scholarly journals Does elevated atmospheric CO2affect soil carbon burial and soil weathering in a forest ecosystem?

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5356 ◽  
Author(s):  
Miquel A. Gonzalez-Meler ◽  
Armen Poghosyan ◽  
Yaniria Sanchez-de Leon ◽  
Eduardo Dias de Olivera ◽  
Richard J. Norby ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Time Scales ◽  
Experimental Studies ◽  
Forest Site ◽  
Soil C ◽  
Soil Weathering ◽  
Oak Ridge ◽  
Soil Mixing ◽  
C Storage ◽  
Advection Term

Most experimental studies measuring the effects of climate change on terrestrial C cycling have focused on processes that occur at relatively short time scales (up to a few years). However, climate-soil C interactions are influenced over much longer time scales by bioturbation and soil weathering affecting soil fertility, ecosystem productivity, and C storage. Elevated CO2can increase belowground C inputs and stimulate soil biota, potentially affecting bioturbation, and can decrease soil pH which could accelerate soil weathering rates. To determine whether we could resolve any changes in bioturbation or C storage, we investigated soil profiles collected from ambient and elevated-CO2plots at the Free-Air Carbon-Dioxide Enrichment (FACE) forest site at Oak Ridge National Laboratory after 11 years of13C-depleted CO2release. Profiles of organic carbon concentration,δ13C values, and activities of137Cs,210Pb, and226Ra were measured to ∼30 cm depth in replicated soil cores to evaluate the effects of elevated CO2on these parameters. Bioturbation models based on fitting advection-diffusion equations to137Cs and210Pb profiles showed that ambient and elevated-CO2plots had indistinguishable ranges of apparent biodiffusion constants, advection rates, and soil mixing times, although apparent biodiffusion constants and advection rates were larger for137Cs than for210Pb as is generally observed in soils. Temporal changes in profiles ofδ13C values of soil organic carbon (SOC) suggest that addition of new SOC at depth was occurring at a faster rate than that implied by the net advection term of the bioturbation model. Ratios of (210Pb/226Ra) may indicate apparent soil mixing cells that are consistent with biological mechanisms, possibly earthworms and root proliferation, driving C addition and the mixing of soil between ∼4 cm and ∼18 cm depth. Burial of SOC by soil mixing processes could substantially increase the net long-term storage of soil C and should be incorporated in soil-atmosphere interaction models.

Impact of pasture establishment on CO2 emissions from a Vertisol: Consequences for soil C sequestration (Martinique, West Indies)

2006 ◽  
Vol 86 (5) ◽  
pp. 779-782 ◽  
Author(s):  
T. Chevallier ◽  
E. Blanchart ◽  
A. Albrecht ◽  
C. Feller ◽  
M. Bernoux
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
West Indies ◽  
C Sequestration ◽  
Soil C ◽  
C Storage ◽  
Digitaria Decumbens ◽  
Market Gardening ◽  
Soil C Sequestration ◽  
Soc Mineralization

Establishing pasture on cultivated tropical Vertisols can increase soil organic carbon (SOC), but it is not known whether this increase results solely from enhanced inputs or also from suppressed mineralization. We measured CO2 emissions from a Vertisol under market gardening, and under “young” and “old” Digitaria decumbens pastures. Emissions of CO2-C increased in pastures, compared to market gardening, but relative SOC mineralization (CO2-C/SOC) decreased, implying the protection of SOC against mineralization with pasture establishment. Key words: Tropical pasture, carbon fluxes, soil organic carbon, physical protection, C storage

scholarly journals Concept of soil organic carbon stock

2020 ◽  
Vol 16 (2) ◽  
pp. 290-294
Author(s):  
Kabir Debbarma
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Fertility ◽  
Management Practices ◽  
Surface Soil ◽  
Experimental Studies ◽  
Chemical Properties ◽  
Organic C ◽  
C Storage

Soil organic carbon (SOC) controls ecosystem and agro-ecosystem function, influencing soil fertility, water holding capacity and many other functions. The total amount of C stored in the surface soil is higher than sub surface soil area. It is estimated that the amount of C in the atmospheric pool is about 766 Pg C and about 566 Pg C in living vegetation. It is also of global importance because of its role in the global carbon cycle and therefore, the part it plays in the mitigation of atmospheric levels of greenhouse gases (GHGs). Different factors such as topography, climate, and soil physico-chemical properties also effect SOC stock in soil. Past long-term experimental studies have shown that soil organic C is highly sensitive to changes in land use, with changes from native ecosystems such as forest or grassland to agricultural systems almost always resulting in a loss of SOC. Land use change in different part of the world has also been observed to influence SOC stocks in different depth of the soil. Proper management of land use and land management practices and application of fertilizers, organic compost and manures could leads to greater C-storage in the soil, improves soil fertility and crop yield.

scholarly journals The undetected loss of aged carbon from boreal mineral soils

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Geert Hensgens ◽  
Hjalmar Laudon ◽  
Mark S. Johnson ◽  
Martin Berggren
Keyword(s):  
Organic Carbon ◽  
Boreal Forest ◽  
Soil C ◽  
Earth Systems ◽  
Nuclear Bomb ◽  
C Cycle ◽  
Water Extractable Organic Carbon ◽  
High Lability ◽  
Mineral Soils ◽  
Terrestrial Biomes

AbstractThe boreal forest is among the largest terrestrial biomes on earth, storing more carbon (C) than the atmosphere. Due to rapid climatic warming and enhanced human development, the boreal region may have begun transitioning from a net C sink to a net source. This raises serious concern that old biogenic soil C can be re-introduced into the modern C cycle in near future. Combining bio-decay experiments, mixing models and the Keeling plot method, we discovered a distinct old pre-bomb organic carbon fraction with high biodegradation rate. In total, 34 ± 12% of water-extractable organic carbon (WEOC) in podzols, one of the dominating boreal soil types, consisted of aged (~ 1000 year) labile C. The omission of this aged (i.e., Δ14C depleted) WEOC fraction in earlier studies is due to the co-occurrence with Δ14C enriched modern C formed following 1950s nuclear bomb testing masking its existence. High lability of aged soil WEOC and masking effects of modern Δ14C enriched C suggests that the risk for mobilization and re-introduction of this ancient C pool into the modern C cycle has gone undetected. Our findings have important implications for earth systems models in terms of climate-carbon feedbacks and the future C balance of the boreal forest.

scholarly journals Higher stand densities can promote soil carbon storage after conversion of temperate mixed natural forests to larch plantations

2020 ◽  
Author(s):  
Meng Na ◽  
Xiaoyang Sun ◽  
Yandong Zhang ◽  
Zhihu Sun ◽  
Johannes Rousk
Keyword(s):  
Forest Management ◽  
Soil Carbon ◽  
Stand Density ◽  
C Sequestration ◽  
Tree Density ◽  
Natural Forests ◽  
Soil C ◽  
C Storage ◽  
Soil C Storage ◽  
Soil C Sequestration

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.

Post-thinning soil organic matter evolution and soil CO2 effluxes in temperate radiata pine plantations: impacts of moderate thinning regimes on the forest C cycle

2012 ◽  
Vol 42 (11) ◽  
pp. 1953-1964 ◽  
Author(s):  
Irene Fernandez ◽  
Juan Gabriel Álvarez-González ◽  
Beatríz Carrasco ◽  
Ana Daría Ruíz-González ◽  
Ana Cabaneiro
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Radiata Pine ◽  
Soil Samples ◽  
Mitigation Strategies ◽  
Change Scenario ◽  
Soil C ◽  
C Storage ◽  
C Cycle ◽  
C And N

Forest ecosystems can act as C sinks, thus absorbing a high percentage of atmospheric CO2. Appropriate silvicultural regimes can therefore be applied as useful tools in climate change mitigation strategies. The present study analyzed the temporal changes in the effects of thinning on soil organic matter (SOM) dynamics and on soil CO2 emissions in radiata pine ( Pinus radiata D. Don) forests. Soil C effluxes were monitored over a period of 2 years in thinned and unthinned plots. In addition, soil samples from the plots were analyzed by solid-state 13C-NMR to determine the post-thinning SOM composition and fresh soil samples were incubated under laboratory conditions to determine their biodegradability. The results indicate that the potential soil C mineralization largely depends on the proportion of alkyl-C and N-alkyl-C functional groups in the SOM and on the microbial accessibility of the recalcitrant organic pool. Soil CO2 effluxes varied widely between seasons and increased exponentially with soil heating. Thinning led to decreased soil respiration and attenuation of the seasonal fluctuations. These effects were observed for up to 20 months after thinning, although they disappeared thereafter. Thus, moderate thinning caused enduring changes to the SOM composition and appeared to have temporary effects on the C storage capacity of forest soils, which is a critical aspect under the current climatic change scenario.

Comparison of carbon and nitrogen storage in mineral soils of graminoid and shrub tundra sites, western Greenland

2016 ◽  
Vol 2 (4) ◽  
pp. 165-182 ◽  
Author(s):  
Chelsea L. Petrenko ◽  
Julia Bradley-Cook ◽  
Emily M. Lacroix ◽  
Andrew J. Friedland ◽  
Ross A. Virginia
Keyword(s):  
Vegetation Type ◽  
Mineral Soil ◽  
Biotic Interactions ◽  
The Arctic ◽  
Soil C ◽  
N Storage ◽  
C Storage ◽  
Arctic Soils ◽  
C Pools ◽  
C And N

Shrub species are expanding across the Arctic in response to climate change and biotic interactions. Changes in belowground carbon (C) and nitrogen (N) storage are of global importance because Arctic soils store approximately half of global soil C. We collected 10 (60 cm) soil cores each from graminoid- and shrub-dominated soils in western Greenland and determined soil texture, pH, C and N pools, and C:N ratios by depth for the mineral soil. To investigate the relative chemical stability of soil C between vegetation types, we employed a novel sequential extraction method for measuring organo-mineral C pools of increasing bond strength. We found that (i) mineral soil C and N storage was significantly greater under graminoids than shrubs (29.0 ± 1.8 versus 22.5 ± 3.0 kg·C·m−2 and 1.9 ± .12 versus 1.4 ± 1.9 kg·N·m−2), (ii) chemical mechanisms of C storage in the organo-mineral soil fraction did not differ between graminoid and shrub soils, and (iii) weak adsorption to mineral surfaces accounted for 40%–60% of C storage in organo-mineral fractions — a pool that is relatively sensitive to environmental disturbance. Differences in these C pools suggest that rates of C accumulation and retention differ by vegetation type, which could have implications for predicting future soil C pool storage.

Soil carbon sequestration with forest expansion in an arctic forest–tundra landscape

2004 ◽  
Vol 34 (7) ◽  
pp. 1538-1542 ◽  
Author(s):  
Heidi Steltzer
Keyword(s):  
Soil Carbon ◽  
Picea Glauca ◽  
White Spruce ◽  
Tree Age ◽  
Forest Expansion ◽  
Soil C ◽  
C Storage ◽  
C Pools ◽  
Sampling Locations

Soil carbon (C) and nitrogen (N) pools were measured under the canopy of 29 white spruce (Picea glauca (Moench) Voss) trees and in the surrounding tundra 3 and 6 m away from each tree at three sites of recent forest expansion along the Agashashok River in northwestern Alaska. The aim was to characterize the potential for forest expansion to lead to increased soil C pools across diverse tundra types. Soil C beneath the trees correlated positively with tree age, suggesting that tree establishment has led to C storage in the soils under their canopy at a rate of 18.5 ± 4.6 g C·m–2·year–1. Soil C in the surrounding tundra did not differ from those under the trees and showed no relationship to tree age. This characterization of the soil C pools at the 3-m scale strengthens the assertion that the pattern associated with the trees is an effect of the trees, because tree age cannot explain variation among tundra sampling locations at this scale. Potential mechanisms by which these white spruce trees could increase soil C pools include greater production and lower litter quality.

scholarly journals Microbial Mechanisms Mediating Increased Soil C Storage under Elevated Atmospheric N Deposition

2012 ◽  
Vol 79 (4) ◽  
pp. 1191-1199 ◽  
Author(s):  
Sarah D. Eisenlord ◽  
Zachary Freedman ◽  
Donald R. Zak ◽  
Kai Xue ◽  
Zhili He ◽  
...  
Keyword(s):  
Forest Floor ◽  
Forest Ecosystems ◽  
N Deposition ◽  
Fungal Communities ◽  
Functional Genes ◽  
Atmospheric N Deposition ◽  
Soil C ◽  
C Storage ◽  
Genes Encoding ◽  
Soil C Storage

ABSTRACTFuture rates of anthropogenic N deposition can slow the cycling and enhance the storage of C in forest ecosystems. In a northern hardwood forest ecosystem, experimental N deposition has decreased the extent of forest floor decay, leading to increased soil C storage. To better understand the microbial mechanisms mediating this response, we examined the functional genes derived from communities of actinobacteria and fungi present in the forest floor using GeoChip 4.0, a high-throughput functional-gene microarray. The compositions of functional genes derived from actinobacterial and fungal communities was significantly altered by experimental nitrogen deposition, with more heterogeneity detected in both groups. Experimental N deposition significantly decreased the richness and diversity of genes involved in the depolymerization of starch (∼12%), hemicellulose (∼16%), cellulose (∼16%), chitin (∼15%), and lignin (∼16%). The decrease in richness occurred across all taxonomic groupings detected by the microarray. The compositions of genes encoding oxidoreductases, which plausibly mediate lignin decay, were responsible for much of the observed dissimilarity between actinobacterial communities under ambient and experimental N deposition. This shift in composition and decrease in richness and diversity of genes encoding enzymes that mediate the decay process has occurred in parallel with a reduction in the extent of decay and accumulation of soil organic matter. Our observations indicate that compositional changes in actinobacterial and fungal communities elicited by experimental N deposition have functional implications for the cycling and storage of carbon in forest ecosystems.

Potential soil carbon sequestration of agricultural land around the world

2021 ◽  
Author(s):  
Sylvia Vetter ◽  
Michael Martin ◽  
Pete Smith
Keyword(s):  
Organic Carbon ◽  
Management Practices ◽  
Agricultural Land ◽  
Ghg Emissions ◽  
C Sequestration ◽  
Organic Soils ◽  
Soil C ◽  
Sequestration Potential ◽  
The World ◽  
Soil C Sequestration

<p>Reducing greenhouse gas (GHG) emissions in to the atmosphere to limit global warming is the big challenge of the coming decades. The focus lies on negative emission technologies to remove GHGs from the atmosphere from different sectors. Agriculture produces around a quarter of all the anthropogenic GHGs globally (including land use change and afforestation). Reducing these net emissions can be achieved through techniques that increase the soil organic carbon (SOC) stocks. These techniques include improved management practices in agriculture and grassland systems, which increase the organic carbon (C) input or reduce soil disturbances. The C sequestration potential differs among soils depending on climate, soil properties and management, with the highest potential for poor soils (SOC stock farthest from saturation).</p><p>Modelling can be used to estimate the technical potential to sequester C of agricultural land under different mitigation practices for the next decades under different climate scenarios. The ECOSSE model was developed to simulate soil C dynamics and GHG emissions in mineral and organic soils. A spatial version of the model (GlobalECOSSE) was adapted to simulate agricultural soils around the world to calculate the SOC change under changing management and climate.</p><p>Practices like different tillage management, crop rotations and residue incorporation showed regional differences and the importance of adapting mitigation practices under an increased changing climate. A fast adoption of practices that increase SOC has its own challenges, as the potential to sequester C is high until the soil reached a new C equilibrium. Therefore, the potential to use soil C sequestration to reduce overall GHG emissions is limited. The results showed a high potential to sequester C until 2050 but much lower rates in the second half of the century, highlighting the importance of using soil C sequestration in the coming decades to reach net zero by 2050.</p>

Soil organic carbon stocks under different páramo vegetation covers in Ecuador’s northern Andes

2021 ◽  
Author(s):  
Marlon Calispa ◽  
Raphaël van Ypersele ◽  
Benoît Pereira ◽  
Sebastián Páez-Bimos ◽  
Veerle Vanacker ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Vegetation Type ◽  
Regional Scale ◽  
Soil Samples ◽  
Related Factors ◽  
Organic C ◽  
Soil C ◽  
C Storage ◽  
Soc Stocks ◽  
Volcanic Ash Soils

<p>The Ecuadorian páramo, a neotropical ecosystem located in the upper Andes, acts as a constant source of high-quality water. It also stores significant amounts of C at the regional scale. In this region, volcanic ash soils sustain most of the paramo, and C storage results partly from their propensity to accumulate organic matter. Vegetation type is known to influence the balance between plant C inputs and soil C losses, ultimately affecting the soil organic C (SOC) content and stock. Tussock-forming grass (spp. Calamagrostis Intermedia; TU), cushion-like plants (spp. Azorella pedunculata; CU) and shrubs and trees (Polylepis stands) are commonly found in the páramo. Our understanding of SOC stocks and dynamics in the páramo remains limited, despite mounting concerns that human activities are increasingly affecting vegetation and potentially, the capacity of these ecosystems to store C.</p><p>Here, we compare the organic C content and stock in soils under tussock-forming grass (spp. Calamagrostis Intermedia; TU) and soils under cushion-like plants (spp. Azorella pedunculata; CU). The study took place at Jatunhuayco, a watershed on the western slopes of Antisana volcano in the northern Ecuadorian Andes. Two areas of similar size (~0.35 km<sup>2</sup>) were surveyed. Fourty soil samples were collected randomly in each area to depths varying from 10 to 30 cm (A horizon) and from 30 to 75 cm (2Ab horizon). The soils are Vitric Andosols and the 2Ab horizon corresponds to a soil buried by the tephra fall from the Quilotoa eruption about 800 yr. BP. Sixteen intact soil samples were collected in Kopecky's cylinders for bulk density (BD) determination of each horizon.</p><p>The average SOC content in the A horizon of the CU sites (9.4±0.5%) is significantly higher (Mann-Whitney U test, p<0.05) than that of the TU sites (8.0±0.4%), probably reflecting a larger input of root biomass from the cushion-forming plants. The 2Ab horizon contains less organic C (i.e. TU: 4.3±0.3% and CU: 4.0±0.4%) than the A horizon, but the SOC contents are undistinguishable between the two vegetation types. This suggests that the influence of vegetation type on SOC is limited to the A horizon. The average SOC stocks (in the first 30 cm from the soil) for TU and CU are 20.04±1.1 and 18.23±1.0 kg/m<sup>2</sup>,<sup></sup>respectively. These values are almost two times greater than the global average reported for Vitric Andosols (~8.2 kg/m<sup>2</sup> ), but are lower than the estimates obtained for some wetter Andean páramos (22.5±5 kg/m<sup>2</sup>, 270% higher rainfall) from Ecuador. Our stock values further indicate that vegetation type has a limited effect on C storage in the young volcanic ash soils found at Jatunhuyaco. Despite a higher SOC content, the CU soils store a stock of organic C similar to that estimated for the TU soils. This likely reflects the comparatively lower BD of the former soils (650±100 vs. 840±30 kg/m<sup>3</sup>). Additional studies are needed in order to establish the vegetation-related factors driving the SOC content and stability in the TU and CU soils.</p>

Sign in / Sign up

Export Citation Format

Share Document