长白山两种森林类型土壤颗粒有机碳和黑碳分布特征

目的]量化长白山原始阔叶红松林和杨桦次生林土壤颗粒有机碳和黑碳含量及分布特征,为研究东北森林土壤有机碳分布和积累提供依据。方法]采用粒径分组方法测定原始阔叶红松林和杨桦次生林土壤表层(A_(11))和亚表层(A_(12))颗粒有机碳(POC)和黑碳(BC)含量,分析其与土壤基本性质(有机质、含水量、p H值、粘粒和团聚体等)的关系。结果]表明:(1)两种森林类型土壤A_(11)和A_(12)POC含量分别为31.89 88.00、5.25 19.45 g·kg~(-1),BC含量分别为8.43 22.40、3.39 12.10 g·kg~(-1),二者随土壤深度增加而显著下降(p0.01)。(2)森林类型显著影响土壤POC和BC,表现为杨桦次生林原始阔叶红松林。(3)两种森林类型土壤POC与土壤有机质、含水量、水稳性团聚体均显著相关,与p H值、粘粒相关性不显著;BC与土壤p H值、粘粒和团聚体相关性均不显著,与含水量显著相关,与有机质仅在A_(11)显著相关。(4)土壤POC和BC显著相关(p0.01)。结论]在长白山地区森林类型显著影响土壤POC和BC含量,杨桦次生林土壤POC和BC显著高于原始阔叶红松林,很大程度上与森林的采伐和火烧有关。两种森林类型土壤POC和BC分布格局是土壤物理化学性质综合作用的结果。

Distributions of Soil Particulate Organic Carbon and Black Carbon of Two Forest Types in Changbai Mountain

Objective]To investigate the distribution of soil particulate organic carbon and black carbon in the virgin broad-leaved Korean pine forest and secondary poplar-birch forest in Changbai Mountain. Method]The content and distribution characteristics of POC and BC in soil were quantified by using particle-size fractionation method. The correlations of POC, BC and soil basic physical and chemical properties (soil organic matter, soil water content, soil pH, water stable aggregates, and so on) were also analyzed. Result]The results showed that (1) The POC in soil A₁₁ and A₁₂ horizon varied from 31.8988.00 and 5.2519.45 g·kg^-1, respectively, while the BC in soil A₁₁ and A₁₂ horizon varied from 8.4322.40 and 3.3912.10 g·kg^-1, respectively, both decreased quickly with soil depth; (2) The soil POC and BC were both affected by forest type, showing that secondary poplar-birch forest > virgin broad-leaved Korean pine forest (p<0.01); (3) Extremely obvious positive correlations were observed between the POC and soil organic matter, soil water content and water stable aggregates (p<0.01), while the correlations between the POC and soil pH and clay content were not found; The correlations between the soil BC and soil pH, soil clay content and soil water stable aggregates were not observed, while significantly positive correlation was found between the soil BC and soil water content.Conclusion]In Changbai Mountains, the distributions of soil POC and BC were significantly affected by forest types, the amounts of POC and BC in the secondary poplar-birch forest were greater than that in the virgin broad-leaved Korean pine forest, which could be explained by the deforestation and the forest fire. The distribution of POC and BC in both forests was the comprehensive results of soil basic physical and chemical properties.