杉木林郁闭度对林下金佛山方竹生长的影响

Effect of Canopy Density of Chinese Fir Stand on the Growth of Understorey Chimonobambusa utilis

金佛山方竹是云南省昭通市竹产业发展的主要竹种之一,近年来种植面积不断增加,且多为林下种植,但在不同林分中金佛山方竹的生长存在着较大差异。调查了5种郁闭度(0.5、0.6、0.7、0.8、0.9)的杉木林下种植的金佛山方竹生长情况,结果显示,随着杉木林郁闭度的增加,金佛山方竹发笋量、笋地径、每丛株数、竹高及胸径等指标均呈下降趋势,而且不同郁闭度对各生长指标的影响达到显著水平。基于调查结果,提出了林下种植金佛山方竹的适宜郁闭度:当在商品林下种植时,上层乔木的郁闭度以0.6为最佳,当在公益林下种植时,上层乔木林郁闭度宜控制在0.6~0.7。

Chimonobambusa utilis is one of the main bamboo species that contributes to the development of bamboo industry in Zhaotong City,Yunnan Province.In recent years,its area of planting has been continuously increasing,and most of them are planted under high forest.However,there are significant differences in the growth of Ch.utilis in different high forest stands.The paper investigates the growth of Ch.utilis under the Chinese fir stands of five different canopy densities(0.5,0.6,0.7,0.8,0.9).The results show that as the canopy density of the Chinese fir stands increases,the number of bamboo shoots,shoot diameter,number of plants per cluster,culm height,and diameter at breast height of Ch.utilis show a downward trend,and the impact of different canopy densities on various growth indicators is significant.Based on the investigation,the paper proposes the suitable canopy density for the understorey planting of Ch.utilis,i.e.,when planting under commercial forests,the optimal canopy density is 0.6,and when planting under public welfare forests,the canopy density should be controlled between 0.6 and 0.7.