桉树林取代马尾松林后不同更新方式对林下植物多样性的影响

Effects of Different Regeneration Methods on Understory Plant Diversity after Eucalyptus Replaced Pinus massoniana

关键词:  桉树人工林  物种组成  植物多样性  植苗更新  萌芽更新

Key words:  Eucalyptus plantation  species composition  plant diversity  seedling regeneration  germination regeneration

摘要:

为探究桉树(Eucalyptus spp.)林取代马尾松(Pinus massoniana)林后不同更新方式(植苗、萌芽)对林下植物多样性的影响，采用空间代替时间结合成对比较法，开展林下植物群落调查及土壤理化性质测定，分析不同林分林下灌草层的物种组成、重要值和多样性特征。结果表明：①4种林分林下植物共有49科99属121种，其中灌木层有35科65属83种，草本层有18科36属38种；桉树林取代马尾松林后，植苗更新及萌芽更新方式下，林下植物群落的物种组成均发生了显著变化。②桉树林取代马尾松林后，植苗更新桉树林均显著提高灌木层及草本层的Shannon-Wiener指数、Simpson指数和Pielou均匀度指数；而萌芽更新林分显著降低灌木层的物种丰富度，但显著提高草本层的物种丰富度、Shannon-Wiener指数和Simpson指数。植苗更新方式有利于桉树林灌木层物种的恢复和多样性的维持，萌芽更新方式则更有利于草本层植物物种的恢复和多样性的维持。③土壤含水量(Soil Moisture Content，SMC)和全氮(Total Nitrogen，TN)是影响4种林分灌木层植物物种组成的主要影响因子，土壤pH值、TN和全磷(Total Phosphorus，TP)是影响4种林分草本层植物物种组成的主要影响因子。在林地转变和经营时，可结合实际采用不同的更新方式恢复林下灌草植物物种丰富度和多样性，实现桉树人工林的可持续经营。

Abstract:

In order to explore the effects of different regeneration methods (seedling planting and germination) on the diversity of understory plants after Eucalyptus plantations replaced Pinus massoniana plantations,the spatial instead of temporal paired comparison method was used to investigate the understory plant community and determine the physical and chemical properties of soil,and analyze the species composition,importance value and diversity characteristics of the understory shrub layer in different stands.The results showed that: ①There are 49 families,99 genera and 121 species of understory plants in the four stands,among them,there are 83 species,65 genera and 35 families in the shrub layer,and 38 species,36 genera and 18 families in the herb layer.After the Eucalyptus plantations replaced the P.massoniana plantations,the species composition of the understory plant community changed significantly under the seedling regeneration and germination regeneration.②After Eucalyptus plantations replaced P.massoniana plantations,Eucalyptus plantations regenerated with seedling planting significantly increased Shannon-Wiener index,Simpson index and Pielou evenness index in the shrub layer and the herb layer;the species richness of the shrub layer was significantly decreased in plantations regeneration stand,but species richness,Shannon-Wiener index and Simpson index of the herb layer was significantly increased.The seedling regeneration method is beneficial to the restoration of shrub layer species and the maintenance of diversity in Eucalyptus forest.The germination regeneration method is more conducive to the restoration of herbaceous plant species and the maintenance of diversity.③Soil Moisture Content (SMC) and Total Nitrogen (TN) were the main factors affecting the species composition of shrub layer plants in the four stands,Soil pH value,TN and Total Phosphorus (TP) were the main factors affecting the species composition of herb layer plants in the four stands.In the transformation and management of plantations,different renewal methods can be used to restore the species richness and diversity of understory shrubs and grasses in combination with the actual situation,so as to realize the sustainable management of Eucalyptus plantation.