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以黑龙江高纬冻土带与青海高山冻土带土壤样品为研究对象,对其中的甘油二烷基甘油四醚脂(GDGTs)含量进行了测定,并分析了其与环境条件的相关性。研究结果表明,所测样品均含有类异戊二烯GDGTs(iGDGTs)和支链GDGTs(bGDGTs)。不同样品中Ri/b值(iGDGTs含量与bGDGTs含量的比值)差异较大,且和土壤含水率呈负相关,证实了Ri/b指标可以用来反映冻土带土壤的干旱情况。BIT指标与土壤含水率呈正相关,表明其具有指示土壤湿度变化的能力。基于bGDGTs的环化指数(CBT)计算出的pH与土壤实测pH相关性很高,表明该指标可用于重建冻土带古土壤pH。然而,基于bGDGTs的甲基化指标(MBT)与年均气温(MAAT)没有表现出相关性,表明温度不是影响冻土带土壤MBT变化的主要因素。
The content of GDGTs in high latitude tundra and Qinghai alpine tundra in Heilongjiang were studied, and their correlations with environmental conditions were analyzed. The results showed that the samples tested contained isoprenoids GDGTs (iGDGTs) and branched GDGTs (bGDGTs). The values of Ri / b in different samples (the ratio of iGDGTs to bGDGTs) are quite different and negatively correlated with the soil water content, confirming that the Ri / b index can be used to reflect the soil drought conditions in the tundra. The BIT index is positively correlated with soil moisture, indicating its ability to indicate changes in soil moisture. The calculated pH value based on the cyclization index (bbT) of the bGDGTs is highly correlated with the measured soil pH, indicating that the indicator can be used to reconstruct the paleosol pH of the frozen soil. However, there was no correlation between methylation index based on bGDGTs (MBT) and mean annual temperature (MAAT), indicating that temperature is not a major factor affecting the MBT of soils in the tundra.