Spatial distribution of soil organic carbon may be predominantly regulated by topography in a small revegetated watershed

<p>Understanding the spatial distribution and controlling factors of soil organic carbon (SOC) at different scales is essential for an accurate estimation of soil organic carbon stocks. Furthermore, this understanding is vital for evaluating the impact of soil management on both soil quality and climate change. This study was conducted in a Loess revegetated small watershed and the effects of the topography and vegetation factors on the content and distribution of SOC at different soil depths were evaluated. Soil profiles (0-200 cm; n = 122) were sampled that represent six vegetation types (i.e., natural mixed forests, artificial mixed forests, artificial forests with a single tree species, shrubbery, and grassland) and four topographic factors (i.e., elevation, slope gradient, slope position, and slope aspect). The following results were obtained: (1) The mean SOC of the 200 cm soil profile ranged from 2.34 g kg-1 to 5.70 g kg-1, decreasing with increasing soil depth. (2) The interactions between vegetation type and topography and soil depth significantly impacted SOC (P < 0.05). Significant differences in the SOC content (P < 0.05) were also found for slope gradient, slope position, slope aspect, and elevation for 0-200cm, 0-160cm, 0-120 cm and 0-200 cm, respectively. (3) The relative contribution of topographic factors to the SOC content exceeded that of vegetation type in entire soil profile. Topography was the dominant factor controlling the spatial distribution of SOC in the studied small watershed. Therefore, topographic factors should be considered more than vegetation types for an accurate estimation of SOC storage in a revegetated small watershed. This is particularly important for the complicated topography of the loess-gully region.</p>

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Influence of Slope Gradient and Aspect on Soil Organic Carbon Content in the Region of Niš, Serbia

Sustainability ◽

10.3390/su13158332 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8332

Author(s):

Snežana Jakšić ◽

Jordana Ninkov ◽

Stanko Milić ◽

Jovica Vasin ◽

Milorad Živanov ◽

...

Keyword(s):

Land Use ◽

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Slope Aspect ◽

Available Phosphorus ◽

Organic Carbon Content ◽

Slope Gradient ◽

Phosphorus And Potassium ◽

Uncultivated Land

Topography-induced microclimate differences determine the local spatial variation of soil characteristics as topographic factors may play the most essential role in changing the climatic pattern. The aim of this study was to investigate the spatial distribution of soil organic carbon (SOC) with respect to the slope gradient and aspect, and to quantify their influence on SOC within different land use/cover classes. The study area is the Region of Niš in Serbia, which is characterized by complex topography with large variability in the spatial distribution of SOC. Soil samples at 0–30 cm and 30–60 cm were collected from different slope gradients and aspects in each of the three land use/cover classes. The results showed that the slope aspect significantly influenced the spatial distribution of SOC in the forest and vineyard soils, where N- and NW-facing soils had the highest level of organic carbon in the topsoil. There were no similar patterns in the uncultivated land. No significant differences were found in the subsoil. Organic carbon content was higher in the topsoil, regardless of the slope of the terrain. The mean SOC content in forest land decreased with increasing slope, but the difference was not statistically significant. In vineyards and uncultivated land, the SOC content was not predominantly determined by the slope gradient. No significant variations across slope gradients were found for all observed soil properties, except for available phosphorus and potassium. A positive correlation was observed between SOC and total nitrogen, clay, silt, and available phosphorus and potassium, while a negative correlation with coarse sand was detected. The slope aspect in relation to different land use/cover classes could provide an important reference for land management strategies in light of sustainable development.

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Spatial variability of soil organic carbon in the West Liao River Basin

Israel Journal of Ecology and Evolution ◽

10.1163/22244662-20181020 ◽

2018 ◽

Vol 64 (1-4) ◽

pp. 25-34

Author(s):

Yong-hua Zhu ◽

Sheng Zhang ◽

Biao Sun ◽

Xiao-kang Xi ◽

Yu Liu ◽

...

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Spatial Variability ◽

Soil Depth ◽

Soil Layer ◽

Kriging Interpolation ◽

Spherical Models ◽

Basin Edge ◽

Depth Increase

Quantification of the pattern and spatial distribution of soil organic carbon (SOC) is essential to comprehending many eco-hydrological processes. To obtain a better understanding of the spatial variability of SOC in a typical farming-pastoral zone, 270 soil samples were collected at 45 sampling sites from every 20 cm soil layer. Semi-variance function theory and ordinary Kriging interpolation were applied to identify the spatial variability of SOC. The results showed that SOC in the area was relatively low and decreased with depth and from the basin edge to the centre with a measured mean content of 0.07–0.65 g/kg. The strongest variability in the zone in the top soil layer (0–40 cm) was in the centre part of the zone, which was supposed to be the most concentrated area of human activities in the zone. As soil depth increase, the degree of variation of SOC decreased. Gaussian, exponential, and spherical models were suggested to successfully simulate SOC in different soil depth zones. The spatial distribution of SOC showed strong variability in the same soil depth zone, with a nugget to sill ratio of less than 14% and a range of 30–160 km.

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The Spatial Distribution Characteristics of Soil Organic Carbon and Its Effects on Topsoil under Different Karst Landforms

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17082889 ◽

2020 ◽

Vol 17 (8) ◽

pp. 2889 ◽

Cited By ~ 2

Author(s):

Xingfu Wang ◽

Xianfei Huang ◽

Jiwei Hu ◽

Zhenming Zhang

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Depth ◽

Soil Layer ◽

Guizhou Province ◽

Impact Factors ◽

Distribution Characteristics ◽

Spatial Distribution Characteristics ◽

Karst Landforms

Karst landforms are widely distributed in Guizhou Province, and the karst terrain is complex. To investigate the spatial distribution characteristics of soil organic carbon (SOC) in topsoil in different karst landforms, a total of 920 samples were taken from different karst landforms. The study areas, Puding, Xingyi, Guanling, Libo and Yinjiang in Guizhou Province, represent the karst plateau (KP), karst peak-cluster depression (KPCD), karst canyon (KC), karst virgin forest (KVF) and karst trough valley (KTV) landforms, respectively. The characteristics of the SOC contents in areas with different vegetation, land use and soil types under different karst landforms were analyzed. The dimensionality of the factors was reduced via principal component analysis, the relationships among SOC content and different factors were subjected to redundancy analysis, and the effects of the main impact factors on SOC were discussed. The results showed that there was a large discrepancy in the SOC contents in the topsoil layers among different types of karst landforms, the changes in the SOC content in the topsoil layer were highly variable, and the discrepancy in the upper soil layer was higher than that in the lower soil layer. The SOC contents in the 0–50 cm topsoil layers in different karst landforms were between 7.76 and 38.29 g·kg−1, the SOC content gradually decreased with increasing soil depth, and the descending order of the SOC contents in different karst landforms was KTV > KVF > KC > KPCD > KP.

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Soil organic carbon in the Sanjiang Plain of China: storage, distribution and controlling factors

Biogeosciences ◽

10.5194/bg-12-1635-2015 ◽

2015 ◽

Vol 12 (6) ◽

pp. 1635-1645 ◽

Cited By ~ 39

Author(s):

D. H. Mao ◽

Z. M. Wang ◽

L. Li ◽

Z. H. Miao ◽

W. H. Ma ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Texture ◽

Soil Depth ◽

Sanjiang Plain ◽

Controlling Factors ◽

Accurate Estimation ◽

The Sanjiang Plain ◽

Ecosystem Carbon

Abstract. The accurate estimation of soil organic carbon (SOC) storage and determination of its pattern-controlling factors is critical to understanding the ecosystem carbon cycle and ensuring ecological security. The Sanjiang Plain, an important grain production base in China, is typical of ecosystems, yet its SOC storage and pattern has not been fully investigated because of insufficient soil investigation. In this study, 419 soil samples obtained in 2012 for each of the three soil depth ranges 0–30, 30–60, and 60–100 cm and a geostatistical method are used to estimate the total SOC storage and density (SOCD) of this region. The results give rise to 2.32 Pg C for the SOC storage and 21.20 kg m−2 for SOCD, which is higher than the mean value for the whole country. The SOCD shows notable changes in lateral and vertical distribution. In addition, vegetation, climate, and soil texture, as well as agricultural activities, are demonstrated to have remarkable impacts on the variation in SOCD of this region. Soil texture has stronger impacts on the distribution of SOCD than climate in the Sanjiang Plain. Specifically, clay content can explain the largest proportion of the SOC variations (21.2% in the top 30 cm) and is the most dominant environmental controlling factor. Additionally, the effects of both climate and soil texture on SOCD show a weakening with increasing soil layer depth. This study indicates that reducing the loss of SOC requires effective conservation and restoration efforts of wetlands and forestlands, as well as sensible fertilization. The results from this study provide the most up-to-date knowledge on the storage and pattern of SOC in the Sanjiang Plain and have important implications for the determination of ecosystem carbon budgets and understanding ecosystem services.

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Spatial Distribution of Glomalin-related Soil Proteins in Coniferous and Broadleaf mixed Temperate Forest

Notulae Botanicae Horti Agrobotanici Cluj-Napoca ◽

10.15835/nbha47411621 ◽

2019 ◽

Vol 47 (4) ◽

pp. 1087-1093

Author(s):

Yongming WANG ◽

Chunhua JI ◽

Zhaoyong SHI ◽

Xubin YIN ◽

Chenzhou LIU

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Temperate Forest ◽

Soil Depth ◽

Soil Layer ◽

Moran’S I ◽

Digital Object Identifier ◽

Moran's I ◽

Soil Layers

Glomalin-related soil protein (GRSP), as an important component of soil organic carbon (SOC) pool, is a glycoprotein produced by the hyphae of arbuscular mycorrhizal fungi (AMF), which play a vital role in carbon and nutrient cycling in forest ecosystem. Here we investigated the spatial distribution of GRSP in plant community of the dominated species not associated with AMF based on a typical coniferous and broad-leaved temperate forest in Mt. Changbai, Northeastern China. Spatial distribution of GRSP including easily extractable GRSP (EEG) and total GRSP (TG) is represented by Moran’s I on different soil depth among seven soil layers of 0-5 cm, 5-10 cm, 10-20 cm, 20-30 cm, 30-50 cm, 50-70 cm and 70-100 cm. The concentrations of EEG and TG decreased with the increase of soil depth according to a logarithmic function. The Moran’s I coefficient of GRSP was negative in all soil layers except TG in 20-30 cm and 50-70 cm soil layers. When EEG and TG were considered, the Moran’s I coefficient was positive in majority of soil layers within the separation distance of less than 4 m but in soil layers of 10-20 cm and 20-30 cm for EEG and in 30-50 cm for TG. The largest Moran’s I coefficient including EEG and TG was observed in the soil layer of 5-10 cm. The spatial distribution of GRSP was discrete in typical coniferous and broad-leaved temperate forest, and was affected by mycorrhizal colonization rate, soil organic carbon and total nitrogen. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

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Mechanism and Evolution of Soil Organic Carbon Coupling with Rocky Desertification in South China Karst

Forests ◽

10.3390/f13010028 ◽

2021 ◽

Vol 13 (1) ◽

pp. 28

Author(s):

Xingfu Wang ◽

Xianfei Huang ◽

Kangning Xiong ◽

Jiwei Hu ◽

Zhenming Zhang ◽

...

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Storage Capacity ◽

Slope Position ◽

Distribution Characteristics ◽

Slope Gradient ◽

Rocky Desertification ◽

Spatial Distribution Characteristics ◽

Karst Landforms

To study the spatial distribution characteristics of soil organic carbon (SOC) coupled with rocky desertification, 1212 soil samples from 152 soil profiles were sampled from different karst landforms, including karst low hills/virgin forest (KLH) in Libo County, a karst peak-cluster depression (KPCD) in Xingyi County, a karst canyon (KC) in Guanling County, a karst plateau basin (KPB) in Puding County and a karst trough valley (KTV) in Yinjiang County. The spatial distribution characteristics of the responses of SOC, SOC density (SOCD), rocky desertification and soil bulk density (SBD) to different influencing factors were analyzed. The relationships among SOC, SOCD, rocky desertification and SBD were analyzed using Pearson correlation analysis. The SOC storage capacity was characterized by using SOCD, and then the SOC storage capacity in different evolution stages of karst landforms was assessed. The SOC contents of KLH, KPCD, KC, KPB and KTV ranged from 6.16 to 38.20 g·kg−1, 7.42 to 27.08 g·kg−1, 6.28 to 35.17 g·kg−1, 4.62 to 23.79 g·kg−1 and 5.24 to 37.85 g·kg−1, respectively, and their average SOCD values (0–100 cm) were 7.37, 10.79, 7.06, 8.51 and 7.84 kg·m−2, respectively. The karst landforms as ordered by SOC storage capacity were KPCD > KPB > KLH > KTV > KC. The SOC content was negatively correlated with the SBD; light rocky desertification may lead to SOC accumulation. The rocky desertification degree and SBD were closely associated with slope position and gradient. Rocky desertification first increased, then decreased from mountain foot to summit, and increased with increasing slope gradient. However, the SBD decreased from mountain foot to summit and with increasing slope gradient. The SOC contents on the northern aspect of the mountains were generally higher than the other aspects. In summary, rock outcrops controlled the SOC contents in the studied regions. The slope position, gradient and aspect influenced the composition and distribution of vegetation, which influenced the evolution of rocky desertification. Therefore, these factors indirectly affected the SOC content. Additionally, the SOCD decreased with increasing rocky desertification. During the different evolution stages of karst landforms, the SOC storage capacity first decreases, then increases.

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Spatial Distribution of Soil Organic Carbon and Total Nitrogen Based on GIS and Geostatistics in a Small Watershed in a Hilly Area of Northern China

PLoS ONE ◽

10.1371/journal.pone.0083592 ◽

2013 ◽

Vol 8 (12) ◽

pp. e83592 ◽

Cited By ~ 18

Author(s):

Gao Peng ◽

Wang Bing ◽

Geng Guangpo ◽

Zhang Guangcan

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Total Nitrogen ◽

Northern China ◽

Small Watershed ◽

Hilly Area

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Topographic Position, Land Use and Soil Management Effects on Soil Organic Carbon (Vineyard Region of Niš, Serbia)

Agronomy ◽

10.3390/agronomy11071438 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1438

Author(s):

Snežana Jakšić ◽

Jordana Ninkov ◽

Stanko Milić ◽

Jovica Vasin ◽

Milorad Živanov ◽

...

Keyword(s):

Land Use ◽

Surface Layer ◽

Spatial Distribution ◽

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Compaction ◽

Soil Management ◽

Forest Land ◽

Topographic Position

Spatial distribution of soil organic carbon (SOC) is the result of a combination of various factors related to both the natural environment and anthropogenic activities. The aim of this study was to examine (i) the state of SOC in topsoil and subsoil of vineyards compared to the nearest forest, (ii) the influence of soil management on SOC, (iii) the variation in SOC content with topographic position, (iv) the intensity of soil erosion in order to estimate the leaching of SOC from upper to lower topographic positions, and (v) the significance of SOC for the reduction of soil’s susceptibility to compaction. The study area was the vineyard region of Niš, which represents a medium-sized vineyard region in Serbia. About 32% of the total land area is affected, to some degree, by soil erosion. However, according to the mean annual soil loss rate, the total area is classified as having tolerable erosion risk. Land use was shown to be an important factor that controls SOC content. The vineyards contained less SOC than forest land. The SOC content was affected by topographic position. The interactive effect of topographic position and land use on SOC was significant. The SOC of forest land was significantly higher at the upper position than at the middle and lower positions. Spatial distribution of organic carbon in vineyards was not influenced by altitude, but occurred as a consequence of different soil management practices. The deep tillage at 60–80 cm, along with application of organic amendments, showed the potential to preserve SOC in the subsoil and prevent carbon loss from the surface layer. Penetrometric resistance values indicated optimum soil compaction in the surface layer of the soil, while low permeability was observed in deeper layers. Increases in SOC content reduce soil compaction and thus the risk of erosion and landslides. Knowledge of soil carbon distribution as a function of topographic position, land use and soil management is important for sustainable production and climate change mitigation.

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