Abstract:

The plasticity of biomass allocation, morphology, light utilization and hydraulic features was compared between the Salix matsudana branches growing under the contrasting light environments. (1) Branch weight ratio(BWR) was higher in the branches growing under unshading condition and connecting to different branches under shading condition(Bhl) than that in the branches of the plants entirely growing under full sunlight(Bhh); BWR was lower in the branches growing under shading condition and connecting to different branches under unshading condition(Blh) than that in the branches of the plants entirely growing in shading condition(Bll), while leaf weight ratio followed the opposite direction.(2) There were no significant differences in morphology between Bhl and Bhh; leaf area ratio, specific branch length and leaves per branch length were higher in Blh than those in Bll. Thus, Blh had higher potential to capture light than Bll.(3) Canopy productivity indices in Bhl and Blh were larger than those in Bhh and Bll, respectively. This implied that light use efficiency of the S. matsudana branches was higher in heterogeneous than homogeneous light conditions.(4) Water saturated deficit and losing water coefficient were smaller in Bhl than those in Bhh, suggesting that Bhl had higher holding water and resistant drought ability than Bhh.

Key words: Salix matsudana, Biomass allocation, Light resource utilization, Hydraulic features