Mineral-associated organic matter (MAOM), the largest soil carbon pool, is formed through a series of organo-mineral interaction mechanisms. However, different organo-mineral fractions relevant to specific stabilization mechanisms and their response to environmental variables are poorly understood, which hinders accurate prediction of MAOM preservation under climate change. We applied sequential chemical extraction to separate MAOM into different organo-mineral fractions. To assess of response of different organo-mineral fractions to climate change, alpine forest soils with high environmental sensitivity along a controlled environmental gradient were selected. Residual OM and weakly adsorbed OM were the primary organo-mineral fractions, accounting for approximately 45.1-67.7 % and 16.4-30.6 %, respectively, of the total organic carbon (TOC). Climate exerted considerable indirect effects on the preservation of organo-mineral fractions through weathering and edaphic and biotic variables. Moreover, organo-mineral fractions were closely associated with metal cations (mainly Fe/Al) and secondary minerals, forming complex networks. Water-soluble OM (WSOM), weakly adsorbed OM and Fe/Al oxyhydroxides-stabilized OM were tightly linked, occupying the central position of the networks, and were closely related to soil pH, moisture and prokaryotic composition, indicating that edaphic and biotic factors might play important roles in maintaining the network structure and topology. In addition, Fe/Al-OM complexes, oxyhydroxides-stabilized OM and residual OM in the network were greatly impacted by climate and weathering factors, including precipitation, temperature and the plagioclase index of alteration (PIA). The complex network among organo-mineral fractions sheds light on MAOM dynamic stabilization for better predicting MAOM preservation under climate change.
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http://dx.doi.org/10.1016/j.scitotenv.2023.165555 | DOI Listing |
Environ Sci Technol
December 2024
Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125, China.
Microbial carbon (C) use efficiency (CUE) drives soil C formation, while physical-chemical protection stabilizes subsequent microbial necromass, both shaped by soil aggregates and minerals. Soils inherit many properties from the parent material, yet the influence of lithology and associated soil geochemistry on microbial CUE and necromass stabilization remains unknow. Here, we quantified microbial CUE in well-aggregated bulk soils and crushed aggregates, as well as microbial necromass in bulk soils and the mineral-associated organic matter fraction, originating from carbonate-containing (karst) and carbonate-free (clastic rock, nonkarst) parent materials along a broad climatic gradient.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
September 2024
School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China.
The turnover and stabilization of soil organic carbon are tightly associated with the properties of litter input. Due to the complexity of litter decomposition and the high heterogeneity of forest soils, there are considerable uncertainties about how soil minerals, microorganisms, and environmental factors jointly regulate the transformation and stability of litter-derived soil organic carbon. Here, we present an overview of the "microbial efficiency-matrix stabilization" framework centered on microbial metabolism and organic carbon transformation, as well as the new "microbial carbon pump" and "mineral carbon pump" theories in forest soil organic carbon transformation and stabilization.
View Article and Find Full Text PDFSci Total Environ
December 2024
Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, Guangdong 510650, China; South China National Botanical Garden, Guangzhou, Guangdong 510650, China; University of Chinese Academy of Sciences, Beijing 100039, China. Electronic address:
Climate models predict longer and more severe droughts, and alterations in the frequency and intensity of rainfall events. However, how changing precipitation patterns affect soil organic carbon (SOC), particulate organic carbon (POC), and mineral-associated organic carbon (MAOC) remains unclear. Here, we conducted a three-year rainfall manipulation experiment with ambient rainfall as the control, removal of half the total rainfall amount with unaltered frequency (DRA), and increased rainfall frequency with the total amounts unchanged (IRF) in a subtropical forest.
View Article and Find Full Text PDFSci Rep
October 2024
College of Life Sciences, Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region, Guizhou University, Guiyang, 550025, China.
J Hazard Mater
May 2024
Department of Environmental Sciences, Government College University Faisalabad, Faisalabad 38000, Pakistan. Electronic address:
Heavy metals (HMs) are common contaminants with major concern of severe environmental and health problems. This study evaluated the effects of organo-mineral amendments (mesquite biochar (MB), zeolite (ZL) and bentonite (BN) alone and in combination) applied at different rates to promote the maize (Zea mays L.) growth by providing essential nutrient and improving the soil physio-chemical properties under zinc (Zn) and lead (Pb) contamination.
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