Feasibility of Reconstructing Climate in Hawai'i Using Dendrochronology

Abstract

Dendrochronology, a method of analyzing annual tree ring growth to study past climates, is commonly used throughout the world (Cook & Jacoby, 1977; GonzalezElizondo et al., 2005; Woodhouse et al., 2002; Li et al., 2011; Griffin et al., 2011; Worbes, 1999; Brienen & Zuidema, 2005). However, few dendrochronological studies have been conducted in Hawaiʻi (Samuelson et al., 2013; Fransisco et al., 2015), where strong temperature seasonality is not prevalent. I assess the application of dendrochronology in Hawaiʻi by investigating if (1) introduced conifers can produce annual tree rings and (2) if a relationship between annual tree ring growth and climate (i.e. temperature, rainfall, and cloud cover) exists. In addition, I investigate whether tree ring growth is sensitive to El Niño events. After digitally analyzing 17 tree cores collected from Hawaiʻi Island, 2 out of 6 sampled trees (33%) had years of first growth match the planting years recorded in the forestry logs, thus indicating annual tree ring production. Moreover, there was an indication that two species (Cryptomeria japonica and Pseudotsuga menziesii) at two windward sites had corresponding tree ring growth. However, there were no strong and significant correlations between tree ring growth and temperature, rainfall, and cloud cover. Furthermore, tree ring growth did not respond to a combination of temperature, rainfall, and cloud cover as tested by a multiple linear regression model. Lastly, tree ring growth did not respond to strong El Niño events. Future studies should investigate the relationship between climate and tree ring growth in Hawaiʻi.