The Heavy Metal Movement Phase II: A field and laboratory study of Panicum virgatum L

Friday, February 12, 2016
McKalee Steen, Grove High School, Grove, OK
The purpose of this project was to see if Kanlow Switchgrass growing at Tar Creek Superfund Site has adapted to deal with the toxic conditions. There were two parts to this project. First, seeds collected from plants at the field site were grown in a laboratory alongside seeds which came from plants not grown in toxic conditions. Independent lab groups were grown in Tar Creek soil and control groups in potting soil for 15 weeks. Plant and soil samples were taken at 11, 13 and 15 weeks.  Second, at the Tar Creek Superfund site, plant samples were collected monthly for 5 months. Plant and soil analysis were conducted from all lab and field collections. All soil and plant materials were digested with acid in open block and both soil and plant tissues were analyzed using an ICP-OES  Spectro Arcos machine. The hypotheses were 1) The plants grown from seeds collected on site would phytoremediate soil better than plants grown from regular seeds and 2) plant samples at Tar Creek would be higher in heavy metal content during active growth as compared to when dormant. Hypothesis 1 was supported. All metals analyzed in soils were lower  over time in the groups grown with plants from Tar Creek collected seeds (with the exception of iron). Hypothesis 2 was also supported. The heavy metal content in plant tissue was higher during active plant growth  and was lower when dormant.These findings suggest that switchgrass growing in toxic conditions develop traits to cope with the extreme environment and pass those traits to their offspring.