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Table of Content

Volume 20 Issue 3
25 July 2004
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Characteristics of methane exchange between Deyeuxia angustifolia wet meadow and atmosphere in the Sanjiang Plain
WANG Yi-Yong, SONG Chang-Chun, ZHENG Xun-Hua, WANG De-Xuan, YAN Bai-Xing, ZHAO Zhi-Chun, LOU Yan-Jing
2004, 20(3):  1-5. 
Abstract ( 695 )   PDF (221KB) ( 1340 )  
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The Sanjiang Plain is the largest marsh-wetland concentrated region in China.Located in the northeast of Heilongjiang Province,the Plain has a total marsh-wetland area of about 83.5×104 hm2 with rich carbon resources.Numerous rivers crisscrossing and lakes dotting this region forming vast tracts of flood plain.The study was carried out at the Ecological Experimental Station of Mire-Wetland in the Sanjiang Plain,Chinese Academy of Sciences(47°35′N,133°31′E;56 m above sea level)at the center of the Sanjiang Plain. In the region the mean annual precipitation is 550~600 mm and the annual mean temperature is 1.9 ℃.Its vegetation is mainly composed of marshes and wet meadows,and its soils are marsh soil,meadow soil and peat soil.For the study a typical type of seasonal waterlogged Deyeuxia angustifolia wet meadow was selected.The methane fluxes were measured by a closed stainless steel chamber and gas chromatography(Agilent 4890)system.The experiment lasted from June 2002 to May 2004,measuring methane fluxes twice a week,and monitoring diurnal change of the flux once a month,with three duplicates at each sample site.Meanwhile,the air temperature inside and outside the chamber, and soil temperature at the surface and 5 cm depth were also measured at the same time.The results show:there is an obviously seasonal variation and uncertain variation of the methane emission from the seasonal waterlogged Deyeuxia angustifolia wet meadow,and the methane flux was controlled by water and temperature.Two methane flux peaks appear in a year, one is in June and the other is in August or September. The methane flux from the Deyeuxia angustifolia wet meadow is averaged 0.297~18.914 mg·m-2·h-1 in the non-frozen season(from May to October),and the methane emission from the Deyeuxia angustifolia wet meadow could still be detected,but much lower in flux during the frozen season(from November to April)in the Sanjiang Plain,accounting for 4.94 percent of the total of a year,which is about 0.048~2.921 mg·m-2·h-1.The lowest CH4 emission appear in January.
Comprehensive evaluation of the eco-resources in Bashang District
LI Xiao-Xiu, MA Li
2004, 20(3):  6-9. 
Abstract ( 676 )   PDF (126KB) ( 1495 )  
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On the basis of the theory and practice of eco-resources carrying capacity,comprehensive evaluation of the eco-resources in Bashang District was planned.Key corresponding indexes were selected in consideration of the local ecological conditions to reflect features of the region objectively and accurately.International and national standards were referred in constructuring indexes and criteria for grading in the comprehensive evaluation of eco-resources.Models and values for the environment were specified.Eventually the evaluation was tried out and verified in pilot zones,thus laying down a solid base for further study of features of the eco-resources in Bashang District. 
Evaluation of service values of the intertidal land eco-system of Dafeng City
SUN Ling, ZHU Ze-Sheng, LIU Yu, ZHANG Ji-Lin
2004, 20(3):  10-14. 
Abstract ( 674 )   PDF (145KB) ( 1717 )  
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Change in land use of the intertidal land resources of Dafeng City was analyzed with the aid of the remote-sensing technique and Landsat-TM data to evaluate service value of the intertidal land eco-system with the Costanza method.The results show that the service value has been on the decline due to irrational land use in the past 18 years.The loss was reckoned to be around 33.45%, or 88.37×104 US$ in 2002.
Development and planning of ecotourism in nature reserves
WAN Xu-Cai, ZHU Ying-Gao, WU Fu-Rong
2004, 20(3):  15-19. 
Abstract ( 758 )   PDF (143KB) ( 2251 )  
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On the basis of the definition and essential characteristics of ecotourism and the conception of nature reserves and significance of their establishment,procedures for developing and contents of planning for ecotourism in nature reserves were explored.The author holds that ecological security is the main principle of ecotourism development in nature reserves,that evaluation of tourism impact on ecological security is the important link,and that involvement of local communities,supervision of responsible departments and guidance of experts concerned are the prerequisites of successful ecotourism development.It is thought that the key points of planning for ecotourism in nature reserves consist of functional zonation,ecotourism capacity definition,ecotourism items,explanation and education system,ecological tourism facilities and local involvement.
Impacts of construction of Qinghai-Tibet Railway on landscape pattern
ZHANG Hui, SHEN Wei-Shou, ZHANG Hua, ZOU Chang-Xin, CAO Xue-Zhang
2004, 20(3):  20-23. 
Abstract ( 763 )   PDF (124KB) ( 1994 )  
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With the aid of the technology of remote sensing(RS)and geographic information system(GIS)the landscapes in the section from Tanggula Mountain Pass to Lhasa City of the Qinghai-Tibet Railway were classified and charted and changes in the landscape pattern before and after the railway construction were analyzed.The results indicated that the impact of the railway construction on the landscape pattern is more serious in the small range alongside the line.
Soil exchangeable Ca and Mg contents and Ca/Mg ratio in greenhouse vegetable fields in Shenyang suburbs
JIANG Yong, ZHANG Yu-Ge, LIANG Wen-Ju
2004, 20(3):  24-27. 
Abstract ( 733 )   PDF (140KB) ( 1897 )  
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In order to explore the changes of exchangeable Ca(ECa)and exchangeable Mg(EMg)in soils under greenhouse vegetable cultivations,a comparative study was carried out with 43 pairs of soil samples gathered from greenhouse vegetable fields and their adjacent upland fields in Shenyang suburbs of China.The results showed that compared with upland soils the average content of ECa and Ca/Mg ratio in greenhouse vegetable soils decreased by 6.38% and 10.34%, respectively,while EMg increased by 4.74%.The Ca/Mg ratios in both soils were significantly correlated with soil ECa((r=)0.721 and 0.757,respectively,n=43,P<0.01) , but not with EMg(r=-0.065 and -0.117,respectively,n=43).The decrease of ECa in greenhouse soils may be attributed to the comparatively higher output of Ca from the greenhouse vegetable system,inadequate Ca supply in fertilization,and lowered soil pH,whereas the increase of EMg may be resulted from the pH value range((5.0)—6.5)that suits the existence of Mg in exchangeable form in the soil,and the high concentrations of Ca2+,K+ and NH+4 that inhabit the selective absorption of Mg2+ by vegetables.
Chemical forms and ecological risks of heavy metals in river sediment at carbonatite mining area
WU Pan, LIU Cong-Qiang, ZHANG Guo-Ping, YANG Yuan-Gen
2004, 20(3):  28-31,36. 
Abstract ( 681 )   PDF (175KB) ( 1740 )  
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Waste from local zinc smelting and lead and zinc milling plants using traditional techniques have severely polluted rivers with heavy metals in the Northwest of Guizhou.Studies on geochemical fractions of heavy metals in the sediment in the Hou River bed reveal that geochemical fractions of heavy metals differed sharply not only between sample sites,but also between elements,which is possibly related to difference in affinity between heavy metals and components of the sediment,contents of clay minerals,organic matter and Fe-Mn oxides in different river sections,and intensity of human activities(discharge of domestic sewage,wastewater from ore milling,slag,etc.).The carbonatite background of the river beds may also be a contributor to release of heavy metals in waste from mining.Assessment of their ecological risks shows that the potential ecological hazards of heavy metals in the sediment are serious.The main factor causing ecological hazards is lead,and then followed by cadmium,copper,zinc.
Coupling effects of water and fertilizers on translocation of nitrate nitrogen in protected land
LIANG Yun-Jiang, YI Yan-Li, XU Guang-Bo, ZHANG Shuang, YIN Ying-Min
2004, 20(3):  32-36. 
Abstract ( 654 )   PDF (176KB) ( 1966 )  
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Coupling effects of water and fertilizers on translocation of nitrate nitrogen in protected land were studied with the design of quadratic orthogonal rotational combinations.The results show that content of nitrate nitrogen in 0-20 cm soil layer is mainly affected by water and nitrogenous fertilizer,and negatively related to the former but positively to the latter.And the effect of water is more significant than that of nitrogenous fertilizer.Contents of nitrate nitrogen in 20-40 cm and 40-60 cm soil layers are also mainly affected by water and nitrogen fertilizer,but the effect of fertilizer is more significant than that of the water.The effects of the two are antagonistic on content of nitrate nitrogen in 0-20 cm soil layer.The effect of phosphate fertilizer is not significant on content of nitrate nitrogen in the three soil layers. 
Characteristics of nitrogen and phosphorus losses with surface runoff in typical sub-watersheds of Jiulong River watershed
HUANG Jin-Liang, HONG Hua-Sheng, ZHANG Luo-Ping, HUANG Yun-Feng, ZENG Yue, CHEN Neng-Wang
2004, 20(3):  37-41. 
Abstract ( 696 )   PDF (168KB) ( 1548 )  
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Five typicl sub-watersheds in the Jiulong River watershed were chosen for monitoring nitrogen and phosphorus losses.Results of the monitoring and analysis show that in the event of storms in agriculture-based watersheds,the N loss with the runoff is dominated with soluble N and the P loss with P combined with silt whereas in natural-forest-based ones,the situation is completely different.Under storms,the maximum total N concentration in the runoff is 2.9-11.3 times as much as that in the runoff normal and the maximum total P concentration 2.9-20.5 times as much.Throughout the entire course of runoff,water volume and N & P concentration vary sharply with the time,showing a similar trend.The concentrations of total N & P and their various forms come up to their respective peaks almost at the same time.The contents of silt N and soluble P fluctated within a limited range whereas those of soluble N and silt P do within a large one.
Effect of interaction of La and Zn on the reactive oxygen scavenging system in leaves of Lemna minor
MA Guang-Yue, SHI Guo-Xin, WANG Xue, XU Qin-Song, WANG Gui-Min, Rafeek Nhaled
2004, 20(3):  42-45. 
Abstract ( 582 )   PDF (259KB) ( 1328 )  
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Effects of single and combined pollution of La and Zn on reactive oxygen scavenging system in leaves of Lemna minor were studied.The results showed that both La and Zn,applied at a rate of 20 mg·L-1,caused obvious damage to Lemna minor,but the latter was much higher than the former in toxicity to the plant.Combined application of La and Zn weakened their respective toxicity to a varying extent,which was demonstrated in slower decline of chlorophyll and soluble protein content and CAT activity,higher GSH and AsA contents and SOD activity,as well as the decline of POD activity.So in terms of toxicity to Lemna minor,the three treatments were in a decreasing order of Zn,La,La+Zn.La and Zn may have interactive relieving effect,which is supposedly related to enhancement of the ability of the reactive oxygen scavenging system in the plant.
Nitrate contamination of vegetables in Wuhu City and effect of countermeasures
WANG You-Bao, DUAN Hong, HUANG Wei
2004, 20(3):  46-48. 
Abstract ( 610 )   PDF (96KB) ( 1783 )  
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In laboratory,nitrate contents in 10 varieties of vegetables common in the terminal market in Wuhu City were analyzed and effects of low-temperature storage and disinfection with abluent on the content were determined.The results showed that nitrate content was reduced efficiently by about 100 mg·kg-1 on average by soaking the vegetable in the solution of the "White Cat" brand abluent for 15 minutes.In storage,nitrate in the vegetable was degrading with the time,but storage under low temperature,i.e.in refrigerator hinders degradation of nitrate in the vegetable.According to the GB 18406.1—2001"Safety Quality of Agricultural Produce-Safety requirements for hazard-free vegetables",among the 10 varieties of vegetables,leafy vegetables,like spinach,Chinese green cabage have much higher contents of nitrate than the criteria while the rest did not.
Residues of pesticides in spring vegetables in southern Jiangsu,China
WU Xiao-Chen, AN Qiong, DONG Yuan-Hua, CHEN Fang, ZHANG Jin-Qiang, WANG Hui
2004, 20(3):  49-52. 
Abstract ( 633 )   PDF (143KB) ( 1470 )  
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Analysis of residues of pesticides in vegetables in southern Jiangsu was conducted in March of 2003. Results indicate that the residues of organochlorine pesticides(OCPs)ranged from not detected(ND)to 31.7(μg·kg-1).The residues of HCHs in the samples from vegetable production bases were higher than those in the samples from traditional vegetable fields.Most of DDT has been resolved into p,p′-DDE and p,p′-DDD.The residues of pyrethroid ranged between ND and 46.9(μg·kg-1).Cypermethrin,fenvalerate and deltamethrin were found to be quite higher than others in the form of residue in vegetables.The residues of carbamate ranged from ND to 111.9(μg·kg-1).The residues of methiocarb and 3-hydroxycarbofuran were widely detected and quite high in concentration,which were much higher in the samples from traditional vegetable fields than from vegetable production bases.The detection rate of aldicarb sulfone was lower than those of aldicarb and aldicarb sulfoxide.The residues of all the pesticides except aldicarb and carbofuran were far below the related national hygiene standard for hazard-free vegetables.
Pyrene contamination and soil enzyme activity
GONG Xuan, LI Pei-Jun, ZHANG Hai-Rong, JIAO Xiao-Guang, GUO Wei
2004, 20(3):  53-55,59. 
Abstract ( 781 )   PDF (143KB) ( 1674 )  
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An experiment was conducted to study changes in enzyme activities in soils exposed to pyrene.The relationship between activities of different enzymes and concentrations of pyrene added were investigated,and sensitive enzymes were cited as eco-toxicological indicators for soil diagnoses of PAHs contamination.The results show that with pyrene (concentration>)50 μg·kg-1,urease activity and dehydrogenase activity were first inhibited and later activated. However,the activity of phosphatase was activated by the addition of pyrene.No obvious change in catalase activity was observed when concentration of pyrene ranged from 50 to 1 200 μg·kg-1.It can be concluded that activities of soil urease, dehydrogenase,and phosphatase could possibly be used as diagnostic indicators of soil contamination with pyrene.
Effects of methamidophos and acetochlor on population and activity of methanogens
DENG Xiao, LIAO Xiao-Lan, TANG Qun-Feng
2004, 20(3):  56-59. 
Abstract ( 695 )   PDF (141KB) ( 1641 )  
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The technologies of anaerobic culture case,gas chromatography and most probable number method were used to investigate effects of methamidophos and acetochlor(0,0.1,0.2,0.5,and 1.0 mg·L-1) on population and activity of methanogens in paddy soil.The results show that the population of methanogens increased by 0.2-44.1 times,and the production of methane per tube by 0.8-2.1 times within 7 days after methamidophos was added,indicating that the stimulating effect rose with the concentration of the chemical.But the growth of methanogens was inhibited within 7 days after acetochlor was added,with the population decreased by 50%-99%,and the production of methane per tube falling significantly.And the retarding effect increased with the concentration of the pesticide.And the population and activity of methanogens returned to the normal level with the days passing on after the 7th day.
Effect of Phanerochaete chrysosporium on biodegradation of dyes in solid media
LI Hui-Rong, WANG An-Song, HUANG Min-Sheng, XU Ya-Tong
2004, 20(3):  60-65,69. 
Abstract ( 679 )   PDF (221KB) ( 1514 )  
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Effect of Phanerochaete chrysosporium on decolorization and degradation of dyes in solid media were measured with spectrophotometry.The results show this fungus could degrade azo dye,anthraquinone dye and polymeric dye effectively in solid media such as agar,sand and soil;plant materials like corncob and wood chip could be used as carbon source for co-metabolism of the fungus;the degradating ability of strain BKM-F-1767 was the strongest,the attackability of the fungus on reactive brilliant blue KN-R was better than on Poly R- 478 and Biebrich scarlet.
Purification and utilization of turtle-breeding wastewater in Lactuca sativa var.romana hydroponics system
LAO Shan-Gen
2004, 20(3):  66-69. 
Abstract ( 668 )   PDF (145KB) ( 2077 )  
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Wastewater from an industrialized turtle-breeding farm,treated with a single application of nitric acid to adjust the ratio of NO3--N and NH4+-N and initial pH,was tested as medium for hydroponics of cos lettuce(Lactuca sativa var.romana).Results show that after two weeks of operation under 22—28 ℃,SS and COD(Cr) in the wastewater with pH ranging between 6—9 was reduced to less than 20 mg·L-1 and 100 mg·L-1,respectively,meeting Grade 1 criteria of the "Integrated Standard for Wastewater Discharge"(GB 8978—1996);and NH4+-N and TP was lowered down to 22.1—30.3 (mg·)L-1 and 0.64—0.69 mg·L-1,respectively,approaching or meeting Grade 2 criteria of the standard(GB 8978—1996).Moreover, the cos lettuce grew quite well in the wastewater with a growth rate of 19.9%—25.1% in biomass.
Mechanism of ozone degrading dimethoate
LU Sheng-Min, Oü Yang-Xiao-Kun , YING Min, LIU Qing-Mei
2004, 20(3):  70-72,76. 
Abstract ( 685 )   PDF (148KB) ( 2062 )  
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Effectiveness of ozone degrading dimethoate in solution and its affecting factors were studied.The results showed that when the initial concentration of ozone was 10 mg·L-1,80% of the dimethoate could be degraded within 5 min.After that,however,the degradation did not significantly increase with the time.The mechanism of ozone reacting with dimethoate was investigated by adding radical scavengers such as bicarbonate and tert-butanol.The results appeared to confirm that the degradation of dimethoate by ozone in the experiment condition followed the mechanism of molecular reaction.At the same time,through GC-MS analysis,omethoate was still found in the water treated with ozone.This shows that harmful byproduct will result from inadequate treatment with ozone.
Impact of transgenic crops on soil-organism
E Zhi-Guo, CHEN Xin, ZHI Gui-Ye
2004, 20(3):  73-76. 
Abstract ( 637 )   PDF (151KB) ( 1429 )  
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Impacts of root exudate and remains of transgenic crops on the soil microorganisms and soil fauna were reviewed.They were demonstrated mainly in the following 3 aspects:1)toxicity to certain soil microorganisms and soil fauna; 2)nutrient supply to soil microorganisms and soil fauna;and 3)long-term cumulative impact on soil organism that needs further studies.
Impact of phosphorus loss on water environment in intensive livestock rearing areas and the countermeasures
ZENG Yue, HONG Hua-Sheng, CHEN Wei-Qi, ZHENG Yu
2004, 20(3):  77-80. 
Abstract ( 658 )   PDF (133KB) ( 2114 )  
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Impacts of the phosphorus losts from livestock waste on water environment were reviewed,and sources and pathways of the loss of phosphorus from livestock waste were analyzed.On such a basis,some countermeasures for management and control of the phosphorus loss were raised from the angle of protecting the water resources.