Fig. 16.

Typical greyscale images used for root morphological trait analysis. Roots from three herbaceous species with contrasting root types are displayed, a grass (a) Bromus erectus Huds. (Poaceae); a forb (b) Sanguisorba minor Scop. (Rosaceae); and a legume (c) Lotus corniculatus L. (Fabaceae). Note that nodules are visible on the legume roots but are typically removed for morphological analyses of roots (and nodule biomass should be separately assessed, see section XX. 2. Nodule investment ). Also, note that roots should not be allowed to overlap too much for accurate length, diameter and volume estimations: this can be achieved by clipping the roots into subunits.