Plant and Soil

, Volume 402, Issue 1–2, pp 47–62 | Cite as

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



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





This research was supported by the U. S. Department of Defense through the Strategic Environmental Research and Development Program (SERDP). We appreciate the technical support provided by Jake Blackstock, Joel Burley, Thomas Christensen, Robert Eaton, Shelly Hooke, Jason Jackson, Lance Kress, John Lewis, Michael Rameriz, Justin Rathel and Karen Sarsony. We thank Dr. Frank Day, Old Dominion University, for reviewing this manuscript prior to submission.


  1. Albaugh TJ, Allen HL, Kress LW (2006) Root and stem partitioning of Pinus taeda. Trees 20:176–185. doi: 10.1007/s00468-005-0024-4 CrossRefGoogle Scholar
  2. Augusto L, Achat DL, Bakker MR, Bernier F, Bert D, Danjon F, Khlifa R, Meredieu C, Trichet P (2015) Biomass and nutrients in tree root systems-sustainable harvesting of an intensively managed Pinus pinaster (Ait.) planted forest. Global Change Biology Bioenergy 7:231–243. doi: 10.1111/gcbb.12127 CrossRefGoogle Scholar
  3. Barton CVM, Montagu KD (2004) Detection of tree roots and determination of root diameters by ground penetrating radar under optimal conditions. Tree Physiol 24:1323–1331CrossRefPubMedGoogle Scholar
  4. Berkhout AJ (1981) Wave field extrapolation techniques in seismic migration, a tutorial. Geophysics 46:1638–1656. doi: 10.1190/1.1441172 CrossRefGoogle Scholar
  5. Borden KA, Isaac ME, Thevathasan NV, Gordon AM, Thomas SC (2014) Estimating coarse root biomass with ground penetrating radar in a tree-based intercropping system. Agrofor Syst 88:657–669. doi: 10.1007/s10457-014-9722-5 CrossRefGoogle Scholar
  6. Butnor JR, Doolittle JA, Kress L, Cohen S, Johnsen KH (2001) Use of ground-penetrating radar to study tree roots in the southeastern United States. Tree Physiol 21:1269–1278CrossRefPubMedGoogle Scholar
  7. Butnor JR, Doolittle JA, Johnsen KH, Samuelson L, Stokes T, Kress L (2003) Utility of ground-penetrating radar as a root biomass survey tool in forest systems. Soil Sci Soc Am J 67:1607–1615CrossRefGoogle Scholar
  8. Butnor JR, Johnsen KH, Wikstrom P, Lundmark T, Linder S (2006) Imaging tree roots with borehole radar. 11th International Conference on Ground Penetrating Radar, Columbus OhioGoogle Scholar
  9. Butnor JR, Barton CVM, Day FP, Johnsen KH, Mucciardi AN, Schroeder RE, Stover DB (2012) Using ground-penetrating radar to detect tree roots and estimate biomass. In: Mancuso S (ed) Measuring roots: an updated approach. Springer, Heidelberg, New YorkGoogle Scholar
  10. Conyers LB, Goodman D (1997) Ground-penetrating radar: an introduction for archaeologists. AltaMira Press, Walnut CreekGoogle Scholar
  11. Cox KD, Scherm H, Serman N (2005) Ground-penetrating radar to detect and quantify residual root fragments following peach orchard clearing. HortTechnology 15:600–607Google Scholar
  12. Cui XH, Chen J, Shen JS, Cao X, Chen XH, Zhu XL (2011) Modeling tree root diameter and biomass by ground-penetrating radar. Sci China-Earth Sci 54:711–719. doi: 10.1007/s11430-010-4103-z CrossRefGoogle Scholar
  13. Cutini A, Chianucci F, Manetti MC (2013) Allometric relationships for volume and biomass for stone pine (Pinus pinea L.) in Italian coastal stands. iForest 6:7. doi: 10.3832/ifor0941-006 CrossRefGoogle Scholar
  14. Daniels DJ (2004) Ground penetrating radar. Institution of Electrical Engineers, LondonCrossRefGoogle Scholar
  15. Dannoura M, Hirano Y, Igarashi T, Ishii M, Aono K, Yamase K, Kanazawa Y (2008) Detection of cryptomeria japonica roots with ground penetrating radar. Plant Biosyst 142:375–380. doi: 10.1080/11263500802150951 CrossRefGoogle Scholar
  16. Day FP, Schroeder RE, Stover DB, Brown ALP, Butnor JR, Dilustro J, Hungate BA, Dijkstra P, Duval BD, Seiler TJ, Drake BG, Hinkle CR (2013) The effects of 11 yr of CO2 enrichment on roots in a Florida scrub-oak ecosystem. New Phytol 200:778–787. doi: 10.1111/nph.12246 CrossRefPubMedGoogle Scholar
  17. Doolittle JA, Minzenmayer FE, Waltman SW, Benham EC, Tuttle JW, Peaslee SD (2007) Ground-penetrating radar soil suitability map of the conterminous United States. Geoderma 141:416–421. doi: 10.1016/j.geoderma.2007.05.015 CrossRefGoogle Scholar
  18. Drexhage M, Colin F (2001) Estimating root system biomass from breast-height diameters. Forestry 74:491–497. doi: 10.1093/forestry/74.5.491 CrossRefGoogle Scholar
  19. Gonzalez-Benecke CA, Gezan SA, Albaugh TJ, Allen HL, Burkhart HE, Fox TR, Jokela EJ, Maier CA, Martin TA, Rubilar RA, Samuelson LJ (2014) Local and general above-stump biomass functions for loblolly pine and slash pine trees. For Ecol Manag 334:254–276. doi: 10.1016/j.foreco.2014.09.002 CrossRefGoogle Scholar
  20. Guo L, Chen J, Cui XH, Fan BH, Lin H (2013a) Application of ground penetrating radar for coarse root detection and quantification: a review. Plant Soil 362:1–23. doi: 10.1007/s11104-012-1455-5 CrossRefGoogle Scholar
  21. Guo L, Lin H, Fan BH, Cui XH, Chen J (2013b) Impact of root water content on root biomass estimation using ground penetrating radar: evidence from forward simulations and field controlled experiments. Plant Soil 371:503–520. doi: 10.1007/s11104-013-1710-4 CrossRefGoogle Scholar
  22. Guo L, Wu Y, Chen J, Hirano Y, Tanikawa T, Li WT, Cui XH (2015) Calibrating the impact of root orientation on root quantification using ground-penetrating radar. Plant Soil 395:289–305. doi: 10.1007/s11104-015-2563-9 CrossRefGoogle Scholar
  23. Hirano Y, Dannoura M, Aono K, Igarashi T, Ishii M, Yamase K, Makita N, Kanazawa Y (2009) Limiting factors in the detection of tree roots using ground-penetrating radar. Plant Soil 319:15–24. doi: 10.1007/s11104-008-9845-4 CrossRefGoogle Scholar
  24. Hodgkins EJ, Nichols NG (1977) Extent of main lateral roots in natural longleaf pine as related to position and age of trees. For Sci 23:161–166Google Scholar
  25. Hruska J, Cermak J, Sustek S (1999) Mapping tree root systems with ground-penetrating radar. Tree Physiol 19:125–130CrossRefPubMedGoogle Scholar
  26. Jackson RB, Canadell J, Ehleringer JR, Mooney HA, Sala OE, Schulze ED (1996) A global analysis of root distributions for terrestrial biomes. Oecologia 108:389–411. doi: 10.1007/bf00333714 CrossRefGoogle Scholar
  27. Jenkins JC, Chojnacky DC, Heath LS, Birdsey RA (2003) National-scale biomass estimators for United States tree species. For Sci 49:12–35Google Scholar
  28. King JS, Giardina CP, Pregitzer KS, Friend AL (2007) Biomass partitioning in red pine (pinus resinosa) along a chronosequence in the upper peninsula of Michigan. Can J For Res 37:93–102. doi: 10.1139/x06-217 CrossRefGoogle Scholar
  29. Law B, Arkebauer T, Campbell JL, Chen J, Sun O, Shwartz M, van Ingen C, Verma S (2008) Terrestrial carbon observations: protocols for vegetation sampling and data submission. Terrestrial Carbon Observations (TCO) Panel of the Global Terrestrial Observing System (GTOS). FAO, RomeGoogle Scholar
  30. Oppenheim AV, Schafer RW (1975) Digital signal processing. Prentice Hall, Englewood CliffsGoogle Scholar
  31. Retzlaff WA, Handest JA, O'Malley DM, McKeand SE, Topa MA (2001) Whole-tree biomass and carbon allocation of juvenile trees of loblolly pine (Pinus taeda): influence of genetics and fertilization. Can J For Res 31:960–970CrossRefGoogle Scholar
  32. Robinson D (2007) Implications of a large global root biomass for carbon sink estimates and for soil carbon dynamics. Proc R Soc B Biol Sci 274:2753–2759. doi: 10.1098/rspb.2007.1012 CrossRefGoogle Scholar
  33. Samuelson LJ, Johnsen K, Stokes T (2004) Production, allocation, and stemwood growth efficiency of Pinus taeda L. stands in response to 6 years of intensive management. For Ecol Manag 192:59–70. doi: 10.1016/j.foreco.2004.01.005 CrossRefGoogle Scholar
  34. Samuelson LJ, Stokes TA, Butnor JR, Johnsen KH, Gonzalez-Benecke CA, Anderson P, Jackson J, Ferrari L, Martin TA, Cropper WP (2014) Ecosystem carbon stocks in pinus palustris forests. Can J For Res 44:476–486. doi: 10.1139/cjfr-2013-0446 CrossRefGoogle Scholar
  35. Stone EL, Kalisz PJ (1991) On the maximum extent of tree roots. For Ecol Manag 46:59–102. doi: 10.1016/0378-1127(91)90245-q CrossRefGoogle Scholar
  36. Stover DB, Day FP, Butnor JR, Drake BG (2007) Effect of elevated Co-2 on coarse-root biomass in Florida scrub detected by ground-penetrating radar. Ecology 88:1328–1334. doi: 10.1890/06-0989 CrossRefPubMedGoogle Scholar
  37. Tanikawa T, Hirano Y, Dannoura M, Yamase K, Aono K, Ishii M, Igarashi T, Ikeno H, Kanazawa Y (2013) Root orientation can affect detection accuracy of ground-penetrating radar. Plant Soil 373:317–327. doi: 10.1007/s11104-013-1798-6 CrossRefGoogle Scholar
  38. Ter-Mikaelian MT, Korzukhin MD (1997) Biomass equations for sixty-five north American tree species. For Ecol Manag 97:1–24. doi: 10.1016/S0378-1127(97)00019-4 CrossRefGoogle Scholar
  39. Vanlear DH, Kapeluck PR (1995) Above and below-stump biomass and nutrient content of a mature loblolly-pine plantation. Can J For Res 25:361–367. doi: 10.1139/x95-040 CrossRefGoogle Scholar
  40. Vanninen P, Ylitalo H, Sievanen R, Makela A (1996) Effects of age and site quality on the distribution of biomass in scots pine (Pinus sylvestris L). Trees 10:231–238. doi: 10.1007/bf02185674 Google Scholar
  41. Zenone T, Morelli G, Teobaldelli M, Fischanger F, Matteucci M, Sordini M, Armani A, Ferre C, Chiti T, Seufert G (2008) Preliminary use of ground-penetrating radar and electrical resistivity tomography to study tree roots in pine forests and poplar plantations. Funct Plant Biol 35:1047–1058. doi: 10.1071/fp08062 CrossRefGoogle Scholar

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

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