内蒙古半干旱地区不同人工林土壤因子与林下植物多样性的相关性

Correlation Between Soil Factors and Understory Plant Diversity in Different Plantations in Semi-Arid Regions of Lnner Mongolia

以内蒙古半干旱地区生态修复工程营造的人工林为研究对象,探究不同林分类型的林下植物多样性、土壤理化性质差异以及土壤因子与林下植物多样性的相关性,并通过搭建结构方程模型评估林分类型、土壤因子对林下植物多样性的影响。结果表明:不同林分类型的植物多样性、土壤理化性质存在显著差异(P<0.05),混交林的林下植物多样性指数、土壤理化性质指数均高于纯林(P<0.05)。多元回归分析结果表明:林分类型、土壤密度、最大持水量、土壤有机碳质量分数、土壤有机质质量分数、土壤全氮质量分数是影响林下植物多样性的主导因素。结构方程模型结果表明:林分类型、土壤理化性质对林下植物多样性分布均具有决定性作用(P<0.01)。其中,林分类型可通过调节土壤理化性质,间接影响林下植物多样性的分布,土壤化学性质也可通过对土壤物理性质的调节,间接影响林下植物多样性的分布。

Taking the plantation forests created through ecological restoration projects in the semi-arid regions of Inner Mongolia as the research object,this study explores the differences in understory plant diversity and soil physicochemical properties among different forest types,as well as the correlation between soil factors and understory plant diversity.A structural equation model was constructed to assess the impact of forest types and soil factors on understory plant diversity.The results showed that there are significant differences(P<0.05)in plant diversity and soil physicochemical properties among different forest types,with the diversity index and soil physicochemical index of mixed forests being higher than those of pure forests(P<0.05).Multivariate regression analysis reveals that forest types,soil density,maximum water holding capacity,soil organic carbon content,soil organic matter content,and soil total nitrogen content are the main factors influencing understory plant diversity.The structural equation model results demonstrate that forest types and soil physicochemical properties play a decisive role in the distribution of understory plant diversity(P<0.01).Specifically,forest types can indirectly impact the distribution of understory plant diversity by adjusting soil physicochemical properties,and soil chemical properties can also indirectly influence the distribution of understory plant diversity through the regulation of soil physical properties.