TY - JOUR

T1 - Dynamics of soil organic carbon in the steppes of Russia and Kazakhstan under past and future climate and land use

AU - Rolinski, Susanne

AU - Prishchepov, Alexander V.

AU - Guggenberger, Georg

AU - Bischoff, Norbert

AU - Kurganova, Irina

AU - Schierhorn, Florian

AU - Müller, Daniel

AU - Müller, Christoph

N1 - Funding Information: The study was part of the project Kulunda (BMBF under grant numbers 01LL0905L and 01LL0905I). We thank for financial support of the following projects: EU FP7 ERA.Net Russia Plus: 449 CLIMASTEPPE, funding Goszadanie of Institute of Steppe ‘Problems of steppe management under the conditions of modern challenges: optimization of the interaction between environmental and socio-economic systems’ No.AAAA-A21-121011190016-1. DFF-Danish ERC Support Program (grant number: 116491, 9127-00001B) and the BMBF project ReKKS under grant number 01LZ1704A. We also thank the GERUKA project, which is funded by the German Federal Ministry of Food and Agriculture (BMEL), the Federal Office for Agriculture and Food (BLE) and the EPIKUR project, which is funded by the Leibniz Association’s ‘Joint Initiative for Research and Innovation’ (‘Pakt für Forschung und Innovation’). I. Kurganova acknowledges support from state assignments of the Pushchino Scientific Centre of Biological Researches of RAS (under grant number AAAA-A18-118013190177-9). The authors acknowledge help by Jannes Breier. We thank Alexander Tsypin for assistance in collection the historical land-use change datasets. We acknowledge the modelling groups, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) and the WCRP’s Working Group on Coupled Modelling (WGCM) for their roles in making available the WCRP CMIP3 multi-model data set. Support of this data set is provided by the Office of Science, U.S. Department of Energy.

PY - 2021/9

Y1 - 2021/9

N2 - Changes in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.

AB - Changes in land use and climate are the main drivers of change in soil organic matter contents. We investigated the impact of the largest policy-induced land conversion to arable land, the Virgin Lands Campaign (VLC), from 1954 to 1963, of the massive cropland abandonment after 1990 and of climate change on soil organic carbon (SOC) stocks in steppes of Russia and Kazakhstan. We simulated carbon budgets from the pre-VLC period (1900) until 2100 using a dynamic vegetation model to assess the impacts of observed land-use change as well as future climate and land-use change scenarios. The simulations suggest for the entire VLC region (266 million hectares) that the historic cropland expansion resulted in emissions of 1.6⋅ 1015 g (= 1.6 Pg) carbon between 1950 and 1965 compared to 0.6 Pg in a scenario without the expansion. From 1990 to 2100, climate change alone is projected to cause emissions of about 1.8 (± 1.1) Pg carbon. Hypothetical recultivation of the cropland that has been abandoned after the fall of the Soviet Union until 2050 may cause emissions of 3.5 (± 0.9) Pg carbon until 2100, whereas the abandonment of all cropland until 2050 would lead to sequestration of 1.8 (± 1.2) Pg carbon. For the climate scenarios based on SRES (Special Report on Emission Scenarios) emission pathways, SOC declined only moderately for constant land use but substantially with further cropland expansion. The variation of SOC in response to the climate scenarios was smaller than that in response to the land-use scenarios. This suggests that the effects of land-use change on SOC dynamics may become as relevant as those of future climate change in the Eurasian steppes.

KW - Carbon emissions

KW - Cropland expansion

KW - Model simulations

KW - Soil carbon stocks

KW - Steppe region

UR - http://www.scopus.com/inward/record.url?scp=85110142491&partnerID=8YFLogxK

U2 - 10.1007/s10113-021-01799-7

DO - 10.1007/s10113-021-01799-7

M3 - Article

AN - SCOPUS:85110142491

VL - 21

JO - Regional environmental change

JF - Regional environmental change

SN - 1436-3798

IS - 3

M1 - 73

ER -