Abstrakt
The research of plant wax n-alkanes preserved in soil and other environments as a way to understanding environmental changes in the past has experienced a surge in interest in recent years. The plant wax n-alkanes preserved in soils reflect vegetation history, different plant forms (typically grasses vs. trees) can be discriminated based on the presence of n-alkanes of various chain lengths.
The fact that vegetation is heavily influenced by climate and the possibility of carbon dating these n-alkanes preserved in soil mean that n-alkanes have a great potential as a paleoproxy. This is of particular interest in European Chernozem regions where δ13C cannot be reliably used to reconstruct past vegetation.
However, considerable post deposition changes in n-alkanes have been observed. In particular, long-chain n-alkanes have been shown to degrade over time.
We are studying the dynamics of n-alkanes using a combination of n-alkane chain-length differentiation and carbon dating on a number of loess-derived soil (namely Chernozems and Luvisols) sites in Czechia with well-described vegetation history, with the aim of ascertaining the changes in n-alkanes over time in relation to the specific chemical and physical properties of these particular soil types. The understanding of these changes will provide a valuable contribution to the highly debated topic of soil development, vegetation history as well as environmental history as a whole in the Central European loess region and in a broader context serve as a reference for future use of plant wax n-alkanes as a reliable paleoproxy.