Permafrost-Affected Soils of the Russian Arctic and their Carbon Pools

Abstract. Permafrost-affected soils have accumulated enormous pools of organic matter during the Quaternary Period. The area occupied by these soils amounts to more than 8.6 million km2, which is about 27% of all land areas north of 50° N. Therefore, permafrost-affected soils are considered to be one of the most important cryosphere elements within the climate system. Due to the cryopedogenic processes that form these particular soils and the overlying vegetation that is adapted to the arctic climate, organic matter has accumulated to the present extent of up to 1024 Pg (1 Pg = 1015 g = 1 Gt) of soil organic carbon stored within the uppermost three meters of ground. Considering the observed progressive climate change and the projected polar amplification, permafrost-affected soils will undergo fundamental property changes. Higher turnover and mineralization rates of the organic matter are consequences of these changes, which are expected to result in an increased release of climate-relevant trace gases into the atmosphere. As a result, permafrost regions with their distinctive soils are likely to trigger an important tipping point within the global climate system, with additional political and social implications. The controversy of whether permafrost regions continue accumulating carbon or already function as a carbon source remains open until today. An increased focus on this subject matter, especially in underrepresented Siberian regions, could contribute to a more robust estimation of the soil organic carbon pool of permafrost regions and at the same time improve the understanding of the carbon sink and source functions of permafrost-affected soils.

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Permafrost-affected soils and their carbon pools with a focus on the Russian Arctic

Solid Earth ◽

10.5194/se-5-595-2014 ◽

2014 ◽

Vol 5 (2) ◽

pp. 595-609 ◽

Cited By ~ 24

Author(s):

S. Zubrzycki ◽

L. Kutzbach ◽

E.-M. Pfeiffer

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Carbon Sink ◽

Fundamental Property ◽

The Arctic ◽

Quaternary Period ◽

Organic Carbon Pool ◽

Property Changes ◽

Permafrost Regions

Abstract. Permafrost-affected soils have accumulated enormous pools of organic matter during the Quaternary period. The area occupied by these soils amounts to more than 8.6 million km2, which is about 27% of all land areas north of 50° N. Therefore, permafrost-affected soils are considered to be one of the important cryosphere elements within the climate system. Due to the cryopedogenic processes that form these particular soils and the overlying vegetation that is adapted to the arctic climate, organic matter has accumulated to the present extent of up to 1024 Pg (1 Pg = 1015 g = 1 Gt) of soil organic carbon stored within the uppermost 3 m of ground. Considering the observed progressive climate change and the projected polar amplification, permafrost-affected soils will undergo fundamental property changes. Higher turnover and mineralisation rates of the organic matter are consequences of these changes, which are expected to result in an increased release of climate-relevant trace gases into the atmosphere. The controversy of whether permafrost regions continue accumulating carbon or already function as a carbon source remains open until today. An increased focus on this subject matter, especially in underrepresented Siberian regions, could contribute to a more robust estimation of the soil organic carbon pool of permafrost regions and at the same time improve the understanding of the carbon sink and source functions of permafrost-affected soils.

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Impact of soil use on aggregate stability and its relationship with soil organic carbon at two different altitudes in the Colombian Andes

Agronomía Colombiana ◽

10.15446/agron.colomb.v37n3.77601 ◽

2019 ◽

Vol 37 (3) ◽

pp. 263-273

Author(s):

Efraín Francisco Visconti-Moreno ◽

Ibonne Geaneth Valenzuela-Balcázar

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Aggregate Stability ◽

Tropical Climate ◽

Mineral Particle ◽

Organic Carbon Content ◽

Rice Soils ◽

Organic Matter Pool ◽

Different Altitudes

The stability of soil aggregates depends on the organic matter, and the soil use and management can affect the soil organicmatter (SOM) content. Therefore, it is necessary to know therelationship between aggregate stability and the content of SOMin different types of soil use at two different altitudes of theColombian Andes. This study examined the conditions of soilaggregate stability expressed as a distribution of the size classes of stable aggregates (SA) and of the mean weighted diameter of the stable aggregates (MWD). To correlate these characteristics with the soil organic carbon (OC), we measured the particulate organic matter pool (POC), the OC associated with the mineral organic matter pool (HOC), the total organic carbon content (TOC), and the humification rate (HR). Soils were sampled at two altitudes: 1) Humic Dystrudepts in a cold tropical climate (CC) with three plots: tropical mountain rainforest, pastures, and crops; 2) Fluvaquentic Dystrudepts in a warm tropical climate (WC) with three plots: tropical rainforest, an association of oil palm and pastures, and irrigated rice. Soils were sampled at three depths: 0-5, 5-10 and 10-20 cm. The physical properties, mineral particle size distribution, and bulk density were measured. The content of SA with size>2.36 mm was higher in the CC soil (51.48%) than in the WC soil (9.23%). The SA with size 1.18-2.36 mm was also higher in the CC soil (7.78%) than in the WC soil (0.62%). The SA with size 0.60-1.18 mm resulted indifferent. The SA with size between 0.30 and 0.60 mm were higher in the WC soil (13.95%) than in the CC soil (4.67%). The SA<0.30 mm was higher in the WC soil (72.56%) than in the CC soil (32.15%). It was observed that MWD and the SA>2.36 mm increased linearly with a higher POC, but decreased linearly with a higher HR. For the SA<0.30 mm, a linear decrease was observed at a higher POC, while it increased at a higher HR.

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Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. III. Distribution and kinetics of soil organic carbon in particle size fractions

Soil Research ◽

10.1071/sr9860293 ◽

1986 ◽

Vol 24 (2) ◽

pp. 293 ◽

Cited By ~ 67

Author(s):

RC Dalal ◽

RJ Mayer

Keyword(s):

Particle Size ◽

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Size Fraction ◽

Organic C ◽

Size Fractions ◽

Particle Size Fractions ◽

Clay Size Fraction ◽

Sand Size

Distribution of soil organic carbon in sand-, silt- and clay-size fractions during cultivation for periods ranging from 20 to 70 years was studied in six major soils used for cereal cropping in southern Queensland. Particle-size fractions were obtained by dispersion in water using cation exchange resin, sieving and sedimentation. In the soils' virgin state no single particle-size fraction was found to be consistently enriched as compared to the whole soil in organic C in all six soils, although the largest proportion (48%) of organic C was in the clay-size fraction; silt and sand-size fractions contained remaining organic C in equal amounts. Upon cultivation, the amounts of organic C declined from all particle-size fractions in most soils, although the loss rates differed considerably among different fractions and from the whole soil. The proportion of the sand-size fraction declined rapidly (from 26% to 12% overall), whereas that of the clay-size fraction increased from 48% to 61% overall. The proportion of silt-size organic C was least affected by cultivation in most soils. It was inferred, therefore, that the sand-size organic matter is rapidly lost from soil, through mineralization as well as disintegration into silt-size and clay-size fractions, and that the clay fraction provides protection for the soil organic matter against microbial and enzymic degradation.

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Assessment of Soil Organic Carbon Stock of Temperate Coniferous Forests in Northern Kashmir

International Journal of Environment ◽

10.3126/ije.v4i1.12186 ◽

2015 ◽

Vol 4 (1) ◽

pp. 161-178

Author(s):

Davood A. Dar ◽

Bhawana Pathak ◽

M. H. Fulekar

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Quality ◽

Carbon Stock ◽

Temperate Forest ◽

Temperate Forests ◽

Forest Site ◽

Soil Organic Carbon Stock ◽

Organic Carbon Stock

Soil organic carbon (SOC) estimation in temperate forests of the Himalaya is important to estimate their contribution to regional, national and global carbon stocks. Physico chemical properties of soil were quantified to assess soil organic carbon density (SOC) and SOC CO2 mitigation density at two soil depths (0-10 and 10-20 cms) under temperate forest in the Northern region of Kashmir Himalayas India. The results indicate that conductance, moisture content, organic carbon and organic matter were significantly higher while as pH and bulk density were lower at Gulmarg forest site. SOC % was ranging from 2.31± 0.96 at Gulmarg meadow site to 2.31 ± 0.26 in Gulmarg forest site. SOC stocks in these temperate forests were from 36.39 ±15.40 to 50.09 ± 15.51 Mg C ha-1. The present study reveals that natural vegetation is the main contributor of soil quality as it maintained the soil organic carbon stock. In addition, organic matter is an important indicator of soil quality and environmental parameters such as soil moisture and soil biological activity change soil carbon sequestration potential in temperate forest ecosystems.DOI: http://dx.doi.org/10.3126/ije.v4i1.12186International Journal of Environment Volume-4, Issue-1, Dec-Feb 2014/15; page: 161-178

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Soil organic carbon and nitrogen sequestration and turnover in aggregates under subtropical leucaena–grass pastures

Soil Research ◽

10.1071/sr18016 ◽

2018 ◽

Vol 56 (6) ◽

pp. 632 ◽

Cited By ~ 4

Author(s):

Kathryn Conrad ◽

Ram C. Dalal ◽

Ryosuke Fujinuma ◽

Neal W. Menzies

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Aggregates ◽

Soil Mass ◽

Δ13c And Δ15n ◽

Organic C ◽

Carbon And Nitrogen ◽

Nitrogen Sequestration ◽

C And N

Stabilisation and protection of soil organic carbon (SOC) in macroaggregates and microaggregates represents an important mechanism for the sequestration of SOC. Legume-based grass pastures have the potential to contribute to aggregate formation and stabilisation, thereby leading to SOC sequestration. However, there is limited research on the C and N dynamics of soil organic matter (SOM) fractions in deep-rooted legume leucaena (Leucaena leucocephala)–grass pastures. We assessed the potential of leucaena to sequester carbon (C) and nitrogen (N) in soil aggregates by estimating the origin, quantity and distribution in the soil profile. We utilised a chronosequence (0–40 years) of seasonally grazed leucaena stands (3–6 m rows), which were sampled to a depth of 0.3 m at 0.1-m intervals. The soil was wet-sieved for different aggregate sizes (large macroaggregates, >2000 µm; small macroaggregates, 250–2000 µm; microaggregates, 53–250 µm; and <53 µm), including occluded particulate organic matter (oPOM) within macroaggregates (>250 µm), and then analysed for organic C, N and δ13C and δ15N. Leucaena promoted aggregation, which increased with the age of the leucaena stands, and in particular the formation of large macroaggregates compared with grass in the upper 0.2 m. Macroaggregates contained a greater SOC stock than microaggregates, principally as a function of the soil mass distribution. The oPOM-C and -N concentrations were highest in macroaggregates at all depths. The acid nonhydrolysable C and N distribution (recalcitrant SOM) provided no clear distinction in stabilisation of SOM between pastures. Leucaena- and possibly other legume-based grass pastures have potential to sequester SOC through stabilisation and protection of oPOM within macroaggregates in soil.

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Tracing soil organic carbon in the lower Amazon River and its tributaries using GDGT distributions and bulk organic matter properties

Geochimica et Cosmochimica Acta ◽

10.1016/j.gca.2012.05.014 ◽

2012 ◽

Vol 90 ◽

pp. 163-180 ◽

Cited By ~ 69

Author(s):

Jung-Hyun Kim ◽

Claudia Zell ◽

Patricia Moreira-Turcq ◽

Marcela A.P. Pérez ◽

Gwenaël Abril ◽

...

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Amazon River ◽

Bulk Organic Matter

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Organic matter mineralisation in contrasting agricultural soils amended with sewage sludge .

Spanish Journal of Soil Science ◽

10.3232/sjss.2014.v4.n2.02 ◽

2014 ◽

Vol 4 ◽

Author(s):

Jose Navarro Pedreño ◽

Ignacio Gómez Lucas ◽

Jose Martín Soriano Disla

Keyword(s):

Organic Matter ◽

Single Dose ◽

Sewage Sludge ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Agricultural Soils ◽

Dry Weight ◽

Soil C ◽

Multiple Sensor ◽

Sludge Application

The mineralisation of organic matter (OM) when sewage sludge was used as amendment in 70 contrasting agricultural soils from Spain was analysed. Soils received a single dose of sewage sludge (equivalent to 50t dry weight ha-1) and the O2 consumption was continuously monitored for 30 days using a multiple sensor respirometer in a laboratory experiment. The cumulative O2 consumption and rates after 8 and 30 days of incubation (O2 cum 8d, 30d and O2 rate 8d, 30d), the respiratory quotient (RQ), the maximum O2 rates over the incubation period (O2 max) and time from the beginning of the incubation when O2 max occurred (Tmax), were determined in both amended and non-amended soils. Sewage sludge application resulted in increased values for O2 max, O2 rate 8d, and O2 cum 30d. Differences were minor for Tmax, RQ 8d and O2 rate 30d. A considerable amount of the initial OM applied was mineralised during the first 8 days. Organic matter decomposition (as expressed by O2 cum 30d) was favoured in soils with high values of pH, carbonates, soil organic carbon and low values of amorphous Mn. Soils with these characteristics may potentially lose soil C after sewage sludge application.

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Effect of Different Tillage Systems on Soil Organic Carbon and Enzymatic Activity

Agronomy ◽

10.3390/agronomy12010208 ◽

2022 ◽

Vol 12 (1) ◽

pp. 208

Author(s):

Małgorzata Szostek ◽

Ewa Szpunar-Krok ◽

Renata Pawlak ◽

Jadwiga Stanek-Tarkowska ◽

Anna Ilek

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Organic Farming ◽

Total Nitrogen ◽

Farming Systems ◽

Conventional Tillage ◽

Tillage Systems ◽

Organic Farming Systems ◽

Organic Matter Fractions

The aim of the study was to compare the effect of conventional, simplified, and organic farming systems on changes in the content of soil organic carbon, organic matter fractions, total nitrogen, and the enzymatic activity. The research was conducted from 2016–2018 on arable land in the south-eastern part of Poland. The selected soils were cultivated in conventional tillage (C_Ts), simplified tillage (S_Ts), and organic farming (O_Fs) systems. The analyses were performed in soil from the soil surface layers (up to 25 cm depth) of the experimental plots. The highest mean contents of soil organic carbon, total nitrogen, and organic matter fractions were determined in soils subjected to the simplified tillage system throughout the experimental period. During the study period, organic carbon concentration on surface soil layers under simplified tillage systems was 31 and 127% higher than the soil under conventional tillage systems and organic farming systems, respectively. Also, the total nitrogen concentration in those soils was more than 40% and 120% higher than conventional tillage systems and organic farming systems, respectively. Moreover, these soils were characterised by a progressive decline in SOC and Nt resources over the study years. There was no significant effect of the analysed tillage systems on the C:N ratio. The tillage systems induced significant differences in the activity of the analysed soil enzymes, i.e., dehydrogenase (DH) and catalase (CAT). The highest DH activity throughout the experiment was recorded in the O_Fs soils, and the mean value of this parameter was in the range of 6.01–6.11 μmol TPF·kg−1·h−1. There were no significant differences in the CAT values between the variants of the experiment. The results confirm that, regardless of other treatments, such as the use of organic fertilisers, tillage has a negative impact on the content of SOC and organic matter fractions in the O_Fs system. All simplifications in tillage reducing the interference with the soil surface layer and the use of organic fertilisers contribute to improvement of soil properties and enhancement of biological activity, which helps to maintain its productivity and fertility.

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Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis

Biogeosciences ◽

10.5194/bg-12-6915-2015 ◽

2015 ◽

Vol 12 (23) ◽

pp. 6915-6930 ◽

Cited By ~ 84

Author(s):

J. E. Vonk ◽

S. E. Tank ◽

P. J. Mann ◽

R. G. M. Spencer ◽

C. C. Treat ◽

...

Keyword(s):

Organic Carbon ◽

Dissolved Organic Carbon ◽

Aquatic Systems ◽

The Arctic ◽

Permafrost Region ◽

Soil Leachate ◽

Discontinuous Permafrost ◽

Spatial Coverage ◽

Continuous Permafrost ◽

Permafrost Regions

Abstract. As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to aquatic ecosystems. Dissolved organic carbon (DOC) is a key regulator of aquatic metabolism, yet knowledge of the mechanistic controls on DOC biodegradability is currently poor due to a scarcity of long-term data sets, limited spatial coverage of available data, and methodological diversity. Here, we performed parallel biodegradable DOC (BDOC) experiments at six Arctic sites (16 experiments) using a standardized incubation protocol to examine the effect of methodological differences commonly used in the literature. We also synthesized results from 14 aquatic and soil leachate BDOC studies from across the circum-arctic permafrost region to examine pan-arctic trends in BDOC. An increasing extent of permafrost across the landscape resulted in higher DOC losses in both soil and aquatic systems. We hypothesize that the unique composition of (yedoma) permafrost-derived DOC combined with limited prior microbial processing due to low soil temperature and relatively short flow path lengths and transport times, contributed to a higher overall terrestrial and freshwater DOC loss. Additionally, we found that the fraction of BDOC decreased moving down the fluvial network in continuous permafrost regions, i.e. from streams to large rivers, suggesting that highly biodegradable DOC is lost in headwater streams. We also observed a seasonal (January–December) decrease in BDOC in large streams and rivers, but saw no apparent change in smaller streams or soil leachates. We attribute this seasonal change to a combination of factors including shifts in carbon source, changing DOC residence time related to increasing thaw-depth, increasing water temperatures later in the summer, as well as decreasing hydrologic connectivity between soils and surface water as the thaw season progresses. Our results suggest that future climate warming-induced shifts of continuous permafrost into discontinuous permafrost regions could affect the degradation potential of thaw-released DOC, the amount of BDOC, as well as its variability throughout the Arctic summer. We lastly recommend a standardized BDOC protocol to facilitate the comparison of future work and improve our knowledge of processing and transport of DOC in a changing Arctic.

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Climate Variability in the Context of Climate Change: El Niño and Other Oscillations

Climate Variability and the Global Harvest ◽

10.1093/oso/9780195137637.003.0006 ◽

2008 ◽

Author(s):

Cynthia Rosenzweig ◽

Daniel Hillel

Keyword(s):

Climate Change ◽

Climate Variability ◽

North Atlantic ◽

El Niño ◽

El Nino ◽

Global Climate ◽

Climate System ◽

The Arctic ◽

The Pacific ◽

Earth’S Climate

The climate system envelops our planet, with swirling fluxes of mass, momentum, and energy through air, water, and land. Its processes are partly regular and partly chaotic. The regularity of diurnal and seasonal fluctuations in these processes is well understood. Recently, there has been significant progress in understanding some of the mechanisms that induce deviations from that regularity in many parts of the globe. These mechanisms include a set of combined oceanic–atmospheric phenomena with quasi-regular manifestations. The largest of these is centered in the Pacific Ocean and is known as the El Niño–Southern Oscillation. The term “oscillation” refers to a shifting pattern of atmospheric pressure gradients that has distinct manifestations in its alternating phases. In the Arctic and North Atlantic regions, the occurrence of somewhat analogous but less regular interactions known as the Arctic Oscillation and its offshoot, the North Atlantic Oscillation, are also being studied. These and other major oscillations influence climate patterns in many parts of the globe. Examples of other large-scale interactive ocean–atmosphere– land processes are the Pacific Decadal Oscillation, the Madden-Julian Oscillation, the Pacific/North American pattern, the Tropical Atlantic Variability, the West Pacific pattern, the Quasi-Biennial Oscillation, and the Indian Ocean Dipole. In this chapter we review the earth’s climate system in general, define climate variability, and describe the processes related to ENSO and the other major systems and their interactions. We then consider the possible connections of the major climate variability systems to anthropogenic global climate change. The climate system consists of a series of fluxes and transformations of energy (radiation, sensible and latent heat, and momentum), as well as transports and changes in the state of matter (air, water, solid matter, and biota) as conveyed and influenced by the atmosphere, the ocean, and the land masses. Acting like a giant engine, this dynamic system is driven by the infusion, transformation, and redistribution of energy.

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