Xingchang Zhang

Chinese Academy of Sciences, Peping, Beijing, China

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Publications (29)47.62 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: In this study, we investigated the dynamics of soil organic carbon (OC) and nitrogen (N) following the conversion of forest to cropland. The cropland had been converted from adjacent forest areas 4, 50, or 100 years previously. Our specific objectives were 1) to determine the dynamics of OC and N in density fractions and of OC and N derived from forest and cropland and 2) to examine the contributions of these changes to changes in total OC and N. Conversion to cropland led to rapid losses of soil OC and N. The decreases in total soil OC and N in the 0–10 cm depth were mainly due to decreases in light-fraction OC and N. In the 10–20 cm depth, the decreases in total soil OC and N were determined by the loss of OC and N from both the light- and heavy-fractions. The losses in forest-derived OC and N were larger than the gains in crop-derived OC and N. The predicted losses of forest-derived OC and N in both depths were almost 2 times the losses of total soil OC and N. The mean residence times of forest-derived OC and N were shorter than those of total soil OC and N. Our findings indicated that the dynamics of soil OC and N after the conversion of forest to cropland were dominated by the losses of forest-derived and light-fraction OC and N.
    Agricultural and Forest Meteorology 08/2014; 194:188–196. · 3.89 Impact Factor
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    Feng Du, Huijun Shi, Xingchang Zhang, Xuexuan Xu
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    ABSTRACT: Drought can impact local vegetation dynamics in a long term. In order to predict the possible successional pathway of local community under drought, the responses of some drought resistance indices of six successional seral species in the semi-arid Loss Hilly Region of China were illustrated and compared on three levels of soil water deficits along three growing months (7, 8 and 9). The results showed that: 1) the six species had significant differences in SOD, POD activities and MDA content. The rank correlations between SOD, POD activities and the successional niche positions of the six species were positive, and the correlation between MDA content and the niche positions was negative; 2) activities of SOD, CAT and POD, and content of proline and MDA had significant differences among the three months; 3) there existed significant interactions of SOD, CAT, POD activities and MDA content between months and species. With an exception, no interaction of proline was found. Proline in leaves had a general decline in reproductive month; 4) SOD, CAT, POD activities and proline content had negative correlations with MDA content. Among which, the correlation between SOD activity and MDA content was significant. The results implied that, in arid or semiarid region, the species at later successional stage tend to have strong drought resistance than those at early stage. Anti-drought indices can partially interpret the pathway of community succession in the drought impacted area. SOD activity is more distinct and important on the scope of protecting membrane damage through the scavenging of ROS on exposure to drought.
    PLoS ONE 06/2014; 9(6):e98872. · 3.53 Impact Factor
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    Mingming Li, Xingchang Zhang, Qing Zhen, Fengpeng Han
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    ABSTRACT: Soil organic carbon (SOC) reflects soil quality and plays a critical role in soil protection, food safety, and global climate changes. This study involved grid sampling at different depths (6 layers) between 0 and 100 cm in a catchment. A total of 1282 soil samples were collected from 215 plots over 8.27 km(2). A combination of conventional analytical methods and geostatistical methods were used to analyze the data for spatial variability and soil carbon content patterns. The mean SOC content in the 1282 samples from the study field was 3.08 g·kg(-1). The SOC content of each layer decreased with increasing soil depth by a power function relationship. The SOC content of each layer was moderately variable and followed a lognormal distribution. The semi-variograms of the SOC contents of the six different layers were fit with the following models: exponential, spherical, exponential, Gaussian, exponential, and exponential, respectively. A moderate spatial dependence was observed in the 0-10 and 10-20 cm layers, which resulted from stochastic and structural factors. The spatial distribution of SOC content in the four layers between 20 and 100 cm exhibit were mainly restricted by structural factors. Correlations within each layer were observed between 234 and 562 m. A classical Kriging interpolation was used to directly visualize the spatial distribution of SOC in the catchment. The variability in spatial distribution was related to topography, land use type, and human activity. Finally, the vertical distribution of SOC decreased. Our results suggest that the ordinary Kriging interpolation can directly reveal the spatial distribution of SOC and the sample distance about this study is sufficient for interpolation or plotting. More research is needed, however, to clarify the spatial variability on the bigger scale and better understand the factors controlling spatial variability of soil carbon in the Loess Plateau region.
    PLoS ONE 12/2013; 8(12):e83061. · 3.53 Impact Factor
  • Mingming Li, Xingchang Zhang, Guowei Pang, Fengpeng Han
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    ABSTRACT: The distribution and storage of soil organic carbon serve as basic data for the study of soil productivity, soil hydrological properties, and the balance among carbon-based greenhouse gases. In this study, the organic carbon storage and density distribution characteristics of the soil in the Zhifanggou catchment on the Loess Plateau were studied based on field investigations, laboratory measurement, and geostatistics analysis. A total of 1,282 soil samples were collected from 215 sites in addition to 10 profiles from the catchment. The landuse within the catchment was divided into 4 types: farmland, grassland, shrubland, and woodland. The following results were obtained. 1. In the Zhifanggou catchment, the average organic carbon content of the soil at a depth of 0–100 cm is between 2.81 and 3.50 g·kg− 1. The soil organic carbon content (SOCC) for different landuse types follows the trend shrubland > woodland > grassland > farmland, whereas the soil bulk density follows. The relationship between soil organic carbon content and bulk density follows a power law function. 2. The soil organic carbon density (SOCD) at a depth of 0–100 cm is 1.24–8.34 kg m− 2. The coefficient of variation is 0.40, indicating a moderate variation in the average carbon density of 2.63 kg m− 2. The soil organic carbon density for different landuse types follows the trend shrubland > woodland > grassland > farmland. In the entire catchment, the proportion of average soil organic carbon density at a depth of 0–20 cm is 50.24%, which decreases with soil depth. The spatial distribution of the soil organic carbon density is closely related to the landuse types and topography. 3. The total soil organic carbon storage (SOCS) at a depth of 0–100 cm in the Zhifanggou catchment is 21.84 × 106 kg. The relationship between soil depth and total organic carbon storage is linear.
    Catena 02/2013; 101:11–16. · 2.48 Impact Factor
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    ABSTRACT: The conversion of natural forest to cropland generally results in the loss of soil organic carbon (OC) and an increase in CO2 flux to the atmosphere. The dynamics of aggregate-associated OC after conversion to cropland are still not well understood. Such an understanding is essential for accurately estimating C flux between soil and the atmosphere. To learn more about OC dynamics after cultivation of natural forest land, we measured total soil and aggregate-associated OC in paired forest and cropland plots in Shaanxi Province, China. The cropland had been converted from adjacent forest 4, 50, and 100 yrs previously. As expected, the conversion to cropland resulted in significant declines in total soil OC concentrations and stocks. The largest decreases occurred during the early stages of cultivation. A century of cultivation decreased total soil OC stocks in the 0–20 cm depth by 0.77 kg m−2. Macroaggregate-associated OC stocks decreased, but microaggregate-associated OC stocks increased following the conversion of forest to cropland. Silt + clay-associated OC stocks were not affected. The reduction in macroaggregate-associated OC stocks was caused by declines in both the amount of soil in the macroaggregate fraction and by decreases in the concentration of macroaggregate-associated OC. The results of this study indicate the conversion of forest to cropland not only reduced total soil OC stocks, but also caused a percentage shift in the distribution of total soil OC among aggregate size classes and among soil depths. These shifts would delay the loss of OC, so the loss of OC in forest soil due to cultivation might thus be lower than expected.
    Soil Biology and Biochemistry 02/2013; 57:876–883. · 4.41 Impact Factor
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    Liping Qiu, Xiaorong Wei, Xingchang Zhang, Jimin Cheng
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    ABSTRACT: The grazing exclusion in degraded grassland has been extensively used to prevent the loss of grassland resources and to improve grassland services. The effects of grazing exclusion on C and N balance, however, have not been well addressed but are essential for assessing grassland C sinks, the sustainable use of grassland resources and the support of grassland services. To understand the response of ecosystem C and N to grazing exclusion in semiarid grassland, we determined the C and N in litter, aboveground biomass, roots and soils from ungrazed grassland fenced at different times in northwest China. Our results showed that the aboveground biomass, root biomass and plant litter were 70-92%, 56-151% and 59-141% higher, respectively, in grazer excluded grassland than in grazed grassland. Grazing exclusion significantly increased C and N stored in plant biomass and litter and increased the concentrations and stocks of C and N in soils. Grazing exclusion thus significantly increased the C and N stored in grassland ecosystems. The increase in C and N stored in soil contributed to more than 95% and 97% of the increases in ecosystem C and N storage. The highest C and N stocks in ecosystems were observed in 17-year grazer excluded grassland. The results from this study indicate that grazing exclusion has the potential to increase C and N storage in degraded semiarid grassland and that the recovery of ecosystem C and N was mainly due to the accumulation of C and N in soils.
    PLoS ONE 01/2013; 8(1):e55433. · 3.53 Impact Factor
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    ABSTRACT: Soil nutrient pattern can be a functional tool for grassland restoration. In order to promote the growth of a specific or group of ex-pected plant species, it is necessary to measure the responses of different species to nutrient – rich patches and detect the differences among them. In this article, we measured aboveground biomass and morphological traits of six species as dry weight, length, surface area, specific root length and diameter of fine roots in response to nitrogen addition patches using ingrowth core method. The six species are Artemisia scoparia, Stipa bungeana, Artemisia sacrorum, Artemisia giraldii, Lespedeza dahurica and Astragalus melilotoides. All are the dominant species in different stages of secondary succession of loess hilly region, China. Twelve in-dividuals of each species were selected to install ingrowth cores. Six of the individuals were used as treatment group, they were treated to install with four cores of no (addition's control), low, medium and high levels of nitrogen additions. Another six of them were used as species' control group, the four installed cores around them had no nitrogen addition. The results showed that: 1) After 105 days in situ, for all the six species, summed dry weight, length and surface area measured in the four cores of the treatment group were significantly greater than the corresponding values in species' control group. In aboveground biomass, however, only A. scoparia in the treatment group had significantly outweighed that in the species' control group. 2) Irrespective of nitrogen additions levels, signifi-cant differences of length, diameter and surface area existed among the six species, which implied that species had their intrinsic species specific morphological traits. 3) In dry weight, length and surface area, the responses of all the six species to nitrogen addition levels were positive, signifi-cantly more roots were grew into the cores with higher nitrogen additions; while in specific root length, the responses were negative. 4) Perhaps the six species had a special nitrogen requirement, as interaction effects of species and addition levels in surface area were found significant. 5) The for-aging precision of the six species to nutrient-rich patches had positive but insignificant correlation with root system size; there existed a significant positive correlation between the precision and the sensitivity to the designed patchy habiats. 6) Among the six species, A. scoparia, A. sacrorum and S. bungeana have higher sensitivity and preci-sion than L. dahurica and A. melilotoides in terms of foraging the nitrogen addition cores or patches. It seems that fast growing species that dominate in early successional stage, like A. scoparia and S. bungeana in our case, obtained more benefits from nutrient patchy habitat. We advised that, in infertile lands, fertiliser be applied in a patchy way journal 34_03.indd 211
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    ABSTRACT: Voronoi area of coexisting spe-cies in a community has an important role in de-termining their performances as it is related with the available resources around individuals. Bio-mass formed within certain Voronoi area prob-ably can be a mark of species that characterised resource competition ability of coexisting species in natural community. In this article, we tried to probe the subject in the following three aspects: 1) what is the apparent relationship between indi-viduals' aboveground biomass and their available Voronoi area for species in natural community? 2) what is the possible theoretic relationship between them? 3) additionally, whether there are any pos-sible indices that can be elicited from species' oc-cupied Voronoi area to reflect species' competitive ability. Using individual-based investigation of aboveground biomass and their corresponding positions, Voronoi area of all individuals of co-existing species in an old field community were computed. The growth of an individual could be regard as a process to compete for resources that is limited by the available area or volume en-compassed by the neighborhood individuals. We extended logistic growth model to describe the relationship between Voronoi area and aboveg-round biomass of coexisting species by relating limiting rhizospheral resource with the Voronoi area around an individual. Theoretically, the in-dividual's aboveground biomass is also controlled by factor-ceiling effects of Voronoi area. So the extended model was fitted with boundary analy-sis method. And also, their linear relationship was fitted. Under the prediction that competive ability is one of the main driving factors of community succession, two parameters as the Voronoi area of coexisting species and the Voronoi area per unit of aboveground biomass were used to check whether they can designate species' competitive abilities and competitive hierarchies. This was presented by fitting the two parameters with the succes-sional niche positions that was represented by the ordination values along abandonment ages of old field communities in the local area. The results showed that: 1) For most species, the linear regression demonstrated that Voronoi area of an individual that occupied larger Voronoi area tended to have greater aboveground biomass. The nonlinear regression of showed that the re-lationship might depend upon species' growth characteristics, like shade tolerance and root pro-liferation. Generally, the relationship could be bet-ter fitted by the extended logistic growth model using boundary analysis method than by the lin-ear regression, except for some shade-preferring or clone species. If factor-ceiling effects were con-sidered, at the highest, about 48% of the variation of aboveground biomass could be interpreted by Voronoi area. For some other species with light preference or clone proliferation, the determina-tion coefficient was around zero. 2) Species' av-eraged Voronoi area had significant and positive Kendall's tau-b and Spearman correlations with journal 31 v02.indb 479 journal 31 v02.indb 479 Feng Du et al. successional niches, and species' per-unit aboveg-round biomass positions of Voronoi area has sig-nificantly negative rank correlation with succes-sional niche positions. These indicate that both of them can reflect species' competitive ability and hierarchy to some extent.
    Polish Journal of Ecology 09/2012; 60(3):479-489. · 0.55 Impact Factor
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    ABSTRACT: Background and Aims Knowledge about the effect of land use change on soil organic carbon (OC) in semiarid grassland is essential for understanding C cycles and for forecasting ecosystem C sequestration. Our objectives were (1) to study the effect of land use change on aggregate size distribution, aggregate-associated OC concentrations, and aggregate-associated stocks in a semiarid grassland area and (2) to relate changes in the aggregate fractions to changes in total soil OC. Methods Cropland and shrubland plots were established in a semiarid grassland area in 1982. We collected soil samples from adjacent grassland, cropland, and shrubland plots 27 years later and measured OC concentrations in the macroaggregate (>0.25 mm), microaggregate (0.25–0.053 mm) and silt+clay (<0.053 mm) fractions. Results Total soil OC concentrations and stocks decreased significantly after the grassland was converted to cropland or shrubland. Soil microbial biomass C, root biomass, and root C also declined. The proportion of soil in the macroaggregate fraction decreased after conversion to cropland or shrubland. Decreases in macroaggregate-associated OC stocks accounted for more than half of the OC losses that occurred when grassland was converted to cropland. The decreases in macroaggregate-associated OC stocks were due to declines in both macroaggregation and macroaggregate-associated OC concentrations after conversion to cropland. In contrast, decreases in microaggregate-associated OC stocks accounted for more than half of the OC losses when grassland was converted to shrubland. The declines in microaggregate-associated OC stocks were primarily due to a decrease in microaggregate-associated OC concentrations after conversion to shrubland. Conclusions Land use changed caused significant decreases in soil OC stocks. Conversion to cropland soil resulted in large decreases in macroaggregate-associated OC stocks whereas conversion to shrubland resulted in large decreases in microaggregate-associated OC stocks. Any changes in land use in semiarid grasslands could cause the grassland soil to become a source of atmospheric CO2; therefore extreme caution should be taken to avoid this hazard.
    Plant and Soil 06/2012; 355(1-2). · 3.24 Impact Factor
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    ABSTRACT: The afforestation of abandoned farmland significantly influences soil organic carbon (OC). However, the dynamics between OC inputs after afforestation and the original OC are not well understood. To learn more about soil OC dynamics after afforestation of farmland, we measured the soil OC content in paired forest and farmland plots in Shaanxi Province, China. The forest plots had been established on farmland 18, 24, 48, 100, and 200 yr previously. The natural (13)C abundance of soil organic matter was also analyzed to distinguish between crop- and forest-derived C in the afforested soils. We observed a nonlinear accumulation of total OC in the 0-80 cm depth of the mineral soil across time. Total soil OC accumulated more rapidly under forest stands aged 18 to 48 yr than under forest stands aged 100 or 200 yrs. The rate of OC accumulation was also greater in the 0-10 cm depth than in the 10-80 cm depth. Forest-derived OC in afforested soils also accumulated nonlinearly across time, with the greatest increase in the 0-20 cm depth. Forest-derived OC in afforest soils accounted for 52-86% of the total OC in the 0-10 cm depth, 36-61% of the total OC in the 10-20 cm depth, and 11-50% of the total OC in the 20-80 cm depth. Crop-derived OC concentrations in the 0-20 cm depth decreased slightly after afforestation, but there was no change in crop-derived OC concentrations in the 20-80 cm depth. The results of our study support the claim that afforestation of farmland can sequester atmospheric CO(2) by increasing soil OC stocks. Changes in the OC stocks of mineral soils after afforestation appear to be influenced mainly by the input of forest-derived C rather than by the loss of original OC.
    PLoS ONE 03/2012; 7(3):e32054. · 3.53 Impact Factor
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    ABSTRACT: A vailability and heterogene-ity of resources have a strong influence on com-munity biomass and diversity, which provided a valuable opportunity to evaluate the responses of vegetation on fertilization, to test whether fertili-sation can accelerate vegetation restoration in in-fertile lands. In loess hilly region of China, most newly abandoned infertile lands often undergo heavy soil erosion. It is urgent to promote the restora-tion of these types of lands. As availability and heterogeneity of soil nutrients have a strong influ-ence on plant community, we conducted a fertili-sation experiment with three-factor treatments, to test whether fertilisation can promote the bio-mass and species richness of an Artemisia sco-paria-dominated old field community. The three factors were: spatial patterns (homogeneity and heterogeneity), levels (low, medium and high), and scales (three levels with small, intermediate, and large patches) of fertiliser application. Above-and below-ground biomass and species richness were recorded. The responses of the plant com-munity to the three factors were evaluated and compared with those of the control (no fertilisa-tion). The results show that: (1) The application of fertiliser in either homogeneous or heterogeneous pattern significantly increased the above-ground and below-ground biomass of the plant commu-nity as compared with the control. (2) In hetero-geneous conditions, the above-ground biomass in nutrient-rich patches was significantly greater than the expected value of 50%. Under intermedi-ate and large scales of the low level and all scales of the medium and high levels, the proportion of 0–15 cm below-ground biomass was also signifi-cantly greater than 50%. (3) Both homogeneous and heterogeneous fertilisation greatly increased community richness as compared to the control. Fertilisation, particularly heterogeneous fertilisa-tion, can effectively increase community biomass and diversity. Under patchy habitat, it seems that the responses of vegetation to heterogeneous fer-tilisation are related to the patches scale and the contrast among patches, nutrient usage efficiency, edge effects on plant and soil, and plant compe-tition are responsible for the responses. The re-sults also suggest that heterogeneous fertilisation should be applied widely in infertile old fields to accelerate secondary succession.
    Polish Journal of Ecology 01/2012; 60(1):133-144. · 0.55 Impact Factor
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    Liping Qiu, Xingchang Zhang, Jimin Cheng, Xianqiang Yin
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    ABSTRACT: Black locust (Robinia pseudoacacia) has been widely planted in the Loess Plateau for soil and water conservation. The effects of black locust on soil properties has significant role in land use and ecosystem management. However, this beneficial effect has been little studied in the Loess Plateau. The soil properties below black locust and native grass growing in Nanxiaohe and Wangdonggou watersheds, located in the loessial gully region of the Loess Plateau, were studied for changes in soil properties after establishment of black locust. The black locust significantly increased soil cation exchange capacity, organic carbon, total nitrogen, nitrate, and carbon:nitrogen and carbon:phosphorus (P) ratios, as well as some enzymes like alkaline phosphatase and invertase in 0–20cm or 0–80cm depths of soil compared to the native grassland in Nanxiaohe and Wangdonggou watersheds. However, the effects on ammonium, total P, and extractable P and potassium were not consistent in both watersheds. There were more obvious differences in soil properties between black locust land and grassland for Nanxiaohe watershed than for Wangdonggou watershed, suggesting that the effects of black locust on most soil properties increase with black locust age. The results indicate that black locust has potential to improve soil properties in the loessial gully region of the Loess Plateau and the improvements were greater in long-term than middle-term black locust stands. KeywordsAfforestation-Black locust-Native grass-Soil properties-The Loess Plateau
    Plant and Soil 07/2010; 332(1):207-217. · 3.24 Impact Factor
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    Fengpeng Han, Wei Hu, Jiyong Zheng, Feng Du, Xingchang Zhang
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    ABSTRACT: The issue of soil organic carbon (SOC) is of increasing concern. Because SOC, as an important soil component in farming systems, is essential for improving soil quality, sustaining food production and quality, and maintaining water quality and as a major part of the terrestrial carbon reservoir, it plays an important role in the global carbon cycle. In this paper, a total of 665 soil samples from different depths were collected randomly in the autumn of 2007, and the spatial variability of SOC content at a small catchment of the Loess Plateau was analysed using classical statistics and geo-statistical analysis. In nonsampled areas classical kriging was utilized for interpolation of SOC estimation. The classic statistical analysis revealed moderate spatial variability with all five layers of SOC-content. In addition, the average SOC content decreased with soil depth and the relationship can be modelled by an exponential equation (y�3.1795x�1.2015, R2�0.9866) and all of the SOC-content data in the different depth were normally distributed. The geo-statistical analysis indicated a moderate spatial dependence in 0�60 cm, while in the 60�80 cm depth spatial dependence was strong. The semi-variogram could be fitted by an exponential model for 0�10 cm depth; by a spherical model for 10�20 cm depth and 60�80 cm depth; and by a Gaussian model for 20�60 cm depth. The range increases with increasing depth. In addition, classical kriging could successfully interpolate SOC content in the catchment. In general, the geo-statistics method on a watershed scale could be accurately used to evaluate spatial variability of the SOC content in the Loess Plateau, China.
    Acta Agriculturae Scandinavica, Section B - Soil & Plant Science 03/2010; 60(2):136-143. · 0.65 Impact Factor
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    Fengpeng Han, Wei Hu, Jiyong Zheng, Feng Du, Xingchang Zhang
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    ABSTRACT: Using soil as a carbon sink to sequester carbon dioxide has attracted much attention. But there is little research on soil organic carbon (SOC) in the Loess Plateau because of the extremely complex topography. In this study, SOC storage was estimated based on a soil survey of a small catchment in the Loess Plateau, northwest China. The SOC content of 169 profiles and the bulk density of 12 profiles were measured. The study area was classified into six different classes: farmland, grassland, shrub land, woodland, gully, Aeolian sandy soil. Results showed that the soil bulk density and SOC content are affected by land use and soil types, and the relationship between them could be expressed by a power function. Grassland had the highest SOC density, and next came farmland. Gully and Aeolian sandy soil had the lowest SOC density. The SOC content per area in the grassland and farmland was higher than the other classes and the shrub land was similar to the woodland while the Aeolian sandy soil and gully were the lowest. All of the changes in the cumulative SOC storage with the increasing depth follows a logarithmic model. The SOC storage in the catchment of farmland, grassland, shrub land, woodland, gully, and Aeolian sandy soil was estimated as 3.32 × 106 kg, 9.45 × 106 kg, 1.023 × 107 kg, 2.73 × 106 kg, 5.76 × 106 kg, and 2.94 × 106 kg, respectively. The total SOC storage of 100 cm depth in the catchment is 3.443 × 107 kg.
    Geoderma 01/2010; 154:261-266. · 2.51 Impact Factor
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    Fengpeng Han, Jiyong Zheng, Wei Hu, Feng Du, Xingchang Zhang
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    ABSTRACT: Inappropriate land use is one of the main reasons for soil erosion and nutrient loss in the hilly loess area of the Liudaogou catchment of the Loess Plateau, a typical topography area of hills and gullies. Good management practices, such as the nutrient variability for the different land uses (woodland, grassland, shrub land, farmland, and gully), would help the farmers. One study of the use of Geographic Information System (GIS) spatial analysis and geostatistic analysis was carried out in the catchment. The results showed that the trend of the content of clay and silt in the different soil ranks was: farmlandBgrasslandBshrub landBgully soil. The sandy soil contained fewer nutrients than did the other soils. The farmland contains fewer total phosphorus (TP) and NH4 �-N. The spatial dependence of the total nitrogen (TN) and the organic matter (OM) in the sandy soil is strong, but is only moderate in the other types of land use except for OM in farmland. The spatial dependence of TP in the different types of land use patterns is strong too, except in woodland, and the dependence of TP is moderate in grassland. The spatial dependence of NO3 �-N and NH4 �-N is not strong, especially NO3 �-N in woodland, shrub land, and farmland. The dependence of NH4 �-N is weak in grassland, gully, and farmland. In the catchment scale, the degree of spatial dependence (GD) is moderate for soil nutrients especially for TN and NH4 �-N, but the different nutrients were modelled in different stationary models. The spatial variability of OM, TP, and NH4 �-N was modelled by a Gaussian model, and the spatial variability of TN and NO3 �-N was modelled by an exponential equation. The nutrients’ distribution in the catchment has been mapped by GIS. From the results, it was seen that annual grass played an important role in the conservation and improvement of soil quality in the Loess Plateau. In addition, the farmland should be given more fertilizer.
    Acta Agriculturae Scandinavica, Section B - Soil & Plant Science 01/2010; 60(1):48-56. · 0.71 Impact Factor
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    ABSTRACT: The northern Loess Plateau is an important cropping-pastoral ecotone and wind–water erosion crisscross region in China, but the distribution of soil organic carbon (C), nitrogen (N) and phosphorus (P) in different land uses across this vulnerable ecoregion is not well understood. This study was carried out to determine the distribution patterns of soil organic C, N and P in native grassland and in two woody lands (Chinese Pine land and Korshinsk Peashrub land) that were established on the native grassland 28years ago. In the north part of the Loess Plateau, the concentrations of soil organic C, N and P were lower than in the southern Loess Plateau either across or within the land use patterns. The concentrations and stocks of organic C and total N were significantly decreased in Chinese Pine and Korshinsk Peashrub lands compared with those in native grassland in the surface 0–40cm soil layer, where more than 70% of the roots were distributed. The decreases in organic C in 0–40cm soil layers were 2.6 and 3.0Mg C ha−1 (26.3 and 27.7%) by Chinese Pine and Korshrinsk Peashrub, while those of total N were 0.6 and 0.4MgN ha−1 (31.5 and 17.2%), respectively, compared with native grassland. Both concentration and stock of total P varied only slightly with land use. The findings suggested that the conversion of natural grass into Chinese Pine and Korshinsk Peashrub resulted in decreased soil organic C and total N in the surface 0 to 40cm soil layer of the northern Loess Plateau. Our results further indicated that a combination of low temperatures, little precipitation and large soil degradation impede increasing C and N stocks by afforestation, and the afforestation on grassland should be viewed very critically in such areas.
    Biogeochemistry 12/2009; 96(1):149-162. · 3.73 Impact Factor
  • Yali Zhang, Xingchang Zhang
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    ABSTRACT: As one interaction outcome of soil nitrogen with rainfall and surface runoff, soil nitrogen loss by runoff virtually is the mass transfer among different carriers, runoff, sediment and soil, etc. Rainfall and surface runoff are main impetuses. Soil is the interface on which the interaction takes place, and the "motherland" from which the nitrogen transports. The soil nitrogen involved in loss by runoff only exists in certain soil horizons, the depth of which is named as Effective Depth of Interaction (EDI). Take the soil mineral nitrogen (NH<sub>4</sub> <sup>+</sup> and NO<sub>3</sub> <sup>-</sup> ) for example. According to the results of simulated rainfall experiment, the EDI of soil nitrogen is analyzed, and the methods to confirm EDI of both NH<sub>4</sub>NO<sub>3</sub>-applied experiments and no- NH<sub>4</sub>NO<sub>3</sub>-applied ones are recommended. Meanwhile the two methods' applicability for other chemicals is discussed here. The results are in the following. First, with the same type of fertilization, there are no evident influences of different fertilizer amount on the EDI. Second, the infiltration, transport by runoff and EDI distribution of nitrogen are controlled by the various characters of ions. The EDI of soil NO<sub>3</sub> <sup>-</sup> is deeper than that of soil NH<sub>4</sub> <sup>+</sup>, the balance 3~9 cm. Third, the EDI distribution takes on spatial changes along the slope, deeper in the middle and lower parts, while shallower in the upper part.
    Bioinformatics and Biomedical Engineering , 2009. ICBBE 2009. 3rd International Conference on; 07/2009
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    Yunqiang Wang, Xingchang Zhang, Chuanqin Huang
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    ABSTRACT: The spatial variability of soil total nitrogen (STN) and soil total phosphorus (STP) levels, which may be greatly affected by land use, plays an important role in both agriculture and the environment, especially with regard to soil fertility, soil quality, and water-body eutrophication. Little research has been done that addresses the spatial patterns of STN and STP under different land use types at a watershed scale. We collected 689 soil surface (0–20 cm) samples, using a grid sampling design, from the Liudaogou watershed (6.89 km2) on the Loess Plateau of North China. Using classical statistical and geostatistical methods, we characterized and compared the spatial heterogeneities of STN and STP under different land use types (farmland, grassland, and shrubland).Concentrations of STN and STP were normally distributed with the exception of STP in grassland, and decreased in the order: farmland > grassland > shrubland. Stepwise multiple regression analysis indicated a strong relationship between STN and soil organic carbon (which was mainly controlled by plant growth and microbial activity), while STP was associated with the content of finer soil particles (which absorb P more readily and whose distribution is related to slope aspect and altitude). Both STN and STP showed moderate variability under different land use types. Nugget ratios for STN showed a moderate spatial dependence and decreased in the order: farmland > grassland > shrubland, whereas STP increased in that order and showed strong, moderate, and weak spatial dependence, respectively. The type of optimal theoretical isotropy models differed for STN and STP as well as for the land use type. We concluded that spatial patterns of STN and STP would change significantly with land use changes currently being implemented to achieve sustainable agriculture development and environmental restoration. Taking land use type into account when considering the spatial variation of STN and STP would increase the accuracy in modeling and prediction of soil nutrient status and nutrient movement at the watershed scale.
    Geoderma 04/2009; · 2.51 Impact Factor
  • Yunqiang Wang, Xingchang Zhang, Chuanqin Huang
    Geoderma 02/2009; 150:141-149. · 2.51 Impact Factor
  • Yunqiang Wang, Xingchang Zhang, Chuanqin Huang
    Geoderma 01/2009; 150:141-149. · 2.51 Impact Factor

Publication Stats

84 Citations
47.62 Total Impact Points

Institutions

  • 2014
    • Chinese Academy of Sciences
      Peping, Beijing, China
  • 2010
    • Northwest A & F University
      • State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau
      Yang-ling-chen, Shaanxi, China
  • 2006
    • Fujian Agriculture and Forestry University
      Min-hou, Fujian, China
  • 2003–2004
    • Northeast Institute of Geography and Agroecology
      • Institute of Soil and Water Conservation
      Beijing, Beijing Shi, China