Answers are grounded in this paper and cite their sources.
Richard T. Busing, Edward E. C. Clebsch, Christopher C. Eagar, Eric F. Pauley, Two Decades of Change in a Great Smoky Mountains Spruce-Fir Forest, Bulletin of the Torrey Botanical Club, Vol. 115, No. 1 (Jan. - Mar., 1988), pp. 25-31
No takes yet. Share an insight, caveat, or question.
Busing et al. (1988) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: