PARENT SESSION
Contributed Oral Session 75: Biogeochemistry: Soil Chemical Flux
Wednesday, August 10, 8:00 AM - 11:30 AM, Meeting Room 513 E, Level 5, Palais des congrès de Montréal
Utilization of ground penetrating radar to quantify the effects of elevated atmospheric CO2 on coarse roots in a scrub oak ecosystem at Kennedy Space Center, Florida USA.
Stover, Daniel*,1, Day, Frank1, Butnor, John2, Drake, Bert3, 1 Old Dominion University, Norfolk, VA2 U.S. Forest Service, South Burlington, VT3 Smithsonian Environmental Research Center, Edgewater, MD
ABSTRACT- The growth and distribution of coarse roots in time and space represent a major gap in our understanding of belowground ecology. Large roots play a critical role in the sequestration of carbon belowground. Ground Penetrating Radar (GPR) was used to investigate differences between coarse roots in a scrub oak ecosystem that has been exposed to elevated atmospheric CO2 for the past nine years at Kennedy Space Center, Florida. GPR is a geophysical technique that utilizes electromagnetic waves (∼100-1,500 MHz) transmitted directly into the ground, which then reflect off a buried object back to the receiving unit. The advantages of this non-destructive method include non-invasive, rapid acquisition of belowground data. In our study, we examined the ability of two different antenna frequencies (900 and 1,500 MHz) to penetrate and discern roots in the dry sandy soil at our field site. Current data suggests that a tradeoff exists between signal resolution and signal depth between different antenna frequencies. The lower frequency antenna can penetrate further into the soil profile, whereas the higher frequency antenna has greater resolution. In addition, our preliminary analysis suggests greater signal reflectance within the elevated CO2 chambers, which could be indicative of more biomass. Although still in its infancy, this method holds much promise for rapid and repeatable identification and quantification of coarse roots, which are currently the most elusive aspect of the long-term study of root systems.
Key words: Roots, Ground Penetrating Radar, Carbon dioxide, Kennedy Space Center