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Table of Content

    15 March 2003, Volume 14 Issue 3
    Effect of human activities on soil environment and plant species diversity of elm sparse woods
    YANG Limin, ZHOU Guangsheng, WANG Guohong, WANG Yuhui
    2003, (3):  321-325. 
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    Human activities have a major impact on the biodiversity of the earth, while biodiversity change is considered as an important global change in its own right. Elm sparse woods is a climax community distributed on the sandland in temperate steppe zone. Its habitat conditions are much more fragile, and are easily destroyed. Our studies on the effect of human activities on soil environment and plant diversity showed that the main soil environmental factors and plant species diversity had some obvious changes, of which, the changes of man made pine woods and heavy grazing disturbance were the largest, and the of man made poplar woods were the in those next place. It is suggested that natural laws and consistency of ecosystem processes in the low and long temporal scale should be considered adequately in the environment management of sandland.
    Effect of low nocturnal temperature stress on fluorescence characteristics and active oxygen metabolism in leaves of Garcinia hanburyi seedlings grown under two levels of irradiance
    CAI Zhiquan, CAO Kunfang, FENG Yulong, FENG Zhili
    2003, (3):  326-330. 
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    The fluorescence characteristics and active oxygen metabolism in leaves in Garcinia hanburyi seedlings grown under two irradiance levels (50% and 8% of full natural sunlight) and nocturnal low temperature (4 ℃) were studied in Xishuangbanna. The results showed that the photochemical efficiency of PSⅡ (Fv/Fm), the quantum yield of PSⅡ linear electron transport (ФPSⅡ) and non photochemical quenching (NPQ) were decreased, but the initial fluorescence yield (F0) were increased with prolonged stress time of low temperature in leaves of Garcinia hanburyi grown under the two different irradiance levels. After three days of recovery treatment, the Fv/Fm and F0 of Garcinia hanburyi grown under 50% natural irradiance were not recovered completely, while those of the seedlings grown in 8% natural irradiance were recovered almost completely, which indicated that the photosynthetic apparatus of Garcinia hanburyi grown under 50% irradiance was injured by photooxidation, but that of seedlings grown in 8% irradiance was only reversibly inactivated by the nocturnal low temperature stress. In the mean time, although the activities of protective enzymes (SOD,CAT, and APX) increased, the O2-. production rate and H2O2 content also increased with the duration of the stress. The MDA also accumulated in leaves of Garcinia hanburyi grown under two different irradiance levels. After three day's recovery, much less active oxygen was produced in leaves of Garcinia hanburyi grown under 8% than that under 50% irradiance. The implication of the results for practice were also discussed.
    Photosynthesis and free radical yield of Litchi chinensis leaves under increased CO2 partial pressure in atmosphere
    SUN Guchou, ZENG Xiaoping, ZHAO Ping, PENG Shaolin
    2003, (3):  331-335. 
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    .The maximum photosynthetic rate of litchi saplings leaves grown under a CO2 partial pressure of 77?5 Pa was 23% lower than that of 39.3 Pa, and slight decreases in respiration rate in light and CO2 compensation point excluding of respiration in light were observed. The maximum rates of carboxylation (Vcmax) and photosynthetic electron transport (Jmax) were decreased in saplings grown under 77?5 Pa CO2 partial pressure. It may suggest that there was a lower energy level of photosystem I(PSI) in the saplings leaves under 77?5 Pa CO2 partial pressure, and free radical yield decreased by 39% in the saplings under 77?5 Pa CO2, as comparied with that under atmospheric CO2. The percentage of infection by Peronophythora litchi increased from 1.8% under atmospheric CO2 to 9.5% under enriched CO2. It may mean that the decreasing photosynthetic and respiration metabolism would make it lower the production of O2-., and leaves were infected by P.litchi more easily. The controlling of the popularization of P.litchi for litchi plantation must be paid wide attention,as air CO2 partial pressure will increase continuously.
    Effects of light on morphological plasticity and biomass allocation of Momordica charantia
    TAO Jianping, ZHONG Zhangcheng
    2003, (3):  336-340. 
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    The growth dynamics, morphological characteristics and biomass allocation of climbing plant Momordica charantia were studied under shading. The results showed that the growth of Momordica charantia had a significant difference under different levels of shading. Under weak light, the plants decreased the chance to increase their modular numbers and accumulate biomass, and had fewer shoots, thinner laminas, longer and thinner petioles, and more slender stems. The plants showed a stronger morphological plasticity under weak light than under strong light, and had a stronger morphological plasticity at early growth stage than at later growth stage. The laminas and stem biomass allocation increased, while branch biomass allocation decreased with decreasing light illumination. Light intensity had little effect on biomass allocation to shoot stems. External support is not necessary for the growth of Momordica charantia under strong light.
    Ecological feedback significance of polyphenols in organic layer of forest soil
    ZHONG Zheke, WANG Renchao, JIANG Bo
    2003, (3):  341-344. 
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    By comparing polyphenols (total polyphenols and condensed tannin) and other chemical and biological properties in soil organic layers during the transformation and regeneration of pure mature spruce stand in middle Europe, the functions of polyphenols in forest ecosystem were approached. The results showed that polyphenols concentration had a significant positive correlation with effective cation exchange capacity (ECEC), but no relation with organic C. The net Nmineralization had no significant correlation with total polyphenols, organic Cand C/Nratio, but had a significant negative correlation with condensed tannin. Polyphenols concentration also positively correlated with 1 mol稬-1 KCl extractable Cand N. It is suggest that although the polyphenols have no obvious physiological function in tree metabolism, it should be paid attention to its ecological feedback significance in the whole ecosystem.
    Relationship between soil enzyme activities and trace element contents in Eucalyptus plantation soil
    LI Yuelin, PENG Shaolin, LI Zhihui, REN Hai, LI Zhi'an
    2003, (3):  345-348. 
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    Canonical correlation analysis on soil enzyme activities and trace element contents in Eucalyptus plantation soil showed that among the test elements, only Zn and Mn affected enzyme activity. Both Zn and Mn increased soil proteinase activity. Zn decreased the activities of soil urease and peroxidase, while Mn promoted them. "Integral soil enzyme factor" could be used as an index of soil fertility. Together with other growth factors, this index should be considered when evaluating soil fertility of Eucalyptus forest sites. It also had a definite significance on the division of Eucalyptus soil families.
    Effect of ecological organic fertilizer on tomato bacterial wilt and soil microbial diversities
    CAI Yanfei, LIAO Zongwen, ZHANG Jia′en, KONG Weidong, HE Chengxin
    2003, (3):  349-353. 
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    The effects of ecological organic fertilizer (EOF) on tomato bacterial wilt and soil microbial community were studied through field trial and fatty acid methyl esters (FAMEs) analysis. The results showed that the incidence rate of tomato bacterial wilt was 100% in continuous cropped soil, and significantly reduced to 39% and 50% when applying EOF at 1.0 kg穖-2 and 0.5 kg穖-2, respectively. There was no significant difference between two fertilization treatments. The fatty acid fingerprints of soil microbial community were greatly changed, and the relative contents of cyc17:0 cited as biomarker for GNbacteria, c18:2 w6 as biomarker for fungi and c16:111c as biomarker for arbuscular mycorrhizal (AM) fungi all increased when applying EOF. The minimum distance of cluster analysis was 1.08 between control and treatments of applying ecological organic fertilizer, and 0.70 between different fertilization treatments. Applying EOFcould adjust soil microbial community structure, benefit for soil beneficial microbes, and develop stability and disease suppression of soil ecological system, and hence, improve soil quality.
    Variation of CO2 concentration in solar greenhouse in Northern China
    WEI Min, XING Yuxian, WANG Xiufeng, MA Hong
    2003, (3):  354-358. 
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    The variation of CO2 concentration in winter spring cultivated solar greenhouse in northern China was studied. The diurnal change of CO2 concentration showed an irregular 'U' shape in most case, the maximum value appeared prior to unveiling straw mat in the morning, and the minimum between12:00 and 14:00 PM. Sometimes, an irregular 'W' shape curve with two valleys was also observed, with the first one appeared prior to the ventilation at noon, and the second occurred between15:00~16:30 PM. During the period of winter spring cultivation, the daily maximum concentration of CO2 in solar greenhouse decreased gradually, while the daily minimum concentration and daytime average concentration dropped first, then went up. At the same time, the time of CO2 depletion lasted longer and longer. In December, CO2 depletion happened 2.1~3.1 hours after morning unveiling. In the next March, however, it moved up to 0.6~1.1 hours after unveiling in the morning. At daytime, both during and after ventilation, solar greenhouse often showed CO2 depletion. The period of CO2 depletion extended from 4~5.8 hours per day in December to 8~8.5 hours per day in March of next year. The spacial distribution of CO2 concentrations within the greenhouse showed that in the morning and in the evening, the order was the front>the middle>the back, and the ground>the canopy>the upper, and at midday, the order was the front <the middle<the back, and the ground>the upper>the canopy. Photon flux density was the most important environmental factor affecting CO2 concentration in greenhouse. Ventilation did not avoided CO2 depletion. Canopy photosynthetic rate and soil respiratory rate were measured at different growth stages of tomato. At seedling stage, CO2 concentration in greenhouse was higher than that outside, due to the vigorous soil respiration and lower canopy photosynthetic rate. But at fruiting stage, severe CO2 depletion occurred because of stronger canopy photosynthesis and weak soil respiration.
    Numerical simulation of flow fields through porous windbreak in shrubby zone
    WANG Yuan, ZHOU Junli, XU Zhong
    2003, (3):  359-362. 
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    By treating the windbreak and shrub with the parameters in a equation, the flow fields through porous windbreak with and without shrub were calculated. The changes in relative wind velocity in horizontal direction, velocity profile and turbulent energy of the section were compared. It is concluded that shrub was very important in windbreak system, which could decrease the wind velocity in front of or some distance in the leeward of the windbreak. The calculated numerical results were compared with the data from wind tunnel experiment where the influence of shrub on flow field was analyzed.
    Dynamics of litter and under-ground biomass in Carex lasiocarpa wetland on Sanjiang Plain
    HE Chiquan
    2003, (3):  363-366. 
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    With net sack and coring methods, this paper analysed the seasonal dynamics of litter and under-ground biomass of Carex lasiocarpa population in Sanjiang Plain wetland. The standing litter showed exponential seasonal dynamics. The decomposition rate of litter was indicated by the rate of its weight loss, and the daily weight loss was gradually decreased from 0.7058 % to 0.2372 %. Carex lasiocarpa population produced 210.8876 g穖-2 litter in its vegetative season (from May 2, to October 10,1999), and its under ground biomass had an obvious vertical structure, like a converse pyramid or a parabola.
    CO2 flux characteristics from degenerated mat cryo-sod soil during plant growing period
    ZHOU Dangwei, CAO Guangmin, ZHANG Jinxia, ZHAO Xinquan, ZHOU Xingmin
    2003, (3):  367-371. 
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    The carbon dioxide (CO2) emission rate was studied in the degenerated mat cryo sod soil covered with alpine Kobresia humilis meadow at the Haibei alpine meadow ecosystem research station, with CID 301ps CO2 analytical instrument during plant growth period (May-Sep, in1998). The results showed that the CO2 emission rate had obvious daily variation and seasonal dynamics. The maximum rate of CO2 emission appeared at 12:00~14:00, and the minimum rate appeared at 6:00~8:00. The max daily amplitude was 462.49 mg·m-2·h-1,while the minimum daily amplitude was 114.97 mg·m-2·h-1 .The CO2 emission rate varied with phonological periods, and the order was exuberance>withering>green up. The maximum daily average value was 480.76 mg·m-2·h-1 (Aug.18th), and the minimum daily average value was 140.77 mg·m-2·h-1 (May.9th). Correlation analysis showed that there was a significant relationship between CO2 emission rate and air temperature, soil surface temperature and soil temperature in 5 cm, 10 cm, 15 cm, 20 cm,and 30 cm. Temperature was the dominant factor that affected the CO2 emission rate in degenerated mat cryo sod soil.
    Greenhouse gases emission or uptake in Inner Mongolia natural and free-grazing grasslands
    WANG Yuesi, XUE Min, HUANG Yao, LIU Guangren, WANG Mingxing, GI Baoming
    2003, (3):  372-376. 
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    GC-MS was used to measure the greenhouse emission of Inner Mongolia Grassland. The results showed that four kinds of typical semi-arid grasslands in Inner Mongolia had their own special seasonal patterns as the source of atmospheric N2O and CO2 emission and the sink of atmopsheric CH4,which were controlled by seasonal weather variation. Different soil and vegetation types and precipitation influenced the intensity of emission and upatake of the gases. Compared with natural grassland,free grazing decreased CH4 uptake and N2Oemission,but increased CO2 emission.
    Response of lettuce to different nitrogen forms
    TIAN Xiaohong, LI Shengxiu, WANG Zhaohui, YIN Xiangtao, CHEN Shixiang
    2003, (3):  377-381. 
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    Solution culture experiment was adopted to investigate the influence of different nitrogen forms on lettuce growth and development and their nitrogenous nutritional characteristics. The results showed that the affinity of the roots of lettuce seedlings to ammonium nitrogen (NH4+-N) was slightly higher than that to nitrate nitrogen (NO3--N). Among three treatments of NO3--N, NH4+-N+NO3--N and NH4+-N, the relative proportion of biological yields of lettuce was 100:56.9:12.4, and that of nitrogen uptake amount was 100:48.9:8.6, respectively. Nitrate nitrogen was the most suitable Nsource to lettuce growth. When the respective proportion of NH4+-N and NO3--N was 50%, the growth of lettuce was inhibited to some extent. When the nitrogen source supplied as solely NH4+-N, lettuce was hard to grow normally. When supplying the same amount of NH4+-N and NO3--N, lettuce showed a tendency to absorb more NH4+-N than NO3--N. At different culture stages, the ratio of NH4+-N to NO3--N absorbtion was less than1. It seemed that lettuce did prefer NH4+-N to NO3--N in absorbtion. However, ammonium nitrogen as nitrogen source was not suitable to lettuce for its metabolism. When nitrate nitrogen was not sufficient, it mainly affected the growth of lettuce shoot; when the ammonium nitrogen in nutrient solution was 50%, the root growth of lettuce seedlings was greatly inhibited, and some pathological symptoms appeared. Taking running water as water source (in which, NO3--N concentration was about 0.5 mol稬-1) and lettuce was cultured by supplying sole NO3--N for two weeks and then supplying NH4+-N, the growth of lettuce was greatly stimulated, in the meantime, the NO3--N contents and total accumulation amount greatly decreased. Supplying urea as Nsource, the growth rate of lettuce was apparently inferior to other nitrogen forms, but no pathological symptoms appeared.
    On hybrid embryo culture in vitro of Syringa L
    ZHOU Li, LUO Fengxia, DAI Limin
    2003, (3):  382-386. 
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    Syringa L. is the famous ornamental shrub in China, but its embryo always dies before seed mature during cross breeding, and hence, the breeding work is very difficult. The main object of this study is using embryo culture in vitro to get the seedling directly and to improve the succeed rate of cross breeding. The factors that influenced the embryo culture were researched in detail. The results showed that the optimal medium for embryo culture was Monnier, and the second was MSor LS, which meant that the embryo of Syringa needed abundant macro elements and microelements, especially Ca2+ and K+. The optimal sugar concentration was 50 g·L-1 . At this level, the sugar could offer enough nutrition and high osmotic pressure for embryo. When the embryo age was 50~60 days, the culture was easy to be succeed. At this time, the cotyledon in ovule began to form, or organ began to differentiation, so, the embryo was very easy to germinate, and the seedling was very easy to form. Proper coconut milk, glutamic acid or glutamine, and activated charcoal could improve the germination and growth of the embryo. When the BA of low concentration (0.01 mg·L-1) was joined in the medium, the germination rate could be improved. The best NAA concentration was 0.01 mg·L-1 .
    Effects of CO2 enrichment, nitrogen and water on photosynthesis, evapotranspiration and water use efficiency of spring wheat
    LI Fusheng, KANG Shaozhong, ZHANG Fucang
    2003, (3):  387-393. 
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    Spring wheat (Triticum aestivum L.) was treated with 2 atmospheric CO2 concentrations (350 and 700 μmol·mol-1), 2 levels of soil moisture (wet and drought), and 5 levels of nitrogen fertilizer (0,50,100,150,200 mg·kg-1 soil). The results showed that elevated atmospheric CO2 increased photosynthetic rate more in drought than in wet treatment. Photosynthetic rate increased with the increase of nitrogen fertilizer. Stomatal conductance decreased with CO2 enrichment, which was more in drought than in wet treatment. CO2 enrichment decreased more evapotranspiration in drought than in wet treatment. The decrease was more apparent with no fertilization. CO2 enrichment increased more leaf water use efficiency in drought than in wet treatment. Canopy WUEincreased with CO2 enrichment and Nfertilization. Thus, the increase in photosynthesis and the reduction in evapotranspiration due to elevated CO2 can ameliorate the negative effects of drought, and increase wheat resistance to water stress.
    A study on multicomponent bidirectional reflectance model for rice
    SHEN Guangrong, WANG Rencao
    2003, (3):  394-398. 
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    In this paper, the bidirectional reflectance factor (BRF) of rice measured in field experiment in1999 and 2000 was compared with the BRFcomputed from the rice multicomponent bidirectional reflectance model that based on the radiative transfer theory, rice canopy geometric structural factors and different characteristics of the different growth period for rice in detail. The contribution of some sensitive factors such as the average inclination angle of all components belonged to rice and LAIwas accurately specified. The results showedthat the rice multicomponent bidirectional reflectance model described above could basically simulate the angular distribution characteristic of reflectance spectrum of rice canopies, and the different peak point of the hotspot effect of rice canopies reached under different conditions. In addition, the regulation of the first order scattering reflectance by soil and water and the multiple scattering reflectance by foliage, stem, fringe and soil changing with the average inclination angle of all components, as well as the contribution of LAIto BRFwere analyzed. All of these laid a foundation to monitor rice growth and estimate its yield. Meanwhile, it also implied that some rice canopy parameters could be accurately estimated by the model through selecting the suitable image bands.
    Water use efficiency and rice yield under different water managements
    QIAN Xiaoqing, SHEN Qirong, XU Yong, WANG Juanjuan, SHEN Hui
    2003, (3):  399-404. 
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    Subtle plot experiment was conducted to study the growth and water use status of rice cultivated on waterlogged soil and upland soil mulched with plastic film, semi decomposed wheat straw and nothing in Nanjing Agricultural University. The results showed that 349 to 473 mm of water were required by rice cultivated on upland soil mulched with film, straw or nothing, and 732.5 mm of water was required on waterlogged soil. The water productive efficiencies for rice grain and biomass were between0.899 to 1.273, and 1.655 to 2.321 g穔g-1, respectively in upland cultivation, while 0.766 and 1.459 g穔g-1 in waterlogged cultivation. Rice cultivated on upland soil mulched with semi decomposed straw achieved 90% or more economic yield on waterlogged soil.
    Characterization of several synthetic and environmental microbial samples by quantitative hybridization
    HUANG Linan, CHEN Yueqin, ZHOU Hui, QU Lianghu
    2003, (3):  405-408. 
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    Limitations of traditional techniques based on selective enrichment and pure culture isolation make it difficult to precisely characterize the natural microbial ecosystems. Molecular techniques are now being developed and used to address these limitations. Group specific 16SrRNAs targeted oligonucleotide probes of different phylogenetic levels are increasingly used to identify and quantify the microbial members in complex environmental samples. Two domain specific probes were used in this study to elementarily characterize the defined mixtures of RNAs extracted from pure culture (synthetic samples) and a RNAsample obtained from landfill leachate (environmental sample). The results demonstrated that 16SrRNAquantitative hybridization provided an excellent estimation of domain level community composition of these samples, and thus, had a huge potential of usefulness in microbial ecology studies.
    Selectivity and tolerance of sea urchin (Hemicentrotus pulcherrimus) to environmental change
    YOU Kai, ZENG Xiaoqi, LIU Hui, ZHANG Xiumei, LIU Qun
    2003, (3):  409-412. 
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    An experimental ecological study of sea urchin (Hemicentrotus pulcherrimus) sampled from coastal waters of Qingdao was focused on the fundamental ecological factors such as temperature, salinity, light intensity and substratum. The results showed that the suitable ecological range of temperature was from 8 ℃ to 22 ℃, and the selectivity to temperature was changed with the previous living temperatures. Hemicentrotus pulcherrimus was a kind of stenohaline creature. Its optimum ecological range of salinity was from 30 to 35. The results also showed that Hemicentrotus pulcherrimus liked to select weak light environment (<50 lux), especially under non food condition. Hemicentrotus pulcherrimus had the positive substratum selectivity to coarse sand and the negative substratum selectivity to silver sand.
    Geostatistical analysis on spatial patterns of Didesmococcus koreanus Borchs and Chilocorus rubidus Hope
    HUANG Baohong, ZOU Yunding, BI Shoudong, ZHU Hongwei, GAO Zhengliang
    2003, (3):  413-417. 
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    The spatial pattern and correlation of Didesmococcus koreanus Borchs and Chilocorus rubidus Hope in different periods were investigated with geostatistics. The results showed that the semivariogram of Didesmococcus koreanus Borchs and Chilocorus rubidus Hope could be described by spherical model, indicating that their spatial pattern were in agreement. The spatial variation was arosed by its spatial autocorrelation in small scales, and the spatial pattern had no apparent changes in different periods. The range varied from 9.56~15.70 m and from 18.83~19.74 m, respectively. The amount and spatial distribution of Chilocorus rubidus Hope was closely related to that of Didesmococcus koreanus Borchs, which revealed that Chilocorus rubidus Hope was the dominant natural enemy of Didesmococcus koreanus Borchs.
    Relationships between plant reproductive strategy and disturbance
    LIU Zhimin, JIANG Deming, GAO Hongying, CHANG Xueli
    2003, (3):  418-422. 
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    Plant reproductive strategy in life history is related to plant adaptation or evolution, ecosystem degradation or restoration, and biodiversity conservation, which are the components of theoretic and applied ecological studies. In this article, several issues concerning the relationships between plant reproductive strategy in life history and disturbance, including Grime's classification of plant reproductive strategies, adaptations of plant vegetative reproduction to disturbances, adaptations of seed morphological traits to disturbance, roles of soil seed bank in disturbance adaptation, and dispersal and germination adaptation of diaspores to disturbance, were briefly reviewed. China's study on relationships between plant reproductive strategy in life history and disturbance in arid zone was also reviewed and discussed.
    Application of succession study in tending and restoration of evergreen broadleaved forest
    DING Shengyan, SONG Yongchang
    2003, (3):  423-426. 
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    The characteristics of synecology, population ecology and physio ecology of main tree species Quercus fabri, Pinus massoniana, Castanopsis sclerophylla, Lithocarpus glaber, Schima superba and C. fargesii of evergreen broadleaved forest in Tiantong National Forest Park, Zhejiang Province were studied by comparative method. The successional process was clarified through the comparative studies of the synecological characteristics of these main tree species, the individual plant structure and renewability were discussed by comparative study of population ecological characteristics of main trees' populations, and the mechanism of replacement with each other of these main tree species was open out by comparative study of physio ecological characteristics of these main trees. Based on the study of comparative ecology of the main dominant evergreen broadleaved forest series, the successional stage and direction and its management could be determined, and the theoretical basis for the planning and management of forest production, and the restoration, reconstruction, and exploiting under artificial disturbance could be offered.
    Advances of several selected topics in landscape ecological studies of grasslands
    TIAN Yuhong, LIU Hongyan
    2003, (3):  427-433. 
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    China's grassland is confronted with a mass degradation, desertification, dramatic declining of productivity, environmental deterioration, and rapid loss of biodiversity, which directly threaten the sustainable development of pasture areas. This situation implies that proper management of grassland is essential in China. Based on abundant literatures in landscape ecological research of grassland, this paper summarizes and analyzes the latest progresses in this field in both China and abroad. Studies on landscape pattern, biodiversity, landscape degradation and restoration, and landscape aesthetic value as well as the advances in research methods are focused, aimed at providing references to research in this field in China. Some management strategies from abroad are also summarized to offer references to the Chinese counterparts.
    A review on research of land surface water and heat fluxes
    SUN Rui, LIU Changming
    2003, (3):  434-438. 
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    Many field experiments were done, and soil vegetation atmosphere transfer(SVAT) models were stablished to estimate land surface heat fluxes. In this paper, the processes of experimental research on land surface water and heat fluxes are reviewed, and three kinds of SVATmodel(single layer model, two layer model and multi layer model) are analyzed. Remote sensing data are widely used to estimate land surface heat fluxes.Based on remote sensing and energy balance equation, different models such as simplified model, single layer model, extra resistance model, crop water stress index model and two source resistance model are developed to estimate land surface heat fluxes and evapotranspiration. These models are also analyzed in this paper.
    Ecological implication and behavior mechanism of food selection of mammalian herbivores
    LI Junnian, LIU Jike
    2003, (3):  439-442. 
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    This paper is aimed to review the research progress in the behavior mechanism of food selection of mammalian herbivore. The study of food preference of mammalian herbivores is a prominent field of research in foraging ecology. It was put forth that nutritious hypotheses, plant secondary compounds hypotheses, nutrient balance hypotheses, optimal foraging theory, and conditioned flavor aversion hypotheses could explain the food preference of mammalian herbivores. Animals learn about foods through affective system and cognitive system. Social learning is a form of phenotype plasticity, and enable individuals to acquire adaptive behavior patterns suitable for local habitats. Early experience by the offspring mediated by social learning through the mother may play an important role in determination of food preference in the life. Where the environment is relatively stable, offspring may copy the food choices of older individuals, whereas in highly fluctuating environments, those individuals that select food on a trial and error basis are likely to obtain a more nutritious diet that those imitating the older adults.
    Ecological risk of Bt transgenic cotton and its management strategy
    MA Jun, GAO Bida, WAN Fanghao, GUO Jianying
    2003, (3):  443-446. 
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    There may be several ecological impacts induced by transgenic cottons, apart from their direct impact on target pest. The interactions between target insect and transgenic cotton, and the way of toxic expressed by transgenic cotton varied with plant spatial parts and different growing stages are regarded as the main cause for insect to develop resistance. In transgenic cotton field, although chemicals applied to control major insect pest could be reduced greatly, insect community structure including insect pests and beneficial organisms is less stable than that of regular cotton field. It is much easier for minor insect pests developing to be major pest. In order to full utilization of transgenic cottons and keep their efficiency on target pest, methods including integrated pest management and breeding higher efficincy transgenic cottons by genetic engineering are proposed for management of pest resistance and non target pests.
    A review on road ecology
    LI Yuehui, HU Yuanman, LI Xiuzhen, Xiao Duning
    2003, (3):  447-452. 
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    Roads are a widespread and increasing feature of most landscapes, and have great ecological effects,e.g., increased mortality of animals and plants and habitat loss from road construction, alteration of the physical and chemical environment, and changes in roadsides vegetation.The great impact on animal population includes roadkills, limiting population, road avoidance causing home arrange shift, modification of movement pattern and barrier effect subdividing habitat and populations. Roads alter landscape spatial pattern and interrupt horizontal ecological flows strongly. These impacts can be assayed by indices of road density, road effect zone and road location. Furthermore, important applications of road ecology to planning, conservation and management are essential and potential. Road ecology presents us a surprising frontier of ecology.
    Advances in extraction and purification of soil microorganism
    XIANG Wansheng, WU Jinshui, XIAO He′ai, LI Xueyuan
    2003, (3):  453-456. 
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    For the studies on soil microbial ecology and bio diversity as well as on the dynamics of C,N,Sand Pin soil,it is necessary to quantitatively extract microorganism from soil. The recent advances on extraction and purification of microorganism from soil were reviewed in this paper. The procedure for extracting microorganism from soil was comprised of three steps,i.e., soil dispersion,separation and purification. Most bacteria in soil could be successively extracted from soil particles by present techniques such as filtration,centrifugation and elutriation. However,filamentous fungi seem more difficult to be extracted than bacteria, because it is tangled with soil particles. Rotating wire frame,aqueous extraction and membrane filter technique,and low speed centrifugation were used for extracting filamentous fungi from soil,but the extraction efficiency was rather low and needed to be raised. Aqueous two phase partitioning system was successfully adopted as a technique for bacteria purification, and it would possibly become a technique suitable for fungi purification. The potential area of research on soil microbial ecology as well as on soil and plant nutrition by using microbial extraction technique was also discussed.
    A review on phytoremediation of organic contaminants
    XIA Huilong, WU Lianghuan, TAO Qinnan
    2003, (3):  457-460. 
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    Plants can take up and accumulate most persistant chemicals such as PCBs and PAHs by roots. Some chemicals such as TNT, TCE, and most organic pesticides can be phytodegraded into polar metabolites, or assimilated to CO2 and water by some plants. On the other hand, more microorganisms in rhizosphere can enhance the degradation rate of organic contaminants in environment. The benefits and some issues on phytoremediation are also discussed.
    Detection technique of microsatellites polymorphism and its application in conservation genetics
    YAN Peng, WU Xiaobing, SHI Yan, ZHANG fang
    2003, (3):  461-464. 
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    Microsatellites are a novel molecular genetic marker,and offer unusual advantages,e.g., with the using of a very few sample, they can be amplified by PCR,which are particularly appropriate in the research of conservation genetics. In this paper,the structure of microsatellites and the principle of the detection technique of microsatellites polymorphism were illustrated, and the advantages and the application of this detection technique were described briefly. For the isolation of microsatellite loci in animals,an enrichment method was introduced. And then,some practical problems of this technique were summarized.
    Structure of the clone populations of Leymus chinensis under different utilization conditions in the Xiliao River Plains
    TIAN Xun, YANG Yunfei
    2003, (3):  465-466. 
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    According to the field investigation in the natural grassland of the Xiliao River Plains,the tillers belonged to four or three age classes,and the rhizomes belonged to four age classes under different disturbance habitats. The numbers of the potential populations composed of winterness seedlings and buds were dominant in the first age class. Winterness seedlings belonged to three age classes, while buds belonged to four age classes under all disturbance habitats. The age structure of the potential populations showed an expanding age structure.
    Diverse boundaries between patches within the sandy landscape in Mu Us sandy land
    CHEN Yufu, DONG Ming
    2003, (3):  467-469. 
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    A terrestrial landscape is a mosaic of heterogeneous landforms, vegetation types, and land uses. Boundaries between neighbor patches become conspicuous components of ecological landscapes. The vegetation cover, plant species number, species similarity, soil organic Ccontent, and soil organic N content crossing neighbor patches in Mu Us sandy land were investigated. The results showed that boundaries determined on the basis of each parameter differed, which compared favorably with the previous studies on ecotone dynamics and ecological boundaries delineation.
    Effects of soil factors on arbuscular mycorrhizae (AM) fungi around roots of wild plants
    GAI Jingping, LIU Runjin
    2003, (3):  470-472. 
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    rhizospheric soil samples were collected from 45 wild plants distributed in Shandong Province during1995~1997. More than forty species of AM fungi were isolated, and the effects of some soil factors on AM fungi were also investigated. It was proved that soil conditions were important factors to the colonization, growth, and distribution of AM fungi. Spore numbers were highest in brown earth, and lowest in alkali saline soil. Glomus occurred in all types of soil. The occurrence frequency of Gigaspora and Scutellospora was much higher in brown earth. The distribution of AM fungi was also affected by soil pH. Glomus occurred in soil with a wide pH range. The greater of soil alkalinity, the more Glomus were found, while the greater of soil acidity, the more Acaulospora were isolated. Scutellospora occurred mostly in soil with pHof 6.0~7.0, and Gigaspora distributed mainly in acid soil.
    Ecophysiological characteristics and productivity of wheat-cotton community
    LI Lingli, TAN Jinfang, LI Wen, MA Zongbin, SUN Dunli, DU Yuanfang
    2003, (3):  473-476. 
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    The eco physiology and productivity of 6-2-2 wheat-early maturing cotton middle maturing cotton were studied in comparison with traditional 62 wheat middel maturing cotton. The results showed that after wheat harvested, the LAI of cotton increased fast, the leaf area duration(LAD) and CGRwere raised obviously, the dry matter rose rapidly, and the accumulated amount was larger than CK. Light use efficiency was 1.13%, 21% more than CK. The effective blossom period was extended 18 d, and the lint yield in both 1998 and 1999 was over 2250 kg·hm-2,21~22% more than CK.
    Formation of blood resin in abiotic Dracaena cochinchinensis inoculated with Fusarium9568D
    JIANG Dongfu, MA Ping, YANG Jing, WANG Xinghong, XU Kunyi, HUANG Yan, CHEN Shaohong
    2003, (3):  477-478. 
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    Fusarium 9568D, which belongs to Fusarium moniliforme, was isolated from the roots of Dracaena cochinchinensis in the suburb of Monglian, Yunnan Province of China. High activities of β glucosidase and cellulase were detected in the broth of Fusarium 9568D. The strain was inoculated in abiotic branch and wood of Dracaena cochinchinensis . After 4~5 months of culture, red resin emerged in the inoculated points. UV IRspectrum analysis and antibiotic assay demonstrated that this resin almost resembled the natural blood resin.
    Detection of heterotrophic bacteria and vibrios in shoal of Bullacta exarata
    WANG Guoliang, LU Tongxia, JIN Shan, YU Hong, QIAN Yunxia, WANG Yinong, LIN Baoding
    2003, (3):  479-480. 
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    The number of heterotrophic bacteria and vibrios in shoal for Bullacta exarata rearing fluctuated mainly within1.25×104~7.21×104cfu·g-1 and 0~1.08×104cfu·g-1,respectively. 173 strains of bacteria, mainly belong to 13 genera were isolated. The predominant genera were composed of Bacillus,Photobacterium,Pseudomonas,Vibrio and some genera of Enterobacteriaceae. The number of bacteria changed in line with the alteration of the temperature,and was especially affected by the organic matter content after the use of pesticide. The predominant genera such as Bacillus were closely related with the environmental deterioration of rearing shoal.
    Effect of human activities on soil environment and plant species diversity of elm sparse woods
    YANG Limin, ZHOU Guangsheng, WANG Guohong, WANG Yuhui
    2003, (3):  321-325. 
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    Human activities have a major impact on the biodiversity of the earth, while biodiversity change is considered as an important global change in its own right. Elm sparse woods is a climax community distributed on the sandland in temperate steppe zone. Its habitat conditions are much more fragile, and are easily destroyed. Our studies on the effect of human activities on soil environment and plant diversity showed that the main soil environmental factors and plant species diversity had some obvious changes, of which, the changes of man made pine woods and heavy grazing disturbance were the largest, and the of man made poplar woods were the in those next place. It is suggested that natural laws and consistency of ecosystem processes in the low and long temporal scale should be considered adequately in the environment management of sandland.
    Effect of low nocturnal temperature stress on fluorescence characteristics and active oxygen metabolism in leaves of Garcinia hanburyi seedlings grown under two levels of irradiance
    CAI Zhiquan, CAO Kunfang, FENG Yulong, FENG Zhili
    2003, (3):  326-330. 
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    The fluorescence characteristics and active oxygen metabolism in leaves in Garcinia hanburyi seedlings grown under two irradiance levels (50% and 8% of full natural sunlight) and nocturnal low temperature (4 ℃) were studied in Xishuangbanna. The results showed that the photochemical efficiency of PSⅡ (Fv/Fm), the quantum yield of PSⅡ linear electron transport (ФPSⅡ) and non photochemical quenching (NPQ) were decreased, but the initial fluorescence yield (F0) were increased with prolonged stress time of low temperature in leaves of Garcinia hanburyi grown under the two different irradiance levels. After three days of recovery treatment, the Fv/Fm and F0 of Garcinia hanburyi grown under 50% natural irradiance were not recovered completely, while those of the seedlings grown in 8% natural irradiance were recovered almost completely, which indicated that the photosynthetic apparatus of Garcinia hanburyi grown under 50% irradiance was injured by photooxidation, but that of seedlings grown in 8% irradiance was only reversibly inactivated by the nocturnal low temperature stress. In the mean time, although the activities of protective enzymes (SOD,CAT, and APX) increased, the O2-. production rate and H2O2 content also increased with the duration of the stress. The MDA also accumulated in leaves of Garcinia hanburyi grown under two different irradiance levels. After three day's recovery, much less active oxygen was produced in leaves of Garcinia hanburyi grown under 8% than that under 50% irradiance. The implication of the results for practice were also discussed.
    Photosynthesis and free radical yield of Litchi chinensis leaves under increased CO2 partial pressure in atmosphere
    SUN Guchou, ZENG Xiaoping, ZHAO Ping, PENG Shaolin
    2003, (3):  331-335. 
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    .The maximum photosynthetic rate of litchi saplings leaves grown under a CO2 partial pressure of 77?5 Pa was 23% lower than that of 39.3 Pa, and slight decreases in respiration rate in light and CO2 compensation point excluding of respiration in light were observed. The maximum rates of carboxylation (Vcmax) and photosynthetic electron transport (Jmax) were decreased in saplings grown under 77?5 Pa CO2 partial pressure. It may suggest that there was a lower energy level of photosystem I(PSI) in the saplings leaves under 77?5 Pa CO2 partial pressure, and free radical yield decreased by 39% in the saplings under 77?5 Pa CO2, as comparied with that under atmospheric CO2. The percentage of infection by Peronophythora litchi increased from 1.8% under atmospheric CO2 to 9.5% under enriched CO2. It may mean that the decreasing photosynthetic and respiration metabolism would make it lower the production of O2-., and leaves were infected by P.litchi more easily. The controlling of the popularization of P.litchi for litchi plantation must be paid wide attention,as air CO2 partial pressure will increase continuously.
    Effects of light on morphological plasticity and biomass allocation of Momordica charantia
    TAO Jianping, ZHONG Zhangcheng
    2003, (3):  336-340. 
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    The growth dynamics, morphological characteristics and biomass allocation of climbing plant Momordica charantia were studied under shading. The results showed that the growth of Momordica charantia had a significant difference under different levels of shading. Under weak light, the plants decreased the chance to increase their modular numbers and accumulate biomass, and had fewer shoots, thinner laminas, longer and thinner petioles, and more slender stems. The plants showed a stronger morphological plasticity under weak light than under strong light, and had a stronger morphological plasticity at early growth stage than at later growth stage. The laminas and stem biomass allocation increased, while branch biomass allocation decreased with decreasing light illumination. Light intensity had little effect on biomass allocation to shoot stems. External support is not necessary for the growth of Momordica charantia under strong light.
    Ecological feedback significance of polyphenols in organic layer of forest soil
    ZHONG Zheke, WANG Renchao, JIANG Bo
    2003, (3):  341-344. 
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    By comparing polyphenols (total polyphenols and condensed tannin) and other chemical and biological properties in soil organic layers during the transformation and regeneration of pure mature spruce stand in middle Europe, the functions of polyphenols in forest ecosystem were approached. The results showed that polyphenols concentration had a significant positive correlation with effective cation exchange capacity (ECEC), but no relation with organic C. The net Nmineralization had no significant correlation with total polyphenols, organic Cand C/Nratio, but had a significant negative correlation with condensed tannin. Polyphenols concentration also positively correlated with 1 mol稬-1 KCl extractable Cand N. It is suggest that although the polyphenols have no obvious physiological function in tree metabolism, it should be paid attention to its ecological feedback significance in the whole ecosystem.
    Relationship between soil enzyme activities and trace element contents in Eucalyptus plantation soil
    LI Yuelin, PENG Shaolin, LI Zhihui, REN Hai, LI Zhi'an
    2003, (3):  345-348. 
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    Canonical correlation analysis on soil enzyme activities and trace element contents in Eucalyptus plantation soil showed that among the test elements, only Zn and Mn affected enzyme activity. Both Zn and Mn increased soil proteinase activity. Zn decreased the activities of soil urease and peroxidase, while Mn promoted them. "Integral soil enzyme factor" could be used as an index of soil fertility. Together with other growth factors, this index should be considered when evaluating soil fertility of Eucalyptus forest sites. It also had a definite significance on the division of Eucalyptus soil families.
    Effect of ecological organic fertilizer on tomato bacterial wilt and soil microbial diversities
    CAI Yanfei, LIAO Zongwen, ZHANG Jia′en, KONG Weidong, HE Chengxin
    2003, (3):  349-353. 
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    The effects of ecological organic fertilizer (EOF) on tomato bacterial wilt and soil microbial community were studied through field trial and fatty acid methyl esters (FAMEs) analysis. The results showed that the incidence rate of tomato bacterial wilt was 100% in continuous cropped soil, and significantly reduced to 39% and 50% when applying EOF at 1.0 kg穖-2 and 0.5 kg穖-2, respectively. There was no significant difference between two fertilization treatments. The fatty acid fingerprints of soil microbial community were greatly changed, and the relative contents of cyc17:0 cited as biomarker for GNbacteria, c18:2 w6 as biomarker for fungi and c16:111c as biomarker for arbuscular mycorrhizal (AM) fungi all increased when applying EOF. The minimum distance of cluster analysis was 1.08 between control and treatments of applying ecological organic fertilizer, and 0.70 between different fertilization treatments. Applying EOFcould adjust soil microbial community structure, benefit for soil beneficial microbes, and develop stability and disease suppression of soil ecological system, and hence, improve soil quality.
    Variation of CO2 concentration in solar greenhouse in Northern China
    WEI Min, XING Yuxian, WANG Xiufeng, MA Hong
    2003, (3):  354-358. 
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    The variation of CO2 concentration in winter spring cultivated solar greenhouse in northern China was studied. The diurnal change of CO2 concentration showed an irregular 'U' shape in most case, the maximum value appeared prior to unveiling straw mat in the morning, and the minimum between12:00 and 14:00 PM. Sometimes, an irregular 'W' shape curve with two valleys was also observed, with the first one appeared prior to the ventilation at noon, and the second occurred between15:00~16:30 PM. During the period of winter spring cultivation, the daily maximum concentration of CO2 in solar greenhouse decreased gradually, while the daily minimum concentration and daytime average concentration dropped first, then went up. At the same time, the time of CO2 depletion lasted longer and longer. In December, CO2 depletion happened 2.1~3.1 hours after morning unveiling. In the next March, however, it moved up to 0.6~1.1 hours after unveiling in the morning. At daytime, both during and after ventilation, solar greenhouse often showed CO2 depletion. The period of CO2 depletion extended from 4~5.8 hours per day in December to 8~8.5 hours per day in March of next year. The spacial distribution of CO2 concentrations within the greenhouse showed that in the morning and in the evening, the order was the front>the middle>the back, and the ground>the canopy>the upper, and at midday, the order was the front <the middle<the back, and the ground>the upper>the canopy. Photon flux density was the most important environmental factor affecting CO2 concentration in greenhouse. Ventilation did not avoided CO2 depletion. Canopy photosynthetic rate and soil respiratory rate were measured at different growth stages of tomato. At seedling stage, CO2 concentration in greenhouse was higher than that outside, due to the vigorous soil respiration and lower canopy photosynthetic rate. But at fruiting stage, severe CO2 depletion occurred because of stronger canopy photosynthesis and weak soil respiration.
    Numerical simulation of flow fields through porous windbreak in shrubby zone
    WANG Yuan, ZHOU Junli, XU Zhong
    2003, (3):  359-362. 
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    By treating the windbreak and shrub with the parameters in a equation, the flow fields through porous windbreak with and without shrub were calculated. The changes in relative wind velocity in horizontal direction, velocity profile and turbulent energy of the section were compared. It is concluded that shrub was very important in windbreak system, which could decrease the wind velocity in front of or some distance in the leeward of the windbreak. The calculated numerical results were compared with the data from wind tunnel experiment where the influence of shrub on flow field was analyzed.
    Dynamics of litter and under-ground biomass in Carex lasiocarpa wetland on Sanjiang Plain
    HE Chiquan
    2003, (3):  363-366. 
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    With net sack and coring methods, this paper analysed the seasonal dynamics of litter and under-ground biomass of Carex lasiocarpa population in Sanjiang Plain wetland. The standing litter showed exponential seasonal dynamics. The decomposition rate of litter was indicated by the rate of its weight loss, and the daily weight loss was gradually decreased from 0.7058 % to 0.2372 %. Carex lasiocarpa population produced 210.8876 g穖-2 litter in its vegetative season (from May 2, to October 10,1999), and its under ground biomass had an obvious vertical structure, like a converse pyramid or a parabola.
    CO2 flux characteristics from degenerated mat cryo-sod soil during plant growing period
    ZHOU Dangwei, CAO Guangmin, ZHANG Jinxia, ZHAO Xinquan, ZHOU Xingmin
    2003, (3):  367-371. 
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    The carbon dioxide (CO2) emission rate was studied in the degenerated mat cryo sod soil covered with alpine Kobresia humilis meadow at the Haibei alpine meadow ecosystem research station, with CID 301ps CO2 analytical instrument during plant growth period (May-Sep, in1998). The results showed that the CO2 emission rate had obvious daily variation and seasonal dynamics. The maximum rate of CO2 emission appeared at 12:00~14:00, and the minimum rate appeared at 6:00~8:00. The max daily amplitude was 462.49 mg·m-2·h-1,while the minimum daily amplitude was 114.97 mg·m-2·h-1 .The CO2 emission rate varied with phonological periods, and the order was exuberance>withering>green up. The maximum daily average value was 480.76 mg·m-2·h-1 (Aug.18th), and the minimum daily average value was 140.77 mg·m-2·h-1 (May.9th). Correlation analysis showed that there was a significant relationship between CO2 emission rate and air temperature, soil surface temperature and soil temperature in 5 cm, 10 cm, 15 cm, 20 cm,and 30 cm. Temperature was the dominant factor that affected the CO2 emission rate in degenerated mat cryo sod soil.
    Greenhouse gases emission or uptake in Inner Mongolia natural and free-grazing grasslands
    WANG Yuesi, XUE Min, HUANG Yao, LIU Guangren, WANG Mingxing, GI Baoming
    2003, (3):  372-376. 
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    GC-MS was used to measure the greenhouse emission of Inner Mongolia Grassland. The results showed that four kinds of typical semi-arid grasslands in Inner Mongolia had their own special seasonal patterns as the source of atmospheric N2O and CO2 emission and the sink of atmopsheric CH4,which were controlled by seasonal weather variation. Different soil and vegetation types and precipitation influenced the intensity of emission and upatake of the gases. Compared with natural grassland,free grazing decreased CH4 uptake and N2Oemission,but increased CO2 emission.
    Response of lettuce to different nitrogen forms
    TIAN Xiaohong, LI Shengxiu, WANG Zhaohui, YIN Xiangtao, CHEN Shixiang
    2003, (3):  377-381. 
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    Solution culture experiment was adopted to investigate the influence of different nitrogen forms on lettuce growth and development and their nitrogenous nutritional characteristics. The results showed that the affinity of the roots of lettuce seedlings to ammonium nitrogen (NH4+-N) was slightly higher than that to nitrate nitrogen (NO3--N). Among three treatments of NO3--N, NH4+-N+NO3--N and NH4+-N, the relative proportion of biological yields of lettuce was 100:56.9:12.4, and that of nitrogen uptake amount was 100:48.9:8.6, respectively. Nitrate nitrogen was the most suitable Nsource to lettuce growth. When the respective proportion of NH4+-N and NO3--N was 50%, the growth of lettuce was inhibited to some extent. When the nitrogen source supplied as solely NH4+-N, lettuce was hard to grow normally. When supplying the same amount of NH4+-N and NO3--N, lettuce showed a tendency to absorb more NH4+-N than NO3--N. At different culture stages, the ratio of NH4+-N to NO3--N absorbtion was less than1. It seemed that lettuce did prefer NH4+-N to NO3--N in absorbtion. However, ammonium nitrogen as nitrogen source was not suitable to lettuce for its metabolism. When nitrate nitrogen was not sufficient, it mainly affected the growth of lettuce shoot; when the ammonium nitrogen in nutrient solution was 50%, the root growth of lettuce seedlings was greatly inhibited, and some pathological symptoms appeared. Taking running water as water source (in which, NO3--N concentration was about 0.5 mol稬-1) and lettuce was cultured by supplying sole NO3--N for two weeks and then supplying NH4+-N, the growth of lettuce was greatly stimulated, in the meantime, the NO3--N contents and total accumulation amount greatly decreased. Supplying urea as Nsource, the growth rate of lettuce was apparently inferior to other nitrogen forms, but no pathological symptoms appeared.
    On hybrid embryo culture in vitro of Syringa L
    ZHOU Li, LUO Fengxia, DAI Limin
    2003, (3):  382-386. 
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    Syringa L. is the famous ornamental shrub in China, but its embryo always dies before seed mature during cross breeding, and hence, the breeding work is very difficult. The main object of this study is using embryo culture in vitro to get the seedling directly and to improve the succeed rate of cross breeding. The factors that influenced the embryo culture were researched in detail. The results showed that the optimal medium for embryo culture was Monnier, and the second was MSor LS, which meant that the embryo of Syringa needed abundant macro elements and microelements, especially Ca2+ and K+. The optimal sugar concentration was 50 g·L-1 . At this level, the sugar could offer enough nutrition and high osmotic pressure for embryo. When the embryo age was 50~60 days, the culture was easy to be succeed. At this time, the cotyledon in ovule began to form, or organ began to differentiation, so, the embryo was very easy to germinate, and the seedling was very easy to form. Proper coconut milk, glutamic acid or glutamine, and activated charcoal could improve the germination and growth of the embryo. When the BA of low concentration (0.01 mg·L-1) was joined in the medium, the germination rate could be improved. The best NAA concentration was 0.01 mg·L-1 .
    Effects of CO2 enrichment, nitrogen and water on photosynthesis, evapotranspiration and water use efficiency of spring wheat
    LI Fusheng, KANG Shaozhong, ZHANG Fucang
    2003, (3):  387-393. 
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    Spring wheat (Triticum aestivum L.) was treated with 2 atmospheric CO2 concentrations (350 and 700 μmol·mol-1), 2 levels of soil moisture (wet and drought), and 5 levels of nitrogen fertilizer (0,50,100,150,200 mg·kg-1 soil). The results showed that elevated atmospheric CO2 increased photosynthetic rate more in drought than in wet treatment. Photosynthetic rate increased with the increase of nitrogen fertilizer. Stomatal conductance decreased with CO2 enrichment, which was more in drought than in wet treatment. CO2 enrichment decreased more evapotranspiration in drought than in wet treatment. The decrease was more apparent with no fertilization. CO2 enrichment increased more leaf water use efficiency in drought than in wet treatment. Canopy WUEincreased with CO2 enrichment and Nfertilization. Thus, the increase in photosynthesis and the reduction in evapotranspiration due to elevated CO2 can ameliorate the negative effects of drought, and increase wheat resistance to water stress.
    A study on multicomponent bidirectional reflectance model for rice
    SHEN Guangrong, WANG Rencao
    2003, (3):  394-398. 
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    In this paper, the bidirectional reflectance factor (BRF) of rice measured in field experiment in1999 and 2000 was compared with the BRFcomputed from the rice multicomponent bidirectional reflectance model that based on the radiative transfer theory, rice canopy geometric structural factors and different characteristics of the different growth period for rice in detail. The contribution of some sensitive factors such as the average inclination angle of all components belonged to rice and LAIwas accurately specified. The results showedthat the rice multicomponent bidirectional reflectance model described above could basically simulate the angular distribution characteristic of reflectance spectrum of rice canopies, and the different peak point of the hotspot effect of rice canopies reached under different conditions. In addition, the regulation of the first order scattering reflectance by soil and water and the multiple scattering reflectance by foliage, stem, fringe and soil changing with the average inclination angle of all components, as well as the contribution of LAIto BRFwere analyzed. All of these laid a foundation to monitor rice growth and estimate its yield. Meanwhile, it also implied that some rice canopy parameters could be accurately estimated by the model through selecting the suitable image bands.
    Water use efficiency and rice yield under different water managements
    QIAN Xiaoqing, SHEN Qirong, XU Yong, WANG Juanjuan, SHEN Hui
    2003, (3):  399-404. 
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    Subtle plot experiment was conducted to study the growth and water use status of rice cultivated on waterlogged soil and upland soil mulched with plastic film, semi decomposed wheat straw and nothing in Nanjing Agricultural University. The results showed that 349 to 473 mm of water were required by rice cultivated on upland soil mulched with film, straw or nothing, and 732.5 mm of water was required on waterlogged soil. The water productive efficiencies for rice grain and biomass were between0.899 to 1.273, and 1.655 to 2.321 g穔g-1, respectively in upland cultivation, while 0.766 and 1.459 g穔g-1 in waterlogged cultivation. Rice cultivated on upland soil mulched with semi decomposed straw achieved 90% or more economic yield on waterlogged soil.
    Characterization of several synthetic and environmental microbial samples by quantitative hybridization
    HUANG Linan, CHEN Yueqin, ZHOU Hui, QU Lianghu
    2003, (3):  405-408. 
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    Limitations of traditional techniques based on selective enrichment and pure culture isolation make it difficult to precisely characterize the natural microbial ecosystems. Molecular techniques are now being developed and used to address these limitations. Group specific 16SrRNAs targeted oligonucleotide probes of different phylogenetic levels are increasingly used to identify and quantify the microbial members in complex environmental samples. Two domain specific probes were used in this study to elementarily characterize the defined mixtures of RNAs extracted from pure culture (synthetic samples) and a RNAsample obtained from landfill leachate (environmental sample). The results demonstrated that 16SrRNAquantitative hybridization provided an excellent estimation of domain level community composition of these samples, and thus, had a huge potential of usefulness in microbial ecology studies.
    Selectivity and tolerance of sea urchin (Hemicentrotus pulcherrimus) to environmental change
    YOU Kai, ZENG Xiaoqi, LIU Hui, ZHANG Xiumei, LIU Qun
    2003, (3):  409-412. 
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    An experimental ecological study of sea urchin (Hemicentrotus pulcherrimus) sampled from coastal waters of Qingdao was focused on the fundamental ecological factors such as temperature, salinity, light intensity and substratum. The results showed that the suitable ecological range of temperature was from 8 ℃ to 22 ℃, and the selectivity to temperature was changed with the previous living temperatures. Hemicentrotus pulcherrimus was a kind of stenohaline creature. Its optimum ecological range of salinity was from 30 to 35. The results also showed that Hemicentrotus pulcherrimus liked to select weak light environment (<50 lux), especially under non food condition. Hemicentrotus pulcherrimus had the positive substratum selectivity to coarse sand and the negative substratum selectivity to silver sand.
    Geostatistical analysis on spatial patterns of Didesmococcus koreanus Borchs and Chilocorus rubidus Hope
    HUANG Baohong, ZOU Yunding, BI Shoudong, ZHU Hongwei, GAO Zhengliang
    2003, (3):  413-417. 
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    The spatial pattern and correlation of Didesmococcus koreanus Borchs and Chilocorus rubidus Hope in different periods were investigated with geostatistics. The results showed that the semivariogram of Didesmococcus koreanus Borchs and Chilocorus rubidus Hope could be described by spherical model, indicating that their spatial pattern were in agreement. The spatial variation was arosed by its spatial autocorrelation in small scales, and the spatial pattern had no apparent changes in different periods. The range varied from 9.56~15.70 m and from 18.83~19.74 m, respectively. The amount and spatial distribution of Chilocorus rubidus Hope was closely related to that of Didesmococcus koreanus Borchs, which revealed that Chilocorus rubidus Hope was the dominant natural enemy of Didesmococcus koreanus Borchs.
    Relationships between plant reproductive strategy and disturbance
    LIU Zhimin, JIANG Deming, GAO Hongying, CHANG Xueli
    2003, (3):  418-422. 
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    Plant reproductive strategy in life history is related to plant adaptation or evolution, ecosystem degradation or restoration, and biodiversity conservation, which are the components of theoretic and applied ecological studies. In this article, several issues concerning the relationships between plant reproductive strategy in life history and disturbance, including Grime's classification of plant reproductive strategies, adaptations of plant vegetative reproduction to disturbances, adaptations of seed morphological traits to disturbance, roles of soil seed bank in disturbance adaptation, and dispersal and germination adaptation of diaspores to disturbance, were briefly reviewed. China's study on relationships between plant reproductive strategy in life history and disturbance in arid zone was also reviewed and discussed.
    Application of succession study in tending and restoration of evergreen broadleaved forest
    DING Shengyan, SONG Yongchang
    2003, (3):  423-426. 
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    The characteristics of synecology, population ecology and physio ecology of main tree species Quercus fabri, Pinus massoniana, Castanopsis sclerophylla, Lithocarpus glaber, Schima superba and C. fargesii of evergreen broadleaved forest in Tiantong National Forest Park, Zhejiang Province were studied by comparative method. The successional process was clarified through the comparative studies of the synecological characteristics of these main tree species, the individual plant structure and renewability were discussed by comparative study of population ecological characteristics of main trees' populations, and the mechanism of replacement with each other of these main tree species was open out by comparative study of physio ecological characteristics of these main trees. Based on the study of comparative ecology of the main dominant evergreen broadleaved forest series, the successional stage and direction and its management could be determined, and the theoretical basis for the planning and management of forest production, and the restoration, reconstruction, and exploiting under artificial disturbance could be offered.
    Advances of several selected topics in landscape ecological studies of grasslands
    TIAN Yuhong, LIU Hongyan
    2003, (3):  427-433. 
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    China's grassland is confronted with a mass degradation, desertification, dramatic declining of productivity, environmental deterioration, and rapid loss of biodiversity, which directly threaten the sustainable development of pasture areas. This situation implies that proper management of grassland is essential in China. Based on abundant literatures in landscape ecological research of grassland, this paper summarizes and analyzes the latest progresses in this field in both China and abroad. Studies on landscape pattern, biodiversity, landscape degradation and restoration, and landscape aesthetic value as well as the advances in research methods are focused, aimed at providing references to research in this field in China. Some management strategies from abroad are also summarized to offer references to the Chinese counterparts.
    A review on research of land surface water and heat fluxes
    SUN Rui, LIU Changming
    2003, (3):  434-438. 
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    Many field experiments were done, and soil vegetation atmosphere transfer(SVAT) models were stablished to estimate land surface heat fluxes. In this paper, the processes of experimental research on land surface water and heat fluxes are reviewed, and three kinds of SVATmodel(single layer model, two layer model and multi layer model) are analyzed. Remote sensing data are widely used to estimate land surface heat fluxes.Based on remote sensing and energy balance equation, different models such as simplified model, single layer model, extra resistance model, crop water stress index model and two source resistance model are developed to estimate land surface heat fluxes and evapotranspiration. These models are also analyzed in this paper.
    Ecological implication and behavior mechanism of food selection of mammalian herbivores
    LI Junnian, LIU Jike
    2003, (3):  439-442. 
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    This paper is aimed to review the research progress in the behavior mechanism of food selection of mammalian herbivore. The study of food preference of mammalian herbivores is a prominent field of research in foraging ecology. It was put forth that nutritious hypotheses, plant secondary compounds hypotheses, nutrient balance hypotheses, optimal foraging theory, and conditioned flavor aversion hypotheses could explain the food preference of mammalian herbivores. Animals learn about foods through affective system and cognitive system. Social learning is a form of phenotype plasticity, and enable individuals to acquire adaptive behavior patterns suitable for local habitats. Early experience by the offspring mediated by social learning through the mother may play an important role in determination of food preference in the life. Where the environment is relatively stable, offspring may copy the food choices of older individuals, whereas in highly fluctuating environments, those individuals that select food on a trial and error basis are likely to obtain a more nutritious diet that those imitating the older adults.
    Ecological risk of Bt transgenic cotton and its management strategy
    MA Jun, GAO Bida, WAN Fanghao, GUO Jianying
    2003, (3):  443-446. 
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    There may be several ecological impacts induced by transgenic cottons, apart from their direct impact on target pest. The interactions between target insect and transgenic cotton, and the way of toxic expressed by transgenic cotton varied with plant spatial parts and different growing stages are regarded as the main cause for insect to develop resistance. In transgenic cotton field, although chemicals applied to control major insect pest could be reduced greatly, insect community structure including insect pests and beneficial organisms is less stable than that of regular cotton field. It is much easier for minor insect pests developing to be major pest. In order to full utilization of transgenic cottons and keep their efficiency on target pest, methods including integrated pest management and breeding higher efficincy transgenic cottons by genetic engineering are proposed for management of pest resistance and non target pests.
    A review on road ecology
    LI Yuehui, HU Yuanman, LI Xiuzhen, Xiao Duning
    2003, (3):  447-452. 
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    Roads are a widespread and increasing feature of most landscapes, and have great ecological effects,e.g., increased mortality of animals and plants and habitat loss from road construction, alteration of the physical and chemical environment, and changes in roadsides vegetation.The great impact on animal population includes roadkills, limiting population, road avoidance causing home arrange shift, modification of movement pattern and barrier effect subdividing habitat and populations. Roads alter landscape spatial pattern and interrupt horizontal ecological flows strongly. These impacts can be assayed by indices of road density, road effect zone and road location. Furthermore, important applications of road ecology to planning, conservation and management are essential and potential. Road ecology presents us a surprising frontier of ecology.
    Advances in extraction and purification of soil microorganism
    XIANG Wansheng, WU Jinshui, XIAO He′ai, LI Xueyuan
    2003, (3):  453-456. 
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    For the studies on soil microbial ecology and bio diversity as well as on the dynamics of C,N,Sand Pin soil,it is necessary to quantitatively extract microorganism from soil. The recent advances on extraction and purification of microorganism from soil were reviewed in this paper. The procedure for extracting microorganism from soil was comprised of three steps,i.e., soil dispersion,separation and purification. Most bacteria in soil could be successively extracted from soil particles by present techniques such as filtration,centrifugation and elutriation. However,filamentous fungi seem more difficult to be extracted than bacteria, because it is tangled with soil particles. Rotating wire frame,aqueous extraction and membrane filter technique,and low speed centrifugation were used for extracting filamentous fungi from soil,but the extraction efficiency was rather low and needed to be raised. Aqueous two phase partitioning system was successfully adopted as a technique for bacteria purification, and it would possibly become a technique suitable for fungi purification. The potential area of research on soil microbial ecology as well as on soil and plant nutrition by using microbial extraction technique was also discussed.
    A review on phytoremediation of organic contaminants
    XIA Huilong, WU Lianghuan, TAO Qinnan
    2003, (3):  457-460. 
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    Plants can take up and accumulate most persistant chemicals such as PCBs and PAHs by roots. Some chemicals such as TNT, TCE, and most organic pesticides can be phytodegraded into polar metabolites, or assimilated to CO2 and water by some plants. On the other hand, more microorganisms in rhizosphere can enhance the degradation rate of organic contaminants in environment. The benefits and some issues on phytoremediation are also discussed.
    Detection technique of microsatellites polymorphism and its application in conservation genetics
    YAN Peng, WU Xiaobing, SHI Yan, ZHANG fang
    2003, (3):  461-464. 
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    Microsatellites are a novel molecular genetic marker,and offer unusual advantages,e.g., with the using of a very few sample, they can be amplified by PCR,which are particularly appropriate in the research of conservation genetics. In this paper,the structure of microsatellites and the principle of the detection technique of microsatellites polymorphism were illustrated, and the advantages and the application of this detection technique were described briefly. For the isolation of microsatellite loci in animals,an enrichment method was introduced. And then,some practical problems of this technique were summarized.
    Structure of the clone populations of Leymus chinensis under different utilization conditions in the Xiliao River Plains
    TIAN Xun, YANG Yunfei
    2003, (3):  465-466. 
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    According to the field investigation in the natural grassland of the Xiliao River Plains,the tillers belonged to four or three age classes,and the rhizomes belonged to four age classes under different disturbance habitats. The numbers of the potential populations composed of winterness seedlings and buds were dominant in the first age class. Winterness seedlings belonged to three age classes, while buds belonged to four age classes under all disturbance habitats. The age structure of the potential populations showed an expanding age structure.
    Diverse boundaries between patches within the sandy landscape in Mu Us sandy land
    CHEN Yufu, DONG Ming
    2003, (3):  467-469. 
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    A terrestrial landscape is a mosaic of heterogeneous landforms, vegetation types, and land uses. Boundaries between neighbor patches become conspicuous components of ecological landscapes. The vegetation cover, plant species number, species similarity, soil organic Ccontent, and soil organic N content crossing neighbor patches in Mu Us sandy land were investigated. The results showed that boundaries determined on the basis of each parameter differed, which compared favorably with the previous studies on ecotone dynamics and ecological boundaries delineation.
    Effects of soil factors on arbuscular mycorrhizae (AM) fungi around roots of wild plants
    GAI Jingping, LIU Runjin
    2003, (3):  470-472. 
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    rhizospheric soil samples were collected from 45 wild plants distributed in Shandong Province during1995~1997. More than forty species of AM fungi were isolated, and the effects of some soil factors on AM fungi were also investigated. It was proved that soil conditions were important factors to the colonization, growth, and distribution of AM fungi. Spore numbers were highest in brown earth, and lowest in alkali saline soil. Glomus occurred in all types of soil. The occurrence frequency of Gigaspora and Scutellospora was much higher in brown earth. The distribution of AM fungi was also affected by soil pH. Glomus occurred in soil with a wide pH range. The greater of soil alkalinity, the more Glomus were found, while the greater of soil acidity, the more Acaulospora were isolated. Scutellospora occurred mostly in soil with pHof 6.0~7.0, and Gigaspora distributed mainly in acid soil.
    Ecophysiological characteristics and productivity of wheat-cotton community
    LI Lingli, TAN Jinfang, LI Wen, MA Zongbin, SUN Dunli, DU Yuanfang
    2003, (3):  473-476. 
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    The eco physiology and productivity of 6-2-2 wheat-early maturing cotton middle maturing cotton were studied in comparison with traditional 62 wheat middel maturing cotton. The results showed that after wheat harvested, the LAI of cotton increased fast, the leaf area duration(LAD) and CGRwere raised obviously, the dry matter rose rapidly, and the accumulated amount was larger than CK. Light use efficiency was 1.13%, 21% more than CK. The effective blossom period was extended 18 d, and the lint yield in both 1998 and 1999 was over 2250 kg·hm-2,21~22% more than CK.
    Formation of blood resin in abiotic Dracaena cochinchinensis inoculated with Fusarium9568D
    JIANG Dongfu, MA Ping, YANG Jing, WANG Xinghong, XU Kunyi, HUANG Yan, CHEN Shaohong
    2003, (3):  477-478. 
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    Fusarium 9568D, which belongs to Fusarium moniliforme, was isolated from the roots of Dracaena cochinchinensis in the suburb of Monglian, Yunnan Province of China. High activities of β glucosidase and cellulase were detected in the broth of Fusarium 9568D. The strain was inoculated in abiotic branch and wood of Dracaena cochinchinensis . After 4~5 months of culture, red resin emerged in the inoculated points. UV IRspectrum analysis and antibiotic assay demonstrated that this resin almost resembled the natural blood resin.
    Detection of heterotrophic bacteria and vibrios in shoal of Bullacta exarata
    WANG Guoliang, LU Tongxia, JIN Shan, YU Hong, QIAN Yunxia, WANG Yinong, LIN Baoding
    2003, (3):  479-480. 
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    The number of heterotrophic bacteria and vibrios in shoal for Bullacta exarata rearing fluctuated mainly within1.25×104~7.21×104cfu·g-1 and 0~1.08×104cfu·g-1,respectively. 173 strains of bacteria, mainly belong to 13 genera were isolated. The predominant genera were composed of Bacillus,Photobacterium,Pseudomonas,Vibrio and some genera of Enterobacteriaceae. The number of bacteria changed in line with the alteration of the temperature,and was especially affected by the organic matter content after the use of pesticide. The predominant genera such as Bacillus were closely related with the environmental deterioration of rearing shoal.