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2011 Vol.9 No.6
Published 2011-12-31
Articles
1
LIU Ge-Fei, XU Peng-Chao, WANG Pan-Hui, TU Xin-Wu, XIONG Wei, XU Li-Hong
Spatial-temporal variation of annual sediment yield during 1960—2000 in the Jinghe Basin of Loess Plateau in China
Quantitative estimation of river sediment yield and its spatial-temporal variation within a river basin is prerequisite to develop an effective strategy for soil erosion control. In this study, the Jinghe basin, where high soil erosion exists, was chosen as representative research area. Based on existing long-term records of 11 hydrological stations, the total river basin was divided into eleven river courses to quantify the spatial-temporal heterogeneity of annual sediment yield during the period of 1960—2000. The results indicated that there was a strong annual sediment yield in Jinghe Basin in the 1960’s, it was 302.49million t/a for the total river basin and the corresponding annual sediment modulus was 6672t/(km
2
·a) on average. There was a visible spatial heterogeneity of annual sediment yield within the basin. The total area of river courses with sediment yield intensity grades of “extreme” and “severe” accounted for 72.6% of the total basin area, which contributed 86.0% of the annual sediment yield of the total basin. The river courses with sediment yield intensity grade of “moderate” and “slight” covered 27.4% of the total basin area and contributed 14.0% of annual sediment yield of total basin. Since 1970’s, the annual sediment yield in Jinghe Basin reduced. Compared with that of 1960’s, the average of annual sediment yield for the whole basin in 1990’s decreased to 265.78million t/a, with a reduction ratio of 12.1%. However, 93.5% of this sediment reduction took place in the river courses with “extreme” grade of sediment yield intensity. This demonstrated that the river courses with “extreme” grade of sediment yield intensity made a substantial contribution to the sediment reduction in Jinghe Basin, especially the river courses in the west region of Jinghe Basin with higher precipitation and better vegetation coverage; while the sediment yield and contribution from the areas with other grades of sediment yield intensity was basically unchanged. Under the future regional climate change with increasing erosive rain-storms, the semi-arid regions of the Jinghe Basin with lower vegetation coverage and resistance against rainfall erosion should be listed as the key area for erosion control.
2011 Vol. 9 (6): 1-7 [
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8
LI Jun-Lan, CA Jiang-Guo, SUN Chi-Yang, CHEN Dun-Jie
Analysis of interaction effects of rainfall intensity, slope degree and slope length on rill erosion
Using simulated rainfall experiment under different conditions（rainfall intensity: 1.5 and 2mm/min, slope gradient: 10°,15°,20°and 25°, slope length: 5 and 10m), the interaction effects of slope, rainfall intensity and slope length on rill erosion were studied by establishing the regression models. The experimental results indicated that: Runoff producing rate per unit width was chosen as the characteristic index of runoff, both rainfall intensity and slope had significant positive effects on it, while the interaction effect of slope and slope length was significant as well. Changes of sediment concentration were mainly determined by slope gradient and rainfall intensity, while the effect of slope length was not significant. Rainfall intensity, slope and slope length had positive effect on velocity of interrill sheet flow, while the effects of these factors on velocity of rill flow were also significant, in addition, the interaction effect of slope gradient and slope length has a significant negative effect on the velocity of rill flow.
2011 Vol. 9 (6): 8-13 [
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14
LI Hong-Wei, WANG Wen-Long, CHE Xiao-Li, GUO Jun-Quan
Effects of non-state discharge on ephemeral gully erosion sediment and hydraulic parameters
The ephemeral gully erosion occupies an important position in the loess plateau erosion. The previous studies on ephemeral gully erosion always do scour experiment under constant flow rate condition. However, under practical conditions, the flow is changing. Few studies are conducted on non-state water flow. We analyzed the effects of non-state discharge on ephemeral gully erosion sediment and hydraulic parameters on plow land of the slope of 14°. Three non-state water flow rates (10-15, 15-20, 20-25L/min) and three constant water flow rates (10, 15 and 20L/min) were designed in the experiment. Results indicated that compared to the non-state discharge, flow velocity and Reynolds number，Froude number and Shear force, stream power and runoff sediment rate of the constant water flow decreased by 6.64%-13.44%, 2.73%-8.26%, 6.15%-49.59%, 0.27%-10.27%, 4.27%-15.77% and 2.02%-19.36% respectively; and the Daycy-weisbach coefficient increased by 23.45%-43.41%.
2011 Vol. 9 (6): 14-21 [
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22
GUO Suo-Pan, LI Zhi-An, DIAO Hui
Institutional system of soil and water conservation monitoring in China
System establishment is the primary work of soil and water conservation monitoring. It is very importance and significative to achieve institutionalized and scientific for the overall processes. The elementary institutional system in China, which can be divided into the following three parts, has been established since 1991. The laws and regulations include
Law of the People's Republic of China on Soil and Water Conservation
and the implementation regulations of State Council and regulations of Ministry of Water Resources and provincial laws. Normative documents can be divided into five sections such as compositive management and monitoring network management, etc. The third part is technical standard system, including 15 promulgated standards and 15 intending to promulgate. All of these institutions are to promote the works of soil and water conservation monitoring.
2011 Vol. 9 (6): 22-26 [
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27
WANG Chi-Guo, Li-Shi-Feng, Chen-Zong-Wei
Design concept and principles of soil and water conservation for production and construction projects
Design concept of soil and water conservation for production and construction projects is one of dominant ideas in the field of soil and water conservation, in addition, it is also the important component of design concept of main work. On the basis of studying different types of design schemes of production and construction projects completed in the last 10 years as well as the implementation effects, the connotation and denotation of the design concept was summarized. To achieve the harmonious coexistence between projects with ecology and landscape at a higher level, there are four parts of the core concept. The first is to protect ecosystem, and the second is to control disturbance range, and the third is to reduce vegetation destruction and soil and water losses, and the fourth is to restore ecosystem effectively and fast. Under the guidance of the design concept, this study raised five basic principles of designing production and construction projects. 1) all-round implementation of controlling measures of soil and water loss according to set the aim in extent of legal liability. 2) Stress should be put on the prevention measures and give priority to taking protective measures for soil and water. 3) Taking different comprehensive treatment of controlling soil and water loss in line with local conditions. 4) Taking proper measures of controlling soil and water loss in during of process in technical and economic appraisal, and the comprehensive utilization for abandoned soil and rock in the procedure of production and construction. 5) The giving priority to taking ecological measures for controlling soil and water loss, the disturbed area of production and construction has changed into harmonious and graceful landscape.
2011 Vol. 9 (6): 27-31 [
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32
DIAO Ting, XIE Yong-Sheng, JIANG Jing-Long, ZHANG Fu, ZHOU Wei
Traditional control measures of soil erosion and their environmental effects on flow and sediment in the water source area of Beijing and Tianjin
The traditional guiding ideology and treatment on soil erosion control pay attention to ecological and economic benefits of the harnessing area，which will reduce the sediment yield. However, the reduction of sediment could lead to the decrease of water, which will aggravate the water contradiction between upstream and downstream in the water source areas of Beijing and Tianjin. Environmental effects of slope measures on water and sediment were studied by investigation and location experiment in Dadai Watershed locating in Fengning County, Chengde City. Results showed that the erosion modulus in slope farmland and artificial grassland substantially exceeded soil loss tolerance in rocky mountain areas of northern China. Natural meadow had higher annual runoff and runoff coefficient than arbor forests and shrub forests. Traditional fish-scale pits measures had significant effects on sediment trapping and reduction of water yield. For moderate and mild degraded grassland under the management of closing hills, the vegetation coverage could improve by 2.84% and 1.97% in shady slope and sunny slope per year. Some traditional measures like fish-scale pits should be limited in areas where occurred serious soil erosion，and their preparation standard should be degraded. Large areas of moderate and mild degraded grassland under the management of closing hills could not only reduce sediment yield，recover vegetation,but also increase runoff.
2011 Vol. 9 (6): 32-37 [
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38
WANG Ji-Jie, CHENG Xun-Jiang, YIN Zhong-Dong
Comprehensive management of small watersheds and its benefits in the hilly area of central Sichuan Province
To achieve comprehensive control model in small watersheds, in the hilly area of Sichuan Province, 212 small watersheds belonging to 37 counties managed by 9 cites were comprehensively treated using integrated farming, ecological and engineering measures for 5 years. Results showed that: 1) As against the original status, the area of farmland with slope over 25° decreased 49.28 times, per capita basic farmland area increased 0.21 times, gross agricultural output value and per capita net income improved by 37.91% and 25.92% respectively, the amount of sediment interception improved 5.41 times, and the ability of runoff interception improved 2.19 times. 2）The increase amplitude of forestry total output value reached to 138.13% brought by ecological measures. Water conservancy and soil and water conservation projects could improve the water use efficiency and protective mechanism of farmlands. After 5 years treatment, the amount of sediment interception improved nearly 5 times, while the ability of runoff interception improved nearly 3 times. 3）The social benefits got remarkable results. Environmental population carrying capacity increased by 5.97% by using grain consumption as the standard, while increased by 37.97% by using value consumption as standard. It indicated that the comprehensive treatment on these small watersheds has got fruitful outcome supported and cooperated by local farmers. Farming measures could bring significant economic efficient, so it should be the starting point of watershed comprehensive management.
2011 Vol. 9 (6): 38-42 [
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43
YAN Dong-Feng, YANG Chi-Tian
Characteristics and influencing factors of soil infiltration of typical forest lands in southern mountains of Henan Province
In order to ascertain soil infiltration capability and analyze its influencing factors at different developmental stages of typical forest lands in southern mountains of Henan Province, soil infiltration process was simulated to analyze their characteristics, effect of physical and chemical properties of soil and root structure on soil infiltration was studied by field sampling and laboratory analysis. The results indicate that, 1）soil infiltration capacity of various types of forest land in 0-10cm layers was higher than that in 10-20cm layers; the initial and stable soil infiltration rate, accumulated infiltration capacity within initial 30 minutes in different soil depths changed in the same order: 30-year-born
Pinus massoniana
coniferous forest> 30-year-born
Quercus acutissima
broad-leaved forest> 30-year-born
Quercus acutissima+Pinus massoniana
mixed coniferous> shrub> 20-year-born
Quercus acutissima
broadleaf forest>20-year-born
Quercus acutissima+Pinus massoniana
mixed coniferous> 20-year-born
Pinus massoniana
coniferous forest. The forest lands that had the highest mean values of final infiltration rate in 20-year-born and 30-year-born forests were
Quercus acutissima
forest (3.140mm/min) and
Pinus massoniana
forest (4.256mm/min). 2）There was a notable relationship (
P
<0.05) between soil permeability index and soil organic matter content, capillary porosity, non-capillary porosity, root volume density, root surface area density; for the soil infiltration capacity the most important indicators of soil physical and chemical characteristics and root structure were capillary porosity and root surface area density respectively, and the canonical correlation coefficient of which were 0.559, 0.773 respectively.
2011 Vol. 9 (6): 43-50 [
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51
CHENG Jie, HE Tian-Meng, CHENG Ji-Min
Responses of distribution of
Artemisia sacrorum
community to climate in semi-arid and semi-humid areas of Loess Plateau
During 2000—2009, field survey and position monitoring were employed to find out responses of the distribution and growth region of
Artemisia sacrorum
community to climate in forest steppe zone, typical grassland zone and desert steppe zone of Loess Plateau. Affected by the temperature, suitable growth range of
Artemisia sacrorum
community presented obvious zonality distribution from sourtheast to northwest, namely, forest steppe zone> typical grassland zone >desert steppe zone, with population density 12.6 plants/m
2
, 8.8 plants/m
2
, 4.6 plants/m
2
respectively and reproductive branches 19 per cluster, 14 per cluster, 3 per cluster respectively. Affected by the rainfall gradient, the horizontal distribution of
Artemisia sacrorum
expanded from forest steppe zones to the typical grassland zone, which means it became the dominate species instead of the companion species. Also, it appeared as the occasional species on gullies and valleys and sand dunes in the desert steppe zone. Therefore, its optimal rainfall limits changed from 500-750mm to 200mm. In addition,
Artemisia sacrorum
extended from its optimal vertical elevation of 1900m to 2200m above sea level. Furthermore, the conclusion indicated that in the condition of global climate changes,
Artemisia sacrorum
as a typical indicting plant gradually widened its ecological amplitude and has become the steady vegetation type in forest steppe zone and typical grassland zone.
2011 Vol. 9 (6): 51-56 [
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57
LEI Yong-Na, ZHANG Xiao-Ping, ZHANG Jian-Jun, LIU Er-Jia, ZHANG Qiang-Yi, CHEN Ni
Suitability analysis of automatic baseflow separation methods in typical watersheds of water-wind erosion crisscross region on the Loess Plateau, China
The water-wind erosion crisscross region on the Loess Plateau is the main source of the coarse sediments of the Yellow River, where eco-environment is very fragile. The baseflow is of great significance to maintain sustainable development of the river ecosystem in this region. In order to test the applicability of automated baseflow separation methods on the water-wind erosion crisscross region on the Loess Plateau, several commonly and widely used methods including minimum smoothing method, HYSEP and recursive digital filter were tested by the runoff data of Kuyehe Watershed. The results show that there were significant difference of baseflow indices of eight methods with the maximum 0.6515 and minimum 0.3305. The statistical characteristics of annual baseflow indices that were used Chapman-Maxwell filtering method and Eckhardt filtering method to estimate are the best with the mean values 0.3868 and 0.3305, respectively, and the standard deviation 0.0428 and 0.0461, respectively. The baseflow discharge curves are smooth, which accords with realistic base flow condition. The verification results show that Nash-Sutcliffe efficiency coefficients were 0.691 and 0.718, respectively, and the average relative errors were 9.83% and 5.05%, respectively. Therefore Chapman-Maxwell filtering method and Eckhardt filtering method separate most objective and stable base flow, which could be used as optimal base flow separation method in this study area. The mean baseflow estimated by Chapman-Maxwell filtering method and Eckhardt filtering method showed a significant negative trend in the near 50 years and the reduction of baseflow account for 41% of the total runoff.
2011 Vol. 9 (6): 57-64 [
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65
HE Ku-Jia, XIE Jin-Sheng-, YANG Zhi-Jie, YIN Yun-Feng, LI De-Cheng, YANG Yu-Cheng
Status, causes and prevention of soil and water loss in
Pinus massoniana
woodland in hilly red soil region of southern China
Soil and water loss in
Pinus massoniana
woodland has become an urgent problem that needs to be solved to control soil and water loss in hilly red soil regions of southern China. Based on the analysis of status and distribution features of soil and water loss in
Pinus massonian
woodland, the main factors resulted in the soil and water loss are discussed, such as status of understory vegetation, human disturbance, topography, rainfall erosion force and soil properties. It indicates that lack of understory vegetation is the most primary and direct reason for the erosion in
Pinus massoniana
woodland; while predatory human disturbances is considered to be the basic reason, and the broken terrain, high rainfall erosion force and soil erodibility supply favorable conditions for the occurrence of soil and water loss understory. It also summarizes the successful experiences of treatment of soil and water loss in
Pinus massoniana
woodland, such as micro-slope reconstruction, replanting understory and enclosure-conservation, aiming at providing reference for controlling soil and water loss under the
Pinus massoniana
forest in future.
2011 Vol. 9 (6): 65-70 [
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71
WANG You-Qing, LIU Xia, TAO Xiao-You, GENG Xian-Shuang, ZHANG Zhen-Guo, ZHANG Guang-Can, LI Huan, CHAN Gui-Mei
Canonical correspondence analysis of land-use pattern change and social-economic development in Yimeng Mountainous area
Making clear of driving force of land-use change in Yimeng Mountainous area is the key to improve man-land relationship. In this study, the 26 counties (urban districts) of Yimeng Mountainous area were taken as examples, and the Canonical Correspondence Analysis (CCA) method was employed to study the correlation between the change of land-use and the level of the social-economic development in Yimeng Mountainous area. The results show that the changes of main land-use types had significant differences between different counties in Yimeng Mountainous area in recent 10 years. Social-economic gross and the dramatic growth of population were the dominant driving force of land-use pattern changes. In Luozhuang District, Rizhao City area and Zaozhuang City area, etc., the socio-economic development level had great effects on land-use pattern changes, which was characterized by the fast expansion of construction land in 10 years. In Yiyuan County, Wulian County and Junan County, etc., land use change took on the fast decrease of cultivated land and expansion of woodlands, and in this areas the development of agricultural industry could account for the driving action of land use pattern changes. In Mengyin County, Ningyang County, etc., the land use change was characterized by the reduction of unused land and lawn, and expansion of water land, which was mainly contributed by the increment of population. The results also indicated that the CCA analysis method could be adopted for the study of land-use pattern change.
2011 Vol. 9 (6): 71-78 [
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79
YANG Wen-Ji, SUN Zhong-Feng, JIAO Feng, WANG Yuan-Chang
Understanding and recommendation for soil and water conservation of 500kV power transmission engineering in North China
Based on 29 samples of 500kV power transmission engineering in North China, geographic distribution characteristics of disturbance area in different geomorphic types are obtained and the causes are analyzed. All these inclusions lead to get the emphasis partitions of power transmission engineerings. Several practical technologies, such as revegetation, geotextile lying and cement grouting transmission tower foundation, are introduced. The application effects of these technologies, which embodied in soil and water loss cutting down and investment reducing, have been verified. Some recommendations were given for soil and water conservation of power transmission engineerings in North China, which could be technical supports on soil and water conservation.
2011 Vol. 9 (6): 79-82 [
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1301
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83
TUN Pan, XIE Liang-Qing
Recording of soil sediment in the Mawoshan Karst Basin of Northwest Guizhou Province
According to the average sediment accumulation rate calculated by Zhang Xinbao with
137
Cs dating method as well as doubt on the research results of Xie Liansheng etc. the basin environmental status, environmental evolution, soil sediment,
137
Cs activity in the Mawoshan Karst Basin of the Northwest Guizhou were represented and discussed again. The results indicated that the uncertainty of source of soil accumulation resulted in complex
137
Cs sources in soil layer. The peak value of
137
Cs could not be used to determine the deposition time, but it may be used as a qualitative criterion of soil erosion intensity. Measuring sediment is an available method to calculate the basin soil erosion in Karst mountainous area when there is no station data and lack of detailed information. Mawoshan Karst Basin with special environmental geological conditions is an ideal location for the studies on Karst rocky desertification.
2011 Vol. 9 (6): 83-87 [
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88
YANG Yong-Hui, WU Ji-Cheng, HAN Qiang-Yuan, HE Fang, HAN Wei-Feng, YANG Xian-Meng
Quantitative analysis of the effect of water-retaining agent on soil pores
In order to ascertain the effect of water-retaining agent on the characteristics and distribution of soil pore in different soil layers, the technique of CT (Computed Tomography) scan was used to study characteristics of soil porosity under potted experiment when
Triticum aestivum
L. harvesting. The results indicated that soil pore number, porosity and pore round rate increased after application of water-retaining agent, which promoted transmission of soil moisture and nutrition. With the increase of applied water-retaining agent, average total pore number, total porosity and into round rate in different soil layers increased, but over a certain amount of applied water-retaining agent the total number of pore increased not obviously, while total porosity and pore round rate decreased, but still higher than the control (CK). The order of biomass and yield of wheat applied with water-retaining agent was as follows: 54mg/kg>81mg/kg>27mg/kg>CK. It was concluded that water retaining-agent improved characteristics of soil pore, promoted the growth of
Triticum aestivum
L. and increased yield. In addition, among different treatments the effect of treatment by appling 54mg/kg of water-retaining agent on the biomass and yield was the highest, and compared to control, the biomass and yield increased by 13.1% and 22.2% respectively.
2011 Vol. 9 (6): 88-93 [
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94
ZHANG Yong-Chao, CHEN Zhi-Cheng, WANG Zhi-Wei, CHEN Kai, YANG Ji-Hua
Species composition and biodiversity of the understory vegetation in Luohan Cliff forestry centre，Tai Mountains
By investigation of the vegetation type, coverage, density of the nine forest stands in Luohan Cliff forestry centre, the species richness, Shannon-Wiener index, Simpson index and Pielou index were used to study the species biodiversity of the forest understory vegetation community. The results show that: 1) The species richness of the plantation understory vegetation is mainly affected by the species richness of herb layer. Among them, Gramineae is the most species, followed by Compositae. 2) Species richness of the understory vegetation of
Pistacia chinensis
&
Robinia pseudoacacia
stand and
Robinia pseudoacacia
stand were the lowest and biggest, respectively. As to Shannon-Wiener index,
Pinus thunbergii
and
Platycladus orientalis
pure stands take the first and last position respectively. As to Simpson index, pure
Platycladus orientalis
forest has the minimum value, while the
Pistacia chinensis
pure forest has the maximum value.
2011 Vol. 9 (6): 94-98 [
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1503
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99
GENG An-Po, GAO Feng, LV Ku-Qiao, ZHANG Jie
Spatial distribution of soil organic matter and total nitrogen in Matiyu small watershed in hilly area of middle southern Shandong Province
By analyzing the representativeness and operability of land use and sample points in general, samples from 97 sites (0-20cm) were collected during October 2010 in Matiyu small watershed in hilly area of middle southern Shandong Province. By employing regression-kriging methods and ‘3S’ technology, the spatial distribution characteristics of soil organic matter and total nitrogen were studied. Results showed: 1) The average values of surface soil organic matter and total nitrogen mass fraction were 20.45 and 1.18g/kg respectively, and the coefficients of variation were 27.68% and 27.97% respectively. Environmental factors included elevation, slope, aspect and NDVI had significant correlations with soil organic matter and total nitrogen, and elevation and cosine value of aspect performed the best among the selected factors. Moreover, the prediction accuracy of regression-kriging was better than that of ordinary kriging. 2) Semivariogram test showed that both regression values of soil organic matter and total nitrogen had strong spatial autocorrelation with the sill values 7.3% and 17.50% respectively. Both residual values of soil organic matter and total nitrogen had medium spatial autocorrelation with the sill values 33.93% and 25.58% respectively. 3) The distribution map of regression-kriging showed that both soil organic matter and total nitrogen mass fraction decreased from the southeast to the northwest, which was similar to the trend of DEM in Matiyu small watershed. The pattern of soil organic matter mass fraction could be ordered as
Quercus acutissima
plantation＞
Pinus thunbergii
plantation＞Vegetable field＞
Zea mays
field＞
Castanea mollissima
plantation＞Grassland. The soil total nitrogen mass fraction could be ordered as
Quercus acutissima
plantation＞Vegetable field＞
Pinus thunbergii
plantation＞
Zea mays
field＞
Castanea mollissima
plantation＞Grassland. At different elevations, the higher the elevation, the larger the soil organic matter and total nitrogen mass fraction, while at different aspects, the pattern of soil organic matter and total nitrogen mass fraction could be ordered as shady slope＞half-sunny slope＞sunny slope.
2011 Vol. 9 (6): 99-105 [
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106
XIAO Qing-Sheng, ZHENG Hai-Jin, YANG Ji, DONG Yun-She, CHEN Xiao-An, SONG Ru-Jun
Coupling relationships of soil erosion/soil and water conservation and climate change
The impact of soil erosion on carbon cycle, the global climate change on soil erosion and the vegetation restoration on soil carbon accumulation were reviewed. The results showed that soil carbon loss is enormous due to soil erosion, however, whether the soil erosion will be carbon source or carbon sink is still in argument. The discussion focused on the carbon mineralization rate of soil organic carbon exposed to the air because of the breakdown of soil aggregates by soil erosion. However the intensity and area of soil erosion are increasing as the rise of global temperature and the change of rainfall patterns, the response of soil erosion to global climate change needs further study. By changing the underlying surface characteristics, soil and water conservation could change the soil organic carbon content and the soil CO
2
emission, and promote soil carbon accumulation, and thus to change the carbon cycle in some extent and inhibit the atmospheric CO
2
concentration. The main research directions in this field in the future were also suggested, such as the carbon cycle modeling in soil erosion processes, the nitrogen transport and transformation process in soil erosion and the soil carbon accumulation mechanism in the process of ecological restoration of erosion badlands.
2011 Vol. 9 (6): 106-113 [
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114
LI Gui-Yuan, FAN Hao-Meng
Study progress on effects of freezing and thawing on phosphorus transformation and migration
Freezing and thawing action causes soil and water losses, so that inorganic pollutants including phosphorus are released to downstream water-body (e.g.,rivers and lakes). Non-point source pollution is likely to happen, which gives rise to some problems, such as decline of soil fertility and deterioration of ecological environment. Firstly, the effects of freezing and thawing on phosphorus transformation and migration were introduced from three aspects, phosphorus in farmland soil, phosphorus in plant body and phosphorus of microbial biomass; and then, some measures to prevent and cure phosphorus losses derived from freezing and thawing were put forward, such as application of organic fertilizer, proper close planting, restoring and improving vegetation, closed forest, conversion of cropland to forest and grass and so on. Finally, future promising studies on effects of freezing and thawing on phosphorus transformation and migration were predicted, which include mechanism of migration and transformation of soil phosphorus in horizontal and vertical direction, mechanism of migration and transformation of phosphorus in plant body, mechanism of migration and transformation of phosphorus of microbial biomass, models of phosphorus losses during freezing and thawing process.
2011 Vol. 9 (6): 114-120 [
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