Carbon Accumulation, Flux, and Fate in Stordalen Mire, a Permafrost Peatland in Transition

AbstractAn experimental heat treatment chamber and control system were developed to perform in-situ X-ray diffraction experiments during low-pressure carburizing (LPC) processes. Results from the experimental chamber and industrial furnace were compared, and it was proven that the built system is reliable for LPC experiments. In-situ X-ray diffraction investigations during LPC treatment were conducted at the German Electron Synchrotron Facility in Hamburg Germany. During the boost steps, carbon accumulation and carbide formation was observed at the surface. These accumulation and carbide formation decelerated the further carbon diffusion from atmosphere to the sample. In the early minutes of the diffusion steps, it is observed that cementite content continue to increase although there is no presence of gas. This effect is attributed to the high carbon accumulation at the surface during boost steps which acts as a carbon supply. During quenching, martensite at higher temperature had a lower c/a ratio than later formed ones. This difference is credited to the early transformation of austenite regions having lower carbon content. Also, it was noticed that the final carbon content dissolved in martensite reduced compared to carbon in austenite before quenching. This reduction was attributed to the auto-tempering effect.

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Organic mulching promotes soil organic carbon accumulation to deep soil layer in an urban plantation forest

Forest Ecosystems ◽

10.1186/s40663-020-00278-5 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Xiaodan Sun ◽

Gang Wang ◽

Qingxu Ma ◽

Jiahui Liao ◽

Dong Wang ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Content ◽

Fine Roots ◽

Soil Layer ◽

Carbon Accumulation ◽

Bulk Soil ◽

Organic Mulch ◽

The Impact ◽

Soc Fractions

Abstract Background Soil organic carbon (SOC) is important for soil quality and fertility in forest ecosystems. Labile SOC fractions are sensitive to environmental changes, which reflect the impact of short-term internal and external management measures on the soil carbon pool. Organic mulching (OM) alters the soil environment and promotes plant growth. However, little is known about the responses of SOC fractions in rhizosphere or bulk soil to OM in urban forests and its correlation with carbon composition in plants. Methods A one-year field experiment with four treatments (OM at 0, 5, 10, and 20 cm thicknesses) was conducted in a 15-year-old Ligustrum lucidum plantation. Changes in the SOC fractions in the rhizosphere and bulk soil; the carbon content in the plant fine roots, leaves, and organic mulch; and several soil physicochemical properties were measured. The relationships between SOC fractions and the measured variables were analysed. Results The OM treatments had no significant effect on the SOC fractions, except for the dissolved organic carbon (DOC). OM promoted the movement of SOC to deeper soil because of the increased carbon content in fine roots of subsoil. There were significant correlations between DOC and microbial biomass carbon and SOC and easily oxidised organic carbon. The OM had a greater effect on organic carbon fractions in the bulk soil than in the rhizosphere. The thinnest (5 cm) mulching layers showed the most rapid carbon decomposition over time. The time after OM had the greatest effect on the SOC fractions, followed by soil layer. Conclusions The frequent addition of small amounts of organic mulch increased SOC accumulation in the present study. OM is a potential management model to enhance soil organic matter storage for maintaining urban forest productivity.

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The dominant microorganisms vary with aggregates sizes in promoting soil carbon accumulation under straw application

Archives of Agronomy and Soil Science ◽

10.1080/03650340.2021.1955354 ◽

2021 ◽

pp. 1-17

Author(s):

Jinjing Lu ◽

Shengping Li ◽

Xueping Wu ◽

Guopeng Liang ◽

Chunhua Gao ◽

...

Keyword(s):

Soil Carbon ◽

Carbon Accumulation ◽

Soil Carbon Accumulation ◽

Straw Application

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Spatiotemporal variations in the organic carbon accumulation rate in mangrove sediments from the Yingluo Bay, China, since 1900

Acta Oceanologica Sinica ◽

10.1007/s13131-021-1864-5 ◽

2021 ◽

Author(s):

Yao Zhang ◽

Xianwei Meng ◽

Peng Xia ◽

Jun Zhang ◽

Dahai Liu ◽

...

Keyword(s):

Organic Carbon ◽

Accumulation Rate ◽

Carbon Accumulation ◽

Spatiotemporal Variations ◽

Mangrove Sediments ◽

Carbon Accumulation Rate ◽

Yingluo Bay

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Relief and calcium from gypsum as key factors for net inorganic carbon accumulation in soils of a semiarid Mediterranean environment

Geoderma ◽

10.1016/j.geoderma.2021.115115 ◽

2021 ◽

Vol 398 ◽

pp. 115115

Author(s):

Vito Armando Laudicina ◽

Carmelo Dazzi ◽

Antonio Delgado ◽

Haydn Barros ◽

Riccardo Scalenghe

Keyword(s):

Inorganic Carbon ◽

Carbon Accumulation ◽

Mediterranean Environment ◽

Key Factors

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The Multiscale Monitoring of Peatland Ecosystem Carbon Cycling in the Middle Taiga Zone of Western Siberia: The Mukhrino Bog Case Study

Land ◽

10.3390/land10080824 ◽

2021 ◽

Vol 10 (8) ◽

pp. 824

Author(s):

Egor Dyukarev ◽

Evgeny Zarov ◽

Pavel Alekseychik ◽

Jelmer Nijp ◽

Nina Filippova ◽

...

Keyword(s):

Carbon Cycling ◽

Western Siberia ◽

Carbon Accumulation ◽

Middle Taiga ◽

Taiga Zone ◽

Field Station ◽

Moss Species ◽

Chamber Method ◽

The Impact

The peatlands of the West Siberian Lowlands, comprising the largest pristine peatland area of the world, have not previously been covered by continuous measurement and monitoring programs. The response of peatlands to climate change occurs over several decades. This paper summarizes the results of peatland carbon balance studies collected over ten years at the Mukhrino field station (Mukhrino FS, MFS) operating in the Middle Taiga Zone of Western Siberia. A multiscale approach was applied for the investigations of peatland carbon cycling. Carbon dioxide fluxes at the local scale studied using the chamber method showed net accumulation with rates from 110, to 57.8 gC m−2 at the Sphagnum hollow site. Net CO2 fluxes at the pine-dwarf shrubs-Sphagnum ridge varied from negative (−32.1 gC m−2 in 2019) to positive (13.4 gC m−2 in 2017). The cumulative May-August net ecosystem exchange (NEE) from eddy-covariance (EC) measurements at the ecosystem scale was −202 gC m−2 in 2015, due to the impact of photosynthesis of pine trees which was not registered by the chamber method. The net annual accumulation of carbon in the live part of mosses was estimated at 24–190 gC m−2 depending on the Sphagnum moss species. Long-term carbon accumulation rates obtained by radiocarbon analysis ranged from 28.5 to 57.2 gC m−2 yr−1, with local extremes of up to 176.2 gC m−2 yr−1. The obtained estimates of various carbon fluxes using EC and chamber methods, the accounting for Sphagnum growth and decomposition, and long-term peat accumulation provided information about the functioning of the peatland ecosystems at different spatial and temporal scales. Multiscale carbon flux monitoring reveals useful new information for forecasting the response of northern peatland carbon cycles to climatic changes.

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A Comparison of some Upland and Valley Soils in the Ungava-Labrador Peninsula

Géographie physique et Quaternaire ◽

10.7202/032566ar ◽

2007 ◽

Vol 38 (3) ◽

pp. 243-256 ◽

Cited By ~ 4

Author(s):

William H. Hendershot

Keyword(s):

Soil Temperature ◽

Black Spruce ◽

Carbon Accumulation ◽

Shallow Depth ◽

Soil Profiles ◽

Tree Line ◽

Climatic Regions ◽

Coarse Texture ◽

Active Mixing ◽

Extractable Iron

ABSTRACT Thirteen soil profiles from northern Québec and Labrador, Canada, near the northern tree-line, were sampled and analysed. Five of these, located on poorly to imperfectly drained sites, are strongly cryoturbated soils with permafrost at a shallow depth. Below the surface horizon they have very uniform profile distributions of pH, carbon and extractable iron and aluminum due to the active mixing of the horizons. The eight soils from well-drained sites have profiles similar to those of soils in similar settings in more temperate climatic regions. One of these, developed in one of the most northerly valleys having a black spruce-larch forest vegetation, has the characteristics of a podzol (spodosol) except that the podzolic B (spodic) horizon is too thin. The other seven profiles all have color B horizons, although the coarse texture prevents their classification as cambic horizons; these soils all have carbon-rich A horizons varying in thickness from 1.5 to 20 cm. Soil temperature at 50 cm depth closely follows the elevational and latitudinal distribution of the soils; a range of 0 to 10° C was observed. Soil development, measured as depth of solum, organic carbon accumulation or degree of B horizon development, is closely related to soil temperature and site position. The presence of permanently frozen ice layers at shallow depth has a marked influence on soil genesis and the properties of the resultant soils.

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