Estimating Tree-Root Biomass in Different Depths Using Ground-Penetrating Radar: Evidence from a Controlled Experiment
Estimating Tree-Root Biomass in Different Depths Using Ground-Penetrating Radar: Evidence from a Controlled Experiment
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使用探地雷达估算不同深度的树根生物量：来自对照实验的证据
DOI：
10.1109/tgrs.2012.2224351
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发表时间：
2013-06-01
影响因子：
8.2
通讯作者：
Zhu, Xiaolin
中科院分区：
文献类型：
--
作者：
Cui, Xihong;Guo, Li;Zhu, Xiaolin
根在生态系统中具有重要的功能。因此，建立根系相关参数，如根的大小，生物量和三维结构是必要的。传统的树木根系测量方法劳动强度大、对自然破坏大，限制了长期研究中的定量和重复评估。探地雷达（GPR）提供了一种无损测量树根的方法。本研究探讨了可行性的探地雷达系统与500 MHz，900 MHz，和2 GHz的测量频率，用于检测树根和估计根生物量在受控的实验条件下，在桑迪地区。经过能量衰减校正和速度分析后，不仅可以定位地下的单个根系，而且可以从处理后的GPR数据中提取与根系生物量相关的参数。主要调查结果如下。首先，振幅和振幅面积指数被证实是更有效的估计根系生物量衰减效应补偿后。这一结果表明，GPR波衰减效应和速度随深度的变化的校准是有益的估计根系生物量从GPR参数。第二，GPR系统频率的选择主要取决于现场条件，特别是土壤含水量。在不同土壤条件下，建议建立根系生物量估算模型时采用较低的频率。第三，基于金属反射体实验的衰减效应校正方法是一种有效的、易于现场实施的衰减效应校正方法。
Roots have important functions in the ecosystem. Therefore, establishing root-related parameters such as root size, biomass, and 3-D architecture is necessary. Traditional methods for measuring tree roots are labor intensive and destructive to nature, limiting quantitative and repeated assessments in long-term research. Ground-penetrating radar (GPR) provides a nondestructive method for measuring tree roots. This study investigates the feasibility of a GPR system with 500-MHz, 900-MHz, and 2-GHz measurement frequencies for detecting tree roots and estimating root biomass under controlled experimental conditions in a sandy area. After energy attenuation correction and velocity analysis, not only the individual root in subsurface is able to be located but also the parameters that correlate well with root biomass can be extracted from the processed GPR data. The major findings were as follows. First, both the amplitude and amplitude-area indices were confirmed to be more effective for estimating root biomass after attenuation-effect compensation. This result suggests that the calibration of GPR wave-attenuation effects and velocity changes with depth are helpful in estimating root biomass from GPR parameters. Second, the selection of GPR system frequency was mainly dependent on field conditions, particularly soil water content. Lower frequency was recommended for developing root biomass estimation model under varied soil conditions. Third, the new method based on the metal reflector experiment was effective and easy to perform in situ for attenuation-effect correction.