A total of 27 different peat types from Sweden were characterized. Botanical composition, particle-size distribution, elementary constituents, degree of decomposition, calorific value, and concentrations of monosaccharide, amino sugar, amino acid constituents, and bitumen were determined. Altogether 62 variables were recorded. The results were examined using principal component analysis (PCA) to probe any relationship between different peat properties and to group similar peat samples. The 41 samples separated into eight different groups.

The main distinction between these peat samples could be explained by differences in the relative amounts of Carex and Sphagnum remains. Carex plants generally seem to be more chemically transformed through microbial decomposition than the Sphagnum fragments, which, in combination with differences in the original chemical compositions, causes chemical dissimilarities between the peat samples. Differences in the degradation pattern for Sphagnum and Carex peats were found when two separate PCAs on parts of the sample set were made.