title: Effect of elevated CO2 on coarse-root biomass in Florida scrub detected by ground-penetrating radar.
abstract: Growth and distribution of coarse roots in time and space represent a gap in our understanding of belowground ecology. Large roots may play a critical role in carbon sequestration belowground. Using ground-penetrating radar (GPR), we quantified coarse-root biomass from an open-top chamber experiment in a scrub-oak ecosystem at Kennedy Space Center, Florida, USA. GPR propagates electromagnetic waves directly into the soil and reflects a portion of the energy when a buried object is contacted. In our study, we utilized a 1500 MHz antenna to establish correlations between GPR signals and root biomass. A significant relationship was found between GPR signal reflectance and biomass (R2 = 0.68). This correlation was applied to multiple GPR scans taken from each open-top chamber (elevated and ambient CO2). Our results showed that plots receiving elevated CO2 had significantly (P = 0.049) greater coarse-root biomass compared to ambient plots, suggesting that coarse roots may play a large role in carbon sequestration in scrub-oak ecosystems. This nondestructive method holds much promise for rapid and repeatable quantification of coarse roots, which are currently the most elusive aspect of long-term belowground studies.
authors.affiliation: Department of Biological Sciences, Old Dominion University, Norfolk, Virginia 23529, USA. dstover@odu.edu
authors.forename: Daniel B
authors.initials: DB
authors.lastname: Stover
authors.forename: L Frank P
authors.initials: LF
authors.lastname: Day
authors.forename: John R
authors.initials: JR
authors.lastname: Butnor
authors.forename: Bert G
authors.initials: BG
authors.lastname: Drake
mesh_terms: D018533:Biomass; D002245:Carbon Dioxide / Q000032:analysis / Q000378:metabolism*; D005431:Florida; D008954:Models, Biological; D018517:Plant Roots / Q000033:anatomy & histology* / Q000254:growth & development / Q000378:metabolism*; D011825:Radar; D012987:Soil
chemical_list: D012987:Soil; D002245:Carbon Dioxide