Soil texture controls vegetation biomass and organic carbon storage in arid desert grassland in the middle of Hexi Corridor region in Northwest China

Soil texture plays an important role in controlling vegetation production and soil organic carbon (SOC) concentration in arid desert grassland ecosystems. However, little is known about the occurrence and extent of these textural effects in the arid desert grasslands of Northwest China. This study used 160 soil profiles taken from 32 desert grassland sites in similar topographical units (alluvial–diluvial fans) in the middle of Hexi Corridor region of Northwest China to investigate vegetation biomass, SOC storage, and soil texture of seven layers in the top 100 cm of soil. The mean aboveground biomass, below-ground biomass, and total biomass in arid desert grassland were 155.3, 95.3, and 256.3 g m–2, respectively. More than 95% of the below-ground biomass was distributed in the top 30 cm of soil. Spatially, vegetation biomass was positively related to soil clay content and silt + clay content. The mean SOC density in the top 100 cm was 2.94 kg m–2 and ~46.8% of the storage was concentrated in the top 30 cm. SOC concentrations and stocks were positively and significantly related to clay content and silt + clay content in the seven soil layers sampled from the top 100 cm. The soil silt + clay content explained 42–79% of the variation in SOC stocks in the different soil depths. In conclusion, soil texture appears to be an important control on vegetation productivity and SOC capacity in arid Hexi Corridor desert grassland soils.

Download Full-text

Multi-Temporal Arable Land Monitoring in Arid Region of Northwest China Using a New Extraction Index

Sustainability ◽

10.3390/su13095274 ◽

2021 ◽

Vol 13 (9) ◽

pp. 5274

Author(s):

Xinyang Yu ◽

Younggu Her ◽

Xicun Zhu ◽

Changhe Lu ◽

Xuefei Li

Keyword(s):

Arable Land ◽

Ground Truth ◽

Northwest China ◽

Hexi Corridor ◽

Ground Truth Data ◽

Land Protection ◽

Promising Tool ◽

Study Results ◽

Multi Temporal ◽

The Mean

Development of a high-accuracy method to extract arable land using effective data sources is crucial to detect and monitor arable land dynamics, servicing land protection and sustainable development. In this study, a new arable land extraction index (ALEI) based on spectral analysis was proposed, examined by ground truth data, and then applied to the Hexi Corridor in northwest China. The arable land and its change patterns during 1990–2020 were extracted and identified using 40 Landsat TM/OLI images acquired in 1990, 2000, 2010, and 2020. The results demonstrated that the proposed method can distinguish arable land areas accurately, with the User’s (Producer’s) accuracy and overall accuracy (kappa coefficient) exceeding 0.90 (0.88) and 0.89 (0.87), respectively. The mean relative error calculated using field survey data obtained in 2012 and 2020 was 0.169 and 0.191, respectively, indicating the feasibility of the ALEI method in arable land extracting. The study found that arable land area in the Hexi Corridor was 13217.58 km2 in 2020, significantly increased by 25.33% compared to that in 1990. At 10-year intervals, the arable land experienced different change patterns. The study results indicate that ALEI index is a promising tool used to effectively extract arable land in the arid area.

Download Full-text

Soil structure dynamics in seedbeds: Effects of soil texture and organic carbon content

10.5194/egusphere-egu2020-21373 ◽

2020 ◽

Author(s):

Mats Larsbo ◽

Nargish Parvin ◽

Maria Sandin

Keyword(s):

Organic Carbon ◽

Soil Texture ◽

Soil Structure ◽

Clay Content ◽

Transport Processes ◽

Image Resolution ◽

Strong Positive Correlation ◽

Pressure Potential ◽

Final State ◽

Pore Size Distributions

<p>The soil structure near the surface of agricultural soils changes with seasons mainly by land management together with climatic and biological factors. Quantitative analysis of post-tillage changes in soil structure and related hydraulic properties are necessary for evaluating and improving models of soil hydrological and transport processes. The objectives of this study were to quantify changes in soil seedbed structure induced by rainfall and drainage and to estimate the e&#64256;ects of soil texture and SOC on these changes. We collected samples from the harrowed layer of twenty-six &#64257;ne to coarse textured Swedish mineral soils. Air-dried soil was placed in cylinders (5 cm high, diameter 5 cm) and exposed to simulated rainfall (5 mm h<sup>&#8722;1</sup> for 4 h) and drainage (-50 cm pressure potential) cycles in the laboratory. We used X-ray tomography to quantify changes in pore networks in a thin surface layer and in the whole cylinder. Infiltration rates at -5 cm pressure potential were measured using a mini disc tension infiltrometer on replicate air-dried samples and on the samples included in the consolidation experiments at the final state. Total imaged specific pore volumes generally decreased from initial to final state and pore size distributions were shifted towards larger proportions of below image resolution pores (< 80 &#956;m). There was a strong positive correlation between clay content and changes in the specific volume of pores<80 &#956;m. Soils with high clay content and soil organic carbon (SOC) content often have strong aggregates that resist change. Nevertheless, both clay and SOC contents were negatively correlated with the changes in specific imaged pore volume. These results highlight the importance of swelling, which is largely controlled by clay content, for seedbed consolidation. In line with previous studies, when excluding coarse textured soil, the changes in surface porosity were negatively correlated with silt content. Changes in infiltration capacity were not significantly correlated to any basic soil properties. Our results suggest that shrinking-swelling should be a central part in any model for seedbed consolidation.</p>

Download Full-text

Spatial Distribution of Soil Organic Carbon and Its Influencing Factors in Desert Grasslands of the Hexi Corridor, Northwest China

PLoS ONE ◽

10.1371/journal.pone.0094652 ◽

2014 ◽

Vol 9 (4) ◽

pp. e94652 ◽

Cited By ~ 16

Author(s):

Min Wang ◽

Yongzhong Su ◽

Xiao Yang

Keyword(s):

Spatial Distribution ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Influencing Factors ◽

Northwest China ◽

Hexi Corridor

Download Full-text

Radiocarbon and Stable Carbon Isotopes in Two Soil Profiles from Northeast India

Radiocarbon ◽

10.1017/s0033822200046762 ◽

2012 ◽

Vol 54 (01) ◽

pp. 81-89 ◽

Cited By ~ 1

Author(s):

Amzad H Laskar ◽

M G Yadava ◽

R Ramesh

Keyword(s):

Organic Carbon ◽

Stable Carbon Isotopes ◽

Agricultural Land ◽

Clay Content ◽

Carbon Dynamics ◽

Northeast India ◽

Turnover Time ◽

Soil Profiles ◽

The Mean ◽

Surface Vegetation

Two soil profiles from northeast India, one from Bakrihawar, an agricultural land, and the other from Chandipur, a virgin hilly area from Assam, are investigated to understand the organic carbon dynamics of the area. Due to frequent flooding, the Bakrihawar soil has accumulated a higher clay content than that of Chandipur. The carbon content is less than 1% by weight in both the sites. The higher clay content is responsible for relatively more soil organic carbon at Bakrihawar. The mean δ13C values at both sites reflect the values of the overlying vegetation. At Bakrihawar, both rice cultivation (C3) and natural C4grasses contribute to higher mean enriched values of13C relative to Chandipur, where the surface vegetation is mostly of C3type. The turnover time of organic carbon, estimated using the residual radiocarbon content, depends strongly on the soil particle size distribution, especially the clay content (i.e. it increases with clay content). To the best of our knowledge, this is the first soil carbon dynamics study of its kind from northeast India.

Download Full-text

Radiocarbon and Stable Carbon Isotopes in Two Soil Profiles from Northeast India

Radiocarbon ◽

10.2458/azu_js_rc.v54i1.15840 ◽

2012 ◽

Vol 54 (1) ◽

pp. 81-89 ◽

Cited By ~ 3

Author(s):

Amzad H Laskar ◽

M G Yadava ◽

R Ramesh

Keyword(s):

Organic Carbon ◽

Stable Carbon Isotopes ◽

Agricultural Land ◽

Clay Content ◽

Carbon Dynamics ◽

Northeast India ◽

Turnover Time ◽

Soil Profiles ◽

The Mean ◽

Surface Vegetation

Two soil profiles from northeast India, one from Bakrihawar, an agricultural land, and the other from Chandipur, a virgin hilly area from Assam, are investigated to understand the organic carbon dynamics of the area. Due to frequent flooding, the Bakrihawar soil has accumulated a higher clay content than that of Chandipur. The carbon content is less than 1% by weight in both the sites. The higher clay content is responsible for relatively more soil organic carbon at Bakrihawar. The mean δ13C values at both sites reflect the values of the overlying vegetation. At Bakrihawar, both rice cultivation (C3) and natural C4 grasses contribute to higher mean enriched values of 13C relative to Chandipur, where the surface vegetation is mostly of C3 type. The turnover time of organic carbon, estimated using the residual radiocarbon content, depends strongly on the soil particle size distribution, especially the clay content (i.e. it increases with clay content). To the best of our knowledge, this is the first soil carbon dynamics study of its kind from northeast India.

Download Full-text

Desertification control on soil inorganic and organic carbon accumulation in the topsoil of desert grassland in Ningxia, northwest China

Ecological Engineering ◽

10.1016/j.ecoleng.2018.12.014 ◽

2019 ◽

Vol 127 ◽

pp. 348-355 ◽

Cited By ~ 3

Author(s):

Hui An ◽

Qiao-Ling Li ◽

Xin Yan ◽

Xiu-Zhi Wu ◽

Ren-tao Liu ◽

...

Keyword(s):

Organic Carbon ◽

Northwest China ◽

Carbon Accumulation ◽

Desert Grassland ◽

Desertification Control ◽

Inorganic And Organic ◽

Soil Inorganic

Download Full-text

Male parent birds exert more effort to reproduce in two desert passerines

Avian Research ◽

10.1186/s40657-021-00273-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Donghui Ma ◽

Mengjie Lu ◽

Zhichang Cheng ◽

Xingnan Du ◽

Xiaoyu Zou ◽

...

Keyword(s):

Reproductive Output ◽

Female Parent ◽

Northwest China ◽

Reproductive Behaviour ◽

Male Parent ◽

Hatching Rate ◽

Feeding Rates ◽

Passerine Species ◽

Arid Desert ◽

Habitat Environment

Abstract Background Parental investment by birds is limited by the habitat environment, and a male parent increases its effort to reproduce in birds that live in high-altitude areas. Methods A study of the reproductive behaviour of the Saxaul Sparrow (Passer ammodendri) and the Isabelline Shrike (Lanius isabellinus) was carried out at the Gansu An’xi Extremely Arid Desert National Nature Reserve in northwest China to determine the reproductive input of passerine species in desert habitats. Results In Saxaul Sparrows, compared to the female parent, the male parent exhibited a significantly higher frequency of nest-defense behaviour (chirping and warning) during nesting, hatching and feeding periods. In addition, in comparison to the female parent, the male parent exhibited almost equal frequencies of nesting and incubation but fed nestlings significantly more times. Similar to the male sparrows, the feeding rates of the male Isabelline Shrikes were significantly higher than those of the females. The hatching rate and fledging rate of the Saxaul Sparrow on average in this study were 81.99 and 91.92%, respectively, while those of the shrike were 69.00 and 96.53%, respectively. Conclusions These two different passerine species living in the same desert environment exhibited the same trend in their reproductive investments. Adapting to desert environments is a strategy that may have evolved in passerines where male parent birds put more effort than females into reproduction to ensure high reproductive output.

Download Full-text

Roots are key to increasing the mean residence time of organic carbon entering temperate agricultural soils

Global Change Biology ◽

10.1111/gcb.15787 ◽

2021 ◽

Author(s):

Christopher Poeplau ◽

Axel Don ◽

Florian Schneider

Keyword(s):

Organic Carbon ◽

Residence Time ◽

Mean Residence Time ◽

Agricultural Soils ◽

The Mean

Download Full-text

Soil Texture Alters the Impact of Salinity on Carbon Mineralization

Agronomy ◽

10.3390/agronomy11010128 ◽

2021 ◽

Vol 11 (1) ◽

pp. 128

Author(s):

Ruihuan She ◽

Yongxiang Yu ◽

Chaorong Ge ◽

Huaiying Yao

Keyword(s):

Soil Texture ◽

Clay Soil ◽

Sandy Loam ◽

Microbial Community Composition ◽

Clay Content ◽

Interactive Effects ◽

Silty Clay ◽

C Mineralization ◽

Negative Effect ◽

Silty Clay Soil

Soil salinization typically inhibits the ability of decomposer organisms to utilize soil organic matter, and an increase in soil clay content can mediate the negative effect of salinity on carbon (C) mineralization. However, the interactive effects of soil salt concentrations and properties on C mineralization remain uncertain. In this study, a laboratory experiment was performed to investigate the interactive effects of soil salt content (0.1%, 0.3%, 0.6% and 1.0%) and texture (sandy loam, sandy clay loam and silty clay soil with 6.0%, 23.9% and 40.6% clay content, respectively) on C mineralization and microbial community composition after cotton straw addition. With increasing soil salinity, carbon dioxide (CO2) emissions from the three soils decreased, but the effect of soil salinity on the decomposition of soil organic carbon varied with soil texture. Cumulative CO2 emissions in the coarse-textured (sandy loam and sandy clay loam) soils were more affected by salinity than those in the fine-textured (silty clay) soil. This difference was probably due to the differing responses of labile and resistant organic compounds to salinity across different soil texture. Increased salinity decreased the decomposition of the stable C pool in the coarse-textured soil, by reducing the proportion of fungi to bacteria, whereas it decreased the mineralization of the active C pool in the fine-textured soil through decreasing the Gram-positive bacterial population. Overall, our results suggest that soil texture controlled the negative effect of salinity on C mineralization through regulating the soil microbial community composition.

Download Full-text