Research On The Current Status Of Wetland And Grassland Eco-environment In The Western Part Of Jilin Province

Wetland is an independent ecosystem evolved by the interaction of water and land systems which is covered by water seasonally or all-year round and inhabited by wet prone animals and plants;it is the greatest degree of biodiversity and highest degree of ecological functions,called the kidney of the earth.It possesses the functions of runoff adjustment,flooding control,water purification,air cleaning, temperature and humidity adaptation,soil erosion control,wind obstruction and dyke protection.It is also the gathering place for wild extinct species,especially rare water birds,in which they perch,breed,migrate and hibernate,therefore,is called gene database of species.Grassland is of significant benefits in ecology and economy as a renewable natural resource.It abounds in all kinds of resources,provides substantial bases for husbandry development and plays an important role in wind obstruction and sand fixation,water and soil conservation,climate adjustment,water resource nourishment, soil improvement,air purification,landscape,noise abatement and biodiversity maintenance etc.The western part of Jilin province comprises Songyan,Baicheng,and Shuangliao of Siping city.It adjoins Heilongjiang in the north,Inner Mongolia in the west and southwest.Its location is at latitude 43°22′～46°18′,longitude 121°38′～126°11′. 1,345,000 hm² is cropland,1,405,200 hm² grassland,498,000 wetland among which 154,000 hm² lake and 344,000 hm² swamp in it.Wetland ecological environment is the result of interaction between human and nature,environment,co-affected by natural and human factors.In recent years,the wetland degeneration worsening and national soil resource safety level reducing in the western part of Jilin province is due to the effects of human activities and vulnerable natural conditions gave rise to the salination,desertification of soil;water,soil loss, and the reduction of productive ability of wetland and grassland.The present research,a grant jointly funded by Jilin provincial government and China geography bureau,an attached grant to the program "Agricultural geography survey of Jilin province,Regional ecological geochemical evaluation of Jilin province" studied the current status of wetland ecological environment in the western part of Jilin province.It is of significant theoretical value to the mechanisms research of elements evolution in wetland and of great significance to the establishment of wetland protection and control measures in the western part of Jilin Province.Objectives:1.Through the analysis of atmospheric deposition in the western part of Jilin province to learn the air quality and possible source of certain elements;2.By analysis of surface water,sediments and water product samples from representative lake to investigate the source,migration and effects of beneficial and toxic elements on water products to do the preliminary evaluation on the ecosystem in the western part of Jilin province;3.Through the elements test in herbivore and forage grass to explore the source, migration,and transformation of beneficial and toxic elements in plant-animal system to evaluate the environmental quality in the grassland to provide substantial bases for the establishment of developing measures for the wetland ecological environment in the western part of Jilin province.Methods:55 air dry and wet deposition monitors were deployed in the wetland and sampling density was 15 per ten thousand km².Based on the sampling principles,28 samples were collected respectively on rainfall and rainless season,and preservatives were added to the samples according to the detection content.32 monitors in Chagan Lake and 22 monitors in Yueliang Lake were set up to collect surface sedimentation. On rainfall and rainless season,44 samples of water products,fish and mussel,which are mostly consumed by local residents,were collected.12 sheep(each grassland type 3 sheep) were selected in the western part of Jilin province,blood,heart,liver,kidney and muscles were tested.The sampling time,lacation and number of forage grass were in accodence with sheep.Detection methods:pH value was measured by acidometer.Dissolved oxygen was detected by iodometry.Chemical oxygen demand was detected by permanganate titration.TDS was measured by weight calculation.FCG and TCG were measured by multitude fermentation according to the guidelines of drinking water sanitation(2001). The detection of Ca²⁺,Mg²⁺,Cl^-,SO₄^2-,HCO₃^-,and CO₃^2- was performed by titration. The measurement of K⁺,Na⁺ and Tfe was done by atomic absorption spectrophotometer.The total nitrogen and phosphate was measured by spectro photometer.The detection of Cu,Zn,As,Pb,Mn,Cr,Hg,Se,B,Th,U,Ni,Co was done by plasma mass spectrograph.The measurement of Ce,Dy,Er,Eu,Gd,Ho,La, Lu,Nd,Pr,Sm,Tb,Tm,Y,and Yb was conducted by plasma mass spectrometry ICP-MS and evaluation was done according to related standards.Sampling location map was drawn by MAPGIS 6.7 software.Other maps were drawn by Microcal Origin 6.0 software.Excel was used to set up database and SPSS 13.0 and SAS.9.0.were utilized to do statistics analysis.Measurement data was expressed as(?)±s for central tendency,pairing data comparison was done by pairing t test or pairing rank sum test;two-sample comparison was done by t test or rank sum test;multiple sample comparison was conducted by variance analysis or rank sum test;water products analyses were done by generalized linear model.The evaluation of air environment was done by major component analysis and enriching factor,the quality of surface water was evaluated by comprehensive assessment and fuzzy mathematics,the quality of surface sedimentation was evaluated by index of geo-accumulation and potential ecological index.The migration of heavy metal in lake,surface sedimentation,and water products was expressed by concentration factors.Results:1.The element of Al,Ca,Fe,K,Mg,Na,N,C had higher yearly deposition flux, all elements exist as solid status in atmospheric deposition.The air quality of the western part of Jilin province was mainly affected by natural source or sandy soil, dusts from weathering,and secondly by artificial pollution.2.In the western part of Jilin province,the water quality in surface water except Dabusu lake was fairly good,the average content of metals,microelements and rare earth elements was low,there was no significant difference in water quality between rainfall and rainless season,the water quality is compliance with standardsâ…¢based on the comprehensive evaluation and fuzzy mathematics.Sodium ion dominates the cations in most lakes,HCO₃^- anions.Fluoride content except Yueliang Lake in the lakes exceeds the standard;arsenic content in some lakes is also above the standard; pH value is slightly basic;eutrophication occurs in most lakes.Based on the fishery water standards and agricultural irrigation water standards,the water quality of Chagan Lake,Yueliang Lake and Longzhao is compliance with the standards,but water quality of Xianghai and Niuxintaobao produces potential hazards to fishery breeding and agricultural irrigation.The water quality of Dabusu Lake is terribly bad with severe salination,water eutrophication;the content of fluoride,arsenic and selenium is above the standard,inadequate for the demands of fishery and agricultural irrigation.3.The detection results of surface sediments in Chagan and Yueliang Lake showed that there were more Ca,Cl,Mg,Hg,Cd,less K,U,Al,Co,Na and organic carbon compared with elements in the soil of western part of Jilin province.The content of Al₂O₃ correlates positively with the level of MgO,Fe₂O₃,CaO,As,Hg,Cr, U,Cu,Zn,Cd,Se,Co,Ni,Th,Mn,N,PA which mainly come from rock or soil weathering and stored in the surface sedimentation as clay mineral and sulfide.There are more Hg,Pb,Ca,N,and less As,Co,Mn,Th,Cl,and Na in the surface sedimentation of Yueliang Lake.In the surface sediments,the level of As,Hg,U,Cd, Cu,Zn,Cr,Se,Mo,Co,Ni,Mn,N,P,MgO,Fe₂O₃,CaO and organic carbon correlates positively with the content of Al₂O₃ significantly,their geochemical action is significantly restricted by clay mineral content.Based on the ecological hazard index,the potential ecological hazard coefficient of heavy metals in Chagan and Yueliang lake was less than 40,potential ecological risk index less than 150,which showed that the potential ecological hazard in the above two lakes produced by heavy metals were slight.Based on the geological index,Igeo of all heavy metals ranges between 0 and 1,which demonstrated that the pollution extent in the research area was slight.The conclusion come from the two evaluation methods is identical.4.The fish in Chagan and Yueliang Lake abounds in protein,several kinds of macro elements and microelements,contains enough water and fat.The content of elements except Se,Zn,and Cr in some samples is compliance with national standards. Several factors such as sampling time,the food habit and active area of fish produce effects on the content of elements in fish.The concentration factors of heavy metals from the water in fish of Chagan and Yueliang Lake average at 2-5 order of magnitude. Mercury has the highest accumulating ability in fish;its accumulating factor is more than 2000,belonging to the highest accumulating element,Zn medium high accumulating element.The accumulating index of Cu in Yueliang Lake is more than 1000,belonging to medium accumulating element,but in Chagan Lake,low accumulating element.Pb and As belong to low accumulating element,the concentration of heavy metals in fish was determined by the content of heavy metals in the water.5.The small-fat-tail sheep abounds in protein and minerals contain sufficient nutrients.The content of cadmium,arsenic and mercury etc is compliance with national requirements of Safety requirements for non-environmental pollution meat and other animal products,but lead above the standard.There was no significant difference in general nutrients and heavy metals content,minerals contents except K, Mg,Fe,Ni,Co,Mo and Cr among the meat among four different grassland types.The distribution of elements is not equal,liver manifest selective accumulation for copper, zinc,manganese,kidney for selenium,cadmium.6.Evaluation on the quality of sheep grass in the western part of Jilin province: The test of grass samples showed that the content of macro elements in the grass from four different grassland types is above the standards which the NRC recommends. There is no significant difference in microelements of grass among four different grassland types except manganese,but the content of Cu,Se,and Zn in the grass is below the demands of ruminant.The detected value of lead,cadmium and arsenic etc is compliance with GB13078-2001,which suggests that the grass was not polluted by heavy metals.There was no correlation in elements content between sheep tissue and grass.Conclusions:1.Macro elements in air in the western part of Jilin province had relatively higher yearly deposition flux.Elements exists as solid in the atmospheric deposition. The dust mainly come from natural source or sandy soil,rock weathering is the primary factor of air quality,secondary human activities.2.The average content of metal elements,microelements and rare earth element is low,there is no significant difference in detection index between rainfall and rainless season,and the overall quality is compliance with typeâ…¢water standards. Eutrophication occurred in the detected lakes,the content of fluoride and arsenic in individual lake is above national standard,water quality monitoring should be enhanced.The hazard produced by the heavy metals in surface sedimentation of Chagan and Yueliang Lake was slight.The heavy metal accumulation in fish was determined by the heavy metal concentration in the water.3.The small-fat-tail sheep abounds in protein and minerals,and contain sufficient nutrients.The content of macro elements in grass from four types of different grassland is above NRC recommends,but the content of Cu,Se and Zn is below the demands of ruminants.There is no correlation in the content of elements between sheep tissue and grass.New ideas:1.The present research involves the investigative and studying methods from multisubjects,such as hygienic toxicology,environmental hygiene,nutrition and food science and geochemistry;it is a result of cooperation and fusion of different subjects.2.It is the first time that the samples of atmospheric deposition,surface water in wetland and lakes,surface sediments of lakes,water products were taken and tested in the western part of Jilin province to learn the current status of ecology in deposition flux and wetland,the source,migration of beneficial and toxic elements in water, sediment and animal systems,and their effects on water products.The present research is of comprehension,systems and three dimensions.3.Samples of,atmospheric deposition,sediment,water,water products,grass, animals etc were taken at the scene and tested by many advanced apparatus such as ICP-MS.The migration and transformation regularities of several elements in animals and water,as well as their ecological effects were evaluated through combination of linear and non-linear statistics.The present research is a good demonstration of combining field investigation with laboratory test.4.Many comprehensive evaluative methods,such as principal component analysis,Enrichment factor methods,comprehensive assessment methods,fuzzy mathematics,geological accumulating index,potential ecological index etc were applied in the present study to do the preliminary evaluation on the wetland ecosystem in the western part of Jilin province,which overcomes the limits of single evaluation method.