武功山芒根系垂直分布及其与土壤养分的关系

根系是植被-土壤的媒介,研究根系与土壤关系有助于掌握养分元素的生物化学循环过程,从而为植被恢复提供理论依据。本研究以武功山芒(Miscanthus sinensis)为研究对象,采用土壤养分常规分析法测定土壤养分,采用根系扫描法测定根系参数(根系生物量密度、根长密度和根表面积密度),进一步采用相关分析、回归分析等统计方法对二者之间的相互关系进行研究。结果表明,根系参数随着土壤深度的增加而减少,80%左右的根系主要分布在0-16cm土层;根系参数与土壤深度符合幂函数关系,根系生物量密度、根长密度、根表面积密度与土壤深度的幂函数方程分别为y=238x-1.555 9(R2=0.891 14),y=169.9x-0.882 05(R2=0.408 36),y=22.397x-0.926 14(R2=0.364 57);0-40cm土层范围内,随着土壤深度的增加土壤有机质、土壤全氮、土壤全磷、土壤有效磷和土壤速效钾含量显著下降(P0.05),土壤全钾、土壤碱解氮含量呈现出轻微的波动趋势;土壤养分与根系参数有不同程度的相关性,其中,与根系参数相关性最强的养分因子是土壤有机质、土壤全氮和土壤全钾(P0.05)。因此,在表层土壤合理施肥有利于芒根系生长发育及其对养分的吸收。

Vertical distribution characteristics of Miscanthus sinensis roots and its relationship to soil nutrients in the Wugong Mountains

Roots are structures that connect vegetation to the soil.Studies of the relationship between roots and soil help understand the biochemical cycle of nutrient elements and provides a theoretical basis for vegetation restoration.In the present study,soil nutrients were studied by normal analysis methods using Miscanthus sinensis Anderss as a model plant from the Wugong Mountains.Root parameters were determined by a root scanner.Correlation analysis and regression analysis were performed to examine the relationship between soil and roots.The results demonstrated that root parameters decreased with an increase in soil depth.Approxi-mately 80% of the roots were distributed in the 0 to 16 cm soil layer.Power functions were fitted between dif-ferent soil layers and root parameters (biomass density,root length density,and root surface area density), and were y=238x-1.5559 (R2=0.89114),y=169.9x-0.88205 (R2=0.40836)and y=22.397x-0.92614 (R2=0.36457),respectively.The content of soil organic matter,total N,total P,available P,and available K de-creased with depth of soil in the 0 to 40 cm soil layer whereas the content of total K and available N fluctuated slightly.Correlations between soil nutrients and root parameters differed among nutrients,whereas organic matter,total N,and total K correlated positively with root parameters (P〈0.05).Therefore,fertilizing effec-tively in the top soil surface layer is beneficial for root development and nutrient uptake.