Variations in the chemical structure and Carbon-13 natural abundance in water-stable macro- and microaggregates in Haplic Chernozem under the contrasting land use variants.

Water-stable macro- (WSA) and free microaggregates (WSA) were isolated from the 2-1 mm air-dry macroaggregates from the surface horizons of Haplic Chernozem in contrasting variants of land use: the steppe and the bare fallow. The C NMR data and the C natural abundance of the Occluded organic matter (OM) (LF) and Clay within WSAs in the steppe obviously indicate a lower degree of microbiological processing of OM within WSA as compared with WSA. This is reflected in lower degrees of decomposition (DI) and aromaticity (ARI) of OM and the C/N ratio, as well as lower C enrichment.

Key periods of peatland development and environmental changes in the middle taiga zone of Western Siberia during the Holocene.

The response of peatlands to climate change can be highly variable. Through understanding past changes we can better predict the response of peatlands to future climate change. We use a multi-proxy approach to reconstruct the surface wetness and carbon accumulation of the Mukhrino mire (Western Siberia), describing the development of the mire since peat formation in the early Holocene, around 9360 cal.

Hypolithic communities shape soils and organic matter reservoirs in the ice-free landscapes of East Antarctica.

The soils of East Antarctica have no rhizosphere with the bulk of organo-mineral interactions confined to the thin microbial and cryptogamic crusts that occur in open or cryptic niches and are collectively known as biological soil crust (BSC). Here we demonstrate that cryptic hypolithic varieties of BSC in the Larsemann Hills of East Antarctica contribute to the buildup of soil organic matter and produce several types of continuous organogenous horizons within the topsoil with documented clusters of at least 100 m. Such hypolithic horizons accumulate 0.

Alteration of rocks by endolithic organisms is one of the pathways for the beginning of soils on Earth.

Subaerial endolithic systems of the current extreme environments on Earth provide exclusive insight into emergence and development of soils in the Precambrian when due to various stresses on the surfaces of hard rocks the cryptic niches inside them were much more plausible habitats for organisms than epilithic ones. Using an actualistic approach we demonstrate that transformation of silicate rocks by endolithic organisms is one of the possible pathways for the beginning of soils on Earth. This process led to the formation of soil-like bodies on rocks in situ and contributed to the raise of complexity in subaerial geosystems.