Plant and Soil

, Volume 402, Issue 1–2, pp 47–62

Surface-based GPR underestimates below-stump root biomass

  • John R. Butnor
  • Lisa J. Samuelson
  • Thomas A. Stokes
  • Kurt H. Johnsen
  • Peter H. Anderson
  • Carlos A. González-Benecke
Regular Article

DOI: 10.1007/s11104-015-2768-y

Cite this article as:
Butnor, J.R., Samuelson, L.J., Stokes, T.A. et al. Plant Soil (2016) 402: 47. doi:10.1007/s11104-015-2768-y



While lateral root mass is readily detectable with ground penetrating radar (GPR), the roots beneath a tree (below-stump) and overlapping lateral roots near large trees are problematic for surface-based antennas operated in reflection mode. We sought to determine if tree size (DBH) effects GPR root detection proximal to longleaf pine (Pinus palustris Mill) and if corrections for could be applied to stand-level estimates of root mass.


GPR (1500 MHz) was used to estimate coarse root mass proximal to 33 longleaf pine trees and compared to the amount of biomass excavated from pits proportional in area to tree basal diameter. Lateral roots were excavated to a depth of 1 m and taproots were excavated in their entirety.


GPR underestimated longleaf pine below-stump mass and the magnitude of the underestimation increased with tree DBH. Non-linear regressions between GPR estimated root mass/excavated root mass and tree diameter at breast height (DBH) were highly significant for both below-stump (lateral + taproot) root mass (p < 0.0001, R2 0.77) and lateral coarse root mass (p < 0.0001, R2 0.65).


GPR underestimates root mass proximal to trees, and this needs to be accounted for to accurately estimate stand-level belowground biomass.


GPR Root mass, taproot Lateral root Below-stump Pinus palustris Longleaf pine 



Diameter at breast height (cm) measured 1.4 m above ground level


Ground penetrating radar



Funding information

Funder NameGrant NumberFunding Note
U.S. Department of Defense (US)
  • RC-2115

Copyright information

© Springer International Publishing Switzerland (outside the USA)  2015

Authors and Affiliations

  • John R. Butnor
    • 1
  • Lisa J. Samuelson
    • 3
  • Thomas A. Stokes
    • 3
  • Kurt H. Johnsen
    • 2
  • Peter H. Anderson
    • 4
  • Carlos A. González-Benecke
    • 5
  1. 1.USDA Forest Service, Southern Research Station, 81 Carrigan Drive, Aiken Center, Room 208University of VermontBurlingtonUSA
  2. 2.USDA Forest ServiceSouthern Research StationAshevilleUSA
  3. 3.School of Forestry and Wildlife SciencesAuburn UniversityAuburnUSA
  4. 4.USDA Forest ServiceSouthern Research StationDurhamUSA
  5. 5.Department of Forest Engineering, Resources and Management College of ForestryOregon State UniversityCorvallisUSA

Personalised recommendations