@article {Wagar332, author = {J. Alan Wagar and Philip A. Barker}, title = {Effectiveness of three Barrier Materials for Stopping Regenerating Roots of Established Trees}, volume = {19}, number = {6}, pages = {332--338}, year = {1993}, doi = {10.48044/jauf.1993.052}, publisher = {Arboriculture \& Urban Forestry (AUF)}, abstract = {In a search for effective barriers to prevent tree root damage to sidewalks, a tough nylon fabric, copper screen, and Biobarrier were tested against regenerating roots in 9-year-old plantations of hybrid cottonwood (Populus trichocarpa Xdeltoides), black cottonwood (P. trichocarpa), and paper birch (Betula papyrifera). Roots were severed flush against vertical walls 3.5 feet from trees. Barrier panels were installed against the severed roots of some wall sections and control sections were left without barriers. Three years afterinstallation, amounts of roots coming through all three kinds of barriers were substantially less than amounts coming through equivalent control sections. Both the nylon and copper greatly stunted roots by constricting them to the size of openings in barrier materials, approximately 1/26- and 1/16-inch, respectively. Biobarrier, designed for slow release of the herbicide trifluralin, stopped all birch roots but let a few cottonwood roots through, apparently those of the most vigorous root systems.}, issn = {1935-5297}, URL = {https://auf.isa-arbor.com/content/19/6/332}, eprint = {https://auf.isa-arbor.com/content/19/6/332.full.pdf}, journal = {Arboriculture \& Urban Forestry (AUF)} }