Influence of land management on soil nutrients and microbial biomass in the central loess plateau, northwest China

2005 ◽  
Vol 16 (5) ◽  
pp. 455-462 ◽  
Author(s):  
G.-M. Jia ◽  
J. Cao ◽  
G. Wang
Keyword(s):  
Microbial Biomass ◽  
Soil Nutrients ◽  
Loess Plateau ◽  
Land Management ◽  
Northwest China

Dung pads increase pasture production, soil nutrients and microbial biomass carbon in grazed dairy systems

2008 ◽  
Vol 84 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Sharon Rose Aarons ◽  
Catherine R. O’Connor ◽  
Hossein M. Hosseini ◽  
Cameron J. P. Gourley
Keyword(s):  
Microbial Biomass ◽  
Soil Nutrients ◽  
Microbial Biomass Carbon ◽  
Biomass Carbon ◽  
Pasture Production ◽  
Dairy Systems

scholarly journals The effects of clouds and aerosols on net ecosystem CO<sub>2</sub> exchange over semi-arid Loess Plateau of Northwest China

2010 ◽  
Vol 10 (5) ◽  
pp. 13337-13372
Author(s):  
X. Jing ◽  
J. Huang ◽  
G. Wang ◽  
K. Higuchi ◽  
J. Bi ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Air Temperature ◽  
Northwest China ◽  
Co2 Uptake ◽  
Observation Data ◽  
Light Use Efficiency ◽  
Clearness Index ◽  
Use Efficiency ◽  
The Difference ◽  
Semi Arid

Abstract. The impacts of clouds and atmospheric aerosols on the terrestrial carbon cycle at semi-arid Loess Plateau in Northwest China are investigated, by using the observation data obtained at the SACOL (Semi-Arid Climate and Environment Observatory of Lanzhou University) site. Daytime (solar elevation angles of larger than 50°) NEE of CO2 obtained during the midgrowing season (July–August) are analyzed with respect to variations in the diffuse radiation, cloud cover and aerosol optical depth (AOD). Results show a significant impact by clouds and aerosols on the CO2 uptake by the grassland (with smaller LAI values) located in a semi-arid region, quite different from areas covered by forests and crops. The light saturation levels in canopy are lower, with a value of about 434.8 W m−2. Thus, under overcast conditions of optically thick clouds, the CO2 uptake increases with increasing clearness index, and a maximum CO2 uptake and light use efficiency of vegetation occur with the clearness index of about 0.37 and lower air temperature. Under other sky conditions the CO2 uptake decreases with the cloudiness but the light use efficiency is enhanced, due to increase in the fraction of diffuse PAR. Additionally, under cloudy conditions, changes in the NEE of CO2 also result from the interactions of many environmental factors, especially the air temperature. In contrast to its response to changes in solar radiation, the carbon uptake shows a negative response to increased AOD. The reason for the difference in the response of the semi-arid grassland from that of the forest and crop lands may be due to the difference in the canopy's architectural structure.

scholarly journals Characteristic analysis of large-scale loess landslides: a case study in Baoji City of Loess Plateau of Northwest China

2011 ◽  
Vol 11 (7) ◽  
pp. 1829-1837 ◽  
Author(s):  
H. B. Wang ◽  
B. Zhou ◽  
S. R. Wu ◽  
J. S. Shi ◽  
B. Li
Keyword(s):  
Loess Plateau ◽  
Large Scale ◽  
Northwest China ◽  
Landslide Inventory ◽  
Small Scale ◽  
Land Utilization ◽  
Characteristic Analysis ◽  
Landslide Inventory Map ◽  
Loess Landslides ◽  
Inventory Map

Abstract. Landslides are one of the most common geologic hazards in the Loess Plateau of northwest China, especially with some of the highest landslide densities found in Shaanxi and adjacent provinces. Prior to assessing the landslide hazard, a detailed landslide inventory map is fundamental. This study documents the landslides on the northwest Loess Plateau with high accuracy using high-resolution Quickbird imagery for landslide inventory mapping in the Changshou valley of Baoji city. By far the majority of landslides are in loess, representing small-scale planar sliding. Most of the large-scale landslides involve loess and bedrock, and the failure planes occurred either along the contacts between fluvial deposits and Neogene argillites, or partially within the bedrock. In the sliding zones of a large scale landslide, linear striations and fractures of the soils were clearly developed, clay minerals were oriented in the same direction and microorganism growths were present. From the analysis of microstructure of sliding soils, it is concluded that the Zhuyuan landslide can be reactivated if either new or recurring water seepage is caused in the sliding surface. It can be concluded that most landslides are attributed to the undercutting of the slope associated with gullying, and numerous ancillary factors including bedrock-loess interface, slope steepness, vegetation cover and land utilization.

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