scholarly journals Spatial Variability and Relationship of Mangrove Soil Organic Matter to Organic Carbon

2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Pasicha Chaikaew ◽  
Suchana Chavanich
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Spatial Variability ◽  
Conversion Factor ◽  
Surface Soil ◽  
Mangrove Forests ◽  
Mangrove Soil ◽  
Subsurface Soil ◽  
Mangrove Soils ◽  
Relationship Of

Degradation and destruction of mangrove forests in many regions have resulted in the alteration of carbon cycling. Objectives of this study were established to answer the question regarding how much soil organic carbon (SOC) is stored in wetland soils in part of the upper northeastern Gulf of Thailand and to what extent SOC is related to organic matter (OM). A total of 29 soil samples were collected in October 2015. Soil physiochemical analyses followed the standard protocol. Spatial distributions were estimated by a kriging method. Linear regression and coefficient were used to determine the suitable conversion factor for mangrove soils. The results showed that surface soil (0–5 cm) contained higher SOC content as compared to subsurface soil (5–10 cm). Considering a depth of 10 cm, this area had a high potential to sequester carbon with a mean ± standard deviation of5.59±2.24%. The spatial variability of OM and SOC revealed that organic matter and carbon decreased with the distance from upstream areas toward the gulf. Based on the assumption that OM is 50% SOC, the conversion factor of 2 is recommended for more accuracy rather than the conventional factor of 1.724.

scholarly journals VARIABILIDADE ESPACIAL DO FLUXO DE CO2 DO SOLO EM POVOAMENTO DE EUCALIPTO

FLORESTA ◽  
2011 ◽  
Vol 41 (2) ◽  
Author(s):  
Alexandre Fonseca D’Andréa ◽  
Marx Leandro Naves Silva ◽  
Diego Antonio França de Freitas ◽  
Nilton Curi ◽  
Carlos Alberto Silva
Keyword(s):  
Organic Matter ◽  
Environmental Factors ◽  
Organic Carbon ◽  
Spatial Variability ◽  
Linear Correlation ◽  
Microbial Biomass Carbon ◽  
Co2 Flux ◽  
Water Evaporation ◽  
Soil Co2 ◽  
Soil Co2 Flux

A matéria orgânica do solo armazena a maior parte do carbono contido nos sistemas terrestres do planeta, sendo a maioria encontrada nos solos com floresta. O objetivo deste trabalho foi quantificar o fluxo de CO2 do solo e a sua variabilidade espacial em povoamento de Eucalyptus sp. Foram avaliados o fluxo de CO2 do solo, fatores ambientais (evaporação de água, temperatura e umidade do solo), atributos relacionados à fertilidade (pH, soma de bases e alumínio trocável), estrutura (densidade do solo e porosidade total) e matéria orgânica do solo (carbono orgânico total e carbono da biomassa microbiana). Análises de correlação linear simples indicaram que parte da variabilidade espacial do fluxo de CO2 do solo pode ser explicada pelo efeito conjunto do teor de carbono orgânico do solo, da biomassa da serapilheira e da presença de árvores no terreno, indicativas da participação de fatores bióticos no processo. No entanto, o fluxo de CO2 do solo é um fenômeno de natureza complexa, não sendo possível identificar um único atributo do solo ou do ambiente que, isoladamente, explique sua variação no espaço.Palavras-chave: Matéria orgânica; fatores ambientais; fertilidade; carbono; respiração do solo.AbstractSoil CO2 flux spatial variability on eucalyptus manmade forest.  The organic matter on soil retains most of carbon contained in the planet terrestrial systems, specially in forest soils. The aim of this work was to quantify soil CO2 flux and its spatial variability on Eucalyptus sp. manmade forest. In order to that, soil CO2 flux, environmental factors (water evaporation, soil temperature and moisture), fertility attributes (pH, bases sum and exchangeable aluminum), structure (bulk density and total porosity), and soil organic matter (total organic carbon and microbial biomass carbon) were evaluated. Simple linear correlation analyses indicated that part of the spatial variability of soil CO2 flux can be explained by the associated effect of soil organic carbon amount, litter biomass and presence of trees, indicatives of participation of biotic factors in the process. However, the soil CO2 flux is a complex phenomenon, been impossible to identify a single soil or environmental attribute, which, individually, could explain its spatial variability. Keywords: Organic matter; environmental factors; fertility; carbon; linear correlation. 

scholarly journals Carbon isotopes and lipid biomarker investigation of sources, transport and degradation of terrestrial organic matter in the Buor-Khaya Bay, SE Laptev Sea

2011 ◽  
Vol 8 (7) ◽  
pp. 1865-1879 ◽  
Author(s):  
E. S. Karlsson ◽  
A. Charkin ◽  
O. Dudarev ◽  
I. Semiletov ◽  
J. E. Vonk ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Water ◽  
Organic Carbon ◽  
Climate Warming ◽  
Surface Sediment ◽  
Positive Feedback ◽  
Coastal Erosion ◽  
Surface Soil ◽  
Mineral Soil ◽  
Laptev Sea

Abstract. The world's largest continental shelf, the East Siberian Shelf Sea, receives substantial input of terrestrial organic carbon (terr-OC) from both large rivers and erosion of its coastline. Degradation of organic matter from thawing permafrost in the Arctic is likely to increase, potentially creating a positive feedback mechanism to climate warming. This study focuses on the Buor-Khaya Bay (SE Laptev Sea), an area with strong terr-OC input from both coastal erosion and the Lena river. To better understand the fate of this terr-OC, molecular (acyl lipid biomarkers) and isotopic tools (stable carbon and radiocarbon isotopes) have been applied to both particulate organic carbon (POC) in surface water and sedimentary organic carbon (SOC) collected from the underlying surface sediments. Clear gradients in both extent of degradation and differences in source contributions were observed both between surface water POC and surface sediment SOC as well as over the 100 s km investigation scale (about 20 stations). Depleted δ13C-OC and high HMW/LMW n-alkane ratios signaled that terr-OC was dominating over marine/planktonic sources. Despite a shallow water column (10–40 m), the isotopic shift between SOC and POC varied systematically from +2 to +5 per mil for δ13C and from +300 to +450 for Δ14C from the Lena prodelta to the Buor-Khaya Cape. At the same time, the ratio of HMW n-alkanoic acids to HMW n-alkanes as well as HMW n-alkane CPI, both indicative of degradation, were 5–6 times greater in SOC than in POC. This suggests that terr-OC was substantially older yet less degraded in the surface sediment than in the surface waters. This unusual vertical degradation trend was only recently found also for the central East Siberian Sea. Numerical modeling (Monte Carlo simulations) with δ13C and Δ14C in both POC and SOC was applied to deduce the relative contribution of – plankton OC, surface soil layer OC and yedoma/mineral soil OC. This three end-member dual-carbon-isotopic mixing model suggests quite different scenarios for the POC vs SOC. Surface soil is dominating (63 ± 10 %) the suspended organic matter in the surface water of SE Laptev Sea. In contrast, the yedoma/mineral soil OC is accounting for 60 ± 9 % of the SOC. We hypothesize that yedoma-OC, associated with mineral-rich matter from coastal erosion is ballasted and thus quickly settles to the bottom. The mineral association may also explain the greater resistance to degradation of this terr-OC component. In contrast, more amorphous humic-like and low-density terr-OC from surface soil and recent vegetation represents a younger but more bioavailable and thus degraded terr-OC component held buoyant in surface water. Hence, these two terr-OC components may represent different propensities to contribute to a positive feedback to climate warming by converting OC from coastal and inland permafrost into CO2.

The relationship of soil organic carbon to 210Pbex and 137Cs during surface soil erosion in a hillslope forested environment

Geoderma ◽  
2013 ◽  
Vol 192 ◽  
pp. 59-67 ◽  
Author(s):  
Mengistu T. Teramage ◽  
Yuichi Onda ◽  
Hiroaki Kato ◽  
Yoshifumi Wakiyama ◽  
Shigeru Mizugaki ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Surface Soil ◽  
Relationship Of ◽  
The Relationship

scholarly journals Surface Soil Organic Carbon Sequestration Under Post Agricultural Grasslands Offset by Net Loss at Depth

2021 ◽  
Author(s):  
Yi Yang ◽  
Terrance Loecke ◽  
Johanness Knops
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Surface Soil ◽  
C Sequestration ◽  
The United States ◽  
Soil Profiles ◽  
Continental Scale ◽  
C Dynamics ◽  
Subsurface Soil ◽  
Soc Stock

Abstract Post agricultural grasslands are considered to accumulate soil organic carbon (SOC) after cultivation cessation. The Conservation Reserve Program (CRP) in the U.S. is a wide scale, covering approximately 8.9 Mha as of 2020, example of row-crop to grassland conversion. To date, SOC sequestration rates, and potential, in CRP has mostly been evaluated at local scales and focused on the surface 20–30 cm of the soil profile. Thus, we lack knowledge of C sequestration rates in CRP lands on a continental scale and of C dynamics in the subsurface soil after agricultural cessation. The Rapid Carbon Assessment (RaCA) project is the most recent effort by the United States Department of Agriculture (USDA) to systematically quantify C stock in the 0-100 cm soil profiles across the conterminous US. Here we analyze data from RaCA to evaluate the C stocks of the CRP on a continental scale of both surface and subsurface soil. We found there was no difference in SOC stock between croplands and CRP lands when comparing the 0-100 cm soil profiles, which indicates that the C sequestration in CRP lands is insignificant overall. We did find that SOC accumulated in the surface soil (0–5 cm) in CRP lands. However, theses C gains in surface (0–5 cm) soil were offset by the lower SOC stock in the subsurface (30–100 cm) of the CRP. We also found that the C: N ratio in the subsurface soil in CRP lands is lower than that of croplands, indicating a lack of labile organic matter inputs in the subsoil. Whether the lower SOC in the subsurface of CRP is caused by legacy effects or is a result of C losses needs to be verified by long-term repeated sampling in both surface and subsurface soil. This analysis highlights the importance of examining C dynamics in subsurface soil after agricultural cessation to accurately measure and improve C sequestration rates in CRP lands.

scholarly journals Fusarium Species in Mangrove Soil in Northern Peninsular Malaysia and the Soil Physico-Chemical Properties

2021 ◽  
Vol 9 (3) ◽  
pp. 497
Author(s):  
Wafa S. Mohamed Zubi ◽  
Masratul Hawa Mohd ◽  
Nik Mohd Izham Mohamed Nor ◽  
Latiffah Zakaria
Keyword(s):  
Plant Pathogens ◽  
Soil Analysis ◽  
Fusarium Species ◽  
Chemical Properties ◽  
Peninsular Malaysia ◽  
Mangrove Forests ◽  
Human Pathogens ◽  
Mangrove Soil ◽  
Physico Chemical ◽  
Mangrove Soils

Fusarium genus comprises important saprophytic and phytopathogenic fungi and is widespread in nature. The present study reports the occurrence of Fusarium spp. in soils from two mangrove forests in northern Peninsular Malaysia and analyzed physico-chemical properties of the mangrove soil. Based on TEF-1α sequences, nine Fusarium species were identified: Fusarium solani species complex (FSSC) (n = 77), Fusarium verticillioides (n = 20), Fusarium incarnatum (n = 10), Fusarium proliferatum (n = 7), Fusarium lateritium (n = 4), Fusarium oxysporum (n = 3), Fusarium rigidiuscula (n = 2), Fusarium chlamydosporum (n = 1), and Fusarium camptoceras (n = 1); FSSC isolates were the most prevalent. Phylogenetic analysis of the combined TEF-1α and ITS sequences revealed diverse phylogenetic affinities among the FSSC isolates and potentially new phylogenetic clades of FSSC. Soil analysis showed varied carbon content, pH, soil moisture, and salinity, but not nitrogen content, between sampling locations. Regardless of the physico-chemical properties, various Fusarium species were recovered from the mangrove soils. These were likely saprophytes; however, some were well-known plant pathogens and opportunistic human pathogens. Thus, mangrove soils might serve as inoculum sources for plant and human pathogenic Fusarium species. The present study demonstrates the occurrence of various Fusarium species in the extreme environment of mangrove soil, thereby contributing to the knowledge on species diversity in Fusarium.

Prediction of organic matter degradability in river sediments

2020 ◽  
Author(s):  
Julia Gebert ◽  
Florian Zander
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Spatial Variability ◽  
River Sediments ◽  
Redox Conditions ◽  
Time Dependent ◽  
Anaerobic Conditions ◽  
Short Term ◽  
Aerobic And Anaerobic

<p>Under anaerobic conditions, degradation of organic matter in river sediments leads to gas formation, with organic carbon being released mainly as CH<sub>4</sub> and CO<sub>2</sub>. Gas bubbles reduce sediment density, viscosity and shear strength, impede sonic depth finding and are suspected to affect the sediments’ rheological properties. Moreover, methane (CH<sub>4</sub>) is a potent greenhouse gas with a global warming potential (GWP<sub>100</sub>) of 28-36. Therefore, the climate impact may vary greatly depending on the way sediments are managed (for example, type and frequency of dredging and relocation in the water body or treatment on land). The objective of this paper is therefore to quantify the time-dependent stability, or inversely, the lability of sediment organic matter (SOM) as a basis for prediction of effects on sediment mechanical properties and on the release of greenhouse gases.</p><p>Within two years, over 200 samples of predominantly fine-grained sediment were collected from nine locations within a 30 km transect through the Port of Hamburg. All samples were, amongst other analyses, subjected to long-term (> 250 days) aerobic and anaerobic incubation for measurement of SOM degradation, yielding a comprehensive data set on the time-dependent change in degradation rates and the corresponding size of differently degradable SOM pools. SOM degradability exhibited a pronounced spatial variability with an approximately tenfold higher anaerobic and a roughly fivefold higher aerobic degradability of upstream SOM compared to downstream SOM. Lower δ<sup>13</sup>C values, higher DNA concentrations and a higher share of organic carbon in the light density fraction as well as elevated chlorophyll concentrations in the water phase support the hypothesis of increased biological sources of SOM at upstream locations and increased SOM degradability in shallow compared to deep layers (Zander et al., 2020).</p><p>First statistical and time series analyses indicate that</p><ul><li>Long-term SOM lability appears to be predictable from short-term measurements.</li> <li>The relationship between short-term and long-term SOM degradation is site-specific and also differs for layers of different age (depth). This supports the above-mentioned variability between sites regarding the size of differently degradable carbon pools, as well as for the depth profile at any one site.</li> <li>The relevance of the available electron acceptors (redox conditions) for SOM degradation, i.e. the ratio between carbon release under aerobic and anaerobic conditions, differs less by site but more so by layers of different age (depth). This is plausible as especially the top layers are exposed to more variability in redox conditions than the deeper layers that are always under reducing conditions.</li> </ul><p>Zander, F., Heimovaara, T., Gebert, J. (2020): Spatial variability of organic matter degradability in tidal Elbe sediments. Journal of Soils and Sediments, accepted for publication.</p>

Spatial heterogeneity and environmental controllers of soil organic carbon stocks in a boreal forest

2020 ◽  
Author(s):  
Udaya Vitharana ◽  
Nora Casson ◽  
Darshani Kumaragamage ◽  
Geoff Gunn ◽  
Scott Higgins ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Spatial Variability ◽  
Boreal Forest ◽  
Spatial Heterogeneity ◽  
Surface Soil ◽  
Local Scale ◽  
Gravel Content ◽  
Soc Stock ◽  
Soc Stocks

<p>The knowledge of spatial heterogeneity and environmental controllers of soil organic carbon (SOC) stocks is essential for upscaling and predicting SOC dynamics under changing land use and climatic conditions.  This study investigated the spatial variability and intrinsic and extrinsic controllers of SOC stocks in a boreal forest catchment (320 ha) at the International Institute for Sustainable Development Experimental Lakes Area in Ontario, Canada. Forty-seven surface soil (0-30 cm) samples, representative of the spatial variability of topography, surface water flow patterns and vegetation distribution, were obtained within the catchment. Air dried soil samples were sieved to separate gravel (>2 mm) and fine-earth (<2 mm) fractions and were analyzed for SOC concentration using the loss-on-ignition method. Core sample method was used to determine the soil bulk density. SOC concentrations in surface soils showed a large spatial variability (1.2% to 50.4%, CV= 111.3%). Thick organic soil layers in the wetlands of the sub-catchment showed the highest SOC concentrations. The surface soil SOC stocks ranged between 14.5 to 240.5 Mg ha-1 with an average stock of 101.5 Mg ha-1. Spatial autocorrelations of SOC stocks were modelled by calculating relevant variograms. The variability of SOC stocks (sill = 834) was dominated by the random variability (nugget=275) whereas the variability of SOC concentration (sill = 2.5) was dominated by the spatially structured variability (nugget = 0). We found a strong spatial autocorrelation of the SOC concentrations within the catchment, but the SOC stocks were less spatially correlated. This was largely due to the heterogeneity in the thickness of the surface soil layer (10 cm - 30 cm) and in the gravel content (0-28.9%). We found that a large over-estimation of SOC stocks (52.5%) could result if these intrinsic factors are not considered. Extrinsic controllers were generally not significantly related to the SOC stock; Spearman’s rank correlation analysis on the entire dataset showed non-significant relationships between the SOC stock and extrinsic controllers, namely NDVI (r = 0.04) elevation (r = 0.2), slope (r = -0.1) and topographic indices, stream power index (r = -0.1), relative position index (r=-0.2) and plan curvature (r = -0.1). However, regression tree analysis revealed local-scale effects of aspect, NDVI, elevation, and distance to ridge on the SOC stocks. Many forest soil databases lack information of gravel content and soil depth. Thus, upscaling boreal forest SOC stocks without these two key intrinsic controllers can lead to higher uncertainties in  SOC stock estimates. Further, the impacts of extrinsic controllers may vary across heterogenous landscapes. Machine learning-based digital soil mapping techniques such as Random Forest models are more appropriate for incorporating local-scale impacts of extrinsic controllers when upscaling SOC stocks of boreal forest soils. </p>

scholarly journals Nutrient Status of Sugarcane Growing Soils of Nizamabad District of Telangana State

2020 ◽  
pp. 1-9
Author(s):  
J. Kamalakar ◽  
T. Prabhakar Reddy ◽  
K. Pavan Chandra Reddy ◽  
D. Vijaya Lakshmi ◽  
Firdoz Sahana ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Land Use Planning ◽  
Surface Soil ◽  
Nutrient Status ◽  
Soil Survey ◽  
Soil Reaction ◽  
Organic Carbon Content ◽  
Available N ◽  
Subsurface Soil ◽  
Telangana State

Sugarcane is a commercial crop predominantly grown in Nizamabad district. Investigating the fertility status of sugarcane growing soil is required to underpin future land use planning. A field soil survey was carried out in major sugar cane growing soils (5 mandals/taluk) of Nizamabad district of Telangana state. A total number of 94 samples were collected from 0-15 cm (surface soil) and 15-30 cm (subsurface soil) depths using global positioning system (GPS) co-ordinates. Collected soil samples were chemically analyzed for the important soil attributes viz., pH, electrical conductivity (EC), organic carbon (OC), nitrogen (N), phosphorus (P), potassium (K), sulphur (S), iron (Fe), zinc (Zn), manganese (Mn) and copper (Cu) using standard analytical procedures. Correlation analysis was performed to study the relationship between the different soil properties. The soil reaction (pH) showed wide variation at surface and subsurface depths showing that soils are slightly acidic to strongly alkaline in nature. Organic carbon content varied from low to high (0.25 to 1.41% and 0.22 to 0.75% at 0-15 and 15-30 cm depths respectively). Whereas available N content were low to high (136 to 310 kg ha-1 and 23 to 166 kg ha-1 at 0-15 cm and 15-30 cm depths respectively), medium to high in available P (12.05 to 103.6 kg ha-1 and 3.6 to 27.90 kg ha-1 at 0-15 cm and 15-30 cm depths respectively), high in available K (242 to 715 kg ha-1 and 108 to 466 kg ha-1 at 0-15 cm and 15-30 cm depths respectively). Further, the soils are deficient to sufficient in available S and Zn, Fe, Mn and Cu were sufficient. Nitrogen was positively correlated with the organic carbon (r=0.883, p<0.05) at surface soil and negatively related at subsurface soil. All the major nutrients viz., N, P, and K correlated positively with OC (r=0.883*, 0.768, and 0.267 respectively) at surface soil. Conclusively, the results of the study area showed in all the sugarcane growing mandals of Nizamabad district necessitating the need for refinement of fertilizer scheduling to sugarcane crop yield and productivity.

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