Characterization of soil carbon from a Svalbard glacier-retreat chronosequence using pyrolysis–GC/MS analysis

Pyrolysis–gas chromatography/mass spectrometry was used to compare soil carbon samples from a glacier-retreat chronosequence in the high Arctic. The analysis considered the relative abundance of different pyrolysis products in an attempt to distinguish significant shifts in the soil-C pool. The relative abundance of the compound classes, pyridines, furfurals, phenols, aromatic hydrocarbon precursors, and cyclopentanones were compared. Based on principal component analysis that explained 90% of the variance in the first and second components, the compound classes were well separated. As such, the compound classes selected were well suited for identifying differences among the samples. The most obvious change indicated the appearance of ligninaceous material in the soil-C pool. This shift appeared to occur between 60 and 100 years after glacial retreat. Another less obvious shift was the change from a largely animal dominated early colonization to algae. This shift occurred between 2 and 16 years after glacial retreat. The results suggest that pyrolysis–gas chromatography/mass spectrometry (pyrolysis–GC/MS) can be an effective tool for drawing distinctions between soil-C at different sites and relationship to cover matter.