A Simple Method for Estimating Root Spatial Distribution and Root Biomass of Shrubs Based on Ground-Penetrating Radar

The spatial distribution and biomass of roots are the key parameters to reflect plant growth and development. The object of this study is to develop a simple method to estimate the spatial distribution and biomass of roots based on GPR data. First, we measured 58 individual full-root systems of Caragana microphylla Lam. by ground-penetrating radar (GPR). Second, we examined the root distribution pattern in horizontal direction using the logistic model. Three critical root traits (i.e., parameters of the logistic model) including total root biomass, active root accretion zone and root growth rate are extracted from the fitted logistic model. Finally, the relationship between canopy area and root traits was tested, which can be further utilized to estimate the root biomass and characterize the root spatial distribution in a large region. GPR is a high-throughput phenotyping tool that allows for the detection of the root spatial distribution and quantitative characteristics.