City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!
Issue link: http://read.dmtmag.com/i/36513
Structural diagnostics testing using sonic tomography and three-dimensional color images (tomograms) provide a flat-plane cross sectional view of the wood density in the trunk or branch that a trained technician can use in conjunc- tion with other diagnostic tools. Under Gianmichele’s leadership, Torino has developed a strong partnership with Forest Pathologist Dr. Paolo Gonthier and his staff and graduate students at the University of Turin. In partnership with the University of California–Berkeley, the University of Turin has developed DNA-based assay protocols for detection of many genera and species of wood decay fungi. DNA-based assay pro- tocols are a very useful tool for confirming the presence of wood decay fungi in trees, be they symptomatic or not, and are employed for trees suspected of having decay causing organisms identified during VTA inspections or in trees damaged by storm events, vehicle impacts, or construction operations. This detection capability sig- nificantly improves Torino’s ability to assess and manage risk in heritage trees with structural defects. Torino also conducts root crown excavations using air spades and pull testing (static integrated assessment) to determine 36 the structural stability of a high-value tree with known structural defects. Unlike Milwaukee where all street and boulevard trees are pruned on a straight six-year cycle with in-house crews, Torino’s 60,000 boulevard trees are pruned via a contract workforce following a variable cycle that is species and location dependent. Weak-wooded, fast- growing species such as Ulmus pumila, Populus spp. and Salix spp. are pruned quite severely every three to five years through modified crown reduction methods. More moderate-growing shade trees such as Platanus acerifolia, Celtis australis, Tilia spp., and Aesculus hip- pocastanum that occur in highest percentages are pruned on a five- to seven-year cycle. The 100,000 additional trees that exist in parks and hillside forests, on riverbanks, and on school and other public grounds are pruned on an as-needed and funding dependent basis to abate hazardous conditions. Torino’s historic tree-lined boulevards, some of which approach 10 kilometers (6.2 miles) in length, are City Trees