its associated PM on plants using outdoor open top chamber experiments. Glycine max (soybean) plants growing in open top chambers were exposed to an elevated diesel exhaust and PM treatment or ambient air treatment along with a control from 9am to 2pm for a total of one week. Plants were measured for ecophysiological, reproductive, and growth traits before and after treatment and again after a recovery period of six weeks.
Results/Conclusions
Based on unpublished data collected during the summer field season of 2013, there are significant results due to elevated exposure of diesel exhaust and diesel PM that warrant further investigation. In terms of reproductive and growth responses of soybeans to the elevated exhaust, there were no statistical differences between the average number of soybean pods (fruit) per plant, soybean seeds within each pod, and average individual seed weight. However, soybean plants had a significantly higher aboveground biomass after the recovery period if they underwent the elevated treatment (elevated mean=28.1g, ambient mean= 21.7g, control mean= 20.3g, P=0.0280). This indicates that although reproductive output was not altered by elevated diesel exposure, energy is being directed towards increased plant growth. This has serious implications for the agricultural community because this could be a negative effect on fruit producing crops, but at the same time could imply higher yields if it is not the fruit portion of the plant being harvested.