武功山芒根系垂直分布及其与土壤养分的关系

摘要

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.%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0-16 cm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-1.5559(R2=0.89114),y=169.9x-0.88205(R2=0.40836),y=22.397x-0.92614(R2=0.36457);0-40 cm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(P〈0.05),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(P〈0.05).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.