Phytolith biogeochemistry and silicon regulation of terrestrial biogeochemical carbon cycle

2021 ◽  
Author(s):  
Zhaoliang Song ◽  
Yuntao Wu
Keyword(s):  
Organic Carbon ◽  
Management Practices ◽  
Net Primary Productivity ◽  
Plant Biomass ◽  
Lignin Content ◽  
C Sequestration ◽  
Active Management ◽  
Abiotic And Biotic Stresses ◽  
Biotic Stresses ◽  
C Cycle

<p>Phytoliths in most terrestrial plant tissues as a result of silica biomineralization may occlude 0.1–6% of organic carbon (C). Phytolith-occluded carbon (PhytOC) comes mainly from photosynthesis and can be stable in soil and sediment environments for several hundred to thousand years. Phytolith turnover may influence terrestrial biogeochemical C cycle either directly through phytolith C sequestration or indirectly through regulating plant biomass C composition and accumulation, and soil organic carbon (SOC) stability. Phytolith C sequestration rates in terrestrial ecosystems of China increase in the following order: grasslands < forests < croplands. Active management practices including cultivation of silicon (Si)-rich plants and amendment of Si-rich materials (e.g., basalt powder and biochar) to increase aboveground net primary productivity (ANPP) and Si supply can significantly increase phytolith C sequestration. The dissolved Si from silicate weathering and phytolith dissolution can decrease plant lignin content and increase the accumulation of plant biomass C through mitigating abiotic and biotic stresses and improving stoichiometry of C, nitrogen (N) and phosphorus (P). The recovery of plant biomass C in response to Si accumulation usually exhibits an S-shaped curve under biotic stress and a bell-shaped curve under abiotic stresses. Generally, Si can recover approximately 30 to 40% of plant biomass C under abiotic and biotic stresses. Phytolith and related dissolved Si in soils can increase SOC stability through phytolith adsorption, Si and aluminum interaction, and Si and iron interaction.</p>

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>

Abiotic and Biotic Stresses and Changes in the Lignin Content and Composition in Plants

2010 ◽  
Vol 52 (4) ◽  
pp. 360-376 ◽  
Author(s):  
Jullyana Cristina Magalhães Silva Moura ◽  
Cesar Augusto Valencise Bonine ◽  
Juliana de Oliveira Fernandes Viana ◽  
Marcelo Carnier Dornelas ◽  
Paulo Mazzafera
Keyword(s):  
Lignin Content ◽  
Abiotic And Biotic Stresses ◽  
Biotic Stresses

scholarly journals Soil organic carbon along an altitudinal gradient in the Despeñaperros nature reserve, Southern Spain

2014 ◽  
Vol 6 (2) ◽  
pp. 2495-2521
Author(s):  
L. Parras-Alcántara ◽  
B. Lozano-García ◽  
A. Galán-Espejo
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Altitudinal Gradient ◽  
Nature Reserve ◽  
Regional Scale ◽  
C Sequestration ◽  
Organic Carbon Content ◽  
Soil System ◽  
Disturbed Soil ◽  
C Cycle

Abstract. Soil organic carbon (SOC) is extremely important in the global carbon (C) cycle as C sequestration in non-disturbed soil ecosystems can be a sink of C and mitigate greenhouse gas driven climate change. Soil organic carbon changes in space and time are relevant to understand the soil system and its role in the C cycle, and this is why the influence of topographic position on SOC should be studied. Seven topographic positions (toposequence) were analyzed along an altitudinal gradient between 607 and 1168 m.a.s.l. in the Despeñaperros nature reserve (Natural Park). At each study site, soil control sections (25 cm intervals) were sampled. The studied soils are mineral soils with > 3% organic carbon content. The main characteristic of the studied soils is SOC reduction with depth; these results were related to the gravel content and to the bulk density. The SOC on the surface was highly variable along the altitudinal gradient ranging between 27.3 and 39.9 g kg−1. The SOC stock (SOCS) in the studied area was influenced by the altitude, varying between 53.8 and 158.0 Mg ha−1. Therefore, the altitude factor must be considered in the SOCS estimation at local-regional scale.

Soil organic carbon dynamics and sequestration potential in cropland-grassland agro-ecosystems

2021 ◽  
Author(s):  
Thomas Guillaume ◽  
David Makowski ◽  
Zamir Libohova ◽  
Luca Bragazza ◽  
Sokrat Sinaj
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
Storage Capacity ◽  
Agricultural Soils ◽  
C Sequestration ◽  
Boundary Line ◽  
Monitoring Networks ◽  
Soil C ◽  
Sequestration Potential

<p>Increasing soil organic carbon (SOC) in agro-ecosystems enables to address simultaneously food security as well as climate change adaptation and mitigation. Croplands represent a great potential to sequester atmospheric C because they are depleted in SOC. Hence, reliable estimations of SOC deficits in agro-ecosystems are crucial to evaluate the C sequestration potential of agricultural soils and support management practices. Using a 30-year old soil monitoring networks with 250 sites established in western Switzerland, we identified factors driving the long-term SOC dynamics in croplands (CR) and permanent grasslands (PG) and quantified SOC deficit. A new relationship between the silt + clay (SC) soil particles and the C stored in the mineral-associated fraction (MAOMC) was established. We also tested the assumption about whether or not PG can be used as carbon-saturated reference sites. The C-deficit in CR constituted about a third of their potential SOC content and was mainly affected by the proportion of temporary grassland in the crop rotation. SOC accrual or loss were the highest in sites that experienced land-use change. The MAOMC level in PG depended on the C accrual history, indicating that C-saturation level was not coincidental. Accordingly, the relationship between MAOMC and SC to determine soil C-saturation should be estimated by boundary line analysis instead of least squares regressions. In conclusion, PG do provide an additional SOC storage capacity under optimal management, though the storage capacity is greater for CR.</p>

CARBON STOCKS, LITTERFALL AND PRUNING RESIDUES IN MONOCULTURE AND AGROFORESTRY CACAO PRODUCTION SYSTEMS

2018 ◽  
Vol 55 (3) ◽  
pp. 452-470 ◽  
Author(s):  
ULF SCHNEIDEWIND ◽  
WIEBKE NIETHER ◽  
LAURA ARMENGOT ◽  
MONIKA SCHNEIDER ◽  
DANIELA SAUER ◽  
...  
Keyword(s):  
Management Practices ◽  
Stand Structure ◽  
Production Systems ◽  
Plant Biomass ◽  
Farming Systems ◽  
C Sequestration ◽  
Agroforestry Systems ◽  
Soil C ◽  
C Stocks ◽  
Pruning Residues

SUMMARYAgroforestry systems (AFS) can serve to decrease ecosystem carbon (C) losses caused by deforestation and inadequate soil management. Because of their shade tolerance, cacao plants are suitable to be grown in AFS, since they can be combined with other kinds of trees and shrubs. The potential for C sequestration in cacao farming systems depends on various factors, such as management practices, stand structure and plantation age. We compared conventionally and organically managed cacao monoculture systems (MCS) and AFS in Sara Ana (Bolivia) with respect to C stocks in plant biomass and to amounts of litterfall and pruning residues. The total aboveground C stocks of the AFS (26 Mg C ha−1) considerably exceeded those of the MCS (~7 Mg C ha−1), although the biomass of cacao trees was greater in the MCS compared to the AFS. Due to higher tree density, annual litterfall in the AFS (2.2 Mg C ha−1 year−1) substantially exceeded that in the MCS (1.2 Mg C ha−1 year−1). The amounts of C in pruning residues (2.6 Mg C ha−1 year−1 in MCS to 4.3 Mg C ha−1 year−1 in AFS) was more than twice those in the litterfall. Annual nitrogen (N) inputs to the soil through pruning residues of cacao and N-fixing trees were up to 10 times higher than the N inputs through external fertiliser application. We conclude that appropriate management of cacao AFS, involving the pruning of leguminous trees, will lead to increases in biomass, litter quantity and quality as well as soil C and N stocks. Thus, we recommend stimulating the expansion of well-managed AFS to improve soil fertility and enhance C sequestration in soils.

scholarly journals Soil organic carbon stocks under different land uses in Chure region of Makawanpur district, Nepal

2019 ◽  
Vol 16 (2) ◽  
pp. 13-23 ◽  
Author(s):  
P Ghimire ◽  
B Bhatta ◽  
B Pokhrel ◽  
G Kafle ◽  
P Paudel
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Management Practices ◽  
C Sequestration ◽  
Organic Carbon Content ◽  
Degraded Forest ◽  
Degraded Land ◽  
Soil C ◽  
Soc Stock

Soil C sequestration through enhanced land use is a good strategy to mitigate the increasing concentration of atmospheric CO2. A study was conducted in Chhatiwan VDC of Makawanpur District to compare soil organic carbon (SOC) stocks of four main land use types such as forest, degraded forest, Khet and Bari land. Stratified random sampling method was used for collecting soil samples. Organic carbon content was determined by Walkley and Black method. Total SOC stock of different types of land followed the order: as Forest (110.0 t ha-1) > Bari (96.5 t ha-1) > Khet (86.8 t ha-1) > Degraded land (72.0 t ha-1). The SOC% declined with soil depths. The SOC% at 0–20 cm depth was highest (1.26 %) that recorded in the forest soils and lowest (0.37%) at 80- 100cm depth in degraded forest land. Thus, the SOC stock varied with land use systems and soil depths. The study suggests a need for appropriate land use strategy and sustainable soil management practices to improve SOC stock. SAARC J. Agri., 16(2): 13-23 (2018)

scholarly journals Decoupling of Carbon and Nitrogen Under Elevated CO2 in a Typical Alpine Ecosystem

2021 ◽  
Author(s):  
Guang Zhao ◽  
Yao Chen ◽  
Yangjian Zhang ◽  
Juntao Zhu ◽  
Nan Cong ◽  
...  
Keyword(s):  
Plant Biomass ◽  
High Sensitivity ◽  
C Sequestration ◽  
High Elevation ◽  
N Fertilization ◽  
Alpine Ecosystems ◽  
N Accumulation ◽  
C Cycle ◽  
C And N ◽  
Underlying Mechanisms

Abstract Aims: Vegetation in high-altitude regions is hypothesized to be more responsive to increasing atmospheric CO2 concentrations due to low CO2 partial pressure. However, this hypothesis and the underlying mechanisms driving this response at an ecosystem scale are poorly understood. We aimed to exploring the biomass allocation and plant carbon-nitrogen relationships in response to elevated CO2 in a Tibet meadow.Methods: Here, a 5-year manipulation experiment was conducted in an alpine meadow (4585 m above sea level) to explore the responses of plant carbon (C), nitrogen (N) and biomass dynamics, as well as their allocation schemes, to elevated CO2 and N fertilization.Results: Elevated CO2 alone significantly enhanced aboveground plant biomass by 98.03 %, exhibiting a stronger CO2 fertilization effect than the global average level (20 %) for grasslands. In contrast to the belowground parts, elevated CO2 caused disproportionally aboveground tissues increment in association with C and N accumulation. These results suggest a potential C limitation for plant growth in alpine ecosystems. N fertilization alleviates the N constraints on CO2 fertilization effects, which strengthened C sequestration capacity for the aboveground plant tissues. Moreover, our results indicate a decoupling between C and N cycles in alpine ecosystems in the face of elevated CO2, especially in the N-enrichment environments.Conclusions: Overall, this study shows a high sensitivity of aboveground plant biomass and decoupled C-N relationships under elevated CO2 for high-elevation alpine ecosystems, highlighting the need to incorporate altitude effects into Earth System Models in predicting C cycle feedback to climate changes.

scholarly journals Soil organic carbon along an altitudinal gradient in the Despeñaperros Natural Park, southern Spain

Solid Earth ◽  
2015 ◽  
Vol 6 (1) ◽  
pp. 125-134 ◽  
Author(s):  
L. Parras-Alcántara ◽  
B. Lozano-García ◽  
A. Galán-Espejo
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Altitudinal Gradient ◽  
Soil Depth ◽  
C Sequestration ◽  
Soil System ◽  
Topographic Position ◽  
Natural Park ◽  
Disturbed Soil ◽  
C Cycle

Abstract. Soil organic carbon (SOC) is extremely important in the global carbon (C) cycle as C sequestration in non-disturbed soil ecosystems can be a C sink and mitigate greenhouse-gas-driven climate change. Soil organic carbon changes in space and time are relevant to understand the soil system and its role in the C cycle. This is why the influence of topographic position on SOC should be studied. Seven topographic positions from a toposequence between 607 and 1168 m were analyzed in the Despeñaperros Natural Park (Jaén, SW Spain). Depending on soil depth, one to three control sections (0–25, 25–50 and 75 cm) were sampled at each site. The SOC content in studied soils was below 30 g kg−1 and strongly decreases with depth. These results were related to the gravel content and to the bulk density. The SOC content from the topsoil (0–25 cm) varied largely through the altitudinal gradient ranging between 27.3 and 39.9 g kg−1. The SOC stock (SOCS) varied between 53.8 and 158.0 Mg ha−1 in the studied area, which had been clearly conditioned by the topographic position. Therefore, results suggest that elevation should be included in SOCS models and estimations at local and regional scales.

Identification of Plant Protein Kinases in Response to Abiotic and Biotic Stresses Using SuperSAGE

2011 ◽  
Vol 12 (7) ◽  
pp. 643-656 ◽  
Author(s):  
Ederson Akio Kido ◽  
Pedranne Kelle de Araujo Barbosa ◽  
Jose Ribamar Costa Ferreira Neto ◽  
Valesca Pandolfi ◽  
Laureen Michelle Houllou-Kido ◽  
...  
Keyword(s):  
Protein Kinases ◽  
Plant Protein ◽  
Abiotic And Biotic Stresses ◽  
Biotic Stresses
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