TY - JOUR

T1 - How temperature and aridity drive lignin decomposition along a latitudinal transect in western Siberia

AU - Dao, Thao Thi

AU - Mikutta, Robert

AU - Wild, Birgit

AU - Sauheitl, Leopold

AU - Gentsch, Norman

AU - Shibistova, Olga

AU - Schnecker, Jörg

AU - Lashchinskiy, Nikolay

AU - Richter, Andreas

AU - Guggenberger, Georg

N1 - Funding Information: The financial support was provided by the German Federal Ministry of Education and Research (03F0616A) within the ERANET EUROPOLAR project CryoCARB. T.T. Dao is grateful for financial support by the Project 911 of Vietnamese Education. A. Richter acknowledges the financial support of the Austrian Science Fund (FWF – I370‐B17). We are grateful to the technical staff of the Institute of Soil Science in Hannover for laboratory assistance and to Susanne K. Woche for comments on the manuscript. Open Access funding enabled and organized by Projekt DEAL.

PY - 2023/9/20

Y1 - 2023/9/20

N2 - Climate change drives a northward shift of biomes in high-latitude regions. This might have consequences on the decomposition of plant litter entering the soil, including its lignin component, which is one of the most abundant components of vascular plants. In order to elucidate the combined effect of climate and soil characteristics on the decomposition pattern of lignin, we investigated lignin contents and its degree of oxidative decomposition within soil profiles along a climosequence in western Siberia. Soil samples were collected from organic topsoil to mineral subsoil at six sites along a 1500-km latitudinal transect, stretching from tundra, through taiga and forest steppe to typical steppe. The stage of lignin degradation, as mirrored by decreasing organic carbon-normalized lignin contents and increasing oxidative alteration of the remnant lignin (acid-to-aldehyde ratios of vanillyl- and syringyl-units [(Ac/Al)V and (Ac/Al)S]) within soil horizons, increased from tundra to forest steppe and then decreased to the steppe. Principal component analysis, involving also climatic conditions such as mean annual temperature and aridity index, showed that the different states of lignin degradation between horizons related well to the activity of phenoloxidases and peroxidases, enzymes involved in lignin depolymerization that are produced primarily by fungi and less importantly by bacteria. The low microbial lignin decomposition in the tundra was likely due to low temperature and high soil moisture, which do not favour the fungi. Increasing temperature and decreasing soil moisture, facilitating a higher abundance of fungi, led to increased fungal lignin decomposition towards the forest-steppe biome, while drought and high pH might be responsible for the reduced lignin decomposition in the steppe. We infer that a shift of biomes to the north, driven by climate change, might promote lignin decomposition in the northern parts, whereas in the south a further retardation might be likely.

AB - Climate change drives a northward shift of biomes in high-latitude regions. This might have consequences on the decomposition of plant litter entering the soil, including its lignin component, which is one of the most abundant components of vascular plants. In order to elucidate the combined effect of climate and soil characteristics on the decomposition pattern of lignin, we investigated lignin contents and its degree of oxidative decomposition within soil profiles along a climosequence in western Siberia. Soil samples were collected from organic topsoil to mineral subsoil at six sites along a 1500-km latitudinal transect, stretching from tundra, through taiga and forest steppe to typical steppe. The stage of lignin degradation, as mirrored by decreasing organic carbon-normalized lignin contents and increasing oxidative alteration of the remnant lignin (acid-to-aldehyde ratios of vanillyl- and syringyl-units [(Ac/Al)V and (Ac/Al)S]) within soil horizons, increased from tundra to forest steppe and then decreased to the steppe. Principal component analysis, involving also climatic conditions such as mean annual temperature and aridity index, showed that the different states of lignin degradation between horizons related well to the activity of phenoloxidases and peroxidases, enzymes involved in lignin depolymerization that are produced primarily by fungi and less importantly by bacteria. The low microbial lignin decomposition in the tundra was likely due to low temperature and high soil moisture, which do not favour the fungi. Increasing temperature and decreasing soil moisture, facilitating a higher abundance of fungi, led to increased fungal lignin decomposition towards the forest-steppe biome, while drought and high pH might be responsible for the reduced lignin decomposition in the steppe. We infer that a shift of biomes to the north, driven by climate change, might promote lignin decomposition in the northern parts, whereas in the south a further retardation might be likely.

KW - climate change

KW - latitudinal gradient

KW - lignin degradation

KW - Siberian soil

KW - soil moisture

KW - temperature

KW - vegetation

UR - http://www.scopus.com/inward/record.url?scp=85171649564&partnerID=8YFLogxK

U2 - 10.1111/ejss.13408

DO - 10.1111/ejss.13408

M3 - Article

AN - SCOPUS:85171649564

VL - 74

JO - European journal of soil science

JF - European journal of soil science

SN - 1351-0754

IS - 5

M1 - e13408

ER -