PT - JOURNAL ARTICLE AU - G.W. Hudler AU - M.A. Beale TI - Anatomical Features of Girdling Root Injury AID - 10.48044/jauf.1981.008 DP - 1981 Feb 01 TA - Arboriculture & Urban Forestry (AUF) PG - 29--32 VI - 7 IP - 2 4099 - http://auf.isa-arbor.com/content/7/2/29.short 4100 - http://auf.isa-arbor.com/content/7/2/29.full AB - The root system of a Norway maple affected by girdling roots was excavated, dissected, and examined microscopically. Cross-sectional area of vessels in the stem xylem affected by the girdle was only 10% that of unaffected wood. Rays in the stem wood were skewed and contained few pits. Bark on the girdled stems was compressed from a normal thickness of about 2.5 cm to 1 mm. The offending roots sustained slight compression of cells where they were in contact with the stem and appeared to remain functional. Thus, girdling roots apparently cause tree decline by reducing stem conductivity and radial communication between tissues.