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2010年7月,采集长白山北坡5个典型植被带(阔叶红松林、明针叶林、暗针叶林、岳桦林和高山苔原)林下土壤,研究了不同海拔梯度下森林土壤的中性单糖分布、数量及其影响因素,并结合中性糖来源差异探讨土壤有机质的生物化学积累机制.结果表明:在长白山不同海拔梯度下,森林土壤的中性糖差异显著,中性糖来源碳在土壤有机碳(SOC)中的相对含量为80.55～170.63 mg.g-1,并且随海拔升高呈递增的趋势.采用多元线性拟合分析发现,生长季平均气温是影响土壤中性糖相对含量的主要因素,低温有助于中性糖的积累.土壤中(半乳糖+甘露糖)/(阿拉伯糖+木糖)为1.62～2.28,且随海拔升高呈增加趋势,说明土壤中微生物来源中性糖的贡献随海拔升高逐渐增加.微生物熵随海拔升高而降低,说明低温条件下微生物活性下降而对外源碳的利用效率提高,植物残体被微生物分解转化后,以微生物同化物的形式固存于土壤中,从而增加了微生物来源中性糖的比例.
In July 2010, five typical vegetation belts (broad-leaved Korean pine, bright coniferous forest, dark coniferous forest, mountain birch and alpine tundra) were collected from the northern slope of Changbai Mountain. The effects of different altitudes on forest soil The results showed that there was a significant difference in the neutral sugar content of forest soils under different altitudes of Changbai Mountain, The relative content of carbon in soil organic carbon (SOC) was 80.55-170.63 mg.g-1, and showed an increasing trend with the elevation increasing.Using multivariate linear fitting analysis, it was found that the average temperature in growing season was the most important factor influencing soil neutrality The main reason for the relative content of sugar, low temperature is conducive to the accumulation of neutral sugars in the soil (galactose + mannose) / (arabinose + xylose) 1.62 ~ 2.28, and increased with increasing altitude, indicating that soil The contribution of neutral sugars from medium microorganism increased with the increase of altitude.The microbial entropy decreased with the increase of altitude, which indicated that the activity of exogenous carbon decreased with the decrease of microbial activity at low temperature and the decomposition of plant residues by microorganisms micro- The bioassimilate forms in the soil, increasing the proportion of neutral sugars from microbial sources.