Assessing Vulnerability of American Holly (Ilex opaca) Trees in Coastal Maritime Forests of N.Y. and N.J.
Coastal maritime forests in northeastern USA are mostly fragmented and currently threatened by climate change. This study focuses on American holly (Ilex opaca) trees located in the coastal maritime forests of Sandy Hook, N.J. and Fire Island, N.Y. to better understand how vulnerable and resilient these forests are to future climate scenarios. There are few published studies that use tree-ring methods in the maritime forests of N.J. and dendrochronological research on holly species has just begun being explored. Our objectives are to evaluate the impacts of sea level rise, tropical cyclones, and saltwater inundation on northeastern coastal forests by analyzing ring damage and growth suppression patterns. We sampled living trees and retrieved cross sections from downed trees from each study site. Due to the severity of recent storms, this study has become increasingly relevant and important in creating necessary foundational research on these unique and rare forests. American holly chronologies are currently being constructed using rigorous cross-dating techniques. Early indications show a sharp decline in growth rate the year following prolonged saltwater inundation due to Superstorm Sandy in 2012. Once completed, we will compare the holly tree-ring records with site-specific meteorological data to determine the climate signal and climate variables that impact tree growth. We will also evaluate the oxygen isotopic composition of each ring in several of the older tree specimens to better understand the signature of atmospheric dynamics. Our oldest sample dates back to the late 1700’s, allowing us to provide extended insights into forests’ response to climate change and storm frequency in the N.Y. metropolitan region.