3D representation of a 50 year old maritime pine (Pinus pinaster) from the Landes de Gascogne Forest, 60 km south of Bordeaux, France. Maritime pine root systems present usually a large vertical root called "tap root". Secondary lateral root initiate all along the tap root, but there are few main structural horisontal root found close to the surface and grow horizontally without forking. Rooting in adult trees is halted at a depth of about one meter by an iron pan or a relatively cemented spodic horizon (densic podzol).
Data has been collected by F. Danjon et al at a very good resolution using a 3D digitizer. Info at fred@pierroton.inra.fr