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2010 Vol.27(11)

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Effect of summer grazing intensity on GHG emission in the North Tibet steppe
2010, 4(11): 1-6.
[Abstract](1503) [PDF 665KB](765)
A grazing intensity experiment was conducted to investigate the effect of summer grazing intensity on GHG emission in the North Tibet steppe dominated by Stipa purpurea through measuring CO2, CH4 and N2O emission with static chamber method. This study indicated that CO2 emission from the S.purpurea steppe increased with the increase of grazing intensity when the grazing intensity was moderate, and it decreased when the grazing density was heavy grazing density. The increase of grazing intensity significantly decreased the absorption of S.purpurea steppe for CH4 (P0.05), but it did not affect the steppe function as a sink of CH4. Lightly grazing intensity had no significant effect on N2O emission of the S.purpurea steppe. However, N2O emission significantly increased when the grazing density was over middle grazing density (P0.05). In this study, the global warming potential (GWP) was used to estimate the total GHG emissions of alpine steppe, the CO2 emissions accounted for nearly 98% of the total emissions, and the CH4 absorption and N2O emission only accounted for 1%, respectively, and their amount was trade off.
The soil respiration characteristics of alfalfa pasture in Hailar regions
2010, 4(11): 7-12.
[Abstract](1663) [PDF 679KB](730)
A field survey was conducted to measure the soil respiration rate of alfalfa varieties pasture (Huanghua, Longmu801, Zahua and Zhaodong) by using Li6400 and to measure root morphology, soil temperature, air temperature and soil water content. The results of this study showed that Huanghua, Longmu801 and Zhaodong showed the maximum of soil respiration rate at 6:00 and the minimum of soil respiration rate at 14:00, 8:00 and 12:00, respectively. The maximum soil respiration rate of Zahua was found at 8:00, and the minimum of soil respiration rate of Zahua was found at 12:00. The soil respiration rate among 4 alfalfa pasture was ZhaodongHuanghua and ZahuaLongmu 801. Soil respiration rate was significantly liner positive correlation with the soil temperature and root system, and was one place quadratic correlation air temperature, and had negative correlation with soil water content.
Soil phosphorus fractions with different reclamation periods in the Tibet Autonomous Region, China
2010, 4(11): 13-20.
[Abstract](1800) [PDF 753KB](659)
Soils with different reclamation period were collected from Jiangzi Counties of Shigatse region and Qiongjie Counties of Shannan region in the Tibet Autonomous Region, China. Soil phosphorus forms with different reclamation periods and rangeland were analyzed by the method of Hedley revised by Tiessen. The results of this study showed that the inorganic phosphorus fractions ranked in the following order: Dil.HClPi>Conc.HClPi>NaOHPi>NaHCO3Pi>H2OPi. Inorganic phosphorus fractions increased with the land reclamation years, in which Dil.HClPi and Conc.HCl`Pi had maximum increase. The rangeland with a small inorganic phosphorus pool in the Qiongjie County had a bigger organic phosphorus bank than when compared to the farmland. Organic phosphorus fractionation decreased when reclamation period was below 50 years, whereas increased when reclamation period was over 50 years.
Effects of growth years of alfalfa on the enzyme activity and nutrient in soil
2010, 4(11): 21-25.
[Abstract](1683) [PDF 491KB](704)
An experiment was conducted to investigate the effects of growth years of alfalfa on the enzyme activity and nutrient in soil for proposing that soil enzyme activity could be considered as one of the most important indexes to indicate soil fertility. The results of this study showed that the enzymes activity of nutrients in soil every soil layers with different growing years was significantly higher or lower than that of control (P0.05). The enzymes activity of urease, catalase and peroxidase were correlated with soil fertilities, implying that the activities of enzymes could be used to indicate the changes of soil fertility and sensitiveness of soil biology. The activity of polyphenol oxidase was not strongly correlated with soil nutrients.
Effect of drought stress on the percentage of the withered leaves and physiological indexes of four ornamental grasses
2010, 4(11): 26-32.
[Abstract](1989) [PDF 672KB](734)
The experiment was conducted to determine the response of the morphological and physiological parameters of four ornamental grass species [Janpanese blood grass (Imperata cylindrical), Variegated miscanthus (Miscanthus sinensis), Finesterm Needlegrass (Stipa tenuissima), Evergold Sedge (Carex oshimensis)]to drought stress by measuring the percentage of withered leaves, leaf relative water content, leaf relative electrolytic leakage, MDA content, SOD activity, contents of proline and chlorophyll. The results of this study showed that leaf relative electrolytic leakage, contents of MDA and proline of the four species increased continuously with the prolonging of drought stress, and they were an obviously positive correlation with the percentage of withered leaves. The content of leaf relative water and chlorophyll of the four species decreased continuously and showed an obviously negative correlation with the percentage of withered leaves. Combining the morphological and physiological parameters, The drought tolerance of four species was in order: Evergold SedgeFinesterm NeedlegrassVariegated miscanthusJanpanese blood grass.
Seed coating formulations and its effects on controlling Pythium diseases of Poa pratensis
Xiao-Jun WANG
2010, 4(11): 33-36.
[Abstract](1612) [PDF 466KB](805)
Based on Pythium diseases caused by the soil borne and seed borne pathogens, an experiment was conducted to develop a seed coating formulations to control Pythium diseases in Poa pratensis at the seedling stage of turf grasses by combing hymexazol, metalaxy and plant growth regulator in Heilongjiang province. This study indicated that the seed coating formulations of drug type and special fertilizer compound type specialized for turf was safe and harmless to the turf grass. These two seed coating formulations not only reduced the incidence of Pythium diseases by 80%97%, but also encouraged the turf grass growth. Seed coating of hymexazol+thiram and hymexazol+thiram+root stimulate increased plant height with 1.632.73 cm, root length with 1.52.5 cm, root weight with 1.541.81 g, tiller with 1.332.00 number.
Assessment model on risk degree of snow disaster and its risk division in Qinghai Plateau
2010, 4(11): 37-42.
[Abstract](1490) [PDF 570KB](818)
Based on the theories and methods of natural disaster risk assessment, assessment model on risk degree of snow disaster for Qinghai Province was established in this study. The meteorological, economic and livestocks factors relating to the snow disaster were selected and their distribution maps were mapped by ArcGIS spatial analysis function, and then using geographic statistical functions of ArcGIS made the snowstorm risk zoning map of Qinghai Province. Present study showed that high risk areas of the snowstorm were mainly distributed in the south region of Qinghai Province, in which Gande, Jiuzhi, Chengduo, Dari and some regions of Yushu and Zeku County were the highest; the low risk areas of snowstorm were mainly distributed in Qaidam Basin and the eastern agricultural areas, in which Mangya, Xunhua, Ledu, Pingan, Jianza were the lowest; the others were in the different partition regions of risk from high to low level.
An application study of the open source spatial information technology in grasslandTaking the topographical map processing by using GRASS GIS as an example
2010, 4(11): 43-52.
[Abstract](1351) [PDF 637KB](687)
GRASS (Geographic Resources Analysis Support System) GIS, a open source spatial information software, was applied in processing the raster data of topographical map in this paper in order to introduce the basic knowledge regarding GRASS GIS and mainly introduced contents were data import, location and coordinate system parameter setting, raster data rectify, data project, data cut and data export. It was proved that the software was proper to process the raster data regarding grassland.
Investigation of grassland resource in Subei County,Gansu
2010, 4(11): 53-65.
[Abstract](1653) [PDF 1297KB](760)
Investigation of grassland resources in Subei County was carried out by the combination of 3S technique, fixedsampling site and route survey. The grassland types, area, distribution and species composition were investigated, and the grassland coverage, height and production were measured. The result showed that: 1)There was 5 181 889 hm2 grassland in Subei County, which was classified into 9 classes embracing 17 subclasses, 29 types of 19 forms; 2)The forage yield of different grassland was 5 093 kg/hm2 in meadow,3 094 kg/hm2 in temperate steppedesert,2 561 kg/hm2 in alpine meadow,1 933 kg/hm2 in alpine shrubmeadow,1 822 kg/hm2 in alpine desert, 1 665 kg/hm2 in temperate desertsteppe,1 183 kg/hm2 in temperate desert,1 143 kg/hm2 in alpine steppe, and 760 kg/hm2 in temperate steppe,respectively; 3)The total yield of fresh froage in Subei was 88 609.171 t/a (30 476.385 t/a as winddried forage), and the theoretic grazing capacity in the grassland should be 1.354 2 million sheepunits; and the livestock in Subei County was 0.407 5 million sheepunits; 4)Plant resources in Subei County were very abundant, 210 plant species (belonged to 129 genera of 42 families)were distributed in the Qilian Mountains region in the southern party of Subei County, in which 185 species were the medium quality forage,25 species was the good quality forage;86 plant species (belonged to 54 genera of 23 families) were distributed in Mazongshan Mountains region, in which 70 speices were the good quality forage.
Study on the soil microbial diversity of different forest types in Xiaolong Mountain
2010, 4(11): 66-70.
[Abstract](1788) [PDF 618KB](827)
The soil samples from 3 types of forest communities (Larix kaempferi, Pinus armandi and mixed forest) in Xiaolong Mountain of Gansu Province were collected to study the microbial abundance, evenness and diversity by plating method. The results showed that the soil microbial flora was greatly impacted by the forest type;and the mildew number in soil of L. kaempferi community was 1.86 times of P. armandi, but the numbers of bacteria, actinomycetes and yeast was 18.6%,18.4% and 15.0% of that in P.armandi community; the evenness of mildew community in soil of P. armandii community was poorer than that of L. kaempferi; L. kaempfer could promote the mildew number,but restrain the growth of bacteria, actinomycetes and yeast, and then affect the abundance of soil microorganisms.
Adaptation of forage plants to saliferous soil and improvement of these forage plants for saliferous soil in the irrigation region of upper reaches of the Tarim River
2010, 4(11): 71-76.
[Abstract](1458) [PDF 675KB](662)
The agricultural production usually relies on the irrigation systems in the southern part of Xinjiang. The longterm irrigation results in the seriously secondary salinization of land in the Shajingzi region, affecting the agricultural economic development. The traditional method of washing alkali and salt is effective, but it consumes a lot of water and easily causes the accumulation of soil salinity. The soil salinity content becomes very high when washing alkali and salt is unavailable, resulting in difficulty to restore vegetation cover, and further becoming the resource of sand storm. In this study, the tolerance salt grasses(Agropyron elongatum and Puccinellia tenuiflora)were selected to control stalinization by absorbing soil salinity and improving the soil structure. The results of this study showed that planting A.elongatum and P.tenuiflora in the salinealkali land reduced the soil salinity content in 060 cm layer, lowered the water table, increased the vegetation cover, and harvested the herbage biomass. This study suggested that planting tolerance salt grasses was an effective way to promote the ecological restoration and reconstruction in the oasis regions.
Improved chilling resistance of Stylosanthes guianensis by combining salicylic acidwith sodium nitroprusside treatments
2010, 4(11): 77-81.
[Abstract](2621) [PDF 549KB](740)
To explore the effects of exogenous salicylic acid (SA) and nitric oxide (NO) treatment on chilling resistance of Stylosanthes guianensis, 35~40 oldday seedlings were employed as experimental materials. Results indicated that separated treatment of SA or NO donor sodium nitroprusside (SNP) could improve activities of antioxidant enzymes of superoxide dismutase (SOD) and catalase (CAT), and contents of total soluble sugar, proline and relative water, and decrease relative electric leakage and malondialdehyde (MDA) content in leaves, thus alleviating negative injuries of chilling stress. Furthermore, combining SA with NO donor sodium nitroprusside treatments could improve the resistance to chilling stress much more than SA or NO treatment separately. It was suggested that both SA and NO are involved in signal transduction for controlling resistance to chilling stress.
Comprehensive evaluation of drought resistance of 39 Bromus inermis germplasms at the seedling stage
2010, 4(11): 82-88.
[Abstract](1588) [PDF 563KB](727)
In the greenhouse, A trial was conducted to comprehensively evaluate the drought resistance of 39 Bromus inermis germplasms introduced from abroad at the seedling stage by measuring the average survival rate, plant height, number of green leaves, aboveground biomass, underground biomass, root/shoot ratio. The results of this study showed that 39 B. inermis germplasms were classified into three groups with the different drought resistance, in which 16 germplasms were stronger and medium drought resistance, respectively, and 7 germplasms were weaker drought resistance. The membership function method was used to calculate the weight value of average survival rate, plant height, number of green leaves, aboveground biomass, underground biomass, and root/shoot ratio for each B.inermis germplasm, and then calculated the comprehensive evaluation value (D). The comprehensive evaluation value (D) suggested that ZXY05P0854 was the strongest drought resistant germplsm at seeding stage and ZXY05P1135 was the weakest at seeding stage.
Responses of two leguminous forage to drought stress and their drought resistance
2010, 4(11): 89-94.
[Abstract](1876) [PDF 662KB](840)
The pot experiment was carried out to compare the drought resistance between Onobrychis viciaefolia and Coronilla varia by measuring their physiological characteristics of under the different drought stress. This study indicated that the increase of soil drought conditions resulted in the increase of the water saturation deficit in leaf, proline content, soluble sugar content, MDA content, superoxide anion free radical content as well as the activities of SOD, CAT and APX of O.viciaefolia and C.varia. Among each treatment, the leaf water saturation deficit and superoxide anion free radical content in C.varia were significantly higher than that in O.viciaefolia, and the proline content and CAT activity in O.viciaefolia were significantly higher than that in C.varia, but the soluble sugar content and MDA content were not significant differences between O.viciaefolia and C.varia. Obvious difference in the SOD activity between O.viciaefolia and C.varia were only found in the control treatment, meanwhile the APX activities of O.viciaefolia and C.varia were significantly different between the control treatment and the severe drought treatment. The comprehensive estimation for drought resistance showed that drought resistance of O.viciaefolia was better than that of C.varia.
Effects of soil moisture on growth and photosynthesis of Euonymus japonicus
2010, 4(11): 95-100.
[Abstract](1680) [PDF 682KB](761)
A pot experiment was conducted to determine the effect of 4 soil moisture gradients (HS, heavydrought stress; MS, middledrought stress; LS, lightdrought stress; CK, control) on increment, leaf shape and dropping, and photosynthesis of Euonymus japonicus. The results of this study showed that MS and HS significantly reduced the increment (P<0.01), and significantly encouraged the leaves to drop (P<0.01) , implying that MS and HS decreased the ornamental quality of E.japonicus. MS and HS also enabled the leaf area to become smaller and changed the leaves from long strip shape to ovate shape as in order: HSMSLSCK (P0.01). The response of photosynthetic rate, transpiration rate, water use efficiency, and light energy efficiency of E.japonicus to soil drought stress showed a similar trendy, indicating that drought stress significantly affect these index. This study suggested that reducing irrigation in the garden greening management is an effectively way to controlling E.japonicus growth and exerting its ornamental quality, which would benefit water saving and pruning.
Yield and quality of mixedsowing pasture of Avena sativa and Pisum sativum
2010, 4(11): 101-108.
[Abstract](1761) [PDF 819KB](711)
An experiment was conducted to determine the yield and quality of mixedsowing pasture of Avena sativa and Pisum sativum for increasing the winter forage, making full use of cropland, and improving soil fertility. The results of this study showed that two seeding rates (195 kg/hm2 A. sativa + 42 kg/hm2 P.sativum; 150 kg/hm2 A.sativa + 60 kg/hm2 P.sativum) were the best, and their yields were 7 246.44 kg/hm2 and 7 133.91 kg/hm2 on 10 September and their crude protein yields were 624.64 kg/hm2 and 670.6 kg/hm2. The best cutting time for A.sativa was the beginning flowering and filling stage. A.sativa grew fast and became a dominant position due to higher height.
The regulation mechanism of the fall dormancy in alfalfa
2010, 4(11): 109-114.
[Abstract](1521) [PDF 529KB](784)
Fall dormancy is a kind of growth characteristics of alfalfa as a special dormancy way to response the environmental changes, and it is not only related to day length and photoperiod, but is related to circadian clock, light, temperature and the relevant genes. The latest studies have indicated that the dormancy phenomenon has been affected by a variety of plant hormones,phytochrome and genes regulation. The hormones and phytochrome of alfalfa plays an important role in the regulation of fall dormancy. The relationship between the fall dormancy, the photoperiod and hormones, phytochrome were reviewed, and the dormancy regulation mechanism was discussed in this paper.
Application of molecular markers in population genetics
2010, 4(11): 115-120.
[Abstract](1370) [PDF 640KB](723)
Construction of molecular markers is a necessary means in the differences of population genetics. Molecular markers technology has greatly developed in the last years. A special problem about genetic difference is determined by selecting the reasonable population to reduce bias as far as possible, choosing the proper genetics markers and evaluating and explaining the results. This paper briefed the application of molecular markers in population genetics and proposed that processing the genetic data using computer programs and internet information was key points in the molecular markers, which would provide accurate data.
Role of animal production in pastoral agritulture ecosystem
2010, 4(11): 121-126.
[Abstract](1608) [PDF 643KB](791)
The animal production is one of original components, core productivities and identifying factors in inpastoral agriculture ecosystem, which is one of criteria of agricultural modernization as well. As a coupling system with multicomponent and multiway, animal production system owns multifunction and is a kind of sustainable ecoagriculture system with the controllable resources cycle. Role of animal production in pastoral agricultural system gradually goes forward with devolvement of pratacultural science, advancement of animal production and social demands, which multifunctionality increases, intensification of technology and management rises and system coupling is strengthened. In spite of that way of system coupling is becoming single, animal production is playing more important rolel role for farmers, regions, countries and human beings.
Effect of botanical fluorine on several serum antioxidase of sheep
2010, 4(11): 127-130.
[Abstract](1449) [PDF 521KB](652)
An experiment was conducted to investigate the effect of botanical fluorine from Potamogoton pectinatus on antoxidation system and production performance of Mongolian sheep. Botanical fluorine with 0、50、100、150 mg/kg in daily ration was used to feed the Mongolian sheep for 5 months, and weight gain and serum antioxidase of Mongolian sheep was measured at the 15 days. This study indicated that Mongolian sheep was not found to be fluorosis toxicosis. The weight gain, serum superoxide dismutases, glutathione peroxidase, serum total antioxidant capacity were not different between Mongolian sheep fed with P.pectinatus and Mongolian sheep fed with Sorghum hybrid Sudangrass. This study suggested that P.pectinatus did not affect the production performance of Mongolian sheep.
Changeable characteristics of three soil microbial groups underdifferent grazing intensities in Loess Plateau
2010, 4(11): 131-136.
[Abstract](1629) [PDF 598KB](625)
An experiment was conducted to investigate the Changeable characteristics of three soil microbial groups at four grazing intensities (0,2.7,5.3 and 8.7 sheep/hm2) in Loess Plateau. The results of this study indicated that the quantities of microbial gradually reduced from 010 cm layer, 020 cm layer, to 2030 cm layer at each grazing intensities. Total number of microorganism was different under different grazing intensities in the same depth layer, indicating that the number was higher at no grazing and moderate grazing intensity, and the number was the highest at overgrazing in Loess Plateau. The quantities of microbial group was not different among grazing intensities, indicating that the highest number of fungi and bacteria were founded in September and the highest number of actinomycete were founded in November.
In vitro dry matter digestibility of mixtures of rice straw and several feeds
2010, 4(11): 137-144.
[Abstract](1580) [PDF 696KB](730)
In vitro dry matter digestibility(IVDMD) was used to estimate the quality of Rumex patientia (RP), Astragalus sinicus (AS), Sorghum hybrid Sudangrass (SHS), S.sudanense (SS), Pennisetum purputeum cv.mott (PPM), Medicago sativa (MS), cassoa hay (CH), rice hay (RS), ammoniated rice hay (ARS) and cassava residues(%,DM), and IVDMD was in order: CR(77.6)RP(61.32)MS(55.26)AS(54.91)MS(52.97)SHS(40.24)PPM(38.70)ARS(36.88)SS(34.15)RS(26.63). Except for AS and MS, IVDMD was significant difference (P0.05) among other feeds. Associative effectiveness (AE) was defined as the difference between the measured IVDMD of mixtures and the weight sum of the individual feeds. Six mixtures (60%RS+10%CR+30X1, X1 was RP,AS,SHS,SS,PPM,MS,CH and ARS; 60%ARS+0.1%CR+0.3%X2, X2 was RP,AS,SHS,SS,PPM,MS and CH; 60%ARS+20%SS+20%X3,X3 was RP,AS,SHS,SS,PPM,MS and CH; 50%ARS+20%SS+30%X4,X4 was the same as X3; 60%RS+20%SS+20%X5,X5 was RP,AS,SHS,PPM,MS,CH,ARS and CR; 50%RS+20%SS+30%X6, X6 was the same as X5) were used to measure the associative effect AE. Positive AE were observed for all mixtures (P0.05) and addition of MS was the best. CH was a good supplement because its effectiveness was better than grasses and early equaled to legumes. Supplement for RS was better than that for ARS.
Effects of different temperatures on rot pattern and quality of alfalfa bales
2010, 4(11): 145-150.
[Abstract](2216) [PDF 697KB](1974)
The impact of storage temperatures (25, 30 and 35 ℃) on the rot patterns and quality of alfalfa quality was studied with stimulated temperature conditions through singlefactor experimental design. The samples were placed in automatic temperature controlled room for 16 days and the samples were taken within 1, 3, 5, 7, 9, 11, 13 and 15 days respectively. The results showed that the number of mildew increased along with the storage temperature and time. The crude protein content was significantly different among treatments and storage times (P0.05) and it was the highest under 30 ℃. The number of mildew was negatively correlated with the crude protein content. Storage temperature did not significantly affect the fiber content (P0.05).
Differentiation in households production in the view of sustainable development evaluation
2010, 4(11): 151-158.
[Abstract](1481) [PDF 829KB](815)
Vast grassland degradation enables professionals and governments to pay attention to the merit and demerit of households production as the basic unit of livestock production and environmental protection; therefore, it is essential to assess the merit and demerit of household in the view of sustainable development. In this study, an index system was established to comprehensively estimate the ability of sustainable development of household for sighting into the features of household and the differences in management characteristics of the household. The established index system included 3 layers, consisting of 1 decision layer, 3 criterion layers and 16 indicators, and ability of sustainable development of 30 households were estimated by using established index system in Bayan Sil, Inner Mongolia. This study indicated that the established framework performed well, corresponding to actual household life. A conclusion was drew that management decisions resulted in differences of productive income and living standards, which further became the key drive affecting the ability of sustainable development of household. This study proposed that the structure of food consumption, productive investment, possession of grassland resources, and return on investment, life consumption, the per capita net income and capital accumulation were main index to estimate the differences of households. The results of this study suggested that strengthening and optimizing production management was an important way to promoting sustainable development of household.
Reformation of grassland use rights in agropastoral zoneA case study in Mayinggou Village, Yongchang County, Gansu
2010, 4(11): 159-165.
[Abstract](1616) [PDF 823KB](729)
The degraded grassland areas in agropastoral area of northern China have accounted for 50 percent of the total grassland area in China. Due to more human population and small grassland area, the householder contract responsibility system (HCRS) is difficult to conduct in the agropastoral areas, resulting in livestock overgrazing in the public grassland and further degradation. A Participatory Rural Appraisal was conducted to collect data and information from 15 householders for determining the changes of livestock number, grassland productivity, production pattern and income between early HCRS and current HCRS in the Mayinggou village, Yongchang County, Gansu Province. The result of this study showed that the overgrazing rate on the grassland decreased by 74.27% after the implementation of HCRS, The farmers changed their concept on grassland management and improved the livestock production pattern, resulting in high income. This study suggested that reformation of grassland use rights would provide a good example and experiences for grassland management in agropastoral area in China.
Summary of rangelands monitoring in Australia
2010, 4(11): 166-170.
[Abstract](1451) [PDF 639KB](854)
Grassland monitoring is a basic part of grassland protection and construction. Attaining dynamic data about grassland resources and ecological conditions by longterm observation benefit sustainable management, ecological reconstruction and decision making. Development of grassland monitoring system and its main content in Australia are introduced in this paper, and major characteristics of grassland monitoring such as stable mechanism of input, rich content and attaching great importance to construction of longterm monitoring fixed site are also analyzed which are worth learning.
Poisonous weed species and their harmfulness in the grassland of
2010, 4(11): 171-173.
[Abstract](3533) [PDF 402KB](876)
The general and random survey was conducted to identify the poisonous weed species during 2003 to 2009 in the native grassland of Yili regions, Xinjiang province. The survey results showed that there were 104 species of poisonous weeds belonging to 12 families, and these poisonous weeds covered 7.3105 hm2, and distributing the whole grassland of YiLi valley. The serious poisonous weeds were Aconitum leucostomum, A.soongoricun, Ligularia narynensis, Stellera chamaejasme, Leonurus heterophyllus, Sophora alopecuroides, Stipa capillata, Geum aleppicum, Eupborbia sp., Cirsium japonicum and Peganum harmalal. The dominant species are A. leucostamum,A.soongoricum and L.narynensis. The dominant plants were A.leucostamum, A.soongoricum and L.narynensis. The number of L.narynensis in the 100 m2 plot was 210 plants in 2003, 1 045 plants in 2006 and 2 347 plants in 2008, and that of A.leucostamum was 48 plants in 2003, 288 plants in 2006, 366 plants in 2008. This study implied that grassland areas of poisonous weed invasion increased quickly and covered the whole Yili valley, and these poisonous weeds germinated early, grew fast and had many reproductive and disperse ways, resulting in severe harmfulness to native grassland.