SUMMARY: Forests in western North Carolina receive some of the highest nitrogen deposition inputs in the southeastern U.S. Further, this area has also experienced a severe drought during the past five years. Chronic inputs of nitrogen deposition, stand density, and drought conditions may result in systematic changes in tree species and forest floor dynamics, thus making these species more susceptible to southern pine beetle infestation. To test this hypothesis, researchers will measure and examine the relationships between wood tissue Δ (‰), a measure of water stress, and variables that respond to chronic nitrogen deposition (e.g., basal area tree growth and forest floor and foliar chemistry) in two live and two dead high elevation spruce plots on Mount Mitchell, North Carolina. Results from this study will help to determine if Mount Mitchell spruce forests are water stressed and/or nitrogen saturated. Results will further determine if water stress and nitrogen saturation predisposed these forests to southern pine beetle attack and subsequent species mortality. 

STATUS: Ongoing

PROGRESS: A manuscript has been drafted and will be submitted to Canadian Journal of Forest Research for publication.

CONTACT:

• Steve McNulty, EFETAC Southern Global Change Program Team Leader, steve_mcnulty@ncsu.edu or 919-515-9489
• Johnny Boggs, EFETAC Southern Global Change Program Biological Scientist, jlboggs@ncsu.edu or 919-513-2973