杉木人工林及林下植被细根生物量和形态分布特征

摘要

采用土钻法对福建三明杉木人工林样地进行根系采样，主要分析了0～80om土层杉木及林下植被≤1mm和1～2mm细根的生物量及形态特征，结果表明：0—80cm土层内杉木和林下植被≤1mm细根生物量分别为191．1g／m^2、32．83g／m^2，1—2mm细根分别为207．5/m^2、10．86g／m^2；≤1mm细根根长分别为5059．67m／m2、1076．27m／m2，1～2mm细根根长分别为962．87m／m^2、52．23m／m^2；≤1mm细根表面积分别为24．62m^2／m^2、3．41m^2／m^2，1—2mm细根表面积分别为3．39m^2／m^2、0．15m^2／m^2．林下植被≤1mm细根的生物量、根长及表面积占其总细根生物量、总根长和总表面积的比例均远高于杉木的．杉木人工林中，杉木≤1mm细根的比根长大于林下植被，而组织密度则小于林下植被；杉木1～2mm细根的比根长略小于林下植被，组织密度也小于林下植被．杉木和林下植被各个径级细根生物量的垂直分布格局基本一致，大致表现为随土层增加呈减少的趋势；根长和表面积垂直分布规律并不明显，但均表现出表层土壤大于底层土壤．各个土层杉木细根的生物量、根长和表面积所占比例明显大于林下植被．0—10cm土层中≤1mm细根林下植被生物量、根长、表面积所占总的生物量、根长、表面积的比例大于杉木．%Soil coring was used to investigate the biomass and morphologic features of the mm and 1 -2 mm in diameter of 0 - 80 cm soil layer for Chinese fir plantation in Sanming roots ≤ 1 , Fujian. The results showed that： the biomass of the roots ≤ 1 mm in diameter for Chinese fir and understory vegetation was 191.1 g/m^2, 32. 83 g/m^2 respectively, the biomass of the roots 1 -2 mm in diameter was 207.5 g/m^2, 10. 86 g/m^2 respectively ; the root length of the roots ≤ 1 mm in diameter for Chinese fir and understory vegetation was 5 059.67 m/m^2, 1 076. 27 In,/m^2 respectively, the root length of the roots 1 - 2 mm in diameter was 962. 87 m/m^2, 52. 23 m/m^2 respectively ; the surface area of the roots ≤1 mm in diameter for Chinese fir and understory vegetation was 24. 62 m^2/m^2, 3.41 m^2/m^2 respectively, the surface area of the roots 1 - 2 mm in diameter was 3.39 m^2/m^2, 0. 15 m^2/m^2 respec-tively. The proportion of biomass, root length and surface area accounted for the total of the roots ≤ 1 mm in diameter for understory vegetation was far above Chinese fir. As for the specific root length of the roots ≤ 1 mm, Chinese fir was greater than understory vegetation, for the tissue density, understo- ry vegetation was greater than Chinese fir; for the specific root length of the roots 1 - 2 ram, Chinese fir was slightly less than understory vegetation, for the tissue density understory vegetation was greater than Chinese fir. The vertical distribution of fine root biomass for Chinese fir and understory vegetation decrease with soil depth ; the vertical distribution of fine root length and surface area were not obvious, but all represent that the surface soil was greater than subsoil. The proportion of biomass, root length,surface area of each soil layer showed ： Chinese fir was greater than understory vegetation. The propor- tion of biomass, root length and surface area of the roots ≤ 1 mm in diameter accounting for the total in 0 - 10 cm soil layer showed that understory vegetation was greater than Chinese fir.