长白山原始阔叶红松(Pinus koraiensis)林及其次生林细根生物量与垂直分布特征

Fine root biomass and its depth distribution across the primitive Korean pine and broad-leaved forest and its secondary forests in Changbai Mountain,northeast China

以我国东北长白山自然保护区内同一海拔梯度的原始阔叶红松林及其次生林——白桦山杨成熟林和白桦山杨幼林为对象,采用土钻取样法对不同演替阶段细根生物量的变化、细根垂直分布规律及其影响因子进行系统地研究。研究结果表明,在原始阔叶红松林的正向演替过程中,林地细根的总生物量逐渐增加,其中主要乔木细根的生物量逐渐增加,而灌木和草本细根的生物量则逐渐降低。在演替过程中,细根的垂直分布逐渐加深。在长白山地区,3块林地中细根生物量的组成分布受林分植被组成的影响;细根的垂直分布与土壤容重、水分含量以及不同土层中C、N含量存在一定的相关性,但与土壤温度则不存在相关关系。

We measured the fine root biomass and its depth distribution of a more than 200-year-old primitive Korean pine and broad-leaved forest and its two 20- and 80-year-old secondary Populus davidiana and Betula platyphylla forests in the Changbai Mountain, northeast China. The soil core method was used for root sampling. The results indicated that the total fine root biomass increased with stand age, ranging from 561.8 g/m^2 and 674.1 g/m^2 for 20-year-old and 80-year-old secondary forests, respectively, to 827.8 g/m^2 for the old primitive mixed forest. Fine root biomass increased in dominant tree species but decreased in the undergrowth other woody species and herbs. Along the successional development from young to old stands, the rooting depth exponentially increased though most of fine roots were distributed in the 0 -- 10 cm soils. In the forests, the effects of soil bulk density, soil moisture, and soil organic C and N contents on fine-root depth distribution were more significant than that of soil temperature.