土壤水盐因子对盐湖防护林体系植被群落分布的影响

Effects of Soil Water and Salt Factors on Vegetation Community Distribution in a Salt Lake Shelterbelt System

[目的]以内蒙古自治区吉兰泰盐湖防风固沙林体系为研究对象,探讨土壤水盐因子对盐湖防护林体系植被群落分布的影响,为该盐湖防护林抚育和管理提供理论依据。[方法]应用数量分类和排序方法,探讨土壤水盐因子对吉兰泰盐湖防护林体系植被群落分布特征的影响。[结果]双向指示种分析将防护林体系共8科16属16种植物划分为6群落类型,其中,以白刺为优势种的植被群落土壤水盐含量与其他群落类型均存在显著差异,不同群落类型下土壤pH值差异并不显著(p>0.05);双向指示种分类结果很好地反映了植物种及植物群落类型与土壤水盐因子的关系,并在CCA排序图上得到较好的验证。除群落Ⅰ外,群落Ⅵ,Ⅴ,Ⅳ,Ⅲ,Ⅱ沿土壤水盐含量降低的方向依次分布,且人工植被群落分布较为集中,表明人工植被配置对防护林植被分布具有一定的影响。环境因子显著性检验结果表明,Na^(+)、Mg^(+)和土壤含水量对防护林体系植被群落分布影响达到显著水平。[结论]就土壤水盐因子而言,土壤Mg^(2+),Na^(+),SO4^(2-)和土壤含水量是影响防护林体系植物群落分布的主要因素。

[Objective]The effects of soil water and salt factors on the distribution of vegetation communitis in the shelterbelt system of Jilantai Salt Lake were investigated,in order to provide theoretical basis for the maintenance and management of the shelterbelt in the salt lake.[Methods]The influences of soil water and salt factors on the distribution characteristics of vegetation community in Jilantai Salt Lake shelter forest system were studied by using quantitative classification and ordination method.[Results]There were significant differences in soil water and salt content between Nitraria tangutorum community and other community types,and there was no significant difference in soil pH value between different community types(p>0.05).The results of TWINSPAN showed that the relationship between plant species and plant community type was very good.The relationship between soil water and salt content was well verified in CCA ordination chart.Except for communityⅠ,communityⅥ,Ⅴ,Ⅳ,ⅢandⅡwere distributed along the decreasing direction of soil water and salt content,and the distribution of artificial vegetation community was relatively concentrated,which indicated that artificial vegetation configuration had a certain impact on the distribution of shelterbelt vegetation.The results of significance test of environmental factors showed that Mg^(2+),Na+and soil water content had a significant effect on the distribution of vegetation community in shelterbelt system.[Conclusion]In terms of soil water and salt factors,soil Mg^(2+),Na^(+),SO^(2-)_(4) and soil water content are the main factors affecting the plant community distribution of shelterbelt system.