Characteristics of Soil C, N, and P Stoichiometry as Affected by Land Use and Slope Position in the Three Gorges Reservoir Area, Southwest China

Land use change and slope position are commonly identified as the key factors affecting the soil organic carbon (C), total nitrogen (N), and total phosphorus (P) traits in distinct ecological scales. However, the directions of these effects are still unclear in some fragile terrestrial ecosystems. This study aimed to determine the characteristics of soil C, N, and P concentrations and stoichiometry as affected by different land uses and slope positions in a representative purple soil hillslope in Three Gorges Reservoir Area (TGRA), China, which is experiencing severe soil erosion and non-point source pollution. A total of 108 soil samples were collected from secondary forest, orchard plantation, and cropland on the upper, middle, and lower slopes, respectively. Soil C, N, and P concentrations and their stoichiometric ratios were determined. The results showed that soil C concentration was not affected by land use, while soil N and P concentrations were both the highest in orchard plantation rather than in secondary forest and cropland, resulting in the lowest C:N, C:P, and N:P ratios in the orchard plantation. Soil C and N concentrations synchronously decreased from upper slope to the lower slope, and soil P concentration was not markedly different among slope positions. This also caused the insignificant difference in soil C:N ratio and the remarkably lowest C:P and N:P ratios on the lower slope. There were significant interactive effects of land use and slope position on the study soil variables except soil P concentration. Our results highlight the effects of land use and slope position on soil C, N, and P traits and point to the decoupling of linkages between soil P and soil C as well as N due to the severe soil erosion and overuse of fertilization in the TGRA.

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Effects of land use on soil erosion and nutrient loss in the Three Gorges Reservoir Area, China

Soil Use and Management ◽

10.1079/sum200170 ◽

2001 ◽

Vol 17 (4) ◽

pp. 288-291 ◽

Cited By ~ 38

Author(s):

Q.H. Meng ◽

L.Z. Yang

Keyword(s):

Land Use ◽

Soil Erosion ◽

Three Gorges Reservoir ◽

Nutrient Loss ◽

Three Gorges Reservoir Area ◽

Three Gorges ◽

Reservoir Area ◽

The Three Gorges Reservoir ◽

The Three Gorges ◽

Effects Of Land Use

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Elevation Gradient Altered Soil C, N, and P Stoichiometry of Pinus taiwanensis Forest on Daiyun Mountain

Forests ◽

10.3390/f10121089 ◽

2019 ◽

Vol 10 (12) ◽

pp. 1089

Author(s):

Lan Jiang ◽

Zhongsheng He ◽

Jinfu Liu ◽

Cong Xing ◽

Xinguang Gu ◽

...

Keyword(s):

Elevation Gradient ◽

C:N Ratio ◽

Phosphate Fertilizer ◽

High Elevation ◽

Driving Factors ◽

Slope Position ◽

Elevation Gradients ◽

Soil C ◽

Soil P ◽

C And N

Researches focused on soil carbon (C), nitrogen (N), and phosphorus (P) content and the stoichiometry characteristics along elevation gradients are important for effective management of forest ecosystems. Taking the soil of different elevations from 900 to 1700 m on Daiyun Mountain as the object, the elevation distribution of total C, N, and P in soil and their stoichiometry characteristics were studied. Also, the driving factors resulting in the spatial heterogeneity of soil stoichiometry are presented. The results show the following: (1) The average soil C and N content was 53.03 g·kg−1 and 3.82 g·kg−1, respectively. The content of C and N at high elevation was higher than that of at low elevation. Soil phosphorus fluctuated with elevation. (2) With increasing elevation, soil C:N ratio increased initially to 17.40 at elevation between 900–1000 m, and then decreased to 12.02 at elevation 1600 m. The changing trends of C:P and N:P were similar, and they all fluctuated with elevation. (3) Elevation, soil bulk density, and soil temperature were the main factors influencing the variation of soil C, N, and C:N. Soil pH and slope position were the driving factors for soil P, C:P, and N:P. The soil is rich in C and N, and has less total phosphorus on Daiyun Mountain. Raising the level of phosphate fertilizer appropriately can help to improve soil fertility and promote plant growth as well. In light of this information, in the near future, it will be necessary to conduct separation management of C, N, and P with regular monitoring systems to maintain favorable conditions for soil.

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Plant Nutrients Appears Decoupled from Soil: Increasing Influences from Changing Climate in the Grassland’s of Inner Mongolia, China

10.21203/rs.3.rs-1080083/v1 ◽

2021 ◽

Author(s):

Xiang Li ◽

Qiang Deng ◽

Lili Chen ◽

Guiyao Liu ◽

Xinrong Shi ◽

...

Keyword(s):

Soil Nutrient ◽

Northern China ◽

Climatic Conditions ◽

Plant Nutrients ◽

Turnover Rates ◽

Geographic Scale ◽

Soil C ◽

Soil P ◽

N:P Ratios ◽

C:P Ratios

Abstract Extremes in weather episodes seem to be the new normal. We need to better understand how changing climatic conditions alter plant growth in grasslands, especially macro nutrient uptake and stoichiometry. However, few studies have examined how warmer/colder or wetter/drier climates influence the nutrient decoupling between plants and soils at the ecosystem level. Here, we investigated the changes in carbon (C), nitrogen (N), and phosphorus (P) concentrations and their stoichiometric ratios in plants and soils from 65 grassland sites along a geographic gradient of temperature and aridity in northern China. Often, we saw inverse responses between plant and soil nutrients with respect to temperature and aridity. Soil C and N were negatively correlated with temperature and aridity. Soil P was negatively correlated with aridity. Plant N was positively correlated with aridity and plant P was negatively correlated with temperature, while plant C had no relationship with either. Temperature and aridity were positively correlated with C:N and negatively correlated with C:P and N:P ratios in soils. However, aridity was negatively correlated with plant C:N ratios. Plant N:P ratios were positively correlated with temperature and aridity, whereas plant C:P ratios had no relationship with either. Our findings suggest at a broad geographic scale, plant nutrients do not always reflect soil nutrient availability. It is conceivable that rapid climate shifts and the resulting changes in element availability, turnover rates, absorption, and use efficiency might cause decoupling of C, N, and P cycles between plants and soils.

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Pengaruh Penggunaan Lahan dan Posisi Lereng Kandungan C-Organik dan Beberapa Sifat Fisik Tanah Inceptisols Jatinangor, Jawa Barat

AGROSAINSTEK Jurnal Ilmu dan Teknologi Pertanian ◽

10.33019/agrosainstek.v4i1.37 ◽

2020 ◽

Vol 4 (1) ◽

pp. 49-53

Author(s):

Erna Dewi ◽

Rachmat Haryanto ◽

Rija Sudirja

Keyword(s):

Land Use ◽

Sampling Method ◽

Block Design ◽

Organic Content ◽

Slope Position ◽

Survey Method ◽

Soil Permeability ◽

Organic C ◽

Randomized Block Design ◽

Lower Slope

The aims of this study is determine the effect of land use and slope position on the organic C and some physical soil in the Jatinangor area, West Java. The study was conducted in April 2018 until October 2018. The study used a Randomized Block Design (RBD) factorial pattern. The first factor is land use (forest and moor) and the second factor is the position of the slope (upper, middle and lower). The sampling method uses survey, comparative and descriptive methods through a physiographic approach (physiography approach) freely, namely the survey method based on the physiographic appearance of the land and soil sampling is carried out by transect on the same slope without taking into account the distance between observation points. Observations made were C-organic, Texture, Content weight and Permeability. The results showed that land use (forest and moor) and slope position (middle and lower top) affected the organic c content and physical properties of the soil such as texture (sand, dust and clay), fill weight and permeability on Inceptisol Jatinangor soil. The use of upland land with lower slope position has the best influence on the c-organic content, texture, weight and soil permeability compared to land use and other slope positions.

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Changes in Soil C, N, and P Concentrations and Stoichiometry in Karst Trough Valley Area under Ecological Restoration: The Role of Slope Aspect, Land Use, and Soil Depth

Forests ◽

10.3390/f12020144 ◽

2021 ◽

Vol 12 (2) ◽

pp. 144

Author(s):

Tianyang Li ◽

Jiangmin Zeng ◽

Binghui He ◽

Zhanpeng Chen

Keyword(s):

Land Use ◽

Ecological Restoration ◽

Soil Depth ◽

Interactive Effects ◽

Slope Aspect ◽

Soil C ◽

Soil P ◽

Soil C And N ◽

C And N ◽

Valley Area

This study aims to investigate the roles of slope aspect, land use and soil depth in altering the soil organic carbon (C), total nitrogen (N), and total phosphorus (P) traits in the karst trough valley area experiencing extensive ecological restoration. A total of 54 soil samples were collected at 0–10, 10–20, and 20–30 cm soil depths from secondary forest, plantation forest, and grassland on the relatively more shaded east-facing slope and the contrasting west-facing slope, respectively. The independent and interactive effects of slope aspect, land use, and soil depth on soil C, N, and P concentrations and stoichiometry were determined. The results show that soil C and N concentrations were markedly higher on the east-facing slope than on the west-facing slope, and soil P concentrations showed an opposite trend, leading to significant differences in soil C:P and N:P but not in C:N ratios between the two aspects. Soil C and N concentrations were not affected by land use, and soil P concentration was significantly higher in plantation forest than in secondary forest and grassland. Soil C and N concentrations significantly decreased with increasing soil depth, but soil P concentration presented no significant changes with soil depth. Both the land use and soil depth did not differ in terms of their elemental stoichiometry. There were no significant interactive effects of slope aspect, land use and soil depth on soil C, N, and P traits. Our results indicate that soil C, N, and P changes are more sensitive to slope aspect rather than land use and soil depth in the karst trough valley area under ecological restoration.

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Variation of deep nitrate in a typical red soil Critical Zone: Effects of land use and slope position

Agriculture Ecosystems & Environment ◽

10.1016/j.agee.2020.106966 ◽

2020 ◽

Vol 297 ◽

pp. 106966 ◽

Cited By ~ 2

Author(s):

Shun-Hua Yang ◽

Hua-Yong Wu ◽

Xiao-Dong Song ◽

Yue Dong ◽

Xiao-Rui Zhao ◽

...

Keyword(s):

Land Use ◽

Critical Zone ◽

Red Soil ◽

Slope Position ◽

Effects Of Land Use

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Effects of land use on water quality in a River Basin (Daning) of the Three Gorges Reservoir Area, China: Watershed versus riparian zone

Ecological Indicators ◽

10.1016/j.ecolind.2020.106226 ◽

2020 ◽

Vol 113 ◽

pp. 106226 ◽

Cited By ~ 6

Author(s):

Jing Zhang ◽

Siyue Li ◽

Changsheng Jiang

Keyword(s):

Water Quality ◽

Land Use ◽

River Basin ◽

Three Gorges Reservoir ◽

Riparian Zone ◽

Three Gorges Reservoir Area ◽

Three Gorges ◽

Reservoir Area ◽

The Three Gorges ◽

Effects Of Land Use

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Continental scale climate, land-use and geological controls of soil P cycling and relations with soil C and N

10.5194/egusphere-egu2020-10893 ◽

2020 ◽

Author(s):

Wolfgang Wanek ◽

Daniel Wasner ◽

Johann Püspök ◽

Theresa Böckle ◽

Lisa Noll ◽

...

Keyword(s):

Land Use ◽

Land Uses ◽

Soil C ◽

Soil P ◽

P Pools ◽

P Cycling ◽

Physico Chemical ◽

P Mineralization ◽

Soil C And N ◽

C And N

Despite the importance of phosphorus (P) as a nutrient for all life, its availability is highly constrained in terrestrial ecosystems. The availability of P to plants and microbes is regulated by abiotic processes (e.g. P sorption/desorption, precipitation/dissolution) and biological activities (microbial P immobilization/organic P mineralization). Due to the strong geochemical component of the P cycle, it can be expected that soil C, N and P cycling may differ in terms of effects of geology, climate and management. Despite advances in our understanding of physico-chemical controls on P availability, there is still little mechanistic understanding of large scale controls on soil P cycling and its relation to soil C and N cycling, due to a lack of broad scale studies using common methodologies.Here we aimed to investigate soil physicochemical and biological factors that drive soil P cycling and may cause a (de)coupling of C, N and P processes. We therefore sampled mineral topsoils (0-10 cm, n=95) across a continental transect in Europe (Southern Spain to Northern Scandinavia), covering major geological, climatic and land use gradients. The soils derived from different land uses (cropland, grassland, forest/woodland) and bedrock types (silicate, sediment, calcareous). We analyzed a wide range of potentially relevant physico-chemical and biological properties and measured gross rates of soil N and P processes by short term (24 h) incubations of soils with 33P and 15N following isotope pool dilution approaches.(i) Across the whole transect land-use effects on soil P pools and processes exceeded those of geology, reflecting the accumulation of fertilizer P in soils of managed ecosystems. Cropland (and grasslands) had higher values of soil total P and soil inorganic P (Pi), available Pi (Olsen P), and gross Pi mobilization rates by abiotic and biotic processes compared to forests. Soil phosphatase activity did not vary between land-uses. Soils on silicate bedrock had significantly higher total and labile P than calcareous soils.(ii) Climate differentially affected P pools and processes. Soil total P, dissolved organic P, and gross Pi desorption decreased with mean annual temperature (MAT; these properties were not sensitive to mean annual precipitation - MAP), while soil phosphatase activity and gross total Pi mobilization through abiotic and biotic processes increased with MAP but were insensitive to MAT. This clearly points to adverse climatic controls of biotic and abiotic soil P processes.(iii) We found strong interlinkages between soil C, N and P pools (soil organic matter and microbial biomass) and soil enzymes (beta-glucosidase, chitinase, phosphatase) but not in related gross processes (respiration, N and P mineralization). Interestingly the slopes of C-P and N-P relations of pools and enzymes differed systematically between land-uses, indicating that land management causes a partial decoupling of P from C and N cycles, reflecting the P-richness of croplands.

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