Effects of Stump Diameter and Stump Height on Sprouting in Quercus phillyraeoides

Abstract

To examine vegetative regeneration in large-diameter Quercus phillyraeoides trees, we investigated the occurrence of sprouting 1-3 years after logging and their survival after 5-6 years in a clear-cutting area. We surveyed six stands, divided into two groups according to average stump diameter: 1) smaller-diameter stands and 2) large-diameter stands: the former was typical in their size and age for traditional use to make charcoal, and the latter was older than typical stands. The sprouting ratio was high in the typical stands at the beginning and end of the study, whereas the large-diameter stands exhibited a lower sprouting ratio at the end of the study. In the large-diameter stands, the sprouting rate decreased as the stump diameter increased, and as the stump height increased between the beginning and end of the study. No peak in stump diameter was found to maximize the number of sprouts, while a difference in stand age affected sprout regeneration. The number of sprouts increased with age, while the number of sprouting stumps, maximum sprout height, and sprout diameter decreased with increasing age. Therefore, Q. phillyraeoides has high sprouting ability, but the sprouting ability decreases with age and the number of non-sprouting individuals increased. These findings indicate that the conventional management practice of cutting trees 6-12 cm in diameter can benefit greatly from the sprouting ability of Q. phillyraeoides. Our results suggest that when stump diameter is large, reducing the stump height could enhance survival after cutting in this species.