Effect of Shading on Growth and Biomass Allocation of Illicium difengpi Seedlings

Abstract:

In order to understand the effect of light intensity on the growth and biomass allocation of Illicium difengpi seedlings, the changes in morphological characteristics and biomass of seedlings at different classes were studied under different shading treatments. The results showed that the plant height, crown width and mean leaf area of seedlings under shading were significantly higher than those under control, while the specific leaf area decreased significantly with increasing of light intensity. The root length of seedlings with different classes under full light were significantly higher than those under shading, except for 50% shading of I-class seedlings. With increasing of light intensity, the root biomass ratio and root to crown ratio of seedlings at all classes increased significantly, and the leaf biomass ratio decreased significantly; seedlings at different classes showed strong adaptability to both high and low light environments, but the total biomass was the biggest under 50% shading, and smaller under full light and 85% shading. The size of seedlings under shading was positively correlated with their initial size, while the difference between II-and I-class seedlings was small, and the growth of III-class seedlings was poor. The number of I-class seedlings was less than 10% under artificial nursery conditions, and the poor seedling quality superimposed on the harsh environment of karst summits might be an important reason for the limitation of its field seedling regeneration. Therefore, it was advisable to use first and secondary seedlings in field regression and artificial cultivation, and to control the light intensity at about 50% light transmission.

Key words:Illicium difengpi;Shading;Seedling grade;Biomass;Ecological adaptability