Heavy metal pollution in soil-plant system is of major environmental concern on a world scale and in China in particular with the rapid development of industry. The heavy metal pollution status in soil-plant system in...Heavy metal pollution in soil-plant system is of major environmental concern on a world scale and in China in particular with the rapid development of industry. The heavy metal pollution status in soil-plant system in China, the research progress on the bioavailability of heavy metals (affecting factors, extraction methods, free-ion activity model, adsorption model, multivariate regression model, Q-I relationship, and compound pollution), and soil remediation are reviewed in the paper. Future research and monitoring is also discussed.展开更多
The distribution of crystal organic fertilizer, urea and compound fertilizer-N in soil and plant system was researched with 15N-trace under tobacco pot experiment. The results showed that the leaf yield of tobacco use...The distribution of crystal organic fertilizer, urea and compound fertilizer-N in soil and plant system was researched with 15N-trace under tobacco pot experiment. The results showed that the leaf yield of tobacco used crystal organic fertilizer was 23.1% and 14.6% higher than that of urea and compound fertilizer treatments respectively. Compound fertilizer also resulted in higher yield of 8.5 % comparing with the urea treatment. Nitrogen content of the plant from the crystal organic fertilizer treatment was 138. 6% and 145.7% as high as that of the compound fertilizer and urea treatments respectively. The absorbed N from the organic fertilizer was 25.1% and 27.9% more than that from the compound fertilizer and urea respectively. However, the absorbed N from the soil with the organic fertilizer was 47.4% and 58.3% more than that with compound fertilizer and urea respectively. The N use efficiency of the organic fertilizer was 9.4% and 10.1% higher than that of the compound fertilizer and urea. It indicated that the crystal organic fertilizer not only had high N use efficiency, but also stimulated tobacco taking up more N from soil.展开更多
Endophytes are hypothesized to be transferred across the soil-plant continuum, suggesting both the transfers of endophytes from environment to plant and from plant to soil. To verify this hypothesis and to assess the ...Endophytes are hypothesized to be transferred across the soil-plant continuum, suggesting both the transfers of endophytes from environment to plant and from plant to soil. To verify this hypothesis and to assess the role of locality, we evaluated the similarity of microbial communities commonly found both in soils and endophytic communities in three arid regions, i.e. the Jornada LTER （Long Term Ecological Research） site in New Mexico, USA, and the research station of Jordan University of Science and Technology （JUST） and Khanasd research station in Badia region of Jordan. Rhizosphere and non-rhizosphere soils, leaves and seeds of Atriplex spp. were sampled. Diversity and distribution of bacteria and fungi across the soil-plant continuums were assessed by tag-encoded FLX amplicon pyrosequencing and sequence alignment. Of the total bacterial OTUs （operational taxonomic units）, 0.17% in Khanasri research station, 0.16% in research station of JUST, and 0.42% in Jornada LTER site were commonly found across all the plant and soil compartments. The same was true for fungi in two regions, i.e. 1.56% in research station of JUST and 0.86% in Jornada LTER site. However, in Khanasri research station, 12.08% of total fungi OTUs were found in at least one soil compartment and one plant compartment. Putative Arthrobacter, Sporosarcina, Cladosporium and members of Proteobacteria and Actinobacteria were found across all the soil-plant continuums. Ascomycota, mainly including Didymellaceae, Pleosporaceae and Davidiellaceae were present across all the soil-plant continuums. Microbial communities in two regions of Jordan were similar to each other, but both of them were different from the Jornada LTER site of USA. SIMPER （similarity percentage） analysis of bacterial and fungal taxa for both soil and endophyte communities revealed that dissimilarities of two bacterial genera （Arthrobacter and Sporosarcina） and two fungal genera （Cladosporium and Alternaria） are very high, so they play key roles in the soil-plant continuums. A weighed Pearson correlation analysis for the specific bacterial OTUs in the soil-plant continuums only showed high similarity between the two regions of Jordan. However, fungal groups showed higher similarities among all regions. This research supports the hypothesis of continuity of certain bacterial and fungal communities across the soil-plant continuums, and also explores the influences of plant species and geographic specificity on diversity and distribution of bacteria and fungi.展开更多
A pot experiment with a sandy loam soil and spring wheat as test crop was conducted to compare the N2O emission from soil system with plant cut off and from soil-plant system with plant kept. The results showed that a...A pot experiment with a sandy loam soil and spring wheat as test crop was conducted to compare the N2O emission from soil system with plant cut off and from soil-plant system with plant kept. The results showed that after urea fertilizer applied, the N2O emission from soil and soil-wheat system decreased exponentially with time, and its total amount was 0.34%~0.63% and 0.33%~0.58% of applied urea-N respectively, no significant difference being found between these two systems. The N2O emission had a very significant negative relationship (P = 0.01) with the biomass of wheat plant. A combined application of urease inhibitor hydroquinone and nitrification inhibitor dicyandiamide could reduce the N2O emission by 50%~83% and 46%~74%, respectivelyl from soil and soil-wheat system. The N2O was mainly produced and emitted from soil, and the soil biochemical regulation, i.e., applying related inhibitors into soil could effectively diminish the urea derived N2O emission.展开更多
This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary la...This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feasibility of the model is well proved in this paper. The numerical simulation results from MSPAS show good agreement with reality. The scheme is used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature of boundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity, turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS is used to simulate the interaction between desert and oasis at night, and again it obtains reasonable results. This indicates that MSPAS can be used to study the interaction between land surface processes and the atmospheric boundary layer over various underlying surfaces and can be extended for regional climate and numerical weather prediction study.展开更多
One purpose of this research is to present accumulation of cadmium （Cd） and copper （Cu） by female Oxya chinensis （Orthopera： Acridoidea） in a simulated soil-plant-insect ecosystem treated with Cd. Fourth-instar...One purpose of this research is to present accumulation of cadmium （Cd） and copper （Cu） by female Oxya chinensis （Orthopera： Acridoidea） in a simulated soil-plant-insect ecosystem treated with Cd. Fourth-instar nymphs of O. chinensis had been fed on wheat （Triticurn aestivum） seedlings contaminated with Cd and Cu for one month. In the ecosystem, the Cd concentration in wheat seedlings rose greatly with the increasing of Cd in the soil, but the Cu concentration in wheat seedlings was not found elevated. There was a highly significant difference（P〈0.05） in Cd concentrations of wheat seedlings and not any significant difference（P〉0.05） in Cu concentrations of wheat seedlings. The Cd and Cu concentration in different body part-head, thorax, abdomen, and hind femur, varied under different Cd concentrations in soil. There were significant differences （P〈0.05） in the four parts of Cd and Cu accumulations with all treatments. The order of Cd accumulation was thorax 〉abdomen 〉head 〉hind femur and the Cu was abdomen 〉thorax 〉 head〉hind femur. The results indicated that Cd and Cu were accumulated from the soil to grasshoppers through the plant; that is to say, Cd and Cu in environment could be transported to animal or human via food chain.展开更多
A series of sensitivity tests are performed to test the stability and sensibility of the Modified Soil-Plant-Atmosphere Scheme (MSPAS), which was wholly introduced in a previous paper. The numerical simulation results...A series of sensitivity tests are performed to test the stability and sensibility of the Modified Soil-Plant-Atmosphere Scheme (MSPAS), which was wholly introduced in a previous paper. The numerical simulation results from the experiments show good agreement with physical reality. Besides, some of the results are illuminating. Together with the first paper, it is concluded that MSPAS is a simple but effective model, and it is practically valuable in the research work of desertification control and reforestation in China.展开更多
Soil-plant systems play an important role in sand fixing and surface protection in the arid desert of China. This study examines the ecohydrological responses after a soil-plant system change for mobile dune stabiliza...Soil-plant systems play an important role in sand fixing and surface protection in the arid desert of China. This study examines the ecohydrological responses after a soil-plant system change for mobile dune stabilization by using a series of soil hydrological experiments and ecological investigation. The study results showed that decades of succession of soil-plant system has endangered the stability of the protection system. With the accumulated water and nutrient, a bio-logical system develops in a thinner and thinner surface soil. Redistribution of precipitation has changed completely in the ecosystem. In 3–15 mm of soil, a high capacity of crust water retention ultimately limits most rainfall from infiltrating below 10–20 cm deep. When that takes place, lower plants begin to compete for water with grasses and shrubs. A drought horizon forms in 20–500 cm depth with shrub transpiration. Artificial shrubs with deep roots obtain hardly rainfall supply and are gradually eliminated from the protection system. All changes in water environment affect the structure and func-tion and stabilization of whole protection systems. It is necessary to establish a relatively stable water environment by managing the soil-plant system for constructing a sustainable protective system in arid desert.展开更多
This study presents a case study on the heavy metal analysis of soil and plant samples around the Murgul copper mine,one of the first and most important mining areas in Turkey.An attempt has been made to investigate t...This study presents a case study on the heavy metal analysis of soil and plant samples around the Murgul copper mine,one of the first and most important mining areas in Turkey.An attempt has been made to investigate the status of trace elements like Al^(3+),Fe^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Ni^(2+),Co^(2+)and Cd^(2+)in soils and plants.The sampling localities were taken from 500 m,600 m,and 1000 m altitudes around the factory and at 1400 m in the forest zone.The aboveground parts and foliage ash of Silene compacta,Tussilago farfara,Smilax excelsa,Rhododendron ponticum,R.luteum,and herbal mix were analysed.The results of analysis have revealed the minimum and maximum concentrations measured in the plants as follows;aluminium(20-8985 mg kg^(-1)),cadmium(0.0-0.5 mg kg^(-1)),cobalt(0.0-5.5 mg kg^(-1)),copper(0.0-347.5 mg kg^(-1)),iron(25-9320 mg kg^(-1)),lead(2-51 mg kg^(-1)),nickel(1.5-16.5 mg kg^(-1)),and zinc(13.0-221.0 mg kg^(-1)).In the soil the concentrations of aluminium,cadmium,cobalt,copper,iron,lead,nickel,and zinc vary between 33-457,0.0-0.0,0.0-0.4,0.1-88.7,14-50,0.3-4.1,0.2-0.8,and 4.0-20.3 mg kg^(-1) respectively.These findings enlighten the fact that copper is generally toxic in the soils as well as plants.Silene compacta has been recorded as a high copper accumulator,behaving as a healthy plant on the polluted sites of the area alongside the Murgul creek(especially at 600 m).This study stresses the fact that it is imperative to assess and monitor the levels of heavy metals in the environment due to anthropogenic activities,including mining,for evaluation of human exposure and for sustainable environment.展开更多
Availability of soil arsenic (As) and plant As at various levels of zinc (Zn) and As applications were examined. A pot-culture experiment with a leafy vegetable, Kalmi (Ipomoea aquatica), on an Inceptisols, was conduc...Availability of soil arsenic (As) and plant As at various levels of zinc (Zn) and As applications were examined. A pot-culture experiment with a leafy vegetable, Kalmi (Ipomoea aquatica), on an Inceptisols, was conducted where As was applied with irrigation water at the rates of 0 mg/L (As control), 0.5 mg/L, 1 mg/L and 2 mg/L and Zn was added to the soil as ZnCl2 solution at the rate of 0 mg/L (Zn control), 1 mg/L, 2 mg/L and 3 mg/L during pot preparation. The experiment was conducted in triplicates for 45 days till the plants were grown to maturity. At the end of the experiment the remedial effect of Zn on As toxicity was examined and as such, yield parameters, As and Zn accumulation in Kalmi plants, residual concentrations of As and Zn in soils and plants were measured. It appeared from the present study that there exists an antagonistic relationship between Zn and As i.e., Zn in soils was found to reduce As availability in soils as well as its accumulation in plants, particularly at an elevated application rate of 3 mg/L Zn. The findings could be used as a strategy to mitigate arsenic toxicity in As contaminated soils.展开更多
study was carried out on the transfer of native and added Ni towards plant both in different soils andat different time by using ￣(63)Ni tracer technique. The transfer of added Ni in soil was greater than native Nian...study was carried out on the transfer of native and added Ni towards plant both in different soils andat different time by using ￣(63)Ni tracer technique. The transfer of added Ni in soil was greater than native Niand declined as time increased. The mobility was greater for soluble plus exchangeable fraction of soil Nibut very smaller for residual and Fe/Mn oxide bound fractions. These indicated that Ni was more mobileand more harmful in soils with a low pH and/or low content of Fe/Mn oxides.展开更多
The purpose of this study is to investigate total mercury （THg） distribution and its bioaccumulation up the soil-plant-grasshopperspider in the Huludao City, which is polluted seriously by chlor-alkali and zinc smel...The purpose of this study is to investigate total mercury （THg） distribution and its bioaccumulation up the soil-plant-grasshopperspider in the Huludao City, which is polluted seriously by chlor-alkali and zinc smelting industry in Northeast of China. Results indicated that average THg concentrations in soil, plant leaves, grasshopper Locusta migratoria manilensis and Acrida chinensis, and spider were 0.151, 0.119, 0.167 and 0.134 mg/kg, respectively. THg spatial distribution suggested that most of mercury came from the chlor-alkali plant and the two zinc smelteries. The highest mercury concentration was found in the wings among different grasshoppers’ organs. Although spiders are the predatory, THg concentrations in their bodies were not high, and only on the same level as in grasshoppers, which might be due to spiders’ special living habits. In the light of the mercury transportation at every stage of the soil-plant-grasshopper-spider food chain, the bioaccumulation factors were 0.03, 0.79–1.11 and 0.80–1.13 respectively. It suggested that mercury biomagnification up terrestrial food chains was not so large and obvious as it was in the aquatic food chain.展开更多
This study focused on the cycling of major and trace elements in the soil-plant system in parts of Southern Benue Trough, Nigeria. Surface soil samples and cassava crop samples were collected from cultivated farmlands...This study focused on the cycling of major and trace elements in the soil-plant system in parts of Southern Benue Trough, Nigeria. Surface soil samples and cassava crop samples were collected from cultivated farmlands underlined by shaly and calcareous soils and were analysed using standard techniques. The results show that shaly soils are relatively acidic (pH, 4.8 - 6.6) with high level of organic matter content (OM, 3.2% - 8.7%) compared to calcareous soils (pH, 5.6 - 7.2;OM 1.6% - 7.0%). The soils are enriched in elemental composition relative to the world average abundances in soil. The maximum levels of K, Al, and Zn were obtained from shaly soils. The computed accumulation factors are generally <1. Elemental levels decreased in the plant parts in the order tuber > leaf > stem. Significant correlation was obtained between elemental associations of calcareous surface soils compared to that of shaly soils. R-mode factor analysis revealed the controls of soil geochemistry to include lithology, anthropogenic and environmental factors. A stepwise linear regression analysis identified soil elemental component, pH and organic matter as some of the factors influencing soil-plant metal uptake.展开更多
In the urbanized territory (the Irkutsk city), the content of sulfur and heavy metals (lead, cadmium, copper, zinc) in soil profile horizons and leaves (needles) arboreal plants were studied. High accumulation of poll...In the urbanized territory (the Irkutsk city), the content of sulfur and heavy metals (lead, cadmium, copper, zinc) in soil profile horizons and leaves (needles) arboreal plants were studied. High accumulation of polluting elements in pine and larch needles, birch and poplar leaves, as well as in all genetic horizons of the city soils was shown. There were revealed elements disbalance in city trees assimilation organs showing in the increase of the polluting elements quota with the parallel decrease of the quota of nitrogen, phosphorus, calcium, magnesium, potassium, manganese. Pollutants concentration in trees needles (leaves) was shown to be closely related to their content in soil horizons. The results speak in favor of high migration ability of polluting elements in soil profile and about possibility their entrance in trees root system and further to assimilation organs from all city soils horizons. It can be concluded that data on accumulation and migration of polluting elements in soils and arboreal trees assimilation organs contribute to adequate assessment of technogenic load on urban ecosystems.展开更多
The characteristics of vertical and horizontal variations of lead element(Pb) in soil plant system of vertical zone in Changbai Mountain National Nature Reserve(CNNR) were studied. The results showed that Pb concentr...The characteristics of vertical and horizontal variations of lead element(Pb) in soil plant system of vertical zone in Changbai Mountain National Nature Reserve(CNNR) were studied. The results showed that Pb concentrations in soils of vertical zone are all above 25 mg/kg, and the average Pb concentration of each soil zone negatively correlates its degree of variation, i.e. brown coniferous forest soil zone has the lowest average Pb concentration of four soil zones, and the highest horizontal variation; however, mountain soddy forest soil has the highest average Pb concentration, and the lowest horizontal variation; the average concentration of plant Pb of each plant zone is lower than the worldwide average level of Pb in plant(Clarke), respectively, and plant Pb content order is consistent with soil Pb content order, but their horizontal variations are different from those in soil zones, the variation of mountain tundra forest zone is highest, but Betula ermanii forest zone the lowest. Vertical variation of plant Pb is obviously higher than that in soils with variation coefficient of 89.76%; the enrichment capability of plant for Pb is depended on the plant types and the different organs of plant; parent material and parent rock, pH values, soil organic matter and soil particle fraction etc. are the main factors influencing variations of Pb content in soil plant system of vertical zone in CNNR.展开更多
In recent time Bangladesh faces a serious problem of soil pollution due to plastic contamination. However, the degree of the extent to which the effects of plastics on plant growth occur is not properly identified. An...In recent time Bangladesh faces a serious problem of soil pollution due to plastic contamination. However, the degree of the extent to which the effects of plastics on plant growth occur is not properly identified. An experiment was conducted to measure the effects of mixed plastic (polyethylene and disposable plastic glass) on the growth of </span><i><span style="font-family:Verdana;">Amaranthus</span></i> <i><span style="font-family:Verdana;">viridis</span></i><span style="font-family:Verdana;">. Different doses of mixed plastics (T0, T1, T2, and T3) were applied with a fixed amount of soil for each of the treatments e.g., T0 (control), T1 (10 gm mixed plastics/3kg soil), T2 (15 gm mixed plastics/3kg soil) and T3 (20 gm mixed plastic/3kg soil), and the growth response of </span><i><span style="font-family:Verdana;">Amaranthus</span></i> <i><span style="font-family:Verdana;">viridis</span></i><span style="font-family:Verdana;"> against plastic was observed for six consecutive weeks. The growth was measured in terms of plant height and girth diameter. The results showed that the presence of mixed plastic had a significant effect on the growth of </span><i><span style="font-family:Verdana;">Amaranthus</span></i> <i><span style="font-family:Verdana;">viridis</span></i><span style="font-family:Verdana;"> and particularly in treatment T3 (3 kg soil/20gm mixed plastic), the plants showed a slower growth response compared to control and the rest of the treatments applied in case of both plant height as well as girth diameter. The statistical analysis (one-way Analysis of Variance) also proved the significance of the treatments (p-values < 0.05) for six consecutive weeks. The experiment was successfully able to set an index on which plastics had their effects on the growth of green amaranth. In addition, the obtained data will be helpful in future research of the study in determining the possible effects of plastic on plant growth viz. green amaranth.展开更多
文摘Heavy metal pollution in soil-plant system is of major environmental concern on a world scale and in China in particular with the rapid development of industry. The heavy metal pollution status in soil-plant system in China, the research progress on the bioavailability of heavy metals (affecting factors, extraction methods, free-ion activity model, adsorption model, multivariate regression model, Q-I relationship, and compound pollution), and soil remediation are reviewed in the paper. Future research and monitoring is also discussed.
文摘The distribution of crystal organic fertilizer, urea and compound fertilizer-N in soil and plant system was researched with 15N-trace under tobacco pot experiment. The results showed that the leaf yield of tobacco used crystal organic fertilizer was 23.1% and 14.6% higher than that of urea and compound fertilizer treatments respectively. Compound fertilizer also resulted in higher yield of 8.5 % comparing with the urea treatment. Nitrogen content of the plant from the crystal organic fertilizer treatment was 138. 6% and 145.7% as high as that of the compound fertilizer and urea treatments respectively. The absorbed N from the organic fertilizer was 25.1% and 27.9% more than that from the compound fertilizer and urea respectively. However, the absorbed N from the soil with the organic fertilizer was 47.4% and 58.3% more than that with compound fertilizer and urea respectively. The N use efficiency of the organic fertilizer was 9.4% and 10.1% higher than that of the compound fertilizer and urea. It indicated that the crystal organic fertilizer not only had high N use efficiency, but also stimulated tobacco taking up more N from soil.
文摘Endophytes are hypothesized to be transferred across the soil-plant continuum, suggesting both the transfers of endophytes from environment to plant and from plant to soil. To verify this hypothesis and to assess the role of locality, we evaluated the similarity of microbial communities commonly found both in soils and endophytic communities in three arid regions, i.e. the Jornada LTER （Long Term Ecological Research） site in New Mexico, USA, and the research station of Jordan University of Science and Technology （JUST） and Khanasd research station in Badia region of Jordan. Rhizosphere and non-rhizosphere soils, leaves and seeds of Atriplex spp. were sampled. Diversity and distribution of bacteria and fungi across the soil-plant continuums were assessed by tag-encoded FLX amplicon pyrosequencing and sequence alignment. Of the total bacterial OTUs （operational taxonomic units）, 0.17% in Khanasri research station, 0.16% in research station of JUST, and 0.42% in Jornada LTER site were commonly found across all the plant and soil compartments. The same was true for fungi in two regions, i.e. 1.56% in research station of JUST and 0.86% in Jornada LTER site. However, in Khanasri research station, 12.08% of total fungi OTUs were found in at least one soil compartment and one plant compartment. Putative Arthrobacter, Sporosarcina, Cladosporium and members of Proteobacteria and Actinobacteria were found across all the soil-plant continuums. Ascomycota, mainly including Didymellaceae, Pleosporaceae and Davidiellaceae were present across all the soil-plant continuums. Microbial communities in two regions of Jordan were similar to each other, but both of them were different from the Jornada LTER site of USA. SIMPER （similarity percentage） analysis of bacterial and fungal taxa for both soil and endophyte communities revealed that dissimilarities of two bacterial genera （Arthrobacter and Sporosarcina） and two fungal genera （Cladosporium and Alternaria） are very high, so they play key roles in the soil-plant continuums. A weighed Pearson correlation analysis for the specific bacterial OTUs in the soil-plant continuums only showed high similarity between the two regions of Jordan. However, fungal groups showed higher similarities among all regions. This research supports the hypothesis of continuity of certain bacterial and fungal communities across the soil-plant continuums, and also explores the influences of plant species and geographic specificity on diversity and distribution of bacteria and fungi.
基金the National Natural Science Foundation of China (No. 39730110) and the Ministryof Foreign Affairs, Belgium (ABOS) through "VL
文摘A pot experiment with a sandy loam soil and spring wheat as test crop was conducted to compare the N2O emission from soil system with plant cut off and from soil-plant system with plant kept. The results showed that after urea fertilizer applied, the N2O emission from soil and soil-wheat system decreased exponentially with time, and its total amount was 0.34%~0.63% and 0.33%~0.58% of applied urea-N respectively, no significant difference being found between these two systems. The N2O emission had a very significant negative relationship (P = 0.01) with the biomass of wheat plant. A combined application of urease inhibitor hydroquinone and nitrification inhibitor dicyandiamide could reduce the N2O emission by 50%~83% and 46%~74%, respectivelyl from soil and soil-wheat system. The N2O was mainly produced and emitted from soil, and the soil biochemical regulation, i.e., applying related inhibitors into soil could effectively diminish the urea derived N2O emission.
基金supported by the National Natural Science Foundation of China (Grant No.40275004)the State Key Laboratory of Atmosphere Physics and Chemistry,and the City University of Hong Kong(Grant No.8780046)the City University of Hong Kong Strategic Research(Grant No.7001038)
文摘This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feasibility of the model is well proved in this paper. The numerical simulation results from MSPAS show good agreement with reality. The scheme is used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature of boundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity, turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS is used to simulate the interaction between desert and oasis at night, and again it obtains reasonable results. This indicates that MSPAS can be used to study the interaction between land surface processes and the atmospheric boundary layer over various underlying surfaces and can be extended for regional climate and numerical weather prediction study.
文摘One purpose of this research is to present accumulation of cadmium （Cd） and copper （Cu） by female Oxya chinensis （Orthopera： Acridoidea） in a simulated soil-plant-insect ecosystem treated with Cd. Fourth-instar nymphs of O. chinensis had been fed on wheat （Triticurn aestivum） seedlings contaminated with Cd and Cu for one month. In the ecosystem, the Cd concentration in wheat seedlings rose greatly with the increasing of Cd in the soil, but the Cu concentration in wheat seedlings was not found elevated. There was a highly significant difference（P〈0.05） in Cd concentrations of wheat seedlings and not any significant difference（P〉0.05） in Cu concentrations of wheat seedlings. The Cd and Cu concentration in different body part-head, thorax, abdomen, and hind femur, varied under different Cd concentrations in soil. There were significant differences （P〈0.05） in the four parts of Cd and Cu accumulations with all treatments. The order of Cd accumulation was thorax 〉abdomen 〉head 〉hind femur and the Cu was abdomen 〉thorax 〉 head〉hind femur. The results indicated that Cd and Cu were accumulated from the soil to grasshoppers through the plant; that is to say, Cd and Cu in environment could be transported to animal or human via food chain.
基金the National Natural Science Foundation of China (Grant No. 40275004) the State Key Laboratory of Atmosphere Physics and Chemistry, and the City University of Hong Kong Grant 8780046 the City University of Hong Kong Strategic Research (Grant No.7001038).
文摘A series of sensitivity tests are performed to test the stability and sensibility of the Modified Soil-Plant-Atmosphere Scheme (MSPAS), which was wholly introduced in a previous paper. The numerical simulation results from the experiments show good agreement with physical reality. Besides, some of the results are illuminating. Together with the first paper, it is concluded that MSPAS is a simple but effective model, and it is practically valuable in the research work of desertification control and reforestation in China.
基金supported by the National Key Tech-nologies R&D Program in the 10th Five-year Plan (2004BA 901A 15)the Knowledge Innovation Project of The Chinese Academy of Sciences (No. KZCX1-09)by the Key Program of National Natural Science Foundation of China (Grant No. 90702001)
文摘Soil-plant systems play an important role in sand fixing and surface protection in the arid desert of China. This study examines the ecohydrological responses after a soil-plant system change for mobile dune stabilization by using a series of soil hydrological experiments and ecological investigation. The study results showed that decades of succession of soil-plant system has endangered the stability of the protection system. With the accumulated water and nutrient, a bio-logical system develops in a thinner and thinner surface soil. Redistribution of precipitation has changed completely in the ecosystem. In 3–15 mm of soil, a high capacity of crust water retention ultimately limits most rainfall from infiltrating below 10–20 cm deep. When that takes place, lower plants begin to compete for water with grasses and shrubs. A drought horizon forms in 20–500 cm depth with shrub transpiration. Artificial shrubs with deep roots obtain hardly rainfall supply and are gradually eliminated from the protection system. All changes in water environment affect the structure and func-tion and stabilization of whole protection systems. It is necessary to establish a relatively stable water environment by managing the soil-plant system for constructing a sustainable protective system in arid desert.
文摘This study presents a case study on the heavy metal analysis of soil and plant samples around the Murgul copper mine,one of the first and most important mining areas in Turkey.An attempt has been made to investigate the status of trace elements like Al^(3+),Fe^(2+),Cu^(2+),Zn^(2+),Pb^(2+),Ni^(2+),Co^(2+)and Cd^(2+)in soils and plants.The sampling localities were taken from 500 m,600 m,and 1000 m altitudes around the factory and at 1400 m in the forest zone.The aboveground parts and foliage ash of Silene compacta,Tussilago farfara,Smilax excelsa,Rhododendron ponticum,R.luteum,and herbal mix were analysed.The results of analysis have revealed the minimum and maximum concentrations measured in the plants as follows;aluminium(20-8985 mg kg^(-1)),cadmium(0.0-0.5 mg kg^(-1)),cobalt(0.0-5.5 mg kg^(-1)),copper(0.0-347.5 mg kg^(-1)),iron(25-9320 mg kg^(-1)),lead(2-51 mg kg^(-1)),nickel(1.5-16.5 mg kg^(-1)),and zinc(13.0-221.0 mg kg^(-1)).In the soil the concentrations of aluminium,cadmium,cobalt,copper,iron,lead,nickel,and zinc vary between 33-457,0.0-0.0,0.0-0.4,0.1-88.7,14-50,0.3-4.1,0.2-0.8,and 4.0-20.3 mg kg^(-1) respectively.These findings enlighten the fact that copper is generally toxic in the soils as well as plants.Silene compacta has been recorded as a high copper accumulator,behaving as a healthy plant on the polluted sites of the area alongside the Murgul creek(especially at 600 m).This study stresses the fact that it is imperative to assess and monitor the levels of heavy metals in the environment due to anthropogenic activities,including mining,for evaluation of human exposure and for sustainable environment.
文摘Availability of soil arsenic (As) and plant As at various levels of zinc (Zn) and As applications were examined. A pot-culture experiment with a leafy vegetable, Kalmi (Ipomoea aquatica), on an Inceptisols, was conducted where As was applied with irrigation water at the rates of 0 mg/L (As control), 0.5 mg/L, 1 mg/L and 2 mg/L and Zn was added to the soil as ZnCl2 solution at the rate of 0 mg/L (Zn control), 1 mg/L, 2 mg/L and 3 mg/L during pot preparation. The experiment was conducted in triplicates for 45 days till the plants were grown to maturity. At the end of the experiment the remedial effect of Zn on As toxicity was examined and as such, yield parameters, As and Zn accumulation in Kalmi plants, residual concentrations of As and Zn in soils and plants were measured. It appeared from the present study that there exists an antagonistic relationship between Zn and As i.e., Zn in soils was found to reduce As availability in soils as well as its accumulation in plants, particularly at an elevated application rate of 3 mg/L Zn. The findings could be used as a strategy to mitigate arsenic toxicity in As contaminated soils.
文摘study was carried out on the transfer of native and added Ni towards plant both in different soils andat different time by using ￣(63)Ni tracer technique. The transfer of added Ni in soil was greater than native Niand declined as time increased. The mobility was greater for soluble plus exchangeable fraction of soil Nibut very smaller for residual and Fe/Mn oxide bound fractions. These indicated that Ni was more mobileand more harmful in soils with a low pH and/or low content of Fe/Mn oxides.
基金supported by the National Natural Science Foundation of China (No 40830535, 40803021)
文摘The purpose of this study is to investigate total mercury （THg） distribution and its bioaccumulation up the soil-plant-grasshopperspider in the Huludao City, which is polluted seriously by chlor-alkali and zinc smelting industry in Northeast of China. Results indicated that average THg concentrations in soil, plant leaves, grasshopper Locusta migratoria manilensis and Acrida chinensis, and spider were 0.151, 0.119, 0.167 and 0.134 mg/kg, respectively. THg spatial distribution suggested that most of mercury came from the chlor-alkali plant and the two zinc smelteries. The highest mercury concentration was found in the wings among different grasshoppers’ organs. Although spiders are the predatory, THg concentrations in their bodies were not high, and only on the same level as in grasshoppers, which might be due to spiders’ special living habits. In the light of the mercury transportation at every stage of the soil-plant-grasshopper-spider food chain, the bioaccumulation factors were 0.03, 0.79–1.11 and 0.80–1.13 respectively. It suggested that mercury biomagnification up terrestrial food chains was not so large and obvious as it was in the aquatic food chain.
文摘This study focused on the cycling of major and trace elements in the soil-plant system in parts of Southern Benue Trough, Nigeria. Surface soil samples and cassava crop samples were collected from cultivated farmlands underlined by shaly and calcareous soils and were analysed using standard techniques. The results show that shaly soils are relatively acidic (pH, 4.8 - 6.6) with high level of organic matter content (OM, 3.2% - 8.7%) compared to calcareous soils (pH, 5.6 - 7.2;OM 1.6% - 7.0%). The soils are enriched in elemental composition relative to the world average abundances in soil. The maximum levels of K, Al, and Zn were obtained from shaly soils. The computed accumulation factors are generally <1. Elemental levels decreased in the plant parts in the order tuber > leaf > stem. Significant correlation was obtained between elemental associations of calcareous surface soils compared to that of shaly soils. R-mode factor analysis revealed the controls of soil geochemistry to include lithology, anthropogenic and environmental factors. A stepwise linear regression analysis identified soil elemental component, pH and organic matter as some of the factors influencing soil-plant metal uptake.
文摘In the urbanized territory (the Irkutsk city), the content of sulfur and heavy metals (lead, cadmium, copper, zinc) in soil profile horizons and leaves (needles) arboreal plants were studied. High accumulation of polluting elements in pine and larch needles, birch and poplar leaves, as well as in all genetic horizons of the city soils was shown. There were revealed elements disbalance in city trees assimilation organs showing in the increase of the polluting elements quota with the parallel decrease of the quota of nitrogen, phosphorus, calcium, magnesium, potassium, manganese. Pollutants concentration in trees needles (leaves) was shown to be closely related to their content in soil horizons. The results speak in favor of high migration ability of polluting elements in soil profile and about possibility their entrance in trees root system and further to assimilation organs from all city soils horizons. It can be concluded that data on accumulation and migration of polluting elements in soils and arboreal trees assimilation organs contribute to adequate assessment of technogenic load on urban ecosystems.
基金WetlandInnovationItemofChineseAcademyofSciences (No .ZKHZ 3 0 6 )
文摘The characteristics of vertical and horizontal variations of lead element(Pb) in soil plant system of vertical zone in Changbai Mountain National Nature Reserve(CNNR) were studied. The results showed that Pb concentrations in soils of vertical zone are all above 25 mg/kg, and the average Pb concentration of each soil zone negatively correlates its degree of variation, i.e. brown coniferous forest soil zone has the lowest average Pb concentration of four soil zones, and the highest horizontal variation; however, mountain soddy forest soil has the highest average Pb concentration, and the lowest horizontal variation; the average concentration of plant Pb of each plant zone is lower than the worldwide average level of Pb in plant(Clarke), respectively, and plant Pb content order is consistent with soil Pb content order, but their horizontal variations are different from those in soil zones, the variation of mountain tundra forest zone is highest, but Betula ermanii forest zone the lowest. Vertical variation of plant Pb is obviously higher than that in soils with variation coefficient of 89.76%; the enrichment capability of plant for Pb is depended on the plant types and the different organs of plant; parent material and parent rock, pH values, soil organic matter and soil particle fraction etc. are the main factors influencing variations of Pb content in soil plant system of vertical zone in CNNR.
文摘In recent time Bangladesh faces a serious problem of soil pollution due to plastic contamination. However, the degree of the extent to which the effects of plastics on plant growth occur is not properly identified. An experiment was conducted to measure the effects of mixed plastic (polyethylene and disposable plastic glass) on the growth of </span><i><span style="font-family:Verdana;">Amaranthus</span></i> <i><span style="font-family:Verdana;">viridis</span></i><span style="font-family:Verdana;">. Different doses of mixed plastics (T0, T1, T2, and T3) were applied with a fixed amount of soil for each of the treatments e.g., T0 (control), T1 (10 gm mixed plastics/3kg soil), T2 (15 gm mixed plastics/3kg soil) and T3 (20 gm mixed plastic/3kg soil), and the growth response of </span><i><span style="font-family:Verdana;">Amaranthus</span></i> <i><span style="font-family:Verdana;">viridis</span></i><span style="font-family:Verdana;"> against plastic was observed for six consecutive weeks. The growth was measured in terms of plant height and girth diameter. The results showed that the presence of mixed plastic had a significant effect on the growth of </span><i><span style="font-family:Verdana;">Amaranthus</span></i> <i><span style="font-family:Verdana;">viridis</span></i><span style="font-family:Verdana;"> and particularly in treatment T3 (3 kg soil/20gm mixed plastic), the plants showed a slower growth response compared to control and the rest of the treatments applied in case of both plant height as well as girth diameter. The statistical analysis (one-way Analysis of Variance) also proved the significance of the treatments (p-values < 0.05) for six consecutive weeks. The experiment was successfully able to set an index on which plastics had their effects on the growth of green amaranth. In addition, the obtained data will be helpful in future research of the study in determining the possible effects of plastic on plant growth viz. green amaranth.
