Correlating stem biomechanical properties of Hawaiian canopy trees with hurricane wind damage

• Published in: Biotropica Vol. 29; no. 2; pp. 145 - 150
• Main Authors: Asner, G.P. (University of Colorado, Boulder, CO.), Goldstein, G
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.1997; Association for Tropical Biology
• Subjects: ACACIA KOA; ACACIA MEARNSII; biomechanics; BOIS; disturbance; elastic modulus; ESPECE; ESPECIES; EUCALYPTUS; EUCALYPTUS ROBUSTA; Failure modes; Forest canopy; Forest trees; GREVILLEA ROBUSTA; HAWAI; HAWAII; hurricane; Hurricanes; indigenous species; Introduced species; INTRODUCED VARIETIES; MADERA; MECHANICAL PROPERTIES; METROSIDEROS; METROSIDEROS POLYMORPHA; Moduli of elasticity; native species; Property damage; PROPIEDADES MECANICAS; PROPRIETE MECANIQUE; SPECIES; Storm damage; Trees; VARIEDADES NATURALIZADAS; VARIETE INTRODUITE; wind; WOOD; Wood density; Hawaii
• ISSN: 0006-3606; 1744-7429
• DOI: 10.1111/j.1744-7429.1997.tb00018.x

Hawaiian forests are subject to the effects of periodic hurricane conditions. Hurricane Iniki struck the island of Kauai, Hawaii on September 11, 1992 with winds exceeding 200 km/h and caused defoliation, felling of trees by snapping and uprooting, and standing tree mortality due excessive limb and leaf loss. The purpose of this study was to evaluate if measured wood mechanical characteristics could be correlated with stem failure of trees under windstorm conditions. A field survey indicated that post-hurricane stem condition (snapped, uprooted, or standing) differed among five common canopy species and was significantly correlated with stem apparent elastic modulus (relative flexibility). Species that tended to snap had significantly higher apparent elastic moduli than those that remained standing or were uprooted. Wood density and stem diameter were not significantly related to stem failure mode. Native trees had a higher percentage per species of standing individuals but also had increased uprooting. Nonnative tree species were more often snapped and fewer were standing after the hurricane. The higher incidence of stem failure for introduced canopy trees may increase the spread of alien understory species following wind disturbance events. These relationships provide a simple means to predict relative differences in stem failure due to high wind conditions and should be considered in planning reforestation efforts on the Hawaiian Islands.