Fine Root Characteristics and Relationship among Morphology,Biomass and Tissue N and C Contents of Aleurites montana Plantation

Taking Aleurites montana plantation as the object,measured root morphology,biomass,carbon and nitrogen concentration of the first five orders roots. Analyzed differences between different diameter,root orders and morphological parameter,relationships of fine root biomass,C and N concentration with fine root orders by means of regression were discussed. The results showed that the root tips,accumulative root length and surface area of root d≤1mm accounted for the majority of total roots,accounting for the total respectively as 99. 66%,88. 42%,69. 82%; Along with the fine root ascending from the first to fifth order,root diameter increased from 0. 86 mm to1. 35 mm,tissue density rose from 0. 11 g / cm3 to 0. 47 g / cm3,root surface area density decreased from 0. 46 m2/m3 to 0. 085 m2/ m3,specific root length reduced from 32. 04 m/g to 16. 41 m/g; Fine root diameter,specific root length,surface area density,tissue density,biomass with root order can be represented by quadratic,exponential,linear,cubic or Gaussian peak functions; From the first to fifth fine root order contribution to the total biomass respectively as 18. 7%,30. 9%,27. 1%,16. 6%,6. 7%; Fine root tissue N concentration reduced from 16. 73 mg / g to 11. 83 mg / g,C concentration increased from 454. 97 mg / g to 494. 43 mg / g with ascending fine root order; Moreover,C / N ratio in roots was mainly affected by tissue N rather than tissue C concentrations,the former affected reached 93%,the later only reached 50%; These results suggested that there are systematic differences in fine root morphology and structure,biomass,and tissue carbon and nitrogen contents among different root orders,this provides an important basis for understanding fine root architecture and function of Aleurites montana.