RT Journal Article SR Electronic T1 Wind-Thrown Trees: Storms or Management? JF Arboriculture & Urban Forestry (AUF) FD International Society of Arboriculture SP 53 OP 69 DO 10.48044/jauf.2014.007 VO 40 IS 2 A1 Moore, G.M. YR 2014 UL http://auf.isa-arbor.com/content/40/2/53.abstract AB Images of wind-thrown trees make for dramatic news coverage. The implied message in most coverage is that strong winds and heavy rain are the cause of the tree failure. However, is the storm the only cause of the tree falling? Many other, and often bigger, trees did not fall. This feature article reviews some of the current literature relating to windthrow of trees. The size and characteristics of tree canopies have a profound influence of the forces that winds exert on tree trunks and roots systems, while the characteristics of tree root systems often determine whether trees fail during storms. The results of a site inspection suggest that there may be other factors, such as the history of the tree and the history of management practices to which the tree has been exposed, which may contribute to its failure during a storm.Site inspections of 80 wind-thrown trees from eight different genera were conducted over a period of 20 years. The inspections revealed that damage to exposed lateral roots (87.5%), the loss of descending roots (88.8%), and evidence of soil compaction at the base of the tree (65%) were often coincident with windthrow. Evidence of trenching near the trunk of the tree (58.8%) and waterlogging of the soil around the base of the tree (56.3%) were also common correlates. The literature surveyed and the results presented not only suggest where aspects of urban tree management might be improved, but may also prove helpful to arborists assessing tree hazards related to possible windthrow. Inspection protocol criteria should include damaged or decayed lateral roots, the loss of descending roots, evidence of site or trenching work close to the trunk, and whether trees are growing in compacted and waterlogged soil.