冀北辽河源油松天然林土壤微生物碳代谢特征研究

本文以冀北辽河源地区不同林龄油松天然林为研究对象,研究其土壤微生物生物量碳、微生物呼吸及微生物代谢熵随油松林龄的变化趋势。结果表明:随着油松天然林林龄的增加,土壤微生物生物量碳逐渐增加;而土壤微生物呼吸则呈现出先减小后增加的趋势;微生物代谢熵表现为随油松林林龄的增加而降低。相关性分析表明,土壤微生物生物量碳、微生物呼吸分别与微生物代谢熵之间呈现高度的极显著线性负相关。微生物生物量碳与微生物呼吸呈极显著正相关,但线性相关程度较弱。土壤微生物生物量碳和微生物呼吸与土壤温度和含水量均呈极显著正相关,而土壤微生物代谢熵则与土壤温度、土壤含水量呈极显著负相关。上述结果表明,在冀北辽河源地区,土壤微生物生物量碳、微生物呼吸、微生物代谢熵与油松天然林林龄密切相关。随着油松天然林林龄的增加,其土壤微生物活性增强,碳代谢效率增加,土壤质量及可持续利用潜力更高,土壤生态体系更加成熟。

Characteristics of Microbial Carbolic Metabolism in Soils of Pinus Tabulaeformis in Liaohe River of Northern Hebei

Taking Pinus tabulaeformis with different ages in Liao River source region as test objects, the variation tendency of MBC, MR and qCO₂ along with ages were studied. The results showed that MBC and MR decreased with increased soil depth but qCO₂ increased with layers of soil in the same stands. With the age increasing, MBC increased gradually. However, MR had a inconsistent trend with MBC. MR had a trend of increasing after decreasing initially. Soil microbial metabolic quotient decreased with the increasing stand age of Pinus tabulaeformis forest. Correlation analysis showed that MBC and MR had a significant positive correlation with soil temperature and water content. Meanwhile, significant positive correlation existed between MBC and MR. qCO₂ had a significant negative correlation with soil temperature, water content, MBC and MR. These results demonstrated that MBC, MR, qCO₂ was closely related to forest age of Pinus tabulaeformis in Liaohe River of northern Hebei. With the increasing age of Pinus tabulaeformis, soil microbial activity was enhanced and the efficiency of carbolic metabolism was increased. In addition, soil had a higher quality, a bigger potential of sustainable use and a more stable soil ecosystem.