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土壤有机碳是土壤质量的关键指标,也是评估陆地生态系统碳库对大气CO2源、汇效应转变的基础。本文分析了腾格里沙漠南缘植被恢复过程中土壤物理性质、有机碳含量及其组分特征。结果表明:在围封后,土壤容重随着植被恢复年限的延长呈指数级减小,孔隙度、黏粒含量和田间持水量则表现出随年限延长而显著增大的趋势;土壤有机碳、微生物量碳、轻组有机碳和重组有机碳含量随着围封抚育年限的延长而显著增加,轻组有机碳占总有机碳的比例随植被恢复年限的延长而增大,而重组碳所占比例则随时间变化显著下降。土壤有机碳与容重呈显著负相关,而与其他参数呈显著正相关,说明其变化受多种因素影响,且对土壤物理性质的变化有重要意义。
Soil organic carbon is a key indicator of soil quality and also serves as a basis for assessing the transboundary effects of terrestrial ecosystem carbon pools on atmospheric CO 2 sources. This paper analyzes the soil physical properties, organic carbon content and its component characteristics during vegetation restoration in the southern edge of the Tengger Desert. The results showed that after enclosure, the bulk density of soil decreased exponentially with the extension of vegetation restoration period, and the porosity, clay content and field water holding capacity showed a trend of increasing remarkably with the extension of years. Soil organic carbon, Microbial biomass carbon, light organic carbon and recombinant organic carbon content increased significantly with the prolongation of sealing and tending life. The proportion of light organic carbon to total organic carbon increased with the extension of vegetation restoration period, while the proportion of recombinant carbon The proportions decreased significantly over time. There was a significant negative correlation between soil organic carbon and bulk density, and significant positive correlation with other parameters, indicating that the changes of soil organic carbon were affected by many factors and had great significance to the change of soil physical properties.