郁闭度对马占相思人工林下植物多样性的影响

Effects of Canopy Density on Understory Plant Diversity of Acacia mangium Plantations

在3种不同郁闭度马占相思人工林下,通过样方调查测定,对其在东莞地区林下的生长情况及多样性进行分析,以期为人工林的抚育间伐管理提供科学依据,并筛选出适宜东莞林下种植的品种。结果表明,林下植被共有13种,分属8科10属;F3林下植被的平均树高、平均地径等生长指标最优;各郁闭度林下植物优势种明显且变化较小,大多为阴性、耐荫性或适应性极强的植物。多样性分析结果表明,植物丰富度指数以F1最多;F2的Shannon-Wiener指数和均匀度指数最大。综上,0.45郁闭度最有利于林下植物的生长,0.65郁闭度次之;0.55郁闭度林下植物丰度波动小,群落相对稳定;朱砂根、假鹰爪、草珊瑚、黄杨能较好地适应东莞,但对其生长繁育仍需进一步观察。

This paper analyzed the growth and diversity of Acacia mangium under three different canopy densities in Dongguan area by means of sample investigation and determination,in order to provide scientific basis for the management of thinning of plantation,and screen out the varieties suitable for planting in Dongguan area.The results showed that there were 13 understory species,belonging to 8 families and 10 genera.The growth index of F3 understory vegetation,such as average tree height and average ground diameter,was the best.The dominant species of the understory plants of each canopy density are obvious and the change is small.Most of them are negative,shade-tolerant or adaptable plants.The results of diversity analysis showed that F1 was the most abundant plant index.The Shannon-Wiener index and evenness index of F2 were the largest.In conclusion,0.45 canopy density is the most favorable for the growth of understory plants,followed by 0.65 canopy density.0.55 canopy density understory plant abundance fluctuation is small,the community is relatively stable;Root vermilion,false eagle’s talon,grass coral and boxwood can better adapt to Dongguan,but their growth and reproduction still need further observation.