不同石漠化治理模式下群落的植物组成及多样性

Species Composition and Diversity in Communities of Different Combating Rock Desertification Models

关键词:  石漠化  造林  顶果木  降香黄檀  纯林  混交林  物种多样性

Key words:  rock desertification  afforestation  Acrocarpus fraxinifolius  Dalbergia odorifera  pure plantations  mixed plantations  species diversity

摘要:

[目的]了解不同石漠化治理模式下,群落物种组成及多样性的恢复格局和过程。[方法]通过2种树种(顶果木、降香黄檀)、3种治理模式(顶果木纯林、降香黄檀纯林、顶果木×降香黄檀混交林)的造林试验和群落生态调查,研究不同石漠化治理模式下群落的物种组成、重要值及多样性演变规律。[结果]经过4年的恢复,3种不同治理模式下灌木层和草本层的物种组成发生显著变化,特别是优势种和共优势种。一些入侵植物如鬼针草、小飞蓬、酢浆草、飞机草、土牛膝、胜红蓟等的数量有所增加,特别是鬼针草,其重要值(10.35~36.32)分别是灌丛(4.44)的2.33~8.18倍。与灌丛(对照)比较,3种不同治理模式群落的植物物种丰富度没有显著差异,但植物多样性指数和均匀度指数存在显著差异。[结论]2种豆科植物和3种治理模式具有相近的治理效果,但混交林治理模式对植物多样性指数和均匀度指数的作用相对较优。在岩溶退耕地和灌丛地实施人工造林可以加速植被的恢复和重建,短期内显著改变群落的物种组成和结构,但在一定程度上存在着外来植物入侵风险。

Abstract:

[Objective] The objective of this study was to understand the restoration pattern and process of species composition and diversity in communities of different combating rock desertification models.[Methods] An afforestation experiment with two tree species (Acrocarpus fraxinifolius and Dalbergia odorifera) and three combating rock desertification models (pure A.fraxinifolius plantations, pure D.odorifera plantations and mixed A.fraxinifolius×D.odorifera plantations) was conducted and the plant communities in these combating models were investigated to reveal the dynamics of species composition, importance value and diversity in different control models.[Results] After 4 years restoration, significant changes existed in plant species composition, especially the dominant and co-dominant species, of shrub and herbaceous layers in different combating models.The numbers of several invasive plants, such as Biden spilosa, Conyza canadensis, Oxalis corniculata, Eupatorium odoratum, Achyranthes aspera, Ageratum conyzoides, increased.The importance value of Biden spilosa(10.35~36.32) was 2.33~8.18 times of that in the shrub (4.44).Compared with the shrub, there was no significant difference in species richness in the three combating models.While significant difference existed in plant species diversity and evenness index.[Conclusion] The control effects of the two legume tree species and three models were similar.The mixed planting model had superior effects on plant species diversity and evenness index than the other models.Afforestation at abandoned farmland and shrub in karst area could accelerate vegetation restoration and reconstruction, significantly change the species composition and community structure in short term, but also emerge plant invasion rick to some extent.