Abstract

Carbon isotope ratios in soil organic matter are often used in paleoecological research for reconstructing climate and plant communities (type of photosynthesis). The difficulties in interpreting isotopic data are related to the integral effect of several factors controlling the ¹³C/¹²C ratio in plants and soils, namely, the environmental conditions and the composition of soil organic matter. The study of Albic Retisols and Luvic Chernozems indicates that the extractable humus fractions are enriched in heavy isotope ¹³C relative to the total soil organic matter. In Retisols, the increased δ¹³С values are typical of humic acids below the humus horizon and for fulvic acids within the entire profile. In Luvic Chernozems, the ¹³C-enriched fraction is only fulvic acids. Thus, changes in the ¹³C/¹²C ratio in soils, in particular, its increase with depth, can be explained by migration of labile humus fractions in the profile and by their accumulation in deeper horizons.

中文翻译：

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白藜芦醇和Luvic黑钙质腐殖酸中碳的同位素组成

摘要

在古生态学研究中，土壤有机质中的碳同位素比通常用于重建气候和植物群落（光合作用的类型）。解释同位素数据的困难与控制植物和土壤中¹³ C / ¹² C比的几个因素的综合作用有关，即环境条件和土壤有机质的组成。Albic的残留物和Luvic Chernozems的研究表明，相对于土壤总有机质，可提取的腐殖质组分富含¹³ C的重同位素。在Retisols，增加的δ ¹³ С值是典型的腐殖质地平线以下腐殖酸和整个轮廓内灰黄霉酸。在Luvic Chernozems，富含¹³ C的馏分只有富里酸。因此，土壤中¹³ C / ¹² C比的变化，尤其是随着深度的增加，可以通过不稳定腐殖质组分在剖面中的迁移以及它们在更深层的积累来解释。