关键词: 平茬高度, 伐桩萌枝, 森林萌蘖更新, 营养元素积累和分配, 中国沙棘(Hippophae rhamnoides ssp. sinensis)

Abstract: As a main method of forest regeneration, stump sprouting plays a crucial role in forest community succession and vegetation restoration. We aimed to investigate the response of stump sprouting capacity to stubble height, unveil its nutrient-accumulation and allocation strategies and determine the appropriate stubble height most favorable for stump sprouting of Hippophae rhamnoides ssp. sinensis. Fifteen-year plants with signs of premature aging were coppiced at 0, 10 and 20 cm from the ground level. With the increase in stubble height, the number of stump sprouts increased linearly, and the survival rate decreased linearly. The height, diameter and cluster width of stump sprouts first increased, reached the highest level at a stubble height of 10 cm and then decreased. The contents and reserves of N, P, K, Ca and Mg showed a similar trend as the growth, positively correlating with each other. Compared with the control (no coppicing), the coppicing increased the nutrient element allocation of leaves, vertical roots and horizontal roots. Magnesium plays an important role in stump sprouting. The findings suggest that coppicing changed the accumulation ability and allocation pattern of nutrient elements, and further affected the sprouting ability of stumps. The best stubble height for stump sprouting and nutrient accumulation potential was 11.0-14.0 cm estimated by the regression.

Key words: stubble height, stump sprouting, forest sprout regeneration, nutrient accumulation and allocation, Hippophae rhamnoides ssp. sinensis