Decadal-Scale Trends in Forest Succession and Climatic Sensitivity in a Red Spruce-Fraser Fir Forest at Roan Mountain, Pisgah and Cherokee National Forests

I used dendrochronological techniques to investigate the temporal stability of a climate signal in relation to successional processes and disturbance events in the heavily disturbed red spruce (Picea rubens Sarg.) and Fraser fir [Abies fraseri (Pursh) Poir.] forest of Roan Mountain, Tennessee and North Carolina. I collected increment cores from all trees within six 0.05 ha plots located in spruce-fir co-dominant stands. I developed a red spruce tree-ring chronology from cores collected in my sampling plots and from trees located elsewhere in the study area. To test the stability of the climate-tree growth relationship, I performed statistical correlation within moving intervals using DendroClim 2002 software. Changes in forest structure coincided with stand-wide disturbance events such as balsam woolly adelgid (Adelges piceae Ratz.) infestation and widespread early twentieth-century logging. I detected shifts in climatic sensitivity during periods of changing forest composition following disturbances. Notably, a significant shift in red spruce temperature sensitivity occurred during the 1940s, coinciding with a period of aggressive logging. Red spruce climatic sensitivity was often sporadic and fluctuating in signal strength, leading to the hypothesis that stand dynamics may play a larger role than climate in limiting spruce tree growth in a frequently disturbed, closed canopy forest.