Scientific Note: Loblolly Pine Traumatic Resin Ducts Serve as Indicators of Cool-Season Weather Events at Nags Head, North Carolina


Avery A. Catherwood

Additional Authors:

Paul A. Knapp and Tyler J. Mitchell




traumatic resin ducts, loblolly pine, dendroclimatology, wood anatomy

We present a method for recording cool-season (mid-October–May) weather events near Nags Head, North Carolina. Standardized traumatic resin duct frequency (TRDsf) formations in loblolly pine (Pinus taeda L.) were determined from earlywood radial growth samples using the number of traumatic resin ducts that occur in response to stressful weather events. Based on a sample of 39 cores collected at Nags Head Woods Ecological Preserve during summer 2020, we tested if the occurrence of traumatic resin ducts in the earlywood was caused by late-season tropical cyclones, mid-latitude windstorms, and snow/ice storms and served as a proxy for extreme weather frequency during 1950–2019. TRDsf was significantly related to years that had at least one documented cool-season weather event. The average TRDsf in a non-storm year was 1.95 while the average for a storm year was 2.99. Further, TRDsf was correlated with the number of cool-season weather events and there was no tree age-related bias to storm-event detection. These results support using TRD frequency to reconstruct cool-season storm history beyond current climate records at locations where older (150+ years) stands of loblolly pine forests exist along coastal North Carolina.