The number of studies investigating root length has increased, particularly in the context of root length measurements observed through windows such as minirhizotrons and rhizoboxes. However, there are currently two obstacles constraining their broader utility: (1) the absence of standardized terminology or units for root length data, and (2) the translation from two-dimensional (2D) to three-dimensional (3D) data. Here, we delineate the fundamental disparities between root length measurements obtained from observation windows and via volumetric soil sampling and propose the adoption of more precise terminology to distinguish 2D planar (pRLD) from 3D volumetric (vRLD) root length density measurements. This differentiation should be accompanied with the use of standardized units and should not endeavour to make blanket conversions between dimensions unless this is supported by specific calibration data.

调查根长的研究数量有所增加，特别是在通过微型根加速器和根茎盒等窗口观察到的根长测量的背景下。然而，目前有两个障碍限制了它们更广泛的应用：（1） 根长数据缺乏标准化术语或单位，以及 （2） 从二维 （2D） 到三维 （3D） 数据的转换。在这里，我们描述了从观察窗口获得的根长测量值和通过体积土壤采样获得的根长测量值之间的根本差异，并建议采用更精确的术语来区分 2D 平面 （pRLD） 和 3D 体积 （vRLD） 根长密度测量值。这种区分应伴随着标准化单位的使用，并且不应试图在尺寸之间进行全面转换，除非有特定的校准数据支持。