scholarly journals Spatial variation and predictions of soil organic matter and total nitrogen based on VNIR reflectance in a basin of Chinese Loess Plateau

2018 ◽  
pp. 0-0 ◽  
Author(s):  
Hongfen Zhu ◽  
Zhanjunm Xu ◽  
Yaodong Jing ◽  
Rutian Bi ◽  
Wude Yang
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Spatial Variation ◽  
Loess Plateau ◽  
Total Nitrogen ◽  
Chinese Loess Plateau ◽  
Chinese Loess

Multi-scale spatial relationships between soil organic matter and influencing factors in basins of the Chinese Loess Plateau

2017 ◽  
Vol 37 (24) ◽  
Author(s):  
朱洪芬 ZHU Hongfen ◽  
南锋 NAN Feng ◽  
徐占军 XU Zhanjun ◽  
荆耀栋 JING Yaodong ◽  
段永红 DUAN Yonghong ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Influencing Factors ◽  
Loess Plateau ◽  
Chinese Loess Plateau ◽  
Spatial Relationships ◽  
Chinese Loess ◽  
Multi Scale ◽  
The Chinese Loess Plateau

Aridity-driven decoupling of δ13C between pedogenic carbonate and soil organic matter

Geology ◽  
2020 ◽  
Vol 48 (10) ◽  
pp. 981-985 ◽  
Author(s):  
Jiawei Da ◽  
Yi Ge Zhang ◽  
Gen Li ◽  
Junfeng Ji
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Pore Space ◽  
C4 Plants ◽  
Atmospheric Co2 ◽  
Chinese Loess Plateau ◽  
Pedogenic Carbonate ◽  
Chinese Loess ◽  
Pedogenic Carbonates ◽  
Soil Pore Space

Abstract Pedogenic carbonate is an invaluable archive for reconstructing continental paleoclimate and paleoecology. The δ13C of pedogenic carbonate (δ13Cc) has been widely used to document the rise and expansion of C4 plants over the Cenozoic. This application requires a fundamental presumption that in soil pores, soil-respired CO2 dominates over atmospheric CO2 during the formation of pedogenic carbonates. However, the decoupling between δ13Cc and δ13C of soil organic matter (δ13CSOM) have been observed, particularly in arid regions, suggesting that this presumption is not always valid. To evaluate the influence of atmospheric CO2 on soil δ13Cc, here we performed systematic δ13C analyses of paleosols across the Chinese Loess Plateau, with the sample ages spanning three intervals: the Holocene, the Late Pleistocene, and the mid-Pliocene warm period. Our paired δ13Cc and δ13CSOM data reveal broadly divergent trending patterns. Using a two-component CO2-mixing model, we show substantial incorporations of atmospheric CO2 (up to 60%) into soil pore space during carbonate precipitation. This result readily explains the enrichment of δ13Cc and its divergence from δ13CSOM. As a consequence, δ13C of pedogenic carbonates formed under semiarid and/or arid conditions are largely driven by regional aridity through its control on soil CO2 composition, and thus cannot be used to evaluate the relative abundance of C3 versus C4 plants. Nonetheless, these carbonates can be applied for atmospheric CO2 reconstructions, even for periods with low CO2 levels.

Spatial variation and soil nitrogen potential hotspots in a mixed land cover catchment on the Chinese Loess Plateau

2019 ◽  
Vol 16 (6) ◽  
pp. 1353-1366 ◽  
Author(s):  
Yun-long Yu ◽  
Zhao Jin ◽  
Henry Lin ◽  
Yun-qiang Wang ◽  
Ya-li Zhao ◽  
...  
Keyword(s):  
Land Cover ◽  
Spatial Variation ◽  
Loess Plateau ◽  
Soil Nitrogen ◽  
Chinese Loess Plateau ◽  
Chinese Loess ◽  
Nitrogen Potential ◽  
The Chinese Loess Plateau

scholarly journals Comparative Analysis on Soil Basic Properties Between Southern and Northern Slopes in Funiu Mountain, China

2014 ◽  
Vol 8 (1) ◽  
pp. 636-641
Author(s):  
Chengyuan Hao ◽  
Hebing Zhang ◽  
Jian Zhou
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Spatial Variation ◽  
Total Nitrogen ◽  
Chemical Properties ◽  
Available Nitrogen ◽  
Soil Available Nitrogen ◽  
Physical And Chemical ◽  
Funiu Mountain ◽  
Total Potassium

The spatial variation of soil physical and chemical properties in Funiu Mountain was studied to provide references for identifying soil spatial variation mechanism in bordering land of China warm temperate zone and northern subtropical region. Using vertical gradient sampling and traditional statistics method, the soil samples at the altitude from 1640 m to 1870 m were collected to compare physical and chemical properties between south and north slopes of the Funiu Mountain. The results showed that soil pH, soil organic matter and soil total nitrogen were remarkably correlated with altitude change, but soil electrical conductivity, soil available nitrogen, available phosphors, available potassium, and total potassium were not related to altitude. With the increase of altitude, soil pH and total nitrogen increased, but soil organic matter decreased. Compared with the soil properties of northern slope in Funiu Mountain, soil acidity, electrical conductivity, and available nitrogen were higher in southern slope. Especially, the soil available nitrogen was much higher than the mean value observed in northern slope samples. The contents of soil organic matter, available phosphorus, available potassium, total nitrogen, and total potassium showed no striking difference on between southern and northern slopes. In conclusion, both altitude and slope direction significantly influenced spatial variation of soil properties in Funiu Mountain. It added to the boundary effect of Qinling Mountains, and revealled the interaction mechanism of the environmental elements such as land-climate-soil-ecosystem in Funiu Mountain.

Restricted utility of δ13C of bulk organic matter as a record of paleovegetation in some loess–Paleosol sequences in the Chinese Loess Plateau

2004 ◽  
Vol 62 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Shucheng Xie ◽  
Jianqiu Guo ◽  
Junhua Huang ◽  
Fahu Chen ◽  
Haibin Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Loess Plateau ◽  
Asian Summer Monsoon ◽  
Loess Soil ◽  
Northwest China ◽  
Chinese Loess Plateau ◽  
Higher Plant ◽  
Chinese Loess ◽  
Bulk Organic Matter ◽  
The Chinese Loess Plateau

Molecular stratigraphic analyses using gas chromatograph-mass spectrometry have been performed in the upper section (S0, L1, S1) of the Yuanbo loess–paleosol sequences in northwest China, with a record extending from the last interglaciation through the present interglaciation. The CPI (Carbon Preference Index) values of both n-alkanols and n-alkan-2-ones display variations between loess deposits and paleosols, showing a correlation with the magnetic susceptibility record, an indicator of the East Asian summer monsoon. The observed variations in the indexes in relation to changes in lithology/paleoclimate are proposed to result from microbial degradation of higher plant lipids in the paleosols. The CPI values of n-alkanes, n-alkanols, and n-alkan-2-ones are negatively correlated with δ13C of bulk organic matter. The correlations suggest that the observed glacial–interglacial variations of δ13C data in the loess stratigraphy reflect the relative importance of the contribution of paleovegetation compared with microorganisms (including both the degradation and the addition of organic matter) and allochthonous loess/soil parent materials. It is thus necessary to evaluate the contributions of the latter two before the paleovegetation can be reconstructed based on the δ13C analysis of bulk organic matter in some loess–paleosol sequences of the Chinese Loess Plateau.

scholarly journals Paleovegetation reconstruction using <i>δ</i><sup>13</sup>C of Soil Organic Matter

2008 ◽  
Vol 5 (2) ◽  
pp. 1795-1823 ◽  
Author(s):  
G. Wang ◽  
X. Feng ◽  
J. Han ◽  
L. Zhou ◽  
W. Tan ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Negative Relationship ◽  
C4 Plants ◽  
Chinese Loess Plateau ◽  
C3 Plants ◽  
Soil Profiles ◽  
Chinese Loess ◽  
Δ13c Value ◽  
Sample Reconstruction

Abstract. The relative contributions of C3 and C4 plants to vegetation at a given locality may be estimated by means of δ13C of soil organic matter. This approach holds great potential for paleoecological reconstruction using paleosols. However, two uncertainties exist, which limits the accuracy of this application. One is 13C enrichment as plant carbon becomes incorporated into soil organic matter. The other is due to environmental influences on δ13C of plants. Two types of data were collected and analyzed with an objective of narrowing the error of paleovegetation reconstruction. First, we investigated δ13C variations of 557 C3 and 136 C4 plants along a precipitation gradient in North China. A strong negative relationship is found between the δ13C value of C3 plants averaged for each site and the annual precipitation with a coefficient of −0.40‰/100 mm, while no significant coefficients were found for C4 plants. Second, we measured δ13C of soil organic matters for 14 soil profiles at three sites. The isotopic difference between vegetation and soil organic matter are evaluated to be 1.8‰ for the surface soil and 2.8‰ for the soil at the bottom of soil profiles. Using the new data we conducted a sample reconstruction of paleovegetation at the central Chinese Loess Plateau during the Holocene and the Last Glaciation, and conclude that, without corrections for 13C enrichment by decomposition, the C4 abundance would be overestimated. The importance and uncertainties of other corrections are also discussed.

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