土壤有机质的碳同位素信息反映了上部的植被和气候状况,但植物体在被微生物分解、利用,转变为土壤有机质的过程中会产生碳同位素的分馏。本研究探讨了高山草甸和典型草原两种不同气候、生态环境条件下,植物转变为土壤有机质过程中的碳同位素组成变化。结果显示:在太白山高海拔地区的4个采样点,表土的δ^13Corg值均随深度的增加而逐渐偏正,到距离地表10~15cm左右时,
Carbon isotopic composition of the soil organic matter (SOM) reflects the situation of the growing plants and climates. However, when the plants are decomposed and utilized by the microbe, carbon isotopic fractionation is likely to occur. The authors studied the variation of the carbon isotopic composition during the transformation of plants into SOM in two different climates and environments of alpine meadow and typical grassland.