Ningxia, China
Ningxia, China

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Liu J.-B.,Beijing Forestry University | Zhang Y.-Q.,Beijing Forestry University | Zhang Y.-Q.,Yanchi Research Station | Wu B.,Beijing Forestry University | And 6 more authors.
Polish Journal of Environmental Studies | Year: 2014

Changes in soil properties during long-term planting require thorough study. The objectives of this study were to determine the influence of planting Caragana microphylla on grassland on soil carbon, nitrogen, and phosphorus to a depth of 20 cm along a 34-year chronosequence encompassing 10 plantation-age groups in northwest, China. We found soil organic carbon increased by -21.84%, 0%, and 39.09% in planting years 5, 21, and 34, respectively. Total nitrogen and total phosphorus began to change in the plantation years 9 and 7, and increased by 70.59% and -28.26% in year 34. Both available nitrogen and available phosphorus increased across the chronosequence. The results indicate that the processes of changes in soil carbon, nitrogen, and phosphorus are different in a long-term chronosequence, and that Caragana microphylla has potential to improve soil properties after it is planted on grassland.

Wei B.,Beijing Forestry University | Ding G.-D.,Beijing Forestry University | Ding G.-D.,Yanchi Research Station | Wu B.,Beijing Forestry University | And 7 more authors.
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2013

Windbreak mechanism under different shrub cover conditions was quantitatively studied by carrying out a field investigation in southwestern marginal zone of the Mu Us Sandy Land, northwestern China. Artemisia ordosica and Salix psammophila shrub land were taken as the object of this study. Bare sand was set as control and the wind velocities at 0.1, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 m height upon research grounds were recorded. By doing statistical analysis of wind velocity measurements, drawing wind profile, calculating the wind profile equation, boundary layer thickness, aerodynamic roughness, we got the conclusion that both A. ordosica and S. psammophila shrub land decreased wind velocity of boundary layer much more significantly than bare land, and this effect decreased with wind velocity increasing. Aerodynamic roughness of shrub land decreased logarithmically with wind velocity increasing. When wind velocity was high, boundary layer displacement thickness would reflect the decrease of wind velocity at observation height more realistically than aerodynamic roughness. Analyzing from the air momentum, the loss of air momentum on the surface covered with vegetation was relatively stable. While the loss of air momentum on bare sand would decrease as wind velocity increasing.

Gao G.,Beijing Forestry University | Gao G.,Yanchi Research Station | Ding G.,Beijing Forestry University | Ding G.,Yanchi Research Station | And 6 more authors.
Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and Engineering | Year: 2014

We constructed an aeolian soil database in the Mu Us Desert. Soil particle size distribution(PSD)was measured with a laser diffraction technique, and the volume-based fractal dimensions were calculated following the standards of Chinese(DCHN), Soviet(DSU), American(DUS), and International(DINT)soil PSC systems. The results indicated that(1)The predominant soil particle size was distributed within the sand classification, which accounted for more than 90%of the total volume; Clay and silt particle contents were much less prevalent. The order of volume-based fractal dimensions was as follow: DSU, DCHN, DINT, and DUS. (2)Significant linear correlations occurred among DCHN, DUS, DINT, and clay, silt and sand particle contents(P<0.01), respectively, with the exception of any significant correlations between DSU and silt and sand particle contents(P<0.05), which showed a poor linear relationship. (3)There were significant positive correlation among DCHN, DINT and DUS(P<0.01), where there were poor correlations between DSU and other fractal dimensions. The linear regression analysis realized mutual transformation among DCHN, DUS and DINT. Taking into consideration soil PSD data, D values, and the observed correlations, we highly recommend that the American soil PSC system should be the optional system for calculating volume-based fractal dimensions of soil PSD. ©, 2014, The Editorial Board of Journal of Basic Science and Engineering. All right reserved.

Deng J.-F.,Beijing Forestry University | Ding G.-D.,Beijing Forestry University | Ding G.-D.,Yanchi Research Station | Wu B.,Beijing Forestry University | And 6 more authors.
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2014

A study of hydrological effects of litter layer and soil layer was carried out in two artificial forest stands (Populus bolleana and Pinus sylvestris var. mongolica) and one natural forest stand (Hedysarum scoparium) in Yanchi County, Ningxia of northwestern China. Its hydrological function of litter and soil was evaluated quantitatively through investigating standard spots, determining soil physical characteristics and water-holding capacity, and experimenting on soil infiltration, determining litter and soil water-holding capacity. The results showed that: 1) the litter total storage capacity of P. sylvestris var. mongolica was the largest, up to 7.86 t/hm2; P. sylvestris var. mongolica stand had both the maximum water capacity and available water capacity, which were 23.73 and 18.26 t/hm2, equivalent to water depth of 2.37 and 1.83 mm separately. 2) The P. sylvestris var. mongolica stand had strong soil water-holding capacity and the maximum of which was 349.12 t/hm2, equivalent to 34.91 mm water depth. The available soil water-holding capacity of P. sylvestris var. mongolica stand was 85.75 t/hm2, which was 3.24 times of H. scoparium stand, equivalent to 8.58 mm water depth. 3) Power function model can better reflect both water absorption speed of ground cover and its immersing time, and soil infiltrating rate and infiltrating time under different rainfall conditions, which had high correlation coefficient. 4) Using Philip infiltration model fitting the soil infiltration process (1 m deep soil), soil infiltration characteristics of different forest stands were obtained.

Zhang Y.-Q.,Beijing Forestry University | Zhang Y.-Q.,Yanchi Research Station | Liu J.-B.,Beijing Forestry University | Jia X.,Beijing Forestry University | And 3 more authors.
Polish Journal of Environmental Studies | Year: 2013

The rate and factors determining changes in the soil carbon pool after afforestation are still poorly understood, especially in arid and semiarid areas. This paper provides a review of the influence effect of afforestation on soil organic carbon (SOC) stocks based on a meta-analysis of 37 publications (including a total of 116 observations in the past 10 years), with the aim of exploring the major factors that can affect changes in soil carbon stocks after afforestation in arid and semiarid areas. This meta-analysis, which was based on a mixed linear model, indicates that the main factors that contribute to SOC accumulation after afforestation are previous land use, plantation age, mean annual precipitation, and mean annual temperature. It suggests that bare areas are the most suitable areas for afforestation, and that regions with precipitation of 250-400 mm and mean annual temperatures of 7.5-15°C have a greater impact on an area's capacity to accumulate SOC following afforestation. It shows that more SOC can be accumulated with the increase of plantation age. However, it also shows that plant species significantly affect SOC accumulation. This research will contribute to the development of policies of environment management and the models concerned with quantifying amounts of soil carbon sequestered by afforestation in these areas.

Gao G.-L.,Beijing Forestry University | Ding G.-D.,Beijing Forestry University | Ding G.-D.,Yanchi Research Station | Zhao Y.-Y.,Beijing Forestry University | And 10 more authors.
Ecological Indicators | Year: 2014

To identify the effects of shelterbelt establishment on soil recovery, we compared soil properties at depths of 0-5, 5-10, and 10-20 cm as affected by Caragana korshinskii shelterbelts across a chronosequence of soil undergoing restoration for 7, 11, and 26 years, as well as reference grasslands in Ningxia, NW China. Fractal dimension of soil particle size distribution (PSD) was also integrated to describe variations in soil properties. The results indicated that (1) fine particles, total porosity, total nitrogen, phosphorous, and available nitrogen, phosphorous, and potassium increased significantly with plantation age (p < 0.05). Sand particles tended to decrease with restoration time, especially in the topsoil layers (0-5 cm). (2) In most cases, selected physicochemical properties of soil in shelterbelts recovered more than in the reference grasslands; moreover, planting Medicago sativa had greatly positive effects on soil nitrogen accumulation due to azotification. (3) Fractal dimensions of soil PSD ranged from 2.3946 to 2.6351. Regression analyses showed fractal dimensions had significant linear correlations with soil physicochemical properties (R2 = 0.511-0.870, p < 0.01), except total potassium (R2 = 0.248). Therefore, we suggest D as a considerable and reliable parameter to reflect variations in soil properties affecting vegetation restoration efforts, and additionally as an implication of desertification. This improved information will contribute to a better understanding of vegetation solutions for anti-desertification efforts. © 2014 Elsevier Ltd.

Gao G.-L.,Beijing Forestry University | Ding G.-D.,Beijing Forestry University | Ding G.-D.,Yanchi Research Station | Wu B.,Beijing Forestry University | And 11 more authors.
PLoS ONE | Year: 2014

Background: Biological soil crusts are common components of desert ecosystem; they cover ground surface and interact with topsoil that contribute to desertification control and degraded land restoration in arid and semiarid regions. Methodology/Principal Findings: To distinguish the changes in topsoil affected by biological soil crusts, we compared topsoil properties across three types of successional biological soil crusts (algae, lichens, and mosses crust), as well as the referenced sandland in the Mu Us Desert, Northern China. Relationships between fractal dimensions of soil particle size distribution and selected soil properties were discussed as well. The results indicated that biological soil crusts had significant positive effects on soil physical structure (P<0.05); and soil organic carbon and nutrients showed an upward trend across the successional stages of biological soil crusts. Fractal dimensions ranged from 2.1477 to 2.3032, and significantly linear correlated with selected soil properties (R2 = 0.494-0.955, P<0.01). Conclusions/Significance: Biological soil crusts cause an important increase in soil fertility, and are beneficial to sand fixation, although the process is rather slow. Fractal dimension proves to be a sensitive and useful index for quantifying changes in soil properties that additionally implies desertification. This study will be essential to provide a firm basis for future policy-making on optimal solutions regarding desertification control and assessment, as well as degraded ecosystem restoration in arid and semiarid regions. © 2014 Gao et al.

Cheng W.,Beijing Forestry University | Zhang Y.,Beijing Forestry University | Zhang Y.,Yanchi Research Station | Wu X.,Beijing Forestry University | And 4 more authors.
2011 International Conference on Remote Sensing, Environment and Transportation Engineering, RSETE 2011 - Proceedings | Year: 2011

In order to rapidly and accurately extract the feature information of sandy area in the north of Yanchi County, the QuickBird high-resolution remote sensing images were selected as data source. The choice of the best segmentation scale was analysed in depth. The way of object-oriented supervised classification and object-oriented classification by rules were used into information extraction. The results show objectoriented image feature classification can quickly extract characteristic information of sandy area in the north of Yanchi County by choosing the appropriate scale image segmentation and rules which is determined by the different characteristics of extraction information. © 2011 IEEE.

Bao Y.,Beijing Forestry University | Bao Y.,Yanchi Research Station | Ding G.,Beijing Forestry University | Ding G.,Yanchi Research Station | And 11 more authors.
Journal of Food, Agriculture and Environment | Year: 2013

This paper analyzes and calculates the structure of wind-sand flow of perpendicular height ranges from 0~30 cm at different positions for the windward slopes on the southern edge of the Mu Us Desert. These results indicate that velocity and volume of sand movement increase correspondingly to the elevation on the windward slopes in this region. The roughness of surfaces increase from the foot of the slope to the top and the surface sand transport rate is an exponential function of the decrease of height of the dunes. Erosion is occurring at a more intense rate than deposition as slope gradients increase. This paper also finds that sand deposition is greater than erosion at slightly concave locations on windward slopes. There is a certain correlation between intensity of dune erosion and sand grain size. The changes of sand grain size from the foot of the slope is fine grained to more coarse sand, respectively.

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