Soil carbon sequestration due to post-Soviet cropland abandonment: estimates from a large-scale soil organic carbon field inventory.
The break-up of the Soviet Union in 1991 triggered cropland abandonment on a continental scale, which in turn led to carbon accumulation on abandoned land across Eurasia. Previous studies have estimated carbon accumulation rates across Russia based on large-scale modelling. Studies that assess carbon sequestration on abandoned land based on robust field sampling are rare. We investigated soil organic carbon (SOC) stocks using a randomized sampling design along a climatic gradient from forest steppe to Sub-Taiga in Western Siberia (Tyumen Province). In total, SOC contents were sampled on 470 plots across different soil and land-use types. The effect of land use on changes in SOC stock was evaluated, and carbon sequestration rates were calculated for different age stages of abandoned cropland. While land-use type had an effect on carbon accumulation in the topsoil (0-5 cm), no independent land-use effects were found for deeper SOC stocks. Topsoil carbon stocks of grasslands and forests were significantly higher than those of soils managed for crops and under abandoned cropland. SOC increased significantly with time since abandonment. The average carbon sequestration rate for soils of abandoned cropland was 0.66 Mg C ha-1yr-1(1-20 years old, 0-5 cm soil depth), which is at the lower end of published estimates for Russia and Siberia. There was a tendency towards SOC saturation on abandoned land as sequestration rates were much higher for recently abandoned (1-10 years old, 1.04 Mg C ha-1yr-1) compared to earlier abandoned crop fields (11-20 years old, 0.26 Mg C ha-1yr-1). Our study confirms the global significance of abandoned cropland in Russia for carbon sequestration. Our findings also suggest that robust regional surveys based on a large number of samples advance model-based continent-wide SOC prediction.
Biodiversity and Ecosystem Research Group, Institute of Landscape Ecology, University of Münster, Heisenbergstraße 2, 48149, Münster, Germany.
Tim-Martin
0000-0001-9930-6058
TM
Wertebach
Biodiversity and Ecosystem Research Group, Institute of Landscape Ecology, University of Münster, Heisenbergstraße 2, 48149, Münster, Germany.
Norbert
N
Hölzel
Biodiversity and Ecosystem Research Group, Institute of Landscape Ecology, University of Münster, Heisenbergstraße 2, 48149, Münster, Germany.|Vegetation Ecology and Botany Group, Osnabrück University of Applied Sciences, Osnabrück, Germany.
Immo
I
Kämpf
Tyumen State University, Semakova Str. 10, Tyumen, 625003, Russia.
Andrey
A
Yurtaev
Tyumen State University, Semakova Str. 10, Tyumen, 625003, Russia.
Sergey
S
Tupitsin
Vegetation Ecology and Botany Group, Osnabrück University of Applied Sciences, Osnabrück, Germany.
Kathrin
K
Kiehl
Biodiversity and Ecosystem Research Group, Institute of Landscape Ecology, University of Münster, Heisenbergstraße 2, 48149, Münster, Germany.
Johannes
J
Kamp
Biodiversity and Ecosystem Research Group, Institute of Landscape Ecology, University of Münster, Heisenbergstraße 2, 48149, Münster, Germany.
Till
T
Kleinebecker
D000383:Agriculture; D002244:Carbon; D057965:Carbon Sequestration; D002681:China; D018556:Crops, Agricultural; D012426:Russia; D012800:Siberia; D012987:Soil / Q000737:chemistry*
D012987:Soil; D002244:Carbon
Western Siberia; carbon sequestration; climate change mitigation; land-use change; self-restoration; soil organic carbon