邻株低磷竞争处理对杉木幼苗生长的影响

以南方林区广泛种植杉木无性系为研究对象,利用室内沙培模拟装置,设置缺磷(0 mg/kg KH2PO4)、低磷(6 mg/kg KH2PO4)和正常供磷(12 mg/kg KH2PO4)3个供磷水平,构建邻株磷竞争环境.结果表明:邻株低磷竞争处理可明显促进杉木苗高生长,但竞争条件下,缺磷处理抑制杉木苗高生长.不同邻株磷竞争处理条件下杉木地径生长差异未达显著水平.在邻株低磷竞争处理条件下杉木根系长度、表面积、直径、体积等形态指标增量最大.

Effect of Competition for Low Phosphorus on Growth of Chinese Fir Seedlings

Objected with Chinese fir planted widely in South China recently,using the sand-culture indoor simulation pots supplying with three different P levels,which were 0 mg /kg,6 mg /kg and 12 mg /kg of KH2PO4respectively,a competition between neighbor trees environment for P was constructed. Main results were as follows. The treatment of competition for low P could obviously promote the height growth of seedlings of Chinese fir,but P deficiency under competition stress inhibited the growth. Effects of all treatments with different supplying P levels and whether competition or not on root collar diameter growth of Chinese fir were not significant,but the synergistic effect on the ground diameter growth had a certain influence. Increments of all the roots morphological indexes,including length,surface area,diameter and volume,were large under competition for low P.