AbstractComparison of basal area increments of paired healthy and declined oak trees shows a marked disjuncture beginning in the early 1950′ at 3 of 4 sample locations across the southeastern United States. An argument is presented that the change in growth was caused (or accelerated) by a series of severe regional droughts in the early 1950′s that impacted the trees which then responded by forming two distinct populations consisting of: 1. relatively healthy trees, and 2. declined trees. Both populations produced less annual basal area increment after several subsequent short‐term droughts, but marked crown deterioration and death appeared in the declined population after a moderately severe drought in the early 1
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