caa a22 4500 606219323 CHVBK 20210128101117.0 cr unu---uuuuu 210128e20151001xx s 000 0 eng 10.1007/s11104-015-2563-9 doi (NATIONALLICENCE)springer-10.1007/s11104-015-2563-9 Calibrating the impact of root orientation on root quantification using ground-penetrating radar [Elektronische Daten] [Li Guo, Yuan Wu, Jin Chen, Yasuhiro Hirano, Toko Tanikawa, Wentao Li, Xihong Cui] Background and aims: Ground-penetrating radar (GPR) has provided a non-invasive means for field root investigation. However, the horizontal cross angle (x) of root orientation intersecting a survey line considerably impacts the amplitude area (A) reflected from a root and impairs the accuracy of GPR-based root quantification. Prediction of A(90°) (the value of A scanning at x = 90°) from multiple A(x) measurements could correct such impact. Previous method of A(90°) prediction focused on target roots at field point scale. The aim of this study is to develop a method to predict A(90°) at field plot scale. Methods: A(90°) was predicted by a pair of A(x) measured at two arbitrary scanning lines together with an estimated soil background amplitude area. Three independent datasets were employed to test the proposed method. The field experiment included radar data collected for six roots of Caragana microphylla in a sandy-clay soil at four cross angles (30°, 45°, 60°, and 90°). The sand box experiment included radar data for 12 dowels at 13 cross angles (0° to 180°, in 15° steps). The simulation experiment included A(x) of 46 simulated roots at 13 cross angles (0° to 180°, in 15° steps). Results: For all experiments, A(90°) was accurately estimated. Root orientation could also be determined. After correcting the impact of cross angle, the accuracy of root diameter estimation improved. Correlation coefficient between actual and estimated root diameters increased from 0.77 to 0.81, with RMSE declining from 9.53 to 7.05mm. Conclusions: A method of correcting the influence of root orientation on root GPR signal at the field plot scale has been established. This method enhances root quantification using GPR. Springer International Publishing Switzerland, 2015 Coarse root nationallicence Field plot scale nationallicence Nondestructive root method nationallicence Root angle nationallicence Root diameter nationallicence Root biomass nationallicence GPR : Ground-penetrating radar nationallicence x : Root angle subtended to the transecting line nationallicence A : Amplitude area nationallicence ∑ A : Sum of the amplitude areas for all reflection waveforms nationallicence Single A max : Amplitude area of the maximum reflection waveform nationallicence B : Amplitude area of the soil background nationallicence EM : Electromagnetic nationallicence RMSE : Root mean square error nationallicence Guo Li College of Global Change and Earth System Science, Beijing Normal University, 100875, Beijing, China aut Wu Yuan State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 100875, Beijing, China aut Chen Jin College of Global Change and Earth System Science, Beijing Normal University, 100875, Beijing, China aut Hirano Yasuhiro Graduate School of Environment Studies, Nagoya University, 464-8601, Nagoya, Japan aut Tanikawa Toko Kansai Research Center, Forestry and Forest Products Research Institute, Nagai-kyutaro, Momoyama, Fushimi, 612-0855, Kyoto, Japan aut Li Wentao State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 100875, Beijing, China aut Cui Xihong State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 100875, Beijing, China aut Plant and Soil Springer International Publishing 395/1-2(2015-10-01), 289-305 0032-079X 395:1-2<289 2015 395 11104 https://doi.org/10.1007/s11104-015-2563-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11104-015-2563-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Guo Li College of Global Change and Earth System Science, Beijing Normal University, 100875, Beijing, China aut NATIONALLICENCE 700 1- Wu Yuan State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 100875, Beijing, China aut NATIONALLICENCE 700 1- Chen Jin College of Global Change and Earth System Science, Beijing Normal University, 100875, Beijing, China aut NATIONALLICENCE 700 1- Hirano Yasuhiro Graduate School of Environment Studies, Nagoya University, 464-8601, Nagoya, Japan aut NATIONALLICENCE 700 1- Tanikawa Toko Kansai Research Center, Forestry and Forest Products Research Institute, Nagai-kyutaro, Momoyama, Fushimi, 612-0855, Kyoto, Japan aut NATIONALLICENCE 700 1- Li Wentao State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 100875, Beijing, China aut NATIONALLICENCE 700 1- Cui Xihong State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, 100875, Beijing, China aut NATIONALLICENCE 773 0- Plant and Soil Springer International Publishing 395/1-2(2015-10-01), 289-305 0032-079X 395:1-2<289 2015 395 11104