Abstract:[Objective] Studying the relationship between soil hydro-physical properties and litter carbon return in restored degraded land is beneficial to understanding the hydrological functions associated with different restoration measures.[Methods] Soil moisture characteristics in different soil layers(0-80 cm) and litter carbon were examined in four typical vegetation types in eroded area of red soil, i.e. Citrus reticulata Banco forest, enclosed forest, Schima superba-Pinus massoniana mixed forest and broad-leaved forest, based on field investigations and laboratory tests.[Results] (1) The soil water content decreased with the increases of soil water suction. The average soil water content with a treatment of 1500 kPa water suction, compared with the treatment of 2.5 kPa water treatment, was reduced more in Citrus reticulata Banco forest[(45.92%) than in other vegetation types(enclosed forest(45.10%), Schima superba-Pinus massoniana mixed forest(38.79%), broad-leaved forest(31.20%)].(2) The soil water content decreased with the increases in soil depth. Among different water suction treatments, soil water content in the bottom soil layer(60-80 cm) varied between 30.11% to 9.72% in Citrus reticulata Banco forest, 31.81% to 24.46% in enclosed forest, 24.46% to 5.49% in Schima superba-Pinus massoniana mixed forest and 8.21% to 0.24% in broad-leaved forest. The reductions in soil water content in broad-leaved forest were smallest among four vegetation types.(3) The total litter carbon significantly varied among four vegetation types, i.e. Schima superba-Pinus massoniana mixed forest(1915.79 kg/hm²) >broad-leaved forest(1414.84 kg/hm²) >forbidden forest(1212.32 kg/hm²) >Citrus reticulata Banco forest(633.88 kg/hm²). The carbon return of broad leaf and saturated water content in broad-leaved forest were larger than those in Schima superba-Pinus massoniana mixed forest, showing greater consistency.[Conclusion] Soil water-preserving and holding capacity in broad-leaved forest is the best. The carbon return of broad leaf had greater impacts on soil water content than other factors.

Abstract:[Objective] The objective of this study is to reveal the soil erosion characteristics of dumping sites in Three Gorges reservoir region in order to provide basis for the management in this area.[Methods] Runoff plots were constructed and simulated artificial rainfall was used in this research.[Results] A significant linear relationship was found between rainfall and erosion amount. The rainfall intensity showed a significant power function correlation with the runoff time, while it showed an exponential regression correlation with the sand content. Fine gravel with high concentration in the dumping sites surface soil reduced the splash and sheet erosions in some extent, however, it intensified the gully erosion under the condition of heavy or continuous rainfall. Furthermore, soil erosion in the dumping sites presented seasonal variations. During the dry season, soil erosion was dominated by sheet erosion and slight gully erosion, and the erosion amount was little. In contrast, in wet season, shallow grooves were converted into ditches rapidly, and the erosion became more severe.[Conclusion] As soil erosion in dumping sites of Three Gorges reservoir region changes seasonally, constructions can be done according to the changes of season to avoid the rainy season. Taking the protective measures to prevent or slow down the development of gully erosion in the rainy season is the focus of soil and water conservation in the study area.

Abstract:[Objective] To study the impacts of micro-topography on plant functional groups, biomass and soil water content in order to provide theoretical reference for environmental construction and reasonable development in the Hunshadake sandy land area.[Methods] The investigations were conducted in sandy land, in Inner Mongolia grassland ecosystem research station(IMGERS). Soil water content, biomass and plant functional groups were investigated under different micro-topographic conditions.[Results] The bottom of hill was dominated by perennial grass, while the top of hill was dominated by perennial grasses and annual or biennial herb. Shrub, subshrub and perennial grasses were distributed on the north-facing slopes, while shrub, subshrub, perennial grasses and annual or biennial herb were distributed on the south-facing slopes. The soil water content(0-50 cm) was showed as follows:bottom of the slope >north-facing slope >south-facing slope >top of the slope, and same trend was showed in biomass. Coefficient of variation of soil water content(0-50 cm) was the greatest at the top of the slope, while it was the lowest at the bottom of the slope. Aedbetween biomass and soil water content, and significant linear correlation existed between biomass an soil water content in top soil(0-5 cm), soil at the depth of 5-10 cm and 20-30 cm(p<0.01).[Conclusion] Micro-topography influences soil water content and florisitics, and there is a significant positive correlation between soil water content and biomass.

Abstract:[Objective] The objective of this study is to analyze the influences of precipitation and human activities on runoff and sediment load in order to provide basis for the benefits evaluation in soil and water conservation.[Methods] The variations of precipitation, runoff and sediment load during 1974-2010 were analyzed in Xiangxi river watershed, by using Mann-Kendall test, linear regression, hydrological frequency curve and double mass curves. Factors that drive the variation of runoff and sediment discharge were quantified.[Results] There was a slightly declining trend in annual precipitation and annual runoff, while there was a significant decreasing trend(α=0.05) in sediment load. Mutation point analyses revealed that abrupt reduction in annual sediment discharge occurred in 1994, while the rapid reduction in annual runoff happened in 1991.[Conclusion] Human activity is the main factor that drives the changes of runoff and sediment loads.

Abstract:[Objective] The aim of this study is to investigate the soil water characteristic curve and its influence factors under different vegetation cover in karst area in order to provide the theoretical basis for the quantitative analysis of soil water movement in karst mountain area.[Methods] Based on field survey and laboratory analysis, this paper studied the soil water characteristic curve of four different vegetation type(wasteland, grassland, bushwood and forest-shrub) in typical karst mountains in Guohua, Pinguo, Guangxi Zhuang Autonomous Region.[Results] All the three models including van Genuchten, Brooks-Corey and Gardner fitted the data well, with correlation coefficients were >0.93 and the sum of squared residuals were <0.0005. Among the three models, van Genuchten model was the best fitted model for calculating the soil water characteristic curve. The soil water-holding capacity showed a significant negative relationship with the positive succession of vegetation, saturated water content, non-capillary porosity and particle content, while it showed an extremely significant positive relationship with soil bulk density, clay content, capillary porosity, initial water content and capillary moisture. Under different vegetation types and the same suction, the soil water-holding ability was great at the surface and deep layer soil but poor in the middle layer soil. Under different soil depth and the same suction, the soil water-holding ability in wasteland was the greatest, while it was the poorest in forest-shrub.[Conclusion] Under different soil depth and the same suction, the soil water-holding ability decreases with the positive succession of the vegetation. The dominant factor that influences the soil water characteristic curve in the study area is soil capillary porosity.

Abstract:[Objective] The purpose of this study is to investigate the dynamic variation of soil water and salt in coastal saline-alkali area in Tianjin, and provide scientific basis for soil utilization and forest planting.[Methods] We took the Robinia pseudoacacia soil in Dagang district of Tianjin City as a case study, to study the annual variation of soil water and salt and salt ions distribution characteristics in different soil layers.[Results] The annual soil water content varied from 11.9%~28.8%, while salt content varied from 4.2%~18.4%. In spring(March to May) and autumn(September to November), soil water content was the lowest while salt content was the highest. Soil salt content increased with the increase of soil depth. Soil pH value ranged from 7.37 to 8.39. The content of K⁺, Na⁺, Ca²⁺, Mg²⁺ and Cl^- was the highest in the top layer(0-10 cm) in spring, and it was 0.04, 4.27, 2.69, 1.04 and 10.03 g/kg, respectively. Except for SO₄^2- and HCO₃^-, the coefficient variation of salt ions(29.99~162.98) in spring was greater than that in summer(2.87~88.13).[Conclusion] Soil water and salt content in different soil layers show an obvious seasonal variation along with local rainfall. Soil in the study area belongs to alkaline soil, and there is no significant seasonal change in soil pH value. Variations in K⁺, Na⁺, Ca²⁺, Mg²⁺ and Cl^- are consistent with soil salt content, while there is no significant seasonal variation in SO₄^2- and HCO₃^-. The distribution of salt ions is extremely uneven in spring.

Abstract:[Objective] The aim of this study is to investigate the effects of ploughing area on soil and water loss, in order to provide basis for soil and water loss in Loess Plateau.[Methods] By artificial rainfall experiments, we studied runoff and sediment yield characteristics at three different slopes with different ploughing area.[Results] The runoff and sediment yield characteristics of cultivated land were not only related to the slope, rainfall intensity and soil moisture content, but also closely related to ploughing area. Under the same slope gradient, the initial runoff occurring time was delayed and the sediment yield was increased with the increase of ploughing area. Under the same ploughing area, runoff and sediment yield rate showed an increasing trend with the increase of slope gradient. And runoff reached to the maximum when the slope was 15ånd the ploughing area was 50%. Under the same gradient, the sediment yield showed an increasing trend with the increase of ploughing area. When the slope gradient was 10°, ploughing area had the greatest influence on sediment yield, and the average sediment yield of ploughing treatment was 8.66 times of no-till treatment. The runoff had the most significant influence on the cumulative sediment yield when the slope gradient was 15°. Runoff rate under different ploughing area became stable approximately 10 min after the initial runoff occurring. Under different slope gradient, sediment production rate of full-tillage was the largest in whole-ploughing, while the smallest in no-till.[Conclusion] With the increasing of ploughing area, the initial runoff occurring time is delayed, runoff decreased, and the sediment yield increased.

Abstract:[Objective] The paper aims to study the characteristics of soil phosphorus adsorption-desorption and its influencing factors under six types of land use, namely rainfed farmland, forest land, orchard, grass land, tea plantations and paddy field in purple hilly area of Eastern Sichuan, in order to provide theoretical support for the risk assessment of phosphorus loss in purple soil under different land use types.[Methods] Soil samples were collected at a depth of 0-20 cm layer from six types of land use in research region, and then soil phosphorus adsorption-desorption parameters were determined according to the culture experiment, and related soil physical and chemical properties were measured. Principal component analysis and twiddle factor analysis methods were used to evaluate the risk of soil phosphorus loss and its main influencing factors.[Results] Soil pH value, organic matter, soil water soluble phosphorus, available phosphorus, total phosphorus, CaCO₃ and available Zn were important factors affecting the adsorption of soil phosphorus. The principal component factor analysis showed that the contribution of soil available phosphorus, total phosphorus, CaCO₃ and available Zn to purple soil phosphorus adsorption capacity were 86.9%, 89.2%, 89.4%, 96.9%, respectively. According to factor analysis, the four parameters of maximum phosphorus absorption capacity(Q_m), maximum buffering capacity(MBC), easy absorption of phosphorus(RDP), intercept value b could be used to forecast the risk of phosphorus loss in purple soil.[Conclusion] Among the six types of land use in the study area, orchard and dry farmland had the higher risk of phosphorus loss, whereas paddy fields and tea garden had the lower risk of phosphorus loss.

Abstract:[Objective] The change rules and characteristics of the surface roughness was analyzed under the station of submerged and unsubmerged and the different vegetation density in order to provide the reference for studying the effect of vegetation on the surface roughness.[Methods] The plastic rods, as a surrogate for vegetation distribution, were used to simulate two different densities in the flushing experiments.[Results] The earth surface roughness changes were different between the submerged vegetation and unsubmerged vegetation. Under the unsubmerged condition, the earth surface roughness decreased with the increase of the average water depth.While submerged depth was low, the earth surface roughness firstly increased and then decreased with the increase of the average water depth. When the submerged depth was very deep, the earth surface roughness tends to be a stable value.[Conclusion] The earth surface roughness value increases along with the vegetation density. Under the same underlying surface, the surface roughness value changes with different flow direction.

Abstract:[Objective] This Paper aimed to investigate the dynamic variation and distribution of soil carbon of natural grassland under different restoration years in order to understand the dynamic characteristics of soil organic and inorganic carbon pool.[Methods] Using field survey and laboratory analysis method, this study analyzed the dynamic variation of soil total carbon of natural grassland under different restoration years(11, 16, 22 and 35 a) in loess hilly region.[Results] Soil organic carbon(SOC) content in the 0-10 cm soil layer surface was increased significantly with the increase of restoration years, while no evident changes were found in the 10-100 cm soil layer. Variations in average soil organic carbon storage of natural grassland at 0-100 cm soil depth decreased initially and then increased with the increase of restoration years. However, it had not reached to the level of farmland. Decalcified phenomenon existed in 0-20 cm soil layer. Soil inorganic carbon(SIC) storage was 2.7 to 4.5 times larger than soil organic carbon storage in 0-100 cm total soil layers. No significant variations occurred in total soil carbon storage as the restoration years increased. Soil inorganic carbon storage accounted for about 75.6% to 86.0% of soil total carbon storage in the 0-100 cm soil. The SIC pool was an important factor that influenced soil total carbon pool in the study area, which also maintained the dynamic balance of soil carbon pool in this region.[Conclusion] In the semi-arid environment of the Loess Plateau, soil carbon sequestration effect in natural grassland is not obvious and the improvement of soil carbon pool is likely to require a considerably long period of time.

Abstract:[Objective] This paper aimed to investigate the mechanism of soil erosion resistance by vegetation restoration and the water stability index of red soil in Ganjiang river basin area.[Methods] Soil samples developed from three parent materials(the granite, red sandstone and quaternary red earth) under different vegetation coverage were selected, to explore the dynamic change of water stability by using hydrostatic balance method.[Results] The dynamic change of water stability of red soils decreased with soil immersion time in all samples. This decreasing trend was less in woodland and shrub land compared to bare land. Soil water stability in both woodland and shrub land improved significantly, compared to bare land developed from all the three parent materials.[Conclusion] The hydrostatic balance method is more suitable to study the dynamic change of water stability. Vegetation restoration is beneficial to the improvement of soil water stability in Gannan area.

Abstract:[Objective] To analyze mineralization features and content of soil organic carbon in order to provide theoretical basis for future research on decomposition process and carbon sequestration capacity of soil under Castanopsis fargesii forests.[Methods] We obtained soil organic carbon data based on field investigation and laboratory analysis. The Origin 8.6 software was employed in the study. A double exponential model was used to investigate the spatial and temporal variation in activated carbon content and organic carbon mineralization intensity.[Results] Both of the soil organic carbon and activated carbon showed obvious surface enrichment, and this surface enrichment increased from the relative low in April to the highest in August, and then decreased gradually. The characteristics of vertical section and temporal variation in soil organic carbon mineralization intensity were similar to that in soil organic carbon and active carbon, and significant changes only occurred on topsoil at 0-20 cm.[Conclusion] Soil organic carbon mineralization intensity is significantly influenced by microbe, temperature and carbon content, and this influence is more significant in soil carbon content.

Abstract:[Objective] In order to provide the basis for vegetation restoration and management in mining area, Heidaigou opencast coal mine dump north in Zhunge'er Banner, Inner Mongolia was selected as the research object.[Methods] We investigated soil profile and collected soil samples by field surveys. Soil physical and chemical properties were analyzed and compared under 9 different vegetation restoration patterns and control plot. Soil quality was evaluated by calculating soil quality index(SQI) under different vegetation restoration patterns.[Results] All vegetation types effectively improved soil quality. Soil bulk density was the minimum in Hippophae rhamnoides Linn. shrub, which was 1.35 g/cm³. Soil moisture content was the maximum in forest composed of Pinus tabulaeformis Carr. +H. rhamnoides Linn.+Caragana korshinskii Kom., which was 13.32%. Soil organic content was the maximum in forest composed of P. tabulaeformis Carr. +Populus sp +Salix babylonica L, which was 9.42 g/kg. Soil available N and available K contents were the highest in forest composed of P. tabulaeformis Carr.+H. rhamnoides Linn.+C. korshinskii Kom., which was 21.32 and 90.21 mg/kg, respectively. Soil available P was the highest in C. korshinskii Kom shrub, which was 6.47 mg/kg. The best soil quality occurred in mixed vegetation composed of H. rhamnoides Linn. and C. korshinskii Kom. Single cropping H. rhamnoides Linn. shrub or C. korshinskii Kom. Shrub also improved soil quality.[Conclusion] Mixed forests of trees and shrubs composed of H. rhamnoides Linn., C. korshinskii Kom., H. rhamnoides Linn. and C. korshinskii Kom. play important role in soil reclamation.

Abstract:[Objective] Soil bio-characteristics of Lonicerae hypoglauca with different planting years was studied in karst mountainous area to provide the basic data for the improvement of L. hypoglauca cultivation in Guizhou Province.[Methods] We used the field observation and laboratory analysis in the study. Soil samples from the root zone of L. hypoglauca were collected to investigate soil bio-characteristics with different planting years in Suiyang County of Guizhou Province.[Results] The amount of microorganism and bacteria(B) in the soil increased in the initial planting years and then decreased gradually, while the amount of actinomycetes(S) and fungi(F) in the soil increased continually with the addition of the planting years. Similarly, the content of C, N and P of soil microorganisms showed an increasing trend at the initial planting years and then decreased with the addition of planting years. The activity of both catalase and urease increased initially and then decreased. In contrast, soil phosphatase showed a decreasing trend initially and then increased with the addition of planting years. The B/F ratio of soil increased initially and then decreased. The number of actinomycetes/fungi(S/F) increased with the planting year. The Shannon-Wiener index of soil microorganisms increased initially and then decreased, while both of the Simpson index and Shannon evenness index decreased with the addition of planting years.[Conclusion] Soil fertility declines and the incidence of virus in root zone increases with the addition of planting year.

Abstract:[Objective] We analyzed the impact of bioturbations on sediment composition, particle size distribution and permeability in order to provide a scientific basis for river pollution control and undercurrent belt repair.[Methods] We investigated the effects of different invertebrates on vertical hydraulic conductivity(VHC) through simulating sediments distrubed by Chironomid larvae, Tubificid and Physa acuta in laboratory conditions.[Results] C. larvae and P. acuta had the greatest impact on permeability. The clogging effect by Tubificid mainly occurred in 3-9 cm under water-sediment interface, resulted in reducing hydraulic conductivity. The granularity effect and distribution characteristics by P. acuta were barely discernible.[Conclusion] Bioturbation of both Chironomid larvae and Physa acuta improves the VHC of sediments, while bioturbation of C. larvae is more remarkable, comparatively. In contrast, Tubificid weakens the permeability of sediment. Bioturbation can modify the structure of sediment deposits, and thereby promote the permeability of streambed sediments.

Abstract:[Objective] The objective of this paper is to analyze the dynamic changes of soil water and salt during the farming period in order to provide the scientific guidance for soil salinization control and the implementation of water-saving irrigation project.[Methods] We designed the experiments according to the soil texture, irrigation methods, crop cultivation and other factors. We calculated and analyzed the variations in water content, moisture content, soil salinity and groundwater salt through the conventional methods. Based on 2 years observation data, we analyzed the dynamic changes of soil moisture, and salt movement.[Results] Soil moisture content increased with the increase of soil depth, and the change frequency in soil moisture content decreased with the increase of soil depth during farming period.[Conclusion] During the farming period, heavy rainfall(drop water) may reduce desalting efficiency, and the surface soil shows an obvious desalting when the groundwater are shallow. Changes in groundwater salinity are closely related to rainfall.

Abstract:[Objective] To evaluate drought resistance of seventeen Hippophae rhamnoides in Ulan Buh Desert in order to provide theoretical basis for the selection of drought resistant species.[Methods] Under different soil moisture conditions, subordinate function values analysis was used to evaluate drought resistance.[Results] (1) With the increasing of drought stress, water saturation deficit, boung water and bound/free water ratio, and cell membrane permeability increased. Water saturation deficit ranged from 22.88% to 64.85%, and maintained at the same high level in Qiuyisike, Ou 11 and Baiqiu. Boung water and bound/free water ratio showed a high level in Shenqiuhong and Ou11. The relative electric conductivity in Chengse and Baiqiu was significantly higher than that in the other varieties.(2) As the acceleration in drought stress, the content of chlorophyll, water-retaining capcity, photosynthetic rate, transpiration rate and stomatal conductance showed a decreasing trend. Yalishanda 12 had the highest content of chlorophyll. The rate of water loss in Chengse and Xiangyang was significantly higher than that in the other varieties. Photosynthetic and transpiration rate in Liaofu 1 and Shenqiuhong declined by a large margin, while the decline of stomatal conductance in Liaofu 1 and Shenqiuhong maintained at a moderate level.[Conclusion] The drought resistance of seventeen Hippophae rhamnoides showed as follows:Liaofu 1 >Ou 11 >Shenqiuhong >Zhuangyuanhuang >Zongqiu >Zhiwuyuan >Baiqiu >Xiboliyahongyun >Qiuyisike >Yalishanda 12 >Chengse >Gaijiasuo >Xiangyang >Juren >Wuhe >Katuni >Haibin.

Abstract:[Objective] The objective of this study is to provide the foundation for selecting the excellent afforestation species in sandy area by establishing the drought resistance evaluation system.[Methods] Two-year-old seedlings of the twelve desert shrubs in Ulan Buh desert ecosystem were selected as the experimental materials. Through measuring seven water physiological indexes, the drought resistances of the twelve desert shrub species were studied by the principal component analysis and cluster analysis.[Results] (1) The water potential of Ephedra distachya, Nitraia tangutorum and Caragana korshinskii was lower than the other nine shrub species. The bound water content and the ratio value of bound water and free water(V_a/V_s) of Zygophyllum xanthoxylon was relatively higher, which was 64.20% and 3.3, respectively. The transpiration rate of Atraphaxis bracteata, Nitraia tangutorum and Tamarix chinensis was significantly lower than the other nine shrub species. The constant weight time of Haloxylon ammodendron and Ephedra distachya was the longest, and it was 144 h. The residual moisture content of Ammopiptanthus mongolicus was the highest(44.80%).(2) The drought resistance of the twelve desert shrubs in Ulan Buh desert ecosystem was significantly influenced by water potential, V_a/V_s, residual moisture content, bound water, transpiration rate and constant weight time, and the cumulative variance contribution rate reached to 87.59%.[Conclosion] According to the drought resistance, twelve desert shrubs can be clustered into 3 categories. Ephedra distachya belongs to the strong drought-tolerant shrub; Haloxylon ammodendron, Nitraia tangutorum and Zygophyllum xanthoxylon belong to the medium drought-tolerant shrub; Hedysannn scoparium, Hedysarum mongolicum, Tamarix elongate, Caragana korshinskii, Ammopiptanthus mongolicus, Atraphaxis bracteata, Calligonum mongolicum and Caragana microphylla belongs to the weak drought-tolerant shrub.

Abstract:[Objective] The objective of this study is to analyze the impact of debris flow on the main river and the possibility of debris flow blocking the main river.[Methods] We conducted experiments for the debris flow blocked river tests, and analyzed the debris flow blocking the river cases in history.[Results] Three basic modes of debris flow blocking river were concluded according to debris flow motion and deposition morphology. These modes included top damming block mode, seepage mixed jamming burst mode and narrow beam progressive blocking mode. Based on three modes, we studied the motion and the disaster mechanism of the debris flow blocking river.[Conclusion] The top rushed damming block mode was characterized as the top leading rushed across the side bank, provenance stuffed the main channel and the fragile parts seeped to the collapsed body. The seepage mixed jamming burst mode was characterized as short-term crammed into the main channel, water permeability mixed jam and increased flow. The narrow beam progressive blockage model was characterized as based groove section of narrow beam, local flow transient increasing and gradual local blockage. The current history in the river blocking events is mainly narrow and progressive blockage, and the results agree with the experimental results.

Abstract:[Objective] The objective of this study is to quantitatively analyze the effects of terrace on river runoff and ecological basic flow(EBF) of Jinghe watershed in Loess Plateau region, to provide theoretical supports for construction of terraces in the watershed.[Methods] The process-based terrace algorithm was developed based on soil and water assessment tool(SWAT) model to simulate river runoff.[Results] The developed model satisfied the accuracy requirements in runoff simulation. With the increase of terrace area, annual runoff and number of days when runoff less than EBF were reduced, and the security level of EBF enhanced dramatically. Terrace could reduce runoff by as much as 4.25×10⁴ m³/(km²·a). Moreover, terrace could adjust the flood and runoff, and this adjustment effect on runoff in wet season was higher than that in dry season. The effects of terrace on EBF showed as:dry season >the normal season >the wet season.[Conclusion] The newly developed terrace algorithm is satisfactory in simulating daily runoff in Jinghe watershed. Increasing terraced area is an effective way to adjust runoff in both wet and dry seasons, and guarantee EBF.

Abstract:[Objective] Comparing the water-holding capacity of litters in six different bamboo forests mixed with Casuarina equisetifolia is of great importance to tree species selection in coastal protection forest.[Methods] By setting the standard plots, samples collection and laboratory immersion experiment, original water-holding rate, water-absorbing characteristic and the water-losing characteristic of litters in 6 mixed forest were measured to compare the water-holding capacity of litters in six different coastal protection mixed forests.[Results] The forest with maximum water-holding rate was Dendrocalamus minor var. amoenus, followed by the Dendrocalamopsis vario-striata, Dendrocalamus brandisii, Bambusa oldhami, Dendrocalamus latiflorus, Bambusa beecheyana var. pubescens. while the forest with higher original water content is D. brandisii, followed by D. minor var.amoenus, B. oldhami, B. beecheyana var.pubescens, D. vario-striata, D. latiflorus. In absorbing and natural drying process, water-holding rate, water-absorbing speed, water-losing rate and water-losing speed of all kinds of litters in mix forest increased rapidly in the first two hours. From then on, the rates slowed down with prolonged immersion time, and gradually became stabilized after 16 hours.[Conclusion] Water-holding rate and water-losing rate of litters increased following a log function with the time immersed in water, and the water-absorbing speed rate and water-losing speed followed a power function

Abstract:[Objective] To seek a reasonable method in soil salinity accumulation controlling between membrane, in order to provide the basis for control the salt accumulation on soil surface.[Methods] Different intermembrance treatments were employed, including:straw covering, laying sand, PAM(polyacrylamide) spraying, compacting and controlled treatment, to analyze the efficacy of the treatment measures.[Results] (1) All the treatments could reduce the moisture evaporation. The evaporation in straw covered, sand spread, spraying PAM, compacting, and the controlled treatment was 0.11, 0.34, 0.59, 1.55 and 2.32 cm, respectively.(2) All the treatments could reduce the moisture evaporation of membrane narrow row, and improve soil moisture of membrane narrow line. At 10 cm depth of the narrow line, the relative reduction of soil moisture in straw covered, laying sand, spraying PAM, compacting, and the controlled treatment was 47%, 45%, 56%, 64% and 77%, respectively.(3) All the treatments reduced salt accumulation in the root zone of the crop. At 10 cm depth of the narrow line, the relative desalination in straw covered, laying sand, spraying PAM, compacting and the controlled treatment was 3%, 2%, 0%,-16% and-28%, respectively.[Conclusion] Applying intermembranes treatments can reduce the water loss and salt accumulation in the root zone. Straw covering is the best methods in reducing soil water loss and salt accumulation in the root zone.

Abstract:[Objective] The objective of this study is to monitor the dynamic change of soil and water loss in the key construction sections in the west section of the second line of west-east natural gas transmission pipeline project in order to provide support for the subsequent long-distance transmission pipeline projects.[Methods] Three key sites, which located in Tianshan mountain area, Tulufan-Hamei basin area and Leoss Plateau area in Xinjiang Uygur Autonomous Region, were monitored. Traditional located monitoring, remote sensing and theoretical analysis was adopted.[Results] The large amount(1.61 million tons) of new-increased soil erosion was caused by the construction of the west section of the second west-east natural gas transmission pipeline project. In particular, around 93.68% of soil erosion occurred at the pipeline working zone.[Conclusion] The construction of the west section of the second west-east natural gas transmission pipeline project has intensified soil erosion in the project areas.

Abstract:[Objective] The aims of this study is to investigate the dynamic change of vegetation coverage and its response to climate change during the past 20 years in Ningxia Hui Autonomous Region in order to provide theoretical foundation and scientific basis for understanding the regional ecological change trend and evaluating of ecological engineering.[Methods] Remote sensing data used in the study was Landsat TM in 1992, 2000, 2006 and 2012. Based on dimidiate pixel model, different vegetation indices for estimating vegetation coverage was calculated, and the dynamic changes of vegetation coverage were monitored.[Results] High vegetation cover was found in the northern and southern parts of Ningxia Hui Autonomous Region, in contrast, the lowest vegetation cover was found in the middle part the region. Vegetation cover increased significantly during past 20 years, with the low vegetation cover area decreased gradually while the middle-and high-vegetation cover area increased about 6434 km². The average vegetation cover in the whole region increased by 6%. In particular, vegetation cover in the Yellow River irrigation area of Northern Ningxia and mountainous area of Southern Ningxia increased by a large margin.[Conclusion] The vegetation increase in the study area is benefit from the implementation of a series of vegetation protection and ecological restoration projects in recent years. The annual change in vegetation coverage is mainly caused by the variation of precipitation.

Abstract:[Objective] The paper aims to estimate nitrogen pollution load in farmland in order to analyze environment pollution caused by livestock and poultry in China.[Methods] This paper estimated the amount of nitrogen nutrient of livestock and poultry based on statistical data. Then, the estimation and gridding of nitrogen pollution load of farmland were done using the method of area weighted interpolation and spatial analysis of GIS.[Results] The gridding of nitrogen pollution load of farmland was consistent with the basic characteristics of provincial data and the administrative boundary was no longer used as a basis for the division of nitrogen pollution load. The paper then used He'nan Province as s case study to verify the precision of gridding of nitrogen pollution load of farmland in China.[Conclusion] The dividing line of high value and low value of nitrogen pollution load of farmland coincided with the 400 mm isohyet. Among provinces in China, the higher nitrogen pollution load of farmland mainly occurred in Beijing City, Guangdong, Sichuan and Hu'nan Province. The lower nitrogen pollution load of farmland mainly occurred in Inner Mongolia Autonomous Region, Xinjiang Uygur Autonomous Region, Tibet Autonomous Region and Qinghai Province.

Abstract:[Objective] We analyzed the dynamic change of landscape pattern of Shengjin Lake in Anhui Province. Ecological security model was established and the driving forces that influence the landscape pattern change were discussed to provide the scientific basis for protecting and recovering Shengjin lake wetland.[Methods] Based on remote sensing and GIS technology, we used TM images in 1986, 2003 and 2011 to analyze the ecological security.[Results] The land use pattern in Shenjin Lake changed greatly. The area of grassland and water decreased dramatically. The diversity index increased while the dominance index declined. The intensified fragmentation in landscape pattern had significantly influenced the regulation and storage capacity of the wetland resources. In addition, the index of wetland ecological security tended to decline year by year.[Conclusion] Due to human activities, the area of nature wetland is reducing, and ecological function is declining. Growths in economy and population are the main driving forces that influence the dynamic change of landscape pattern in Shengjin Lake wetland.

Abstract:[Objective] This study explored the influences of urbanization on the cultivated land resources in Anhui Province in order to provide theoretical base for policy making in urbanization development and cultivated land protection.[Methods] The reduced area of cultivated land caused by urbanization was calculated by using the logarithmic mean divisia index(LMDI) decomposition method. By using SPSS software, the coupling functional relationship between urbanization and the decline in cultivated land area was investigated by curve estimation based on the optimum goodness of fit. According to the Logistic regression model, the evolution trend of urbanization in Anhui Province was predicted. Moreover, based on the obtained coupling relationship between urbanization and cultivated land resources as well as the evolution trend of urbanization, the impacts of urbanization on the cultivated lands were estimated.[Results] The results indicated that, during the period from 1996 to 2011, the area of cultivated land reduced at a rate of approximately 1097.87 hm² per year due to the urbanization in Anhui Province, and every 1% increase in urbanization rate resulted in 795.20 hm² decline in the area of cultivated land. The quadratic curve fitting was optimal for describing the relationship between urbanization and the cultivated land resources. The urbanization of the population in Anhui Province was expected to reach to 58.44% and 68.25% in 2020 and 2030, respectively. Specifically, before 2020, due to the effects of urbanization, the cultivated lands were expected to reduced by 3804.94 hm² per year, and every 1% increase in urbanization rate would result in 2549.37 hm² decline in cultivated land area. From 2021 to 2030, the cultivated lands were expected to be reduced by 11179.42 hm² per year, and every 1% increase in urbanization rate would result in 11395.94 hm² decline in cultivated land area.[Conclusion] The impacts of the urbanization on cultivated land are expected to be intensified, and the protection of cultivated land will be a great challenge in the future.

Abstract:[Objective] The objectives of the study are to investigate the characteristics of soil phosphorus fractions on Heilu soil and its relationships with AM fungi colonization under no-till and stubble retention, in order to understand the phosphate use efficiency in rain feed agricultural system.[Methods] Total phosphorus, available phosphorus and phosphorus fraction and arbuscular mycorrhizal(AM) fungi colonization were determined using classical methods for maize crop under 4 tillage managements:conventional tillage, tillage +stubble retention, no-till, no-till +stubble retention in the Loess Plateau.[Results] After nine-year conservation tillage implementation, the content of P in soil layer of 0-5 cm increased. Compared to conventional tillage, the fraction of H₂O-P, NaHCO₃-P_i and NaOH-P_i was increased by 84.6%, 85.2% and 56.6%, respectively, under conservation tillage. Labile phosphorus(H₂O-P_i, NaHCO₃-P_i) and potential labile phosphorus(NaOH-P_i) accounted for 11.4% and 4.5% of total inorganic phosphorus. The total phosphorus showed a significantly positive correlation with available phosphorus and phosphorus fraction. Compared to conventional tillage, the AM fungi colonization increased by 20.8% and 16.5% under no-till manage ment.[Conclusion] The content of soil phosphorus was significantly improved under no-till and stubble retention, and the AM fungi colonization had a positive response to no-till.

Abstract:[Objective] In order to reveal the mechanism of soil reinforcement by roots, soil-root composites was selected to study the tribological properties between roots of Pinus tabulaeformis and soil by using the finite element program ANSYS 12.0.[Methods] Soil-root composites was regarded as the discrete model which was composed of root, soil and root-soil contact face. The root was analyzed by the linear elastic constitutive model, and the soil was analyzed by the elastic perfectly plastic constitutive model. The model parameters were calculated according to the triaxial compression test. The pulling out test of single root was simulated by nonlinear finite element in different burial depths and various root diameters. The relationship between friction and slip is analyzed and the curve was drawn. The results from numerical analysis were used to compare with the experimental data from the pulling out test.[Results] The results of the finite element numerical simulation were agree with the pulling out tests as the initial friction and peak friction increased with the increase of burial depth and root diameter.[Conclusion] The established finite element model can be used for the analysis of the root-soil friction characteristics, and it provides the basis for further numerical analysis.

Abstract:[Objective] Taking Xiangjiang river basin in Hunan Province as the research object, we studied the compensation for watershed ecology, in order to provide the theory basis for pollution comprehensive treatment and regional balanced development in Xiangjiang River basin.[Methods] The standard coefficient of ecological compensation was determined by comparing the value of 2012 GDP per capita, the total population, the per capita gross industrial production value and the discharging quantity of sewage per ten thousand yuan GDP with the average value in eight cities(Changsha, Xiangtan, Zhuzhou, Hengyang, Yueyang, Yongzhou, Chenzhou and Loudi). The excessive and unused quantity of sewerage drainage was calculated by the differences between per capita value of each city with the average values. The compensation price was determined according to the proportion of main factors price and the sewerage drainage in each city. The ultimate standard of compensation was considered according to the ecological compensation standard coefficient in Xiangjiang river basin.[Results] The ecological compensation funds for Changsha, Zhuzhou, Xiangtan, Hengyang, Yueyang, Chengzhou, Yongzhou and Loudi City was 40.050, 4.407, 4.301, 3.382, 0.904, 5.614, 6.028 and 3.795 million yuan, respectively.[Conclusion] Quantity of sewerage drainage in Changsha, Zhuzhou and Xiangtan City are more than the theory emission permits, while the actual sewerage drainage in other 5 cities were less than the permits.

Abstract:[Objective] The natural regeneration of Ailanthus altissima in Nankai University were investigated in order to provide the scientific basis for urban natural forest construction and management.[Methods] We used the quadrat sampling method to investigate the quantity, ground diameter and height of A. altissima in Nankai University. The gather intensity indexes including C_x, I, K, m^*, C and I_Δ were used to analyze the spatial distribution pattern of natural regeneration seedling in A. altissima.[Results] (1) A. altissima regenerated naturally in urban greenland. The peak regeneration occurred at seedlings with ground diameter of 2~3 mm. The height level frequency distribution of seedlings showed a "intermittence" type, which was mainly distributed at the height of 2~4 cm.(2) The value of C_x, K, m^*, C, I, I_Δ was 2.24, 1.26, 2.81, 1.79, 1.24 and 1.79, respectively.[Conclusion] Rigid pavement influences the distance of natural regeneration and the spatial distribution of seedlings.

Abstract:[Objective] This study analyzed the vegetation types of forest water conservation capacity and total water conservation value of forest ecosystem in Jilin Province in order to provide the basis for forest sustainable operating and management.[Methods] Based on the measurements of rainfall interception rate and rainfall of forest ecosystems, we obtained forest water conservation converting by analyzing the relationship between rainfall interception rate and forest canopy and precipitation. By reusing the shadow engineering method, we got the economic value of forest water conservation.[Results] (1) The average annual rainfall was 1179.9 mm in Jilin. The order of water holding capacity was:natural forest >plantation >arbor >economic forest.(2) The amount of forest water conservation was 7.24×10¹⁰ m³. The value of forest water conservation was 1.81×10¹¹ yuan per year.[Conclusion] (1) As the water outflow was greater than inflows, Jilin Province belonged to water-deficient area in both population and ecology.(2) The forest vegetation type in Jilin Province is rich, but spatial distribution of vegetation is uneven.

Abstract:[Objective] Based on previous research of wind erosion and deposition in oasis-desert zone, we aimed to explore the influences of Alhagi sparsifolia stumping and topography on sand surface erosion and deposition in Cele County of Xinjiang Uygur Atonomous Region.[Methods] Erosion pins were used and topographic surveys and wind velocity observations were conducted.[Results] The surfaces of stumping belts and reservation belts were dominated by wind erosion due to the large decreasing of vegetation coverage at the beginning of A. sparsifolia stumping in spring. Wind deposition occurred on the surfaces of A. sparsifolia quadrates due to the increased vegetation coverage in summer. Slight wind erosion mainly occurred on the surface with sparse vegetation and low topographic position. In autumn, as the vegetation coverage on the land surface maintained maximum and stable, wind erosion and deposition decreased, and the sand surface was dominated by wind deposition.[Conclusion] A. sparsifolia stumping with width of 4 m and 3 m for stumping belt and preserving belt, respectively, may not effectively prevent wind erosion in spring, but can effectively prevent wind erosion in summer and autumn.

Abstract:[Objective] To study the application of Groasis(water-box) technique of Holland in the afforestation in Minqin desert area, we aimed to provide reference data for larger scale water-saving afforestation in desert areas.[Methods] By choosing 11 afforestation tree species, fields tests were conducted in returning land, inter dunes and introduction garden in Minqin desert area. The survival rate, soil moisture of these tree species were measured as well.[Results] The results showed that:(1) Soil moisture content of 11 afforestation tree species in abandoned farmland was Calligonum mongolicum >Hedysarum scoparium >Caragana korshinskii >Tamarix chinensis >Picea mongolica >Pinus sylvestris >Populus euphratica >Amygdalus mongolica >Hippophae rhamnoides >Ulmus pumila >Elaeagnus angustifolia.(2) Within all 3 soil types, the moisture content in the sand resist trees cultivated by water-box was 2 to 5 times higher than that in the normal cultivation.(3) The survival rate in all sand resist trees cultivated by water-box was improved by 25% to 70%, compared with the normal cultivation.[Conclusion] The water-box can effectively improve the water use efficiency for the sand resist tree species.

Abstract:[Objective] This paper aims to demonstrate the spatial autocorrelation and the pattern of soil pH value in order to find the main influencing environmental factors.[Methods] Classical statistics and 3S technology were used.[Results] The spatial distribution of soil pH value in different soil depth showed a highly positive spatial autocorrelation and had obvious spatial clusters, nearly no isolated distribution was found. The factors influencing the spatial distribution of soil pH value in different soil depth ranked as:vegetation coverage, rocky desertification and geological background.[Conclusion] The spatial heterogeneity of soil pH value was affected by the content of acid materials under different vegetation covers, and the influence of rocky desertification and geological background on soil pH value is a comprehensive reflection of typical karst environment.

Abstract:[Objective] To investigate the optimal density of Mongolian pine(Pinus sylvestris var. mongolica) plantation for sand fixation in order to provide reference for the analysis of dynamic water balance, decline causes and stand stability evaluation in the study area.[Methods] We took the Mongolia pine filed in the southern edge of Horqin sandy land, Zhanggutai, Liaoning Province as a case study to monitor soil moisture variation(0-200 cm), rainfall in growing season and leakage below 200 cm. The surveys were conducted in three different Mongolia pine fields with various plantation densities(400 plants/hm², 600 plants/hm² and 800 plants/hm²).[Results] The temporal and spatial variation trends of soil moisture in all the three plantation densities were consistent. Soil layer at 0-30 cm was influenced by rainfall dramatically, while soil layer at 60-200 cm was only influenced by rainfall >40 mm. Soil moisture regression processes dissipated from lysimeter type to evaporation-leakage type after rainfall. Soil moisture showed significant differences among three plantation densities(p<0.05) in topsoil(0-200 cm):400 plants/hm² >600 plants/hm² >800 plants/hm². Water leakage was observed in all three plantation densities below 200 cm. The 800 plants/hm² field had the least leakage.[Conclusion] In wet years, water balance can be maintained in all three densities, while water deficit and recession may occur in normal year and years with extreme precipitation. The optimal planting density of Mongolian pine is around 400 plants/hm² in the sandy land.

Abstract:[Objective] We took the fescue and miscellaneous grass meadow steppe in the north slope of Tianshan mountain as the research object in order to study the effect of cutting intensity on aboveground and underground biomass of grassland.[Methods] Four treatments including no grazing, light grazing, moderate grazing and heavy grazing were set to investigate the biomass of grassland ecosystem.[Results] With the increase of grazing intensity, herbaceous biomass and litter decreased, and this decrease trend increased gradually. Compared to the no grazing treatment, biomass in light grazing, moderate grazing and heavy grazing were decreased by 27.51%, 45.28%, 65.05%, respectively. The underground biomass of no grazing, light grazing, moderate grazing and heavy grazing in September increased by 16.05%, 13.07%, 19.15%, 19.08%, respectively, from June. Biomass in 0-20 cm soil layer accounted for 85% of the total underground biomass, and the decreasing trend of underground biomass with the increasing soil depths was obvious.[Conclusion] The effect of grazing intensity on aboveground biomass was:light grazing >no grazing >moderate grazing >heavy grazing. The maximum aboveground biomass occurred in July, which was significantly higher than that in September. The effect of grazing intensity on the underground biomass in 0-100 cm soil depth was light grazing >no grazing >moderate grazing >heavy grazing. The vertical distribution trend of underground biomass was the same in all different grazing intensities. Underground biomass mainly distributed in 0-10 cm soil layer, and it accounted for 70% of the total underground biomass. In addition, underground biomass reduced with the increase of soil depths. Variations in underground biomass were great in September than in June.

Abstract:[Objective] The objectives of the study are to analyze the changes in soil nutrients with vegetation recovery in order to understand and evaluate the functional restoration of vegetation ecosystem, and to adjust speed the vegetation succession and accelerate the ecological recovery.[Methods] Three ecological restoration patterns, natural grassland(grazing forbidden), farmland(fallow) and planted alfalfa(returning to forest and grassland), were investigated to analyze the influence of ecological restoration on soil nutrients.[Results] The natural grassland has bigger effects than farmland then followed by planted alfalfa on soil. As the soil depth increased, all soil nutrients decreased. With the time of recovery, soil nutrients gradually accumulated. The soil fertility index in alfalfa fields was lower than that in farmland and increased in the early period of recovery and then declined with time.[Conclusion] Vegetation recovery in the loess hilly region in Ningxia would obviously increase the contents of soil nutrients and improve the fertility of soil. But alfalfa, which was extensively managed on dry fields(no fertilizer applied but only mowing), would seriously decrease soil fertility.

Abstract:[Objective] The objective of the study is to explore the effect of monosodium glutamate wastewater manure(hereinafter referred to as manure) mixed with inorganic fertilizer on the root absorption characteristics and humus composition of rhizosphere soil of watermelon(Citrullus lanatus).[Methods] The present study was conducted to determine the effects of different treatments, i.e. CK(control, no fertilization); N₁₀₀(pure urea, hereinafter referred to as inorganic fertilizer); M₁₀N₉₀(the proportion of manure and inorganic fertilizer is 10% and 90%); M₃₀N₇₀(the proportion of manure and inorganic fertilizer is 30% and 70%) and M₅₀N₅₀(the proportion of manure and inorganic fertilizer is 50% and 50%) on root activity, construction levels of root system, root morphological characteristics and root exudates, as well as humus composition in the rhizosphere soil of watermelon.[Results] The results indicated that in comparison to N₁₀₀ treatment, M₃₀N₇₀ treatment significantly increased root activity, and promoted the root growth of watermelon. At the same time, M₃₀N₇₀ treatment also increased the total root length, root surface area, specific root surface area, root volume and root tip number, while the root average diameter obviously decreased. The total root length in the M₃₀N₇₀ treatment increased by 74.63%, 40.84%, 28.41% and 19.37%, and the specific root surface area was increased by 39.42%, 30.82% and 20.89% compared to the treatments of CK, N₁₀₀, M₁₀N₉₀ and M₅₀N₅₀, respectively. In addition, M₃₀N₇₀ treatment obviously increased the contents of root exudates and humic acid, and increased the ratio of humic acid to fulvic acid, showing 137.36%, 47.95% and 33.33% increase in humic acid content compared with the treatments of CK, N₁₀₀ and M₁₀N₉₀, respectively. However, in M₁₀N₉₀ and M₅₀N₅₀ treatments, less effects was observed than that in M₃₀N₇₀ treatment.[Conclusion] Monosodium glutamate wastewater mixed with inorganic fertilizer, especially M₃₀N₇₀ treatment, is beneficial to the root absorption characteristics and humus composition in the rhizosphere soil of watermelon, and it is recommended as the suitable fertilization proportion in the practice.

Abstract:[Objective] We aimed to study the effects of BGB microbial agents on the survival rate of Pinus tabulaeformis afforest, height of tree and growth of ground diamete, and investigate the changes in soil nutrient and water content with the utilization of BGB microbial agents, in order to provide theoretical basis and technical support for vegetation restoration in Loess Plateau.[Methods] We applied three different amounts of BGB microbial agents at different slopes to observe its influence on P. tabulaeformis and soil nutrient.[Results] The BGB microbial agents not only significantly increased the survival rate of plant and promoted the height of tree and the growth of ground diameter, but also dramatically increased soil nutrient content and water content. And this effect decreased as the soil was deeper and the slope was steeper. Moreover, BGB microbial agents influenced soil available phosphorus and organic matters significantly, and improved soil water content dramatically, especially at the depth of 20-40 cm.[Conclusion] BGB microorganism bacterium agent has a significant effect on the survival rate and amount of growth of P. tabulaeformis afforest and soil nutrient.

Abstract:[Objective] The objective of this paper is to study the allelopathy effects of hyperaccumulator straw on heavy metal accumulation of accumulator in order to provide basis for the study of phytoremediation of cadmium-contaminated soil.[Methods] By applying different straws of hyperaccumulators(Youngia erythrocarpa, Bidens pilosa, Solanum photeinocarpum and Siegesbeckia orientalis) in cadmium contaminated soil, the effects of hyperaccumulator straw on growth and cadmium accumulation of Capsella bursa-pastoris were studied.[Results] The above-ground biomass, total biomass, resistance coefficient and leaf SPAD(soil and plant analyzer development) value of C. bursa-pastoris was increased by applying four Cd-hyperaccumulators straws in soil, compared with the control treatment. By applying straw of Y. erythrocarpa in soil, the cadmium contents in root, stem, leaf and above-ground part of C. bursa-pastoris were increased by 11.81%, 102.07%, 12.00% and 54.95%, respectively, compared with the control treatment. The available cadmium concentration in soil was also increased. By applying the straws of B. pilosa, S. photeinocarpum and S. orientalis in soil, cadmium content in C. bursa-pastoris was decreased. By applying straw of Y. erythrocarpa in soil, the cadmium accumulation in above-ground part and whole plant of C. bursa-pastoris was 42.11 and 54.74μg/plant, which was 83.09% and 54.11% greater than that in the control treatment, respectively. By applying the straws of B. pilosa, S. photeinocarpum and S. orientalis in soil, cadmium accumulation in C. bursa-pastoris was decreased.[Conclusion] Applying the straw of Y. erythrocarpa in soil can improve the cadmium accumulation of C. bursa-pastoris, which is beneficial to the remediation of soil contaminated by cadmium.

Abstract:[Objective] The purpose of this study is to research the heavy metal pollution of Lonicera hypoglauca and soil of its producing area, in order to provide guidance for quality guarantee, origin of prevention and control of soil heavy metals and good agricultural practices of L. hypoglauca.[Methods] We collected L. hypoglauca and the soil samples from Guizhou Province. The contents of Cu, As, Pb, Cd, Hg, Cr were detected by the ICP-MS. Single factor pollution index and comprehensive pollution index were calculated.[Results] The average contents of As, Pb, Cd, Cr, Hg and Cu in soil were 9.79, 14.30, 0.10, 19.89, 0.12 and 3.81 mg/kg, respectively, which satisfied the requirements of national standard(GB15618-1995). The comprehensive soil pollution indexes at root zone and non-root zone were 0.46 and 0.83, respectively, which was safe and below the warning line. The average contents of Cr, As, Cd, Pb and Cu in flower were 5.19, 0.16, 1.87, 0.39 and 6.86 mg/kg, respectively, and Hg was not detected in the flower. The content of Hg, As, Pb and Cu satisfied the requirements of national standard(WM/T 2-2004). The average content of Cd was far beyond the limited level, indicating that L. hypoglauca had a strong ability to concentrate Cd.[Conclusion] Soil environmental quality in the study area is suitable for planting L. hypoglauca

Abstract:[Objective] To understand the spatial distribution of heavy metal concentrations in Dioscorea opposita Thunb. planted soils and the influences of soil properties and socio-economic factors on the heavy metal concentrations in order to selecte the priority areas for the D. opposita Thunb. platation.[Methods] Soil samples were collected using the grid sampling method, and the element concentrations were tested in laboratory, then the relationships of data was analyzed with geostatistics and spatial analysis methods in SPSS and ArcGIS 9.3.[Results] The four elements, except for Cr, showed a positive correlation with each other; Cr, Pb and As followed a normal distribution in the soil data and Cd, Hg followed a normal distribution after logarithmic conversion; Hg showed little spatial correlation according to the nugget effect analysis.[Conclusion] The heavy metal concentrations in the D. opposita Thunb. soils in Hebei Province were closely related to their parent material, soil texture, and organic matter contents and the degree of industrialization, urbanization and agricultural intensities of a city.

Abstract:[Objective] This paper aims to provide scientific support for land resource management and its sustainable use in Zhangjiakou City of Hebei Province through studying the evolution of land ecological security and its spatial variation.[Methods] This paper developed an index system for the evaluation of land ecological security according to land natural attributes, land use condition, land pollution and degradation, landscape pattern, land ecological construction and land social-economic condition. The paper also evaluated the land ecological security condition in 2000 and 2010 of Zhangjiakou City using the comprehensive index method, and analyzed the changes of land ecological security and its spatial heterogeneity.[Results] The land ecological security value in most counties of Zhangjiakou City increased from 2000 to 2010, and the land ecological security in most counties were in secure situation, less secure situation, and sensitive situation. The counties with land ecological security condition in risk and deteriorating situation mainly located in Zhangjiakou urban center and its surrounding areas.[Conclusion] The land ecological security situation in Zhangjiakou City has become better in the past 10 years, which may be attributed to the "grain for green project" and other ecological restoration projects.

Abstract:[Objective] This paper aimed to investigate the land use change and its driving forces in Zhangbei County, Hebei Province to provide references for the decision-making in land use management and sustainable use of land resources in this region.[Methods] Based on the TM remote sensing images in 1989, 1995, 2000, and 2010, using the technology and method of remote sensing, geographic information system and multivariate statistical analysis, this paper analyzed the spatial and temporal variations of land use in Zhangbei County. Factors driving land-use change were investigated.[Results] The main land-use types in Zhangbei County were arable land, forest land and grass land. During the period of 1989-2010, arable land and grass land decreased and forestland and construction land increased, especially in the period from 2000 to 2010. As to the land use types, arable land and grassland mainly changed into forestland and construction land. As to the spatial variation, forest land increased significantly in the eastern edge of Zhangbei Bashang Plateau, and the construction land expanded dramatically in the central plain of the county.[Conclusion] Major land-use change has occurred in Zhangbei County in the past 20 years owing to the influence of natural and social-ecnomic factors.

Abstract:[Objective] To compensate for the defects in the evaluation index system and the used methods in diagnosis on the social risk of the rural land comprehensive consolidation, this paper analyzed the level for the social risk of the rural land comprehensive consolidation.[Methods] After defining the social risk of rural land comprehensive consolidation, the index system of social risk assessment from the perspective of environment, institution, economy and society were established. Then the social risks of the fertile land development project in Jiangning District of Nanjing City were assessed by objective and subjective synthetic method and fuzzy comprehensive evaluation model.[Results] The social risk of this project was between the third level(medium risk) and fourth level(small risk), but it was closer to the third level. This indicated the risk of this project was not high, which would not result in great social instability. However, the existing risks still need to be prevented.[Conclusion] In order to further avoid the social risks caused by rural land comprehensive consolidation, we can take some measures, such as perfecting targets of rural land comprehensive consolidation, improving public participation mechanism, strengthening project supervision, assessing risks scientifically so that to promote the development of rural land comprehensive consolidation healthily and effectively.

Abstract:[Objective] Taking Pingdu City in Shandong Province as a case study, this paper analyzed the changes in land use pattern, land-type connectivity and core patches of cultivated land and construction land from 2005 to 2013, in order to provide a scientific basis for protecting area cultivated land effectively and planning construction land reasonable.[Methods] Based on the analysis of landscape index, we calculated integral index of connectivity(ⅡC), probability of connectivity(PC) and the important value of patch connectivity(dI) to reveal the connectivity of land types and importance of patches of cultivated land and construction land.[Results] (1) Compared with cultivated land, the distribution of construction land was strongly influenced by human activities;(2) The connectivity of construction land increased significantly, while the connectivity of cultivated land decreased from 2005 to 2013;(3) The core patch area of cultivated land accounted for 99% of cultivated land area, in contrast, the core patch area of construction land accounted for 79% of construction land area.[Conclusion] Due to the high-connectivity and high utilization efficiency, the core patches of cultivated land need to be well protected. The core patches of construction land need to be well planed and utilized due to its good connectivity and satisfactory geographic location. It is necessary to control expansion of construction land, the emissions of pollutants, and to protect the surrounding cultivated land.

Abstract:[Objective] We aimed to investigate the characteristics of vegetation community along different slopes in Xibaipo highway of Hebei Province in order to choose the optimal slope vegetation restoration technology.[Methods] A random sampling method was conducted to investigate the community composition and structure on 4 different types of slopes.[Results] Species diversity showed significant differences among 4 different types of slopes. The vegetation coverage on soil slope was the lowest and the species diversity in rocky slope was the least under spontaneous recovery. In contrast, the species diversity and vegetation coverage was the highest on slopes by using ecological bags vegetation recovery technique.[Conclusion] Both ecological bags recovery and net-suspended spray seeding techniques can improve the vegetation recovery on highway slope, and ecological bags recovery is the most effective method.

Abstract:[Objective] Taking Shiyang River basin as case study, the temporal-spatial variation of water utilization efficiency among different cities was evaluated in order to understand the relationship between water resource utility efficiency and urban population scale.[Methods] Data envelope analysis(DEA) model and Malmquist total factor productivity(TFP) index were used in the study.[Results] (1) The integrated utilization efficiency of water resources presented a‘V’shape growth curve, with a increase trend in pure technical efficiency change(PECH) index while a decrease trend in scale efficiency change(SECH) index. Similar results were also found by the Malmquist index analysis.(2) A positive correlation was found between population scale and water resource utility efficiency.[Conclusion] (1) Gulang and Yongchang County should increase the input of elements, while other Counties of Liangzhou, Minqin and Jinchuan County should maintain the existing investment scale when improving industrial structure adjustment and the optimizing water use structure.(2) Advanced water use techniques and efficient water resources management is crucial to the improvement of water resource utility efficiency in Shiyang River basin.

Abstract:[Objective] This paper analyzed the temporal and spatial evolution of the land use/cover change in Gelmud basin in order to provide a reference basis for the coordination of Gelmud's development and protection.[Methods] We analyzed the temporal and spatial evolution of the land use/cover change in Gelmud basin during the period from 2000 to 2010 with the support of RS and GIS technology. The main data sources included the TM remote sensing images in 2000, 2005, 2010 and the vector data in 2010 of the study area.[Results] The unused land has become the main land use/cover type in Golmud basin.(1) The greatest changed occurred in construction land, it increased by 227.83%; While the least change occurred in the forest land, it increased by 1.24%.(2) The grassland, cultivated land, construction land and forest land was transformed into the unused land, forest, waters and unused land, which was originated from the unused land, construction land, forest and unused land, respectively. In addition, water area was mainly transformed into the unused land which was originated from the unused land;(3) The difference value of land utilization index △P was-3.04 during the land use adjustment period from 2000 to 2005, and it was 1.62 during the land use development period from 2005 to 2010;[Conclusion] The cultivated land, forest land, construction land showed an increasing trend, while the grassland, water area showed a decreasing trend in Gelmud basin. The information entropy of the land use structure is small and the diversity of land use is low in Gelmud basin.

Abstract:[Objective] The aim of this study is to investigate the influences of land use change on ecosystem services value in Kashi City in order to provide scientific foundation for land use management.[Methods] We analyzed the effects of land use change on ecosystem services from 1997 to 2010 in Kashi City. The evaluation formula and sensitivity analysis was used, based on the ecosystem services value evaluation results obtained from previous studies. Ecosystem services value was predicted according to the change of land use type in the integrated land use planning in Kashi City(2010-2020).[Results] The land use structure in Kashi City changed greatly from 1997 to 2020 by planning. The land use degree showed a trend of increase, while the total ecosystem services value was decreasing year by year. Particularly, the service value of cultivated land and waters was decreasing contunuously. The sensitivity index showed that ecosystem services value was inelasticity and the result was reliable.[Conclusion] In practical implementation process of land use planning in Kashi City, more attention need to be paid on intensive land use and land use structure optimization, to maintain the balance and stability of the ecosystem.

Abstract:[Objective] Selecting Chan-Ba ecological district(CBE) of Xi'an City, Shaanxi Province as a typical urban area in the north of Qinling Mountains, the study aims to provide support for the regional urban development and ecological construction based on the analysis of the sustainability of new area development from two aspects, i.e. landscape pattern and the value of ecosystem services.[Methods] Using on the remote sensing data, the study quantitatively analyzed land use and landscape change, and detected changes in landscape-scale ecosystem and in values of ecosystem services in newly developing urban areas.[Results] (1) In period from 2004 to 2014, the conversion of rural area to urban area is obvious, the proportion of agricultural land reduced significantly while construction land increased by 88.2%, and ecological landscape by more than 201.5%, meaning the significant increase of region's "ecological content".(2) The significant changes occurred in the ecological service value in farmland, vegetated land and wet land, and nearly 65% of farmland ecosystem services value were lost. In 2014, more than 85% of the region's ecological functions and services were from the vegetated land and water.[Conclusion] The changes of ecological land was dynamic in past decade in CBE, and the value of ecological service in urban area increased significantly, showing a great improvement of the environment during the urbanization. This means that the policy of ecological construction is good for the construction and development of regional ecosystems.

Abstract:[Objective] In order to address the "low yield" issue caused by no irrigation in the east Greater Khingan Range region of Inner Mongolia, high yield and high efficiency irrigation programs are needed in this region.[Methods] We took the traditional soybean as the test crop, to investigate the crop yield, water productivity and economic benefits under sprinkler irrigation system.[Results] The local agriculture model could not provide enough water for soybean growth without irrigations. The soybean yield increased by 20% when irrigated 2 times by using the sprinkler irrigation technique, but the economic benefits were not improved. The total soybean yield was the highest when irrigated 4 times by using the sprinkler irrigation technique, but the soybean crop water productivity was lower, compared to the crop irrigated by 3 times, and unnecessary waste of water resources occurred.[Conclusion] By 3 times irrigation with 200 m³/hm² quota of water in different growing periods(flowering, fruiting and seed filling periods) of soybean, the soybean production can be increased by 47.8%, and the maximum economic benefits can be obtained.

Abstract:[Objective] The spatial and temporal changes in soil nutrients in hilly area of Southern Sichuan basin was investigated in order to provide support for the soil quality management and the agricultural sustainable development.[Methods] Using the data of the second soil survey in 1982 and the soil fertility monitoring data in 2011, the article analyzed spatial and temporal changes in soil nutrients in Changxing township, Yibin City under the SPSS 17.0 and ArcGIS 9.3 platforms.[Results] (1) Among the five soil indicators, the highest coefficient of variation was available phosphorus, the rest indexes varied between 22.18% to 37.03%, indicating a moderate variation.(2) Semivariogram analyses indicated that the nugget/sill of soil nutrients ranged from 25% to 75% in 1982, showing a medium variation. Both of the structural and human factors had influence on it. In 2011, the spatial autocorrelation of each index was weak, and the human factor played a dominant role.(3) The ordinary Kriging interpolation showed that nearly half of the study area have high nitrogen, and the area with total nitrogen and alkali-hydrolyzable nitrogen content in high grade and above accounted for 39.26% and 47.94% respectively. Although phosphorus increased slightly, the content of available phosphorus below 5 mg/kg accounted for 52.68% of the area, indicating a serious phosphorus deficiency. The potassium content in the area of an upper-middle class reduced, mostly in the middle and lower levels, or even extremely low levels.[Conclusion] After nearly 30 years of land use, the soil nutrient in the northern area is higher than in the south, with more emphasis on nitrogen and little on phosphorus and potassium fertilizer. More effots should be devoted to limiting inputs of nitrogen and adding phosphorus and potassium in the south of the study area.

Abstract:[Objective] In order to evaluated the soil water conservation features of three artificial vegetation types in Yindingge mining area of Datian County, Fujian Province.[Methods] Four index of infiltration, maximum water-holding capacity, available storage capacity of soil and non-capillary pore were calculated and analyzed.[Results] (1)The maximum value of initial infiltration rate, stable infiltration rate and average infiltration rate appeared in Eucahetus dunnii×Pinus massoniana forest type, meanwhile, the difference of initial infiltration rate and steady infiltration rate in parent material layer and leached layer is smaller, the next was E. dunnii×Paulownia tomentosa forest type, the third was P. massoniana×Cunninghamia lanceolata forest type.(2)The relationship between infiltration rate and infiltration time of all vegetation types was a significantly power regression.(3) The maximum value of maximum water-holding capacity, available storage capacity of soil and non-capillary pore appeared in E. dunnii×P. tomentosa forest type, the next was E. dunnii×P. massoniana forest type, the third was P. massoniana×C. lanceolata forest type.(4) Using principal component analysis method to evaluate the soil water conservation features, the order express E. dunnii×P. tomentosa forest type >E. dunnii×P. massoniana forest type >P. massoniana×C. lanceolata forest type.[Conclusion] The better soil amelioration effects in abandoned mines belonged to E. dunnii×P. tomentosa forest type, it could be applied in the similar area.

Abstract:[Objective] The aim of this study is to explore the effect of urbanization on temperature change in regions nearby cities in order to realize the climate and enviroment change in regional scale.[Methods] Based on the temperature data recorded by meteorological stations nearby Beijing and Tianjin cities during 1973-2008, annual and seasonal temperature variations and the impact of urban heat island(UHI) on meteorological stations(known as urban impact indicator, U_ii) were analyzed, with the consideration of urban size, relative position of meteorological station to city and winds. The bias in surface air temperature records was estimated as well.[Results] (1) Due to the influence of urbanization, the warming rate in Beijing station was faster than that in Tianjin station during 1973-2008, and the warming rate reached to 0.65℃/10 a and 0.17℃/10 a in Beijing station and Tianjin station, respectively.(2) The impacts of UHI on the same station were different in different seasons, and this impact was much more severe in Beijing station, compared to Tianjin station.(3) Urbanization had a strong influence on the surface temperatures in Beijing and Tianjin stations, and urbanization contributed the most to the warming of annual minimum temperature, and the contribution rate reached to 56% and 100% in two cities, respectively.[Conclusion] The impact of urbanization needs to be considered when studying regional climate change in the areas nearby cities.

Abstract:[Objective] We aimed to quantitatively assess the soil water deficit under vegetation in the semiarid loess hilly region in order to provide theoretical support for the selection of vegetation types and ecological restoration pattern.[Methods] The compared soil water deficit index(CSWDI) and plot compared soil water deficit index(PCSWDI) of Caragana korshinskii, Populus simonii Carr and Pinus tabulaeformis in soil profiles of 0-600 cm deepth were calculated to quantify soil water deficit and its profile distribution under different vegetation types on April, May, June and July in Wuzhai County, Northwestern Shanxi Province.[Results] Soil water deficit appeared in all three artificial forestland. Soil water deficit was found in P. simonii and C. korshinskii in soil layers between 0 and 200 cm, however, it was hardly found in P. simonii between 200 and 600 cm. Below 200 cm, soil water deficit increased with increasing CSWDI in C. korshinskii. The P. tabulaeformis had led to a serious deep soil desiccation, especially in soil layers from 0 to 200 cm. Soil water deficit decreased in the layers below 200 cm with the increase of soil depths in P. tabulaeformis. PCSWDI of C. korshinskii, P. simonii and P. tabulaeformis was 0.16,-0.12 and 0.31, respectively. The soil water deficit of P. tabulaeformis was more severe than that in the others two forestland. The dried soil layer was distributed in all three artificial forestland with a different degree, mainly for mild and moderate dry layer distribution. Extreme dry layer presented in shallow soil of P. tabulaeformis.[Conclusion] The soil water deficit in the P. tabulaeformis was the severest among the three artificial forests in the loess hilly regions.

Abstract:[Objective] The paper aims to study the evolution processes, variation characteristics, influence factors of the water storage ponds in Changwu tableland according to the survey data in recent years, in order to illuminate the possible role of the water storage pond as a surface water body to recharge of the groundwater.[Methods] Data of water storage ponds was collected by field surveys.[Results] (1) The number and area of water storage pond generally showed a decreasing trend in the study period. In the early 1980s, the changes were relatively slow. However, it shrank faster in the later years. From the year 2010 to 2014, the number and area of water storage pond reduced at a maximum rate per year of-5.71% and-4.80%, respectively.(2) With the economic and social development, the role of water storage pond played in the countryside becomes smaller. With the village layout changes and the ignorance of pond management, lots of ponds are disappearing. Moreover, the storage time of extant ponds becomes shorter, and many of them changed into seasonal storage ponds.(3) As the pond area decreased, the groundwater level also declined, indicating a possible relationships between them. The loss of ponds' replenishment may somehow cause changes in the groundwater level.[Conclusion] Under the influence of human activities, the water storage pond in the Changwu tableland was seriously reduced, and some actions should be taken to recover and construct the water storage ponds in future.

Abstract:[Objective] To study how shear strength change with the variation of water content and dry density in undisturbed and disturbed loess paleosol in order to provide the basis for selecting the parameters in design and construction of slope project, tunneling and underground structure engineering in loess area[Methods] Direct shear tests were conducted on undisturbed and disturbed paleosol with different water contents and dry densities.[Results] Under the same dry density, cohesion of both undisturbed and disturbed paleosol decreased with the increase of water content. While under the same moisture content, the cohesion of undisturbed paleosol was greater than the cohesion of disturbed paleosol. The internal friction angle increased with the increase of the water content.[Conclusion] The shear strength index of loess paleosol increases with the decrease of moisture content. An exponential relationship exists between cohesion and water content, and a quadratic parabola relationship exists between internal friction angle and water content.

Abstract:[Objective] We aimed to study the spatial and temporal variation of land surface temperature in order to provide a scientific basis for the further understanding of regional land-atmosphere interactions and surface energy exchange in China.[Methods] By statistical analysis, the spatial change of ground temperature in recent 50 years in China has been discussed.[Results] (1) In recent 50 years, the average ground temperature in China showed an increasing trend at a rate of 0.29℃/10 a. Significant increase occurred since 2000. The ground temperature in recent 50 years has increased in all seasons, while it increased most in winter.(2) The spatial distribution of ground temperature showed an increasing trend from the north to the south in all seasons, but it was slightly different in different seasons.(3) In recent 50 years, in most area of China, the ground temperature increased dramatically, especially in the north part of China, the increasing rate of temperature reached to 0.2~0.6℃/10 a.[Conclusion] In recent 50 years, the average surface temperature of China showed a significant increasing trend, and spatially increased from the north to the south.

Abstract:[Objective] The objective of this study is to analyze the spatial change of rock desertification in karst region in order to provide the scientific basis for reasonable planning and integrated contorl of decision making department.[Methods] The research was conducted in Panlong watershed located in Wenshan Prefecture, the south-eastern part of Yunnan Province. The map of rock desertification intensity was interpreted from the remote sensing images in 1990, 2002 and 2009. The topographic factors(altitude, grade and exposure) that influenced the spatial distribution of rock desertification were analyzed by using overlay analysis method.[Results] From 1990 to 2009, rock desertification in Panlong watershed showed a increasing trend, and the distribution of rock desertification varied remarkably at the spatial scale.[Conclusion] The changes of landscape pattern and the spatial distribution of rock desertification were significantly influenced by topographic factors.

Abstract:[Objective] We aimed to analyze the spatial and temporal variations of soil erosion in Nanting river basin in order to provide the scientific basis for soil and water conservation and frontier ecological environment construction.[Methods] Based on the universal soil loss equation(USLE), RS and GIS technologies were applied to estimate the soil erosion modulus in Nanting river basin in 1990, 2000 and 2010.[Results] Erosion modulus showed an initial increasing trend and followed by a decreasing trend during the study period. The average annual erosion modulus increased from 24.75 t/(hm²·a) in 1990 to 30.05 t/(hm²·a) in 2000, and then decreased to 25.87 t/(hm²·a) in 2000. Although the intensive and extreme intensive erosions only accounted for 19.94% of the total erosion area, they contributed as much as 73.56% of the total amount of erosion in the study area. From 1990 to 2000, the moderate and light erosion areas were reduced by 1059.85 km², while the extreme intensive erosion areas were increased by 112.29 km². From 2000 to 2010, the erosion areas for all erosion intensities were decreased, except for the light erosion. The erosion modulus increased with the increase of slope when the slope was less than 20°, while it decreased with the increase of slope when the slope was more than 20°. High erosion modulus was mainly distributed in 500~2000 m.[Conclusion] Soil erosion control has achieved initial success in Nanting river basin, although intensified soil erosion still occurs in local areas.

Abstract:[Objective] We aimed to establish a more scientific and reasonable ecology evaluation model of remote sensing information in order to provide scientific basis for sustainable development of study area.[Methods] The NDVI(normalized difference vegetation index) and dimidiate pixel model were used to monitor vegetation coverage as the evaluation index of vegetation coverage information; Thermal inertia method was used to inverse soil moisture content in the study area, and it was taken as the index of vegetation coverage information and soil fertility; Soil texture coding image was obtained by visual interpreting, and the soil physical clay content was taken as the index to evaluate compaction situation; The bare land ratio was extracted by linear spectral mixture decomposition model.[Results] The ecological evaluation index system was built from the perspective of land use, and the ecological evaluation remote sensing information model which unit is pixel was established.[Conclusion] The vegetation coverage largely affects the vegetation coverage of study area; the overall evaluation accuracy of this study is improved by 15% more than the traditional methods.

Abstract:[Objective] The characteristics of grain production and land carrying capacity in Hubei Province from 1949 to 2012 were analyzed in order to provide theoretical support for decision-making and overall planning in land resources use and population sustainable development.[Methods] Relative fluctuation index, land resources carrying capacity(LCC) model and land resource carrying capacity index(LCCI) model were introduced to evaluate the grain production and the spatial pattern of land carrying capacity.[Results] (1) During 1949-2012, there were six stages in the development of annual grain production in Hubei Province. Grain production showed an upward tendency with periodic fluctuations caused by natural disasters and policy.(2) The growth rate in population was less than that in grain yields. Per capita grain showed four obvious fluctuation periods.(3) Food deficits and overpopulation remained primary characteristics of land carrying capacity in Hubei Province in 2012. The grain surplus areas were located in the middle part of Hubei Province, while the overpopulated areas were located in the western mountainous region and southeast of Wuhan urban circle.[Conclusion] Protecting arable land, developing science and technology, increasing yield per unit area, expanding the scale of production, and implementing sound policy is essential to the sustainable development of agriculture in Hubei Province.

Abstract:[Objective] We aimed to identify the driving factors that influence the cultivated land use system security in order to provide basis for the protection of cultivated land and guarantee of food security.[Methods] Bayan County, a typical black soil region of Northeastern China was selected as a case study to identify the driving factors that influence the security of cultivated land use system. "3S" technology was used, correlation analysis and Logistic regression model were employed. Single factor evaluation and Kriging methods was used to reveal the influence degree and spatial distribution of driving forces.[Results] (1) The landform type, soil type, soil texture, available phosphorus, drainage capability and safety policies and regulations showed a positive effect on cultivated land use system security. While elevation, the ratio vegetation index, water loss, population density and soil erosion showed a negative effect on cultivated land use system security.(2) The driving factors broke the original land use pattern, and presented a spatial distribution properties based on the geographic space.[Conclusion] (1) Each driving factor has different effects on the cultivated land use system security in the study area.(2) The impacts of driving factors on the cultivated land use system security show different spatial distribution and various patterns.