Tree size does not influence cyclone damage in tropical rainforest, North Queensland, Australia

Tropical Cyclone Larry hit the coast of Queensland, Australia on 20 March 2006, causing widespread damage throughout the area, especially in the ‘Mabi’ Type 5b rainforest fragments of the Atherton Tablelands. Highly damaged areas were surveyed to examine reasons for vulnerability of individual trees to cyclone damage. This study considered the role of size (both diameter at breast height (DBH) and height) in determining the level of cyclone damage to trees. Tree damage (uprooting, limb damage, and snapping) in five plots in the Mabi fragments was evaluated and tree DBH was measured. The heights of ten emergent trees and ten non-emergent trees were also estimated. There were a range of tree sizes and levels of damage in the plots. Severe limb damage was the most common impact to trees (24.9% of total trees), followed by stem snapping (20.1%), while 89.6% experienced some form of damage. There was no relationship between DBH and the type of cyclone damage received. This result remained the same regardless of the DBH classes used or whether limb damage classes were pooled or separate. Height differences between trees also did not contribute to any significant difference in cyclone damage. These findings are contrary to findings in other studies of the relationship between tree size and cyclone damage. Plant functional traits, such as wood density; rather than tree size, may therefore play a role in determining the response of individual trees to wind disturbance from cyclones in Mabi rainforest.