Modeling tree root diameter and biomass by ground-penetrating radar.
Modeling tree root diameter and biomass by ground-penetrating radar.
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DOI：
10.1007/s11430-010-4103-z
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发表时间：
2011-01-01
期刊：
影响因子：
--
通讯作者：
Zhu, X. L.
中科院分区：
文献类型：
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作者：
Cui XiHong, Cui XiHong;Chen Jin, Chen Jin;Zhu, X. L.
根在生态系统功能中起着关键作用，因为它们将水和养分从土壤转移到植物。传统的根系测量方法是劳动密集型和破坏性的，这限制了长期研究中定量和可重复的评估。探地雷达（GPR）提供了一种无损测量植物根系的方法。基于2 GHz频率探地雷达的优势，提出了一种实用的估算根系生物量的新方法。首先，通过采集少量根系样本，测量平均根物质密度。其次，在沙区可控的实验条件下，建立了基于探地雷达的根径估算模型，利用该模型对根径进行估算。第三，利用估算的根直径，假设根的形状为圆柱形，计算根体积。最后，通过平均根物质密度和根体积估算根系生物量。研究结果表明：(1)直径大于0.5 cm的粗根密度相对均匀；(2)从2 GHz频率天线剖面数据中提取新的波形参数DeltaT，该参数与根深无关，可以构建精度较高的根直径估计模型；(3)田间试验结果表明，基于gpr的方法估算粗根生物量是可行和有效的。这些发现有助于改进基于GPR的根径和生物量估算模型，并提示GPR数据在根系研究中的潜力。
Roots play a key role in ecosystem functioning as they transfer water and nutrients from soil to plants. Traditional methods for measuring roots are labor-intensive and destructive in nature, which limits quantitative and repeatable assessments in long-term research. Ground-penetrating radar (GPR) provides a non-destructive method to measure plant roots. Based on the superiority of GPR with 2 GHz frequency, we developed a new, practical method to estimate root biomass. First, average root matter density was measured by collecting a small number of root samples. Second, under controlled, experimental conditions in a sandy area, a root diameter estimation model base on GPR was developed from which root diameter was estimated. Third, root volume was calculated using the estimated root diameter and assuming the shape of roots to be cylindrical. Finally, root biomass was estimated by averaging root matter density and root volume. Results of this study suggest the following: (1) the density of coarse roots with diameters greater than 0.5 cm is relatively uniform; (2) a new wave shape parameter, DeltaT, extracted from profile data of 2 GHz frequency antenna is independent of root depth, thus enabling the construction of a root diameter estimation model with high accuracy; and (3) results of a field experiment demonstrated the GPR-based method to be feasible and effective in estimating biomass of coarse roots. These findings are helpful for improving GPR-based root diameter and biomass estimation models and suggest the potential of GPR data in studying root systems.