TY - JOUR

T1 - Formation of mineral-associated organic matter in temperate soils is primarily controlled by mineral type and modified by land use and management intensity

AU - Bramble, De Shorn E.

AU - Ulrich, Susanne

AU - Schöning, Ingo

AU - Mikutta, Robert

AU - Brandt, Luise

AU - Poll, Christian

AU - Kandeler, Ellen

AU - Mikutta, Christian

AU - Konrad, Alexander

AU - Siemens, Jan

AU - Yang, Yang

AU - Polle, Andrea

AU - Schall, Peter

AU - Ammer, Christian

AU - Kaiser, Klaus

AU - Schrumpf, Marion

N1 - Funding Information: This work was funded by the DFG Priority Program 1374 ‘Biodiversity‐Exploratories’ (DFG project numbers 433273584 and 193957772) and the Max Planck Society. Funding for De Shorn E. Bramble, Alexander Konrad and Yang Yang was provided by the International Max Planck Research School for Biogeochemical Cycles (IMPRS‐gBGC), the Justus Liebig University Giessen and the Chinese Scholarship Council (CSC) respectively. Open Access funding enabled and organized by Projekt DEAL.

PY - 2023/12/8

Y1 - 2023/12/8

N2 - Formation of mineral-associated organic matter (MAOM) supports the accumulation and stabilization of carbon (C) in soil, and thus, is a key factor in the global C cycle. Little is known about the interplay of mineral type, land use and management intensity in MAOM formation, especially on subdecadal time scales. We exposed mineral containers with goethite or illite, the most abundant iron oxide and phyllosilicate clay in temperate soils, for 5 years in topsoils of 150 forest and 150 grassland sites in three regions across Germany. Results show that irrespective of land use and management intensity, more C accumulated on goethite than illite (on average 0.23 ± 0.10 and 0.06 ± 0.03 mg m−2 mineral surface respectively). Carbon accumulation across regions was consistently higher in coniferous forests than in deciduous forests and grasslands. Structural equation models further showed that thinning and harvesting reduced MAOM formation in forests. Formation of MAOM in grasslands was not affected by grazing. Fertilization had opposite effects on MAOM formation, with the positive effect being mediated by enhanced plant productivity and the negative effect by reduced plant species richness. This highlights the caveat of applying fertilizers as a strategy to increase soil C stocks in temperate grasslands. Overall, we demonstrate that the rate and amount of MAOM formation in soil is primarily driven by mineral type, and can be modulated by land use and management intensity even on subdecadal time scales. Our results suggest that temperate soils dominated by oxides have a higher capacity to accumulate and store C than those dominated by phyllosilicate clays, even under circumneutral pH conditions. Therefore, adopting land use and management practices that increase C inputs into oxide-rich soils that are under their capacity to store C may offer great potential to enhance near-term soil C sequestration.

AB - Formation of mineral-associated organic matter (MAOM) supports the accumulation and stabilization of carbon (C) in soil, and thus, is a key factor in the global C cycle. Little is known about the interplay of mineral type, land use and management intensity in MAOM formation, especially on subdecadal time scales. We exposed mineral containers with goethite or illite, the most abundant iron oxide and phyllosilicate clay in temperate soils, for 5 years in topsoils of 150 forest and 150 grassland sites in three regions across Germany. Results show that irrespective of land use and management intensity, more C accumulated on goethite than illite (on average 0.23 ± 0.10 and 0.06 ± 0.03 mg m−2 mineral surface respectively). Carbon accumulation across regions was consistently higher in coniferous forests than in deciduous forests and grasslands. Structural equation models further showed that thinning and harvesting reduced MAOM formation in forests. Formation of MAOM in grasslands was not affected by grazing. Fertilization had opposite effects on MAOM formation, with the positive effect being mediated by enhanced plant productivity and the negative effect by reduced plant species richness. This highlights the caveat of applying fertilizers as a strategy to increase soil C stocks in temperate grasslands. Overall, we demonstrate that the rate and amount of MAOM formation in soil is primarily driven by mineral type, and can be modulated by land use and management intensity even on subdecadal time scales. Our results suggest that temperate soils dominated by oxides have a higher capacity to accumulate and store C than those dominated by phyllosilicate clays, even under circumneutral pH conditions. Therefore, adopting land use and management practices that increase C inputs into oxide-rich soils that are under their capacity to store C may offer great potential to enhance near-term soil C sequestration.

KW - fertilization

KW - forests

KW - grasslands

KW - grazing

KW - iron oxides and clay minerals

KW - soil organic matter

KW - thinning and harvesting

KW - tree species selection

UR - http://www.scopus.com/inward/record.url?scp=85177656966&partnerID=8YFLogxK

U2 - 10.1111/gcb.17024

DO - 10.1111/gcb.17024

M3 - Article

C2 - 37986273

AN - SCOPUS:85177656966

VL - 30

JO - Global change biology

JF - Global change biology

SN - 1354-1013

IS - 1

M1 - e17024

ER -