Comparison of two image analysis software for root trait analysis of single and mixed species grasslands

Abstract

Diverse root architectures can allow more efficient resource acquisition in multispecies plant communities. These beneficial root architectures and traits can be measured through imaging and automatic root analysis. However, the commonly used root trait analysis software WinRHIZO inaccurately estimates root volume where there are heterogeneous root diameters. The recently released software RhizoVision Explorer uses a different root volume calculation method, suited to samples with variation in diameter. In this study, an image set of roots from monocultures and mixtures of six grassland species was analyzed by WinRHIZO and RhizoVision Explorer. For roots from the top 10 cm of the soil profile, WinRHIZO root length and volume estimates were lower than RhizoVision Explorer. RhizoVision Explorer overestimated the length of simulated fine roots, while the opposite was true for WinRHIZO. This resulted in lower average diameter estimates by RhizoVision Explorer. Further validation of the effect of factors such as image quality and root staining on the accuracy of RhizoVision Explorer's root measurements could inform a standard protocol for root trait analysis.