TWMLA’s Bryan Denig, SITES AP, ISA Certified Arborist, ASLA, is working with a team of researchers from Cornell’s Urban Horticulture Institute (UHI) for the National Park Service to evaluate the health of the National Mall’s iconic elm trees. Led by Dr. Nina Bassuk, professor in the Horticulture Section of the School of Integrative Plant Science and director of the UHI, the team is assessing tree pathology, soil compaction, and failure risk for approximately 600 trees throughout this iconic landscape.