巨尾桉工业原料林下植物多样性与土壤因子的关系

采用野外调查与室内分析相结合的方法,研究了巨尾桉工业原料林下植物多样性、土壤因子的变化特征以及二者之间的关系。结果表明,物种丰富度指数是草本层最高,而Simpson指数,Shannon—Wiener指数和均匀度指数是灌木层最高。巨尾桉林地土壤水分含量的变化规律为:母质层淀积层腐殖质层,有机质、水解氮、有效磷和速效钾含量的变化规律为:腐殖质层淀积层母质层。腐殖质层、淀积层和母质层的土壤水分含量、有机质含量与灌木层或草本层丰富度指数、多样性指数和均匀度指数无显著相关性;腐殖质层速效钾含量与草本层Simpson指数极显著相关;淀积层速效钾含量与灌木层Simpson指数极显著相关;水解氮与灌木层及草本层以Simpson指数为基础的均匀度指数,以Shannon—Wiener指数为基础的均匀度指数极显著相关;母质层土壤各因子含量与灌木层或草本层多样性指数无显著相关。研究结果为巨尾桉林的可持续经营管理提供理论基础和科学依据。

Relationship Between Undergrowth Vegetation Species Diversity and Soil Factors in Industrial Raw Material Forests of Eucalyptus Grandis×E. Urophylla

Changes of soil factors and undergrowth vegetation species diversity indices, as well as their relationship, in the Eucalyptus industrial raw material forests of Yunnan Province are studied through filed investigation and laboratory analysis. Results show that species richness of herb layer is the highest, while Simpson index, Shannon-Wiener index and Evenness index of shrub layer are the highest. Meanwhile, soil moisture contents in different soil layers under the E. grandis×E. urophylla plantation show the order of parent material horizon> illuvial horizon> humus horizon. However, organic matter content, hydrolytic nitrogen, and available phosphorus and potassium decrease with depth and show the order of humus horizon> illuvial horizon> parent material horizon. Correlation analysis shows that species richness, biodiversity index and evenness index of shrub and grass layers are not significantly correlated with soil moisture and organic matter content in any soil layer. The K content of humus layer and Simpson diversity index of herb layer are significantly correlated. It is also true for the relationship between the K content of illuvial horizon and Simpson index of shrub layer. And there is a notable correlation between the N content and diversity index-based evenness index of shrub and herb layers. The soil factors of parent material and the diversity indices of herb and shrub layers are not correlated. The findings from the study may provide a theoretical basis and scientific evidences for the sustainable management of Eucalyptus industrial raw material forests.