MAINTAINING GENETICALLY-DETERMINED ROOT SYSTEM CHARACTERISTICS USEFUL FOR URBAN TREES

THE COST OF REPAIRING AND REPLACING PUBLIC PROPERTY DAMAGED BY SHALLOW TREE ROOTS TOTALS MILLIONS OF DOLLARS ANNUALLY. THE UNEVEN GRADE OF THESE SIDEWALKS ALSO PRESENTS A LIABILITY FOR MUNICIPALITIES. THE PROBLEM IS LIKELY TO BE COMPOUNDED BY THE PROPOSED PLANTING OF AN ADDITIONAL 60 MILLION URBAN TREES. WE HAVE IDENTIFIED A POPULATION OF SEEDLING TREES WITH KNOWN ROOT GROWTH CHARACTERISTICS, SPANNING THE CONTINUUM FROM VERY SHALLOW TO VERY DEEP ROOTED. THESE TREES ARE BEING MICROPROPAGATED TO INCREASE THE NUMBER OF INDIVIDUALS. THE MICROCUTTINGS WILL BE ROOTEDIN CONTAINERS WITH 2 DIFFERENT SOIL TYPES AND THEIR ROOT SYSTEM MORPHOLOGY ANALYZED. MICROCUTTINGS WILL ALSO BE GROWN IN SPECIALLY DESIGNED GLASS ROOTING BOXES THAT FACILIATE MONITORING ROOT GROWTH. IF THE PATTERN OF ROOT GROWTH OF THE PROGENY MIRRORS THE DEEP VS SHALLOW ROOTING OFTHE PARENT, IT WILL INDICATE THAT ROOT GROWTH PATTERNS CAN BE IDENTIFIED, SELECTED, AND CLONED. DEEP ROOTED SELECTIONSOF URBAN TREES COULD THEN BE IDENTIFIED, CLONALLY PROPAGATEDAND PLANTED IN THE PUBLIC RIGHT-OF-WAY, THUS CONTRIBUTING TO THE GENETIC DIVERSITY OF OUR URBAN ENVIRONMENT WITHOUT COMPROMISING PUBLIC PROPERTY AND SAFETY.