带状改造对川中丘陵区柏木人工林林下植物多样性的影响

Effects of Strip Reform on Understory Plant Diversity of Cupressus funebris Plantations in Hilly Areas of Central Sichuan

对川中丘陵区35 a～40 a生、天然更新差的柏木纯林进行了不同宽度的带状采伐实验,目的是研究不同采伐带宽对柏木林下灌草物种多样性以及柏木生长量的影响。分别于2011年、2012年、2014年和2016年调查了保留带林下植物物种多样性以及柏木年均生长量。数据分析显示,不同采伐带对灌木层、草本层的生物多样性指数、林分生长量均产生了不同影响,随年份的增加8 m、10 m保留带林下灌木物种多样性指数逐渐高于其他带宽,且显著高于对照(P<0.05),而草本物种多样性指数相对于灌木物种多样性呈逐渐降低趋势;保留柏木年均株高、年均胸径生长量显著大于对照(P<0.05),其中8 m、10 m带最高。据以上结果,就本实验的5种处理而言,对于改良低效柏木人工林林下植物多样性适宜的采伐带宽度应为8 m和10 m。

In order to study the effects of different cutting bands on the species diversity and the growth of cypress trees in the pure cypress forest with 35~40 years old and poor natural regeneration in the hilly area of central Sichuan.In 2011,2012,2014 and 2016,investigations were made on the species diversity of understory plants and annual growth of cypress trees.The data analysis showed that different cutting zones had different effects on the biodiversity index and stand growth of shrub and herbage layers.With the increase of years,the species diversity index of 8 m and 10 m wide shrubs was higher than that of other bandwidth,and significantly higher than that of the control group (P<0.05),but the diversity index of herbaceous species showed a gradual decrease relative to the shrub species diversity.Average annual growth of plant height and DBH of the reserved cypress were significantly higher than those of the control group (P<0.05).The highest annual growth of 8 m and 10 m wide reserved cypress was found in the reserved cypress.For the five treatments,the suitable cutting bands for improving the plant diversity under the inefficient cypress plantation should have the width of 8 m and 10 m.