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

authored by

Susanne Rolinski, Alexander V. Prishchepov, Georg Guggenberger, Norbert Bischoff, Irina Kurganova, Florian Schierhorn, Daniel Müller, Christoph Müller

Abstract

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.

Organisation(s)

Institute of Soil Science
Section Soil Chemistry
Leibniz Research Centre FZ:GEO

External Organisation(s)

University of Copenhagen
Institute of Steppe of the Ural Branch of the Russian Academy of Sciences
Russian Academy of Sciences (RAS)
State Authority for Mining, Energy and Geology (LBEG)
Leibniz Institute of Agricultural Development in Transition Economies (IAMO)
Humboldt-Universität zu Berlin (HU Berlin)
Potsdam Institute for Climate Impact Research

Type

Article

Journal

Regional environmental change

Volume

21

ISSN

1436-3798

Publication date

09.2021

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Global and Planetary Change

Sustainable Development Goals

SDG 13 - Climate Action, SDG 15 - Life on Land

Electronic version(s)

https://doi.org/10.1007/s10113-021-01799-7 (Access: Open)