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    15 May 2004, Volume 15 Issue 5
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    Bryophyte biomass in dark coniferous forest of Changbai Mountain
    YE Ji, HAO Zhanqing, DAI Guanhua
    2004, (5):  737-740. 
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    In this paper,the floor and epiphytic bryophyte biomass was sampled from the dark coniferous forest on the north slope of Changbai Mountain,with an altitude from 1100 m to 1700 m.The floor bryophyte biomass was measured by the method of transect sampling,and epiphytic bryophyte biomass was measured by McCune method.The results showed that bryophytes distributed unevenly,and their biomass changed greatly with increasing altitude.The biomass was the least (543 kg穐m-2) at 1 100 m,but the greatest (5 097 kg穐m-2) at 1 250 m.The changes of bryophytes biomass could indicate different environmental situations.The biomass change of Hylocomium splendens and Rhytidiadelphus triquetrus with ascending altitude had some relativity with the community character of forest ecosystem.The biomass of Hylocomium splendens increased,but that of Rhytidiadelphus triquetrus decreased with altitude ascending from 1 100 m to 1 700 m.Moreover,the biomass changes could also show the needed physiological conditions of different bryophytes.
    Forest landscape change and its driving force during past ten years in Bilahe forest region,Inner Mongolia
    CHEN Wenbo, XIAO Duning, ZHENG Jiao, GUO Fuliang, JIANG Yingpeng
    2004, (5):  741-747. 
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    Based on RS and GIS,this paper studied the forest landscape change during the past ten years in Bilahe forest region,Inner Mongolia,from the aspects of general landscape features,individual patch characteristics,and relationship among patches.The results showed that the forest landscape changed a lot due to the stronger human intervention on forest ecosystem.The general tendency was that the human patches (residential area and cultivated land) were!expanding quickly,whereas the natural patches (forest patches,etc.) were shrinking gradually.The results of area transformation matrix showed that in 1997,30.87% of cultivated lands were transformed from Quercus mongolica.According to the analysis of landscape heterogeneity,the patches were increased by 68 80%,but their average area was reduced by 4.82%.In 1988,the landscape dominated by few patches changed to a landscape with comparatively even distribution of patches,due to the decrease of landscape dominance and contagion,and the increase of landscape diversity.Based on the analyses of physical geography and social economics in the study area and the regions related,this paper discovered that the most decisive driving forces of landscape changes were fire intervention,deforestation,and reclamation of virgin land.
    Dynamics of biomass and stem volume of Picea asperata stands in artificial restoration process of subalpine coniferous forest
    HE Hai, QIAO Yongkang, LIU Qing, WU Yan, LIN Bo
    2004, (5):  748-752. 
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    The dynamics of aboveground biomass and stem volume in subalpine coniferous Picea asperata plantations with different stand ages in 70 years of artificial restoration process were studied by adopting the concept of space as a substitute for time.The results indicated that before 20 years of stand age,the biomass of spruce single tree grew quite slow,with that of the twigs and needles accounting for about 50%;after 20 years,it increased obviously,with 60% of biomass accumulated in stem;from 30 to 40 years,the increasing rate of biomass relatively slowed down,and maintained a rapid growth after 40 years.The biomass of spruce population showed a similar trend,though the period of relative slow-down of growth continued from 30 to 50 years.For the biomass of community as a whole,it presented a general continuous increase,but varied greatly for different layers.In shrub layer,the biomass rose rapidly at the early stage of plantation establishment and gradually decreased after 20 years,while that of the herbaceous plants reduced continuously and accounted less than 0.2% of the total biomass of community when the stand reached 70 years.Both the mean annual increment and the current annual increment of stem volume of spruce single tree went up with the increasing stand age,and more rapidly at the later stages.Similar changes were observed for the stock volume of the plantations,with the only difference that the current annual increment from 30 to 50 years was relatively reduced.Based on the data from stem analysis and growth ring measurement,regression models of stem volume with DBH and tree height of 70 years Picea asperata plantation were established.
    Effect of enhanced ammonium nutrition (EAN) at different growth stages on wheat growth and nitrogen utilization
    SUN Chuanfan, DAI Tingbo, JING Qi, CAO Weixing
    2004, (5):  753-757. 
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    Field experiments were conducted in 1998～2000 to investigate the effects of EAN applied at different growth stages (basal,tillering,jointing,booting and whole growth stage) on wheat growth and nitrogen utilization.Compared with single NO3-,EAN as basal fertilizer,tillering dressing and jointing dressing promoted dry matter and nitrogen accumulation after heading,LAI at booting stage,and chlorophyll content of wheat.Grain yield was also increased significantly.Nevertheless,there was no obvious promoting effect of EAN at booting dressing.No significant response of plant growth under EAN was observed over whole growth stage,compared with EAN at early stages,indicating that EAN after jointing was not effective to increase nitrogen utilization and wheat growth.But,it was more effective on decreasing N leaching than other EAN treatments.All EAN treatments increased nitrogen flow efficiency (NFE) and nitrogen recovery efficiency (NRE),compared with single NO3-,but EAN treatments before jointing had significant effects on increasing nitrogen utilization.Besides these,EAN as jointing dressing improved the leaf photosynthetic characteristics during the late developmental stage and the remobilization of dry matter to grain,while EAN as basal fertilizer and tillering dressing was more related to increased tillering.
    Systematic analysis on water ecological adaptability of upland crops in loess hilly zone
    WANG Longchang, XIE Xiaoyu, WANG Lixiang, BIAN Xinmin
    2004, (5):  758-762. 
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    Based on the survey and experimental results,this paper analyzed the time-sequence relationship between crop growth and rainfall distribution,and the potential water use rate,water supply-demand equilibrium and deficit features of different upland crops in the loess hilly zone of south Ningxia.The model of water ecological adaptability index (WEAI) was proposed to evaluate these features of upland crops.The results showed that autumn crops were superior to summer crops in the coupling characteristics between crop growth and rainfall distribution.There were also differences in rainfall potential use rate among crops,the order being: perennial crops>root and stem crops>grain crops; autumn crops>summer crops.The water satiety rate and water ecological adaptability were higher for autumn crops than for summer crops,and higher in rainy years than in dry years.In line with water ecological adaptability index,the 6 main crops could be put in order of millet>potato>panic>flax>pea>spring wheat.The results of this study may provide theoretic basis for drawing up the decision scheme of cropping system in upland regions.
    Physiological mechanism of rice seedlings in low temperature-and damping-off disease resistance induced by calcium application into soil.
    LIU Feng, ZHANG Jun, ZHANG Wenji, WANG Honggang
    2004, (5):  763-766. 
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    Applying calcium oxide into soil could improve the ability of rice seedlings in low temperature-and damping-off disease resistance.After treated with calcium,the active oxygen eliminating enzyme activities of rice seedlings increased significantly.Compared with control,the SOD activity in seedling's root and shoot increased.The POD activity in rice seedling's root also increased,but decreased in shoot.The CAT activities decreased at the early stage,but increased at late stage.The soluble protein content in seedling's root and shoot was higher than that of the control.In the PAGE pattern of isoperoxidase,the band number of shoot increased,but that of root decreased.All these changes were part of reasons that applying calcium oxide into soil improved the resistance of rice seedlings to cold and damping-off disease.
    Effects of lower limit of subsurface drip irrigation on tomato growth and its yield in plastic tunnel
    ZHUGE Yuping, ZHANG Yulong, ZHANG Xudong, FENG Yongjun, LI Jun, HUANG Yi, LIU Mingda
    2004, (5):  767-771. 
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    A subsurface drip irrigation experiment was conducted in a plastic tunnel to study the effects of different lower limits of subsurface drip irrigation on tomato growth and its yield.The lower limits of subsurface drip irrigation were expressed by soil water suctions detected by tensiometers placed in 30 cm soil layer.The designed values of soil water suction in this experiment were 10,16,25,40 and 63 kPa,respectively.The results showed that the height and biomass of tomato plant decreased significantly with increasing lower limits of subsurface drip irrigation.Parabolic regression curves were suitable to simulate the relationships of stem diameter of tomato plant,yield,and water use efficiency (WUE) with lower limits of subsurface drip irrigation.The relationship between the ratio of stem diameter to plant height of tomato and lower limit could be simulated by three-dimensional multinomial regression curve.The growth of tomato root and shoot and their ratio(R/S) varied under different lower limits of subsurface drip irrigation.The tomato plant grew well,R/S was favorable,and the yield and WUE were higher when soil water suction was in the range of 25～33 kPa.When this range was served as the criteria for subsurface drip irrigation,the soil water content at the beginning of irrigation should be lower,and the irrigation frequency should be fewer than that of conventional irrigation.This range of soil water suction was in favor of improving the WUE and decreasing labor cost for tomato cultivation in plastic tunnel.
    Dynamics of organic C in black soil of Northeast China,simulated by CENTURY model I.Accumulation of soil organic carbon under natural conditions
    GAO Lupeng, LIANG Wenju, JIANG Yong, WEN Dazhong
    2004, (5):  772-776. 
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    By using CENTURY model,this paper simulated the dynamics of organic carbon and its fractions,including active,slow and passive pools,in black soils under natural condition at Nenjiang,Beian,Hailun and Harbin in Heilongjiang Province and at Gongzhuling in Jilin Province.The results showed that soil organic carbon had increased for a long time,and tended to reach the steady state.In the steady state,soil organic carbon reached 7914.72～11672.78 g·m-2,which decreased from north to south in general.The active,slow and passive fractions were 3 36%～4.62%、50.54%～55.47% and 36.47%～41.95% of soil organic carbon pool,respectively,which indicated that slow and passive fraction were the main body of soil organic carbon in native ecosystem.The simulated results were in agreement with some observed results,which can be used as the original data in the study on the dynamics of soil organic matter after cultivation.
    A dynamic knowledge model for nitrogen and water management of cotton
    ZHANG Huaizhi, ZHU Yan, CAO Weixing, ZHOU Zhiguo, ZHANG Lizhen
    2004, (5):  777-781. 
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    Through analyzing and extracting the newest research results on nitrogen and water management of cotton,a dynamic knowledge model for decision-making on total nitrogen and water supply levels and their distribution among main growth stages of cotton under different environments and yield targets was developed,with the principles of nitrogen balance and water demand and by integrating the factors of climate,soil,yield and variety.Case studies on the knowledge model with the experiment data sets of different eco-sites,varieties and soil characters indicaed a good model performance in decision-making and applicability.
    Effect of long-term fertilization on crop yield and soil fertility of upland red soil
    KONG Hongmin, HE Yuanqiu, WU Dafu, LI Chengliang
    2004, (5):  782-786. 
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    The studies on the influence of long-term fertilization on crop yield and soil fertility of upland red soil showed that P was the most deficient in this soil,and hence,phosphorus fertilizer had the best effect on crop yield.Applying lime and microelements could not significantly increase the crop yield.The concentration of P and K in peanut could be increased if fertilizer was applied,indicating that the supply level of soil nutrients decided the nutrient concentration in plants.The reconstructive efficiency of soil available nutrient pool was dependent on the surplus or deficit of soil nutrients.When the surplus of nutrients was 1 kg·hm-2,N was increased by 0.6～6.2 mg·kg-1,P was increased by 0.20～0.28 mg·kg-1,and K was increased by 1.1～8.5 mg·kg-1 .The changing in results was due to the loss of N and K from soil.The nutrient supplying capability of soil was the quantity of the nutrients which soil could provide by weathering to satisfy the plant growth.The amount of P fixed by soil was 43.5 kg·hm-2·yr-1,and that of N and K provided by soil was 40.5 and 55 kg·hm-2·yr-1,respectively.
    Influence of long-term fertilization on phosphorus fertility of calcareous soil I. Organic matter,total phosphorus and available phosphorus
    XIE Linhua, LÜ Jialong, ZHANG Yiping, LIU Xuanwei, LIU Lihua
    2004, (5):  787-789. 
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    A 23 years-located experiment of wheat-corn rotation showed that long term application of animal manure combined with chemical fertilizer contributed greater to the contents of soil organic matter,total phosphorus,inorganic phosphorus and available phosphorus.Applying chemical fertilizer could increase soil organic matter,total phosphorus,inorganic phosphorus and available phosphorus contents,but the increment was lower than treatments animal manure and fallow.Compared with no fertilization,different fertilization treatment had its own distribution characteristics of soil organic matter,total phosphorus and available phosphorus in 0～100 cm soil layer.
    Influence of long-term fertilization on phosphorus fertility of calcareous soil Ⅱ.Inorganic and organic phosphorus.
    XIE Linhua, LÜ Jialong, ZHANG Yipping, LIU Lihua
    2004, (5):  790-794. 
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    By the Jiang-Gu inorganic phosphorus fractionation method and the Bowman-Cole organic phosphorus fractionation method,this paper studied the forms and compositions of inorganic and organic phosphorus in 0～100 cm layer of calcareous soil after 23 years located experiment.The result showed that the content of inorganic phosphorus was in the order of treatment animal manure>fallow>chemical fertilizer>low rate straw>high rate straw>medium rate straw>no fertilizer.The IP i value of inorganic phosphorus forms in different fertilizer treatments had the following characteristics:a) it was relatively low for Ca2-P,Ca8-P and Al-P,but relatively high for Ca10 -P,Fe-P and O-P;b) comparing with no fertilizer treatment,treatments animal manure and fallow had a notably high IP i value of Ca2-P,Ca8-P and Al-P and a low IP i value of Ca10 -P,Fe-P and O-P;while treatment chemical fertilizer had a high IP i value of Ca2-P,Ca8-P,Al-P and O-P,but a low IP i value of Ca10 -P and Fe-P;c) as for available phosphorus source (Ca2-P,Ca8-P and Al-P),their content was higher in treatment animal manure than in treatment chemical fertilizer,and higher in treatment chemical fertilizer than in treatments straws.A combined application of straw and chemical fertilizer could increase soil organic phosphorus content notably.Applying animal manure could increase the content of all organic phosphorus forms,while applying chemical fertilizer could promote the transformation of soil resistant organic phosphorus to labile and medium labile organic phosphorus.No fertilizer treatment had a relatively lower content of labile and medium labile organic phosphorus,but a relatively high content of resistant organic phosphorus.For treatment fallow,it had a relatively low content of soil organic matter and organic phosphorus,but a relatively high content of labile and medium resistant organic phosphorus.
    Effect of grazing on grassland under protective plantation in the ecotone between agriculture and animal husbandry of Songnen plain
    HE Nianpeng, WU Ling, Zhou Daowei
    2004, (5):  795-798. 
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    Based on the current special position that grassland under protective plantation is one of the most important grazing spaces of the ecotone between agriculture and animal husbandry in Songnen plain,an experiment was conducted to investigate the effect of grazing on grassland under protective plantation.The results showed that no-grazing grassland in the grassland under protective plantation was seriously degenerated,but light and moderate grazing could stimulate the growth of grass and the product and quality of grassland.The index of grassland quality(IGQ) of no-grazing grassland was the lowest(15.51),attributing to serious degradation,while that of light grazing grassland was the highest(86.41),and the IGQ was decreased with increasing grazing intensity.Therefore,in order to stimulate the grass growth of the grassland,fully utilize the leaves of poplar,and increase the available forage resources,light and moderate grazing intensity should be advocated,but no-grazing and extreme grazing should be avoided.
    Numerical analysis on ecological gradient of plant communities in Donggou catchment,Hebei Province,China
    ZHU Yuan, QIU Yang, FU Bojie, ZHANG Ying
    2004, (5):  799-802. 
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    Based on DCCA-OAC,the plant communities in Donggou catchment,Bashang region,Hebei Province,were classified into 8 types of community.The environmental gradient,structural gradient and human-disturbance could be well expressed in the ordination plot.Axis 1 reflected the spatial pattern of plant communities along the gradient of altitude and slope,while axis 2 showed the plant community distribution on different aspects.The plant communities showed a distribution gradient along moisture gradient as shown by the combination of both axes of DCCA.The communities exhibited different trends in the synusia and species composition.Betula platyphylla was only existed on the high and steep northern aspect.The dominate species of shrub and herbaceous synusia on northern aspect were Potentilla fruticosa and Carex rigescens respectively,while on southern aspect were Artemisia spp.and Agropyron cristatum.The distribution along altitude and slope also existed among dominate species of each synusia on southern aspect.In addition,human disturbance,including grazing,farming and logging,had significant influence on the temporal and spatial distribution of communities.In general,the better the habitat,the more intensive the human disturbance.
    Yield characteristics and genetic diversity of main alfalfa varieties in China
    SUN Jianhua, WANG Yanrong
    2004, (5):  803-808. 
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    The dry matter (DM) yield and its characteristics of 28 alfalfa varieties were evaluated in the 4th year under space sowing condition.The results showed that there existed significant difference (P<0.01) in DM yield and its characteristics among the varieties.The highest and higher DM yield were obtained form varieties Xinjiang Deye (452.8 g穚lant-1) and Gannong No.3(373.0 g穚lant-1),respectively,and the varieties with the highest height and branch/plant at the 3rd cutting were Gannong No.3,Xinjiang Deye,Weixian,Tumu No.2,Xinmu No.1,and Zhaodong.The correlation analysis between DM yield and its characteristics indicated that the main factors affecting yield were the height and the branch/plant.The genetic diversity of DM yield and its components in 28 alfalfa varieties showed that the variations of DM yield and yield components of within-variety were larger than those of among-variety in majority of test varieties.The CV of all characteristics were presented in order of 3rd No.branch/plant>DM yield/plant>1st No.branch/plant>2nd No.branch/plant>Spring height>3rd height>2nd height>leaf width>budding height>leaf length>1st height.
    Soil water environment of artificial vegetation in Jinshajiang dry-hot volley
    WANG Keqin, SHEN Youxin, CHEN Qibo, WANG Zhenhong
    2004, (5):  809-813. 
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    Jinshajiang dry-hot volley has the characteristics of extremely hot and dry climate due to its specific local climate,where universally exists moisture deficit and the problem of soil water environment of artificial vegetation becomes more serious than other arid and semi-arid areas.The environmental determination in the typical sector of dry-hot volley Yuanmou showed that the existed arboreous forests evidently showed the characteristics of soil drying.Soil was short of moisture for a long term.In November after the rain season was over,soil water content in two-meter-deep soil layer was only 15% (equal to 35% of field capacity).Later on,soil water content continued decreasing and reached the lowest point in May (9%),which was near to wilting moisture of trees (the wilting moisture of surface eroded dry red soil of Yuanmou was 9.0%).As a result,trees grew slowly.As for Radonaea wiscosa shrubbery,its soil water content at the same layer was relatively 42.68% higher than that of arboreous trees.The soil moisture of natural grass slope was evidently better than that of arboreous trees and shrubbery,and was 34.36% and 22.22% higher,respectively.This kind of soil drying problem didn't come into notice in the vegetation restoration of Jinshajiang dry-hot volley,which would greatly restrict the sustainable development of artificial vegetation.
    Plant diversity variations in zokor-mound communities along a successional stage
    JIANG Xiaolei, ZHANG Weiguo, Yang Zhenyu, DU Guozhen
    2004, (5):  814-818. 
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    Using an approach of spatial sequence instead of temporal sequence,this paper studied the composition and diversity of plant species on zokor-mound along a successional gradient in alpine meadow.The results indicated that the species composition and structure of vegetations on zoker-mound along different successional stages were quite different from those of original vegetations.During the early stage of succession,the pioneer species with numerous widely dispersed seeds or spores (r strategy),such as Elsholtzia ciliata,Chenopodium glaucum,Potentilla anserina,and Ajania tenuifolia,dominated in the community.As the progression of succession,the proportion of species with vegetative expansion (k strategy),such as Saussurea hieracioides,Elymus nutans,Kobresia kansuensis,and Kobersia capillifolia,increased in the community.The analysis of Alpha diversity indicated that both species richness and evenness,in increasing order,changes as stage 1<stage 2<stage 3<stage 4<original vegetation,while Simpson index (D) and Shannon-Wiener index (H') increased significantly as the progression of succession.The analysis of Beta diversity showed that the similarity coefficient of species composition of community between stage 1 and stage 4 and between stage 1 and original vegetation was the lowest (0.18),while that of community between stage 1 and stage 2 was the highest (0.62).The functional diversity of lif form also manifested some obvious changes along the successional gradient,showing that plant community and mini-habitat changed along a successional gradient on zokor-mound.
    Effect of restorative measures on quantitative characters of reproduction for Leymus chinensis population in the degenerated grassland
    LI Hong, YANG Yunfei
    2004, (5):  819-823. 
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    Studies on the reproductive characters of Leymus chinensis population in two plots showed that the density of L.chinensis population declined significantly in plowing plot,while the density of reproductive tillers varied insignificantly.The reproductive tiller had longer ear,longer inter-node,higher ratio of reproductive growth,higher seeding percentage,more ear-nodes,more spikelets,more florets and grains in plowing plot than in enclosing plot.The grain yield,net weight of grain,and the weight of 1000 grains was 2.68 times,3.49 times and 1.3 times higher in plowing plot than in enclosing plot,respectively.The reproductive tillers with double-spikelet were 16% more in plowing plot than in enclosing plot,and they developed more double-spikelets.Relatively,the reproductive tiller in plowing plot developed few double-spikelets,more florets and more grains,so that,the grain yield of the population was enhanced largely.The reproductive allocations of L.chinensis didn't response differently to both plowing and enclosing at three module levels,including population to reproductive tiller,reproductive tiller to ear,and ear to grain,but the allocation of population to ear and to grain,and the allocation of reproductive tiller to grain were significantly higher in plowing plot than in enclosing plot.
    Properties of organic matter in natural and reclaimed steppe soil
    PING Lifeng, DOU Sen, ZHANG Jinjing, GUAN Song
    2004, (5):  824-826. 
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    The properties of organic matter in steppe chernozem,steppe wind-blown soil and cultivated wind-blown soil were studied by analyzing the status of organo-mineral complex and the combined status and composition of humus.The results showed that different types and utilization patterns of soil had very different effects on the properties of soil organic matter.The amounts of total organic carbon,biomass C,heavy fraction C,extractable humus (HE) and loosely-combined humus and the humification degree were higher in steppe chernozem than in wind-blown soil.Steppe soil had higher amounts of total organic carbon,biomass C,heavy fraction C,HE and different combined humus than sunflower wind-blown soil,but humification degree had no obvious difference.
    Dynamics of ecological footprints of agricultural region in Hexi oasis of Gansu Province
    LIN Haiming, XIE Peng
    2004, (5):  827-832. 
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    This paper studied the dynamics of ecological footprints(EF),degree of sustainable development and its tendency of Hexi oasis agricultural region in Gansu.The results showed that the EF displayed an increasing trend from 0.426 hm2 to 2.158 hm2 in 1949～2000,which was 0.693 hm2 in 1949～1970,1.029 hm2 in 1975～1980,and 2.288 hm2 in 1985～2000.The ecological capacity (EC)was also increased from 0.550 hm2 in 1949 to 1.762 hm2 in 2000.Comparing with EF,the EC increased at low speed,which reached 0.782 hm2 in 1949～1970 and 1.715 hm2 in 1975～2000.Meanwhile,the sustainable development of Hexi region maintained ecological remainder during 1949～1975.However,it emerged ecological deficit in 1980,and resumed in 1985.The sustainable development of Hexi region has been successive ecological deficit since 1991.The degree was keeping negative increment at acceleration,and got to -0258 hm2 in 1991～2000.These results showed that the regional economic development of Hexi region was far away from sustainable development,and was in no-sustainable state.
    Simulation of hydrological response to land-cover changes
    CHEN Junfeng, LI Xiubin
    2004, (5):  833-836. 
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    Hydrological modeling methodology had a quick development in recent years.In this article,a distributed hydrological model SWAT was used to simulate the rainfall-runoff relationship of the Suomo Basin under different land covers in order to evaluate the impact of land-cover changes on runoff,evapotransperation and peak flow.The results showed that if the land-cover changed from non-vegetation-cover to full-forest-cover scenarios,the runoff depth decreased,evaporation increased,while the reduced extent of runoff in dry season was less than that in rainy season,and in the first rainy season,the reduced extent of runoff was more than that in the second rainy season.With the same recurrent flood flow,the peak flow value under full-forest-cover scenario was 31.2% less than that under non-vegetation-cover scenario.The effect of land-cover between current cover and optimum cover on hydrology was small for large storm,and big for small storm events.
    Spatially explicit Landscape Model-LANDIS I.Mechanism
    XU Chonggang, HU Yuanman, CHANG Yu, LI Xiuzhen, BU Renchang, HE Hongshi
    2004, (5):  837-844. 
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    Spatially explicit landscape models are the models that spatially explicitly simulate the ecological processes at landscape scale on heterogeneous landscape.LANDIS is a spatially explicit landscape model of forest landscape disturbance,succession and management.By recording the absence/presence of species in terms of 10-yr age cohorts at site level,the semi-quantitative description of fire and windthrow disturbances,and the representation of age-cohorts by bit-wise array,it is possible for LANDIS to simulate the ecological processes at species,site and landscape level.We addressed in detail the approaches used in simulating seed dispersal,disturbances of fire and windthrow,and harvesting.The deficiencies of the model were also discussed to provide feedback for model development.
    Response of parasitic wasps of cotton bollworm to different cotton varieties with transgenic Bacillus thringienthsis genes
    YU Yueshu, YANG Yizhong, LU Yanhui
    2004, (5):  845-848. 
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    The relationship between the parasitic wasp population number of cotton bollworm (Helicoverpa armigera) and the varieties of cotton was studied by releasing and collecting the eggs and larvae of cotton bollworm on transgenic and non-transgenic cottons.The research results from2000 to 2003 showed that the parasitic rates of the eggs and larvae of cotton bollworm were notably lower in transgenic cotton field than in non-transgenic cotton field.At the same time,the effect of transgenic and non-transgenic cottons on the selection behavior of the parasitic wasp Microplitis mediatar of the larvae of cotton bollworm was studied by using “Y” olfactometer.The results showed that the selection response about the parasitic wasp Microplitis mediatar of cotton bollworm on non-transgenic cotton was prior to the transgenic cotton.
    Effect of insect pest on activated oxygen metabolism in lanceolate leaves of Populus euphratica under different water condition
    WAN Dongshi, LI Hongyu, ZHOU Gongke, LIANG Houguo, ZHANG Lixin
    2004, (5):  849-852. 
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    This paper studied the effect of insect pest on the activities of protective enzymes SOD and CAT and the contents of H2O2 and H2O2 in lanceolate leaves of Populus euphratica under different soil water conditions.The results showed that soil water deficiency did not increase SOD and CAT activities and H2O2 and H2O2 contents in lanceolate leaves,but under this condition,insect pest increased them.When soil water was abundance,insect pest couldn't increase the activities of SOD and CAT and the contents of H2O2 and H2O2 in lanceolate leaves.It's concluded that insect pest had an important role in death of Populus euphratica under soil water deficiency.
    Influence of temperature on insect-resistance of transgenic hybrid poplar 741.
    LIU Junxia, GAO Baojia, ZHANG Juhong, WANG Yongfang, WANG Jinmao
    2004, (5):  853-855. 
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    The study showed that the insect-resistance of transgenic hybrid poplar 741 was closely related with temperature.The total mortality and accumulative mortality of Gypsy moth (Lmantriadispar L.) larvae increased with increasing temperature,and the sensitivity of larvae to the clones of transgenic hybrid poplar 741 and temperature decreased gradually with the increasing instars.Temperature had a promotion to the development of larvae fed on CK.When the temperature was high,the development of larvae quickened,the development period shortened,and the weight increasing rate and the frass increasing quantity quickened,but the development rate of larvae fed on transgenic hybrid poplar 741 was not obvious with varied temperature.The regressive equation of temperature and Clostera anachoreta(Fabricius) mortality during 1998～2000 year indicated that high resistant and medium resistant clones' temperature-insect mortality curve presented an obvious regressive relation.
    Repellent effect of volatile oil from whitefly (Syngonium podophyllum) on aphids and its chemical constituents
    ZHOU Qiong, LIANG Guangwen, KONG Chuihua, HUANG Shoushan
    2004, (5):  856-858. 
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    The interference effect of volatile oil from whitefly (Syngonium podophyllum) on aptera aphid,guard aphid (Aphis gossypii),mustard aphid (Lipaphis erysimi) and red peach aphid (Myzus persicae) was studied by using four arms olfraetometes.The results showed that the volatile oil had distinct repelling effect.The staying periods of test aphids in test areas were obviously shorter than in control areas,and the selecting frequencies were less than the control,too.The volatile oil did not show repelling effect on red peach aphid at the test concentrations.The components of the volatile oil from S.podophyllum were analysed by GC-MS.43 constituents were identified.
    Behavioral and morphological indices for phase transformation of oriental migratory locust Locusta migratoria manilensis
    GUO Zhiyong, SHI Wangpeng, ZHANG Long, WANG Guilong
    2004, (5):  859-862. 
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    Based on the data obtained from laboratory and field experiments,this paper established the morphological and behavioral indices for phase solitaria (S) and phase gregaria (G) of oriental migratory locust Locusta migratoria manilensis.S-females and S-males jumped 1.4 times·min-1,and the frequency of turning was 1.3 times·min-1 for S-females and 1.4 times·min-1 for S-males.G-females and G-males jumped 1.6 times·min-1,and the frequency of turning was 1.6 times·min-1 for G-females and 1.5 times·min-1 for G-males.Both jumping and turning behaviours were significantly greater (P<0.05) for gregaria locusts than for solitairia locusts.These behavioral parameters of the frequency of locust jumping and turning can be used as “the behavioral indices for phase transformation".The F/C ratio and the E/F ratio might be used as the morphological indices for phase transformation of the gregaria and solitaria of Locusta migratoria manilensis.The F/C ratio goes up as the locust grows,but the F/C ratio of females from the 4th instar to adult is less than that of the male of the same instar and phase.Comparing with the F/C and E/F ratio of the male,those of the female exhibited significant difference in the same phase.The F/C ratio of the fourth instar,fifth instar and adults were 2.5,2.8 and 3.3 for S-females,and 2.6,2.9 and 3.5 for S-males.As for G-females and and G-males,the F/C ratio of the fourth instar,fifth instar and adults were 2.5,2.8,3.3 and 2.5,2.7,3.1,respectively.The E/F ratios of adults can be used as “the morphological phase indices for phase transformation".
    Production and properties of chitinase from Beauveria bassiana Bb174 in solid state fermentation
    ZHANG Jie, CAI Jingmin, WU Ke, JIN Shengxian, PAN Renrui, FAN Meizhen
    2004, (5):  863-866. 
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    This paper studied the chitinase production of Beauveria bassiana Bb174 under solid state fermentation condition.The optimal medium consisted of wheat bran and silkworm chrysalis at the ratio of 4:1,supplemented with 1 g peptone·L-1 as nitrogen source and some other mineral nutrients.The enzyme activity reached 126 units per gram dry medium after cultured for 2 days at 28 ℃ and natural pH by inoculated 3 ml spore suspension into this medium.The optimal temperature and pH for chintinase production were 40 ℃ and 5.0,respectively.The temperature to lose 50% activity of the enzyme was 48 ℃ after incubated at 30～70 ℃ for 1 h.The enzyme was stable at 30～40 ℃ and pH 4～6,and the Km and Vmax values were 0.52 mg·ml-1 and 0.7△E680·h-1,respectively.
    Effect of organic materials in controlling cucumber seedling diseases
    YUAN Fei, PENG Yu, ZHANG Chunlan, SHEN Qirong
    2004, (5):  867-870. 
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    In this work,pot experiments with organic materials were carried out to study the alleviation of Fusarim wilt and Rhizictonia wilt of cucumber and the changes of soil microorganism.The results showed that rice straw,pig feces and wood chip could alleviate Fusarium wilt and Rhizoctonia wilt of cucumber,and the effect of rice straw was most significant,followed by pig feces and wood chip.The amount of soil microbes was higher in organic materials treatments than in control. The total amount of actinomyces and epidhyte which can inhibit the growth of pathogen was the highest in rice straw treatment,followed by pig feces treatment.No significant change of soil microbial amount was found in wood chip treatment.
    Revulsive response of protein and enzyme activity of degradative Bacilluss strains by phenanthrene
    ZHONG Ming, ZHOU Qixing, XU Huaxia, WU Xiaodan, LI Yushuang
    2004, (5):  871-874. 
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    Three strains of Bacillus sp.BA11,BA19 and BA27,which can grow when phenanthrene is taken as the sole source of carbon and energy,were isolated from an oil-contaminated soil.Their crude extract was used to test the activities of polyphenol oxidase and catalase.The results demonstrated that all the three strains did not show a significant change in the activity of both enzymes when phenanthrene was lower than 200 mg稬-1 .Under different phenanthrene concentration,the enzyme activities of strains BA19,BA27 showed a higher stabilization than BA11.Using the SDS-PAGE contrasted the difference of proteins between the strains in normal medium and the strains growing on phenanthrene,the results showed that BA27 growing on phenanthrene synthesized a new protein with 27 000 dal of molecular weight.At the same time,the synthesis of some proteins was cancelled.We conjecture that the new protein induced by phenanthrene may be related to the ability of phenanthrene degradation and the stabilization of enzyme activity by the strain.
    Diversity and stability of arthropod assemblage in tea orchard
    CHEN Yigen, XIONG Jinjun, HUANG Mingdu, GU Dejiu
    2004, (5):  875-878. 
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    Two tea orchards,simplex tea orchard with weeds removed manually or by herbicides (STO) and complex tea orchard with the weed Hedyotis uncinella(CTO),each with an area of 0.4 hm2,were established in 1995 in Yingde Hongxing Tea Plantation,Guangdong Province.The primary eigenvalues,species richness index (R),assemblage diversity index (H'),evenness index (J) and species concentration index (C) of arthropod assemblage were employed and compared to assess the efficacy of STO and CTO on the diversity and stability of arthropod assemblage.Stability indexes Ss/Si and Sn/Sp and variation coefficient of diversity index ds/dm were utilized as well.The results demonstrated that the R of arthropod assemblage in CTO ranged from 4 to 8,with the highest of 7.7403,while that in STO varied mainly between 4 to 6.The average R of arthropod assemblage in CTO was 5.4672?0.3483,higher than that in STO (4.8809?0.3175).The H' of arthropod in CTO (3,8535?0.1232) was higher,in contrast to the value in STO (3.4654?0.1856).The J in CTO was higher,while the species concentration index (C) was lower,in comparison to STO.The stability indexes Ss/Si and Sn/Sp of CTO were greater than those of STO,while the ds/dm in CTO (0.1107) was lower than that in STO (0.1855).All these indicated that the diversity of arthropod assemblage was better preserved in CTO,and the arthropod assemblage in CTO was more stable.
    Genetic diversity of Fujian local duck populations in different ecological type
    XIAO Tianfang, ZHENG Xiancheng, WU Qiwen
    2004, (5):  879-882. 
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    A total of 40 short primers of arbitrary nucleotide sequence were used singly in polymerase chain reaction to amplify DNA fingerprints in pools of DNA representing seven duck populations from two ecological areas in Fujian Province.9 primers which discriminated between the breed-specific DNA pools were used further to amplify individual pool components.Shannon index was used to calculate the genetic diversity and its partition within and between the seven duck populations.The relationships between seven duck populations and ecological environment,and their variation patterns were studied by RAPD.The results showed that the genetic diversity in east Fujian (67.97%) was higher than that in west Fujian (59.05%).Genetic differentiation was estimated to be about 32.03% among populations of east Fujian,and about 40.95% among populations of west Fujian.The genetic distance index matrix and UPMGA dendrogram indicated that Liancheng white duck,Taining duck,Longyan duck and Sanming duck in west Fujian had closer genetic relationships,and Longhai Jinding duck and Putian black duck in east Fujian had the similarly.There were some evidences showing that relevance existed between the variation and the geographical position.
    Community diversity of entomogenous fungi in Dabie Mountains in Anhui
    WANG Sibao, LIU Jingnan, WANG Chengshu, FAN Meizhen, LI Zengzhi
    2004, (5):  883-887. 
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    The abundance,Shannon-Wiener's diversity index (H'),Pielou's evenness (E) and K-dominance curves were calculated for community diversity of entomogenous fungi in the Dabie Mountains.The results showed that the species number,diversity value,evenness and dominance were distinctly different among different habitats,altitudes,seasons and horizontals.These indexes reflected the community structure of entomogenous fungi,and revealed the relations among different entomogenous fungal communities.By means of Bray-Curtis Measure and UPGMA clustering analysis,entomogenous fungi were vertically distributed from lower altitude upwards into 3 belts,i.e.,warm humid low-mountains zone(alt.<900 m),cool humid mid-mountains zone(alt.900～1 200 m),and cold humid high-mountains zone(alt.>1 200 m).
    Acute toxicity and bio-concentration factor of three pesticides on Brachydanio rerio
    DING Zhonghai, YANG Yi, JIN Hongjun, SHAN Zhengjun, YU Hongxia, FENG Jianfang, ZHANG Xiaofeng, ZHOU Jiayan
    2004, (5):  888-890. 
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    The acute toxicity and bio-concentration factor of imidacloprid,triazophos and pyridaben were measured by using Brachydanio rerio as test organism.The 96 h LC50 value of these pesticides was 281.37 mg·L-1,8.37 mg·L-1 and 11.66 μg·L-1,respectively.The concentrations of pesticides and the exposure duration of 14 days for BCF tests were designed according to results of the acute toxicity tests and relevant guideline.At the exposure concentrations of 0.5 and 5 mg·L-1,the bio-concentration factor (BCF) of imidacloprid was 1.52 and 0.97,respectively; while at the exposure concentrations of 0.02 and 0.2 mg·L-1,that of triazophos was 9.00 and 8.45,respectively.For pyridaben,the BCF was respectively 5600 and 4920 at the exposure concentrations of 0.1 and 1μg·L-1 .
    Accumulation and translocation of lead in soil-crop system of green food production
    LI Liguang, HE Xingyuan, CAO Zhiqiang, CHEN Wei
    2004, (5):  891-894. 
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    In this paper,the accumulation and translocation of lead in soil-crop ecosystems were studied through fertilization with chemical fertilizer,manure and bio-fertilizer.The results showed that the soil total Pb content was decreased with soil depth.It was 11.14 and 9.37 mg·kg-1 in 0～15 and 15～30 cm after harvest,respectively.Rice root absorbed lead from soil,and transferred it to stem-leaf and grain.The Pb content in rice plant was root>stem and leaf>grain,which was increased with rice growth.The grains of 606-14 and Liao 294 contained 0.008 and 0.007 mg·kg-1 of Pb,respectively,which is under the standard of green food.Variance analysis indicated that the grain yield of different varieties had a significant variance,but no significant variance was found among different treatments.It could be summarized that manure or bio-fertilizer could be the substitute of chemical fertilizer in producing rice.
    Effect of arsenic on soil urease activity
    HE Wenxiang, MA Aisheng, WU Yongjun, ZHU Minge
    2004, (5):  895-898. 
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    By simulation method,this paper studied the urease activity in arsenic polluted soils.The results showed that arsenic could activate soil urease activity after added for one year.With arsenic addition,soil urease activity remarkably increased,and there existed a significantly positive correlation.The Vmax of soil urease increased with arsenic addition,while the Km of urease in high and low fertility soil was unchanged and slight increased,respectively.It is proved that As could accelerate the separating velocity of enzyme-urea complexes.This paper also illustrated that soil properties were important to study the relationship between soil enzyme and pollutants.
    Methods for studying soil microbial diversity
    ZHONG Wenhui, CAI Zucong
    2004, (5):  899-904. 
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    This paper gave a review on the main methods for studying soil microbial diversity.Traditionally,the analysis of soil microbial communities relied on culturing techniques,using a variety of culture media.However,only a small fraction of the soil microbial community has been cultured and isolated with this approach.Other methods such as Biolog GN analysis,phospholipids fatty acids analysis and nucleic acid-based analysis can be used to study and characterize soil microbes which currently cannot be cultured,and to get more and complete information about soil microbial community.
    Selectivity and influence of parasite plants on their hosts.
    HU Fei, KONG Chuihua
    2004, (5):  905-908. 
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    More and more studies have demonstrated that parasite plants have strong selectivity on their hosts,which is correlated with nutrients,secondary metabolites and hardship.It is beneficial to the growth and development of parasite plants under multiple hosts.Parasite plants can change the direction of photosynthate flow and influence the adjustable ability of leaf stomata on their hosts.The growth and development of these hosts are dramatically influenced.Furthermore,parasite plants are able to have strong impacts on biomass,composition diversity,and fluctuation of the community in which they occurred.An increasing number of studies showed that the interactions between parasitic plants and their hosts may compare with those between herbivores and plants.The influence of climate changing on the relationships between parasite plants and their hosts is at beginning.Recently,most of parasite plants have more economical values other than harmful weeds.Therefore,researches on the relationships between parasite plants and their hosts are of significance both in theoretical and practical aspects.
    Comprehensive assessment on sustainable development of livestock production
    SHI Guanghua, SUN Zhenjun, GAO Jixi
    2004, (5):  909-912. 
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    To assess the sustainable development of livestock production is not only helpful to learn about the present status of the livestock development,but also of great significance to predict the trend of the development of livestock husbandry and to stipulate the appropriate policies and laws in livestock husbandry.After summarizing and analyzing the present methods and theories adopted in the assessment of global sustainable development,and taking into account the characteristics of livestock production,the authors provided a new comprehensive assessment method and theory.
    Bryophyte biomass in dark coniferous forest of Changbai Mountain
    YE Ji, HAO Zhanqing, DAI Guanhua
    2004, (5):  737-740. 
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    In this paper,the floor and epiphytic bryophyte biomass was sampled from the dark coniferous forest on the north slope of Changbai Mountain,with an altitude from 1100 m to 1700 m.The floor bryophyte biomass was measured by the method of transect sampling,and epiphytic bryophyte biomass was measured by McCune method.The results showed that bryophytes distributed unevenly,and their biomass changed greatly with increasing altitude.The biomass was the least (543 kg穐m-2) at 1 100 m,but the greatest (5 097 kg穐m-2) at 1 250 m.The changes of bryophytes biomass could indicate different environmental situations.The biomass change of Hylocomium splendens and Rhytidiadelphus triquetrus with ascending altitude had some relativity with the community character of forest ecosystem.The biomass of Hylocomium splendens increased,but that of Rhytidiadelphus triquetrus decreased with altitude ascending from 1 100 m to 1 700 m.Moreover,the biomass changes could also show the needed physiological conditions of different bryophytes.
    Forest landscape change and its driving force during past ten years in Bilahe forest region,Inner Mongolia
    CHEN Wenbo, XIAO Duning, ZHENG Jiao, GUO Fuliang, JIANG Yingpeng
    2004, (5):  741-747. 
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    Based on RS and GIS,this paper studied the forest landscape change during the past ten years in Bilahe forest region,Inner Mongolia,from the aspects of general landscape features,individual patch characteristics,and relationship among patches.The results showed that the forest landscape changed a lot due to the stronger human intervention on forest ecosystem.The general tendency was that the human patches (residential area and cultivated land) were!expanding quickly,whereas the natural patches (forest patches,etc.) were shrinking gradually.The results of area transformation matrix showed that in 1997,30.87% of cultivated lands were transformed from Quercus mongolica.According to the analysis of landscape heterogeneity,the patches were increased by 68 80%,but their average area was reduced by 4.82%.In 1988,the landscape dominated by few patches changed to a landscape with comparatively even distribution of patches,due to the decrease of landscape dominance and contagion,and the increase of landscape diversity.Based on the analyses of physical geography and social economics in the study area and the regions related,this paper discovered that the most decisive driving forces of landscape changes were fire intervention,deforestation,and reclamation of virgin land.
    Dynamics of biomass and stem volume of Picea asperata stands in artificial restoration process of subalpine coniferous forest
    HE Hai, QIAO Yongkang, LIU Qing, WU Yan, LIN Bo
    2004, (5):  748-752. 
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    The dynamics of aboveground biomass and stem volume in subalpine coniferous Picea asperata plantations with different stand ages in 70 years of artificial restoration process were studied by adopting the concept of space as a substitute for time.The results indicated that before 20 years of stand age,the biomass of spruce single tree grew quite slow,with that of the twigs and needles accounting for about 50%;after 20 years,it increased obviously,with 60% of biomass accumulated in stem;from 30 to 40 years,the increasing rate of biomass relatively slowed down,and maintained a rapid growth after 40 years.The biomass of spruce population showed a similar trend,though the period of relative slow-down of growth continued from 30 to 50 years.For the biomass of community as a whole,it presented a general continuous increase,but varied greatly for different layers.In shrub layer,the biomass rose rapidly at the early stage of plantation establishment and gradually decreased after 20 years,while that of the herbaceous plants reduced continuously and accounted less than 0.2% of the total biomass of community when the stand reached 70 years.Both the mean annual increment and the current annual increment of stem volume of spruce single tree went up with the increasing stand age,and more rapidly at the later stages.Similar changes were observed for the stock volume of the plantations,with the only difference that the current annual increment from 30 to 50 years was relatively reduced.Based on the data from stem analysis and growth ring measurement,regression models of stem volume with DBH and tree height of 70 years Picea asperata plantation were established.
    Effect of enhanced ammonium nutrition (EAN) at different growth stages on wheat growth and nitrogen utilization
    SUN Chuanfan, DAI Tingbo, JING Qi, CAO Weixing
    2004, (5):  753-757. 
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    Field experiments were conducted in 1998～2000 to investigate the effects of EAN applied at different growth stages (basal,tillering,jointing,booting and whole growth stage) on wheat growth and nitrogen utilization.Compared with single NO3-,EAN as basal fertilizer,tillering dressing and jointing dressing promoted dry matter and nitrogen accumulation after heading,LAI at booting stage,and chlorophyll content of wheat.Grain yield was also increased significantly.Nevertheless,there was no obvious promoting effect of EAN at booting dressing.No significant response of plant growth under EAN was observed over whole growth stage,compared with EAN at early stages,indicating that EAN after jointing was not effective to increase nitrogen utilization and wheat growth.But,it was more effective on decreasing N leaching than other EAN treatments.All EAN treatments increased nitrogen flow efficiency (NFE) and nitrogen recovery efficiency (NRE),compared with single NO3-,but EAN treatments before jointing had significant effects on increasing nitrogen utilization.Besides these,EAN as jointing dressing improved the leaf photosynthetic characteristics during the late developmental stage and the remobilization of dry matter to grain,while EAN as basal fertilizer and tillering dressing was more related to increased tillering.
    Systematic analysis on water ecological adaptability of upland crops in loess hilly zone
    WANG Longchang, XIE Xiaoyu, WANG Lixiang, BIAN Xinmin
    2004, (5):  758-762. 
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    Based on the survey and experimental results,this paper analyzed the time-sequence relationship between crop growth and rainfall distribution,and the potential water use rate,water supply-demand equilibrium and deficit features of different upland crops in the loess hilly zone of south Ningxia.The model of water ecological adaptability index (WEAI) was proposed to evaluate these features of upland crops.The results showed that autumn crops were superior to summer crops in the coupling characteristics between crop growth and rainfall distribution.There were also differences in rainfall potential use rate among crops,the order being: perennial crops>root and stem crops>grain crops; autumn crops>summer crops.The water satiety rate and water ecological adaptability were higher for autumn crops than for summer crops,and higher in rainy years than in dry years.In line with water ecological adaptability index,the 6 main crops could be put in order of millet>potato>panic>flax>pea>spring wheat.The results of this study may provide theoretic basis for drawing up the decision scheme of cropping system in upland regions.
    Physiological mechanism of rice seedlings in low temperature-and damping-off disease resistance induced by calcium application into soil.
    LIU Feng, ZHANG Jun, ZHANG Wenji, WANG Honggang
    2004, (5):  763-766. 
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    Applying calcium oxide into soil could improve the ability of rice seedlings in low temperature-and damping-off disease resistance.After treated with calcium,the active oxygen eliminating enzyme activities of rice seedlings increased significantly.Compared with control,the SOD activity in seedling's root and shoot increased.The POD activity in rice seedling's root also increased,but decreased in shoot.The CAT activities decreased at the early stage,but increased at late stage.The soluble protein content in seedling's root and shoot was higher than that of the control.In the PAGE pattern of isoperoxidase,the band number of shoot increased,but that of root decreased.All these changes were part of reasons that applying calcium oxide into soil improved the resistance of rice seedlings to cold and damping-off disease.
    Effects of lower limit of subsurface drip irrigation on tomato growth and its yield in plastic tunnel
    ZHUGE Yuping, ZHANG Yulong, ZHANG Xudong, FENG Yongjun, LI Jun, HUANG Yi, LIU Mingda
    2004, (5):  767-771. 
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    A subsurface drip irrigation experiment was conducted in a plastic tunnel to study the effects of different lower limits of subsurface drip irrigation on tomato growth and its yield.The lower limits of subsurface drip irrigation were expressed by soil water suctions detected by tensiometers placed in 30 cm soil layer.The designed values of soil water suction in this experiment were 10,16,25,40 and 63 kPa,respectively.The results showed that the height and biomass of tomato plant decreased significantly with increasing lower limits of subsurface drip irrigation.Parabolic regression curves were suitable to simulate the relationships of stem diameter of tomato plant,yield,and water use efficiency (WUE) with lower limits of subsurface drip irrigation.The relationship between the ratio of stem diameter to plant height of tomato and lower limit could be simulated by three-dimensional multinomial regression curve.The growth of tomato root and shoot and their ratio(R/S) varied under different lower limits of subsurface drip irrigation.The tomato plant grew well,R/S was favorable,and the yield and WUE were higher when soil water suction was in the range of 25～33 kPa.When this range was served as the criteria for subsurface drip irrigation,the soil water content at the beginning of irrigation should be lower,and the irrigation frequency should be fewer than that of conventional irrigation.This range of soil water suction was in favor of improving the WUE and decreasing labor cost for tomato cultivation in plastic tunnel.
    Dynamics of organic C in black soil of Northeast China,simulated by CENTURY model I.Accumulation of soil organic carbon under natural conditions
    GAO Lupeng, LIANG Wenju, JIANG Yong, WEN Dazhong
    2004, (5):  772-776. 
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    By using CENTURY model,this paper simulated the dynamics of organic carbon and its fractions,including active,slow and passive pools,in black soils under natural condition at Nenjiang,Beian,Hailun and Harbin in Heilongjiang Province and at Gongzhuling in Jilin Province.The results showed that soil organic carbon had increased for a long time,and tended to reach the steady state.In the steady state,soil organic carbon reached 7914.72～11672.78 g·m-2,which decreased from north to south in general.The active,slow and passive fractions were 3 36%～4.62%、50.54%～55.47% and 36.47%～41.95% of soil organic carbon pool,respectively,which indicated that slow and passive fraction were the main body of soil organic carbon in native ecosystem.The simulated results were in agreement with some observed results,which can be used as the original data in the study on the dynamics of soil organic matter after cultivation.
    A dynamic knowledge model for nitrogen and water management of cotton
    ZHANG Huaizhi, ZHU Yan, CAO Weixing, ZHOU Zhiguo, ZHANG Lizhen
    2004, (5):  777-781. 
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    Through analyzing and extracting the newest research results on nitrogen and water management of cotton,a dynamic knowledge model for decision-making on total nitrogen and water supply levels and their distribution among main growth stages of cotton under different environments and yield targets was developed,with the principles of nitrogen balance and water demand and by integrating the factors of climate,soil,yield and variety.Case studies on the knowledge model with the experiment data sets of different eco-sites,varieties and soil characters indicaed a good model performance in decision-making and applicability.
    Effect of long-term fertilization on crop yield and soil fertility of upland red soil
    KONG Hongmin, HE Yuanqiu, WU Dafu, LI Chengliang
    2004, (5):  782-786. 
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    The studies on the influence of long-term fertilization on crop yield and soil fertility of upland red soil showed that P was the most deficient in this soil,and hence,phosphorus fertilizer had the best effect on crop yield.Applying lime and microelements could not significantly increase the crop yield.The concentration of P and K in peanut could be increased if fertilizer was applied,indicating that the supply level of soil nutrients decided the nutrient concentration in plants.The reconstructive efficiency of soil available nutrient pool was dependent on the surplus or deficit of soil nutrients.When the surplus of nutrients was 1 kg·hm-2,N was increased by 0.6～6.2 mg·kg-1,P was increased by 0.20～0.28 mg·kg-1,and K was increased by 1.1～8.5 mg·kg-1 .The changing in results was due to the loss of N and K from soil.The nutrient supplying capability of soil was the quantity of the nutrients which soil could provide by weathering to satisfy the plant growth.The amount of P fixed by soil was 43.5 kg·hm-2·yr-1,and that of N and K provided by soil was 40.5 and 55 kg·hm-2·yr-1,respectively.
    Influence of long-term fertilization on phosphorus fertility of calcareous soil I. Organic matter,total phosphorus and available phosphorus
    XIE Linhua, LÜ Jialong, ZHANG Yiping, LIU Xuanwei, LIU Lihua
    2004, (5):  787-789. 
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    A 23 years-located experiment of wheat-corn rotation showed that long term application of animal manure combined with chemical fertilizer contributed greater to the contents of soil organic matter,total phosphorus,inorganic phosphorus and available phosphorus.Applying chemical fertilizer could increase soil organic matter,total phosphorus,inorganic phosphorus and available phosphorus contents,but the increment was lower than treatments animal manure and fallow.Compared with no fertilization,different fertilization treatment had its own distribution characteristics of soil organic matter,total phosphorus and available phosphorus in 0～100 cm soil layer.
    Influence of long-term fertilization on phosphorus fertility of calcareous soil Ⅱ.Inorganic and organic phosphorus.
    XIE Linhua, LÜ Jialong, ZHANG Yipping, LIU Lihua
    2004, (5):  790-794. 
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    By the Jiang-Gu inorganic phosphorus fractionation method and the Bowman-Cole organic phosphorus fractionation method,this paper studied the forms and compositions of inorganic and organic phosphorus in 0～100 cm layer of calcareous soil after 23 years located experiment.The result showed that the content of inorganic phosphorus was in the order of treatment animal manure>fallow>chemical fertilizer>low rate straw>high rate straw>medium rate straw>no fertilizer.The IP i value of inorganic phosphorus forms in different fertilizer treatments had the following characteristics:a) it was relatively low for Ca2-P,Ca8-P and Al-P,but relatively high for Ca10 -P,Fe-P and O-P;b) comparing with no fertilizer treatment,treatments animal manure and fallow had a notably high IP i value of Ca2-P,Ca8-P and Al-P and a low IP i value of Ca10 -P,Fe-P and O-P;while treatment chemical fertilizer had a high IP i value of Ca2-P,Ca8-P,Al-P and O-P,but a low IP i value of Ca10 -P and Fe-P;c) as for available phosphorus source (Ca2-P,Ca8-P and Al-P),their content was higher in treatment animal manure than in treatment chemical fertilizer,and higher in treatment chemical fertilizer than in treatments straws.A combined application of straw and chemical fertilizer could increase soil organic phosphorus content notably.Applying animal manure could increase the content of all organic phosphorus forms,while applying chemical fertilizer could promote the transformation of soil resistant organic phosphorus to labile and medium labile organic phosphorus.No fertilizer treatment had a relatively lower content of labile and medium labile organic phosphorus,but a relatively high content of resistant organic phosphorus.For treatment fallow,it had a relatively low content of soil organic matter and organic phosphorus,but a relatively high content of labile and medium resistant organic phosphorus.
    Effect of grazing on grassland under protective plantation in the ecotone between agriculture and animal husbandry of Songnen plain
    HE Nianpeng, WU Ling, Zhou Daowei
    2004, (5):  795-798. 
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    Based on the current special position that grassland under protective plantation is one of the most important grazing spaces of the ecotone between agriculture and animal husbandry in Songnen plain,an experiment was conducted to investigate the effect of grazing on grassland under protective plantation.The results showed that no-grazing grassland in the grassland under protective plantation was seriously degenerated,but light and moderate grazing could stimulate the growth of grass and the product and quality of grassland.The index of grassland quality(IGQ) of no-grazing grassland was the lowest(15.51),attributing to serious degradation,while that of light grazing grassland was the highest(86.41),and the IGQ was decreased with increasing grazing intensity.Therefore,in order to stimulate the grass growth of the grassland,fully utilize the leaves of poplar,and increase the available forage resources,light and moderate grazing intensity should be advocated,but no-grazing and extreme grazing should be avoided.
    Numerical analysis on ecological gradient of plant communities in Donggou catchment,Hebei Province,China
    ZHU Yuan, QIU Yang, FU Bojie, ZHANG Ying
    2004, (5):  799-802. 
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    Based on DCCA-OAC,the plant communities in Donggou catchment,Bashang region,Hebei Province,were classified into 8 types of community.The environmental gradient,structural gradient and human-disturbance could be well expressed in the ordination plot.Axis 1 reflected the spatial pattern of plant communities along the gradient of altitude and slope,while axis 2 showed the plant community distribution on different aspects.The plant communities showed a distribution gradient along moisture gradient as shown by the combination of both axes of DCCA.The communities exhibited different trends in the synusia and species composition.Betula platyphylla was only existed on the high and steep northern aspect.The dominate species of shrub and herbaceous synusia on northern aspect were Potentilla fruticosa and Carex rigescens respectively,while on southern aspect were Artemisia spp.and Agropyron cristatum.The distribution along altitude and slope also existed among dominate species of each synusia on southern aspect.In addition,human disturbance,including grazing,farming and logging,had significant influence on the temporal and spatial distribution of communities.In general,the better the habitat,the more intensive the human disturbance.
    Yield characteristics and genetic diversity of main alfalfa varieties in China
    SUN Jianhua, WANG Yanrong
    2004, (5):  803-808. 
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    The dry matter (DM) yield and its characteristics of 28 alfalfa varieties were evaluated in the 4th year under space sowing condition.The results showed that there existed significant difference (P<0.01) in DM yield and its characteristics among the varieties.The highest and higher DM yield were obtained form varieties Xinjiang Deye (452.8 g穚lant-1) and Gannong No.3(373.0 g穚lant-1),respectively,and the varieties with the highest height and branch/plant at the 3rd cutting were Gannong No.3,Xinjiang Deye,Weixian,Tumu No.2,Xinmu No.1,and Zhaodong.The correlation analysis between DM yield and its characteristics indicated that the main factors affecting yield were the height and the branch/plant.The genetic diversity of DM yield and its components in 28 alfalfa varieties showed that the variations of DM yield and yield components of within-variety were larger than those of among-variety in majority of test varieties.The CV of all characteristics were presented in order of 3rd No.branch/plant>DM yield/plant>1st No.branch/plant>2nd No.branch/plant>Spring height>3rd height>2nd height>leaf width>budding height>leaf length>1st height.
    Soil water environment of artificial vegetation in Jinshajiang dry-hot volley
    WANG Keqin, SHEN Youxin, CHEN Qibo, WANG Zhenhong
    2004, (5):  809-813. 
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    Jinshajiang dry-hot volley has the characteristics of extremely hot and dry climate due to its specific local climate,where universally exists moisture deficit and the problem of soil water environment of artificial vegetation becomes more serious than other arid and semi-arid areas.The environmental determination in the typical sector of dry-hot volley Yuanmou showed that the existed arboreous forests evidently showed the characteristics of soil drying.Soil was short of moisture for a long term.In November after the rain season was over,soil water content in two-meter-deep soil layer was only 15% (equal to 35% of field capacity).Later on,soil water content continued decreasing and reached the lowest point in May (9%),which was near to wilting moisture of trees (the wilting moisture of surface eroded dry red soil of Yuanmou was 9.0%).As a result,trees grew slowly.As for Radonaea wiscosa shrubbery,its soil water content at the same layer was relatively 42.68% higher than that of arboreous trees.The soil moisture of natural grass slope was evidently better than that of arboreous trees and shrubbery,and was 34.36% and 22.22% higher,respectively.This kind of soil drying problem didn't come into notice in the vegetation restoration of Jinshajiang dry-hot volley,which would greatly restrict the sustainable development of artificial vegetation.
    Plant diversity variations in zokor-mound communities along a successional stage
    JIANG Xiaolei, ZHANG Weiguo, Yang Zhenyu, DU Guozhen
    2004, (5):  814-818. 
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    Using an approach of spatial sequence instead of temporal sequence,this paper studied the composition and diversity of plant species on zokor-mound along a successional gradient in alpine meadow.The results indicated that the species composition and structure of vegetations on zoker-mound along different successional stages were quite different from those of original vegetations.During the early stage of succession,the pioneer species with numerous widely dispersed seeds or spores (r strategy),such as Elsholtzia ciliata,Chenopodium glaucum,Potentilla anserina,and Ajania tenuifolia,dominated in the community.As the progression of succession,the proportion of species with vegetative expansion (k strategy),such as Saussurea hieracioides,Elymus nutans,Kobresia kansuensis,and Kobersia capillifolia,increased in the community.The analysis of Alpha diversity indicated that both species richness and evenness,in increasing order,changes as stage 1<stage 2<stage 3<stage 4<original vegetation,while Simpson index (D) and Shannon-Wiener index (H') increased significantly as the progression of succession.The analysis of Beta diversity showed that the similarity coefficient of species composition of community between stage 1 and stage 4 and between stage 1 and original vegetation was the lowest (0.18),while that of community between stage 1 and stage 2 was the highest (0.62).The functional diversity of lif form also manifested some obvious changes along the successional gradient,showing that plant community and mini-habitat changed along a successional gradient on zokor-mound.
    Effect of restorative measures on quantitative characters of reproduction for Leymus chinensis population in the degenerated grassland
    LI Hong, YANG Yunfei
    2004, (5):  819-823. 
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    Studies on the reproductive characters of Leymus chinensis population in two plots showed that the density of L.chinensis population declined significantly in plowing plot,while the density of reproductive tillers varied insignificantly.The reproductive tiller had longer ear,longer inter-node,higher ratio of reproductive growth,higher seeding percentage,more ear-nodes,more spikelets,more florets and grains in plowing plot than in enclosing plot.The grain yield,net weight of grain,and the weight of 1000 grains was 2.68 times,3.49 times and 1.3 times higher in plowing plot than in enclosing plot,respectively.The reproductive tillers with double-spikelet were 16% more in plowing plot than in enclosing plot,and they developed more double-spikelets.Relatively,the reproductive tiller in plowing plot developed few double-spikelets,more florets and more grains,so that,the grain yield of the population was enhanced largely.The reproductive allocations of L.chinensis didn't response differently to both plowing and enclosing at three module levels,including population to reproductive tiller,reproductive tiller to ear,and ear to grain,but the allocation of population to ear and to grain,and the allocation of reproductive tiller to grain were significantly higher in plowing plot than in enclosing plot.
    Properties of organic matter in natural and reclaimed steppe soil
    PING Lifeng, DOU Sen, ZHANG Jinjing, GUAN Song
    2004, (5):  824-826. 
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    The properties of organic matter in steppe chernozem,steppe wind-blown soil and cultivated wind-blown soil were studied by analyzing the status of organo-mineral complex and the combined status and composition of humus.The results showed that different types and utilization patterns of soil had very different effects on the properties of soil organic matter.The amounts of total organic carbon,biomass C,heavy fraction C,extractable humus (HE) and loosely-combined humus and the humification degree were higher in steppe chernozem than in wind-blown soil.Steppe soil had higher amounts of total organic carbon,biomass C,heavy fraction C,HE and different combined humus than sunflower wind-blown soil,but humification degree had no obvious difference.
    Dynamics of ecological footprints of agricultural region in Hexi oasis of Gansu Province
    LIN Haiming, XIE Peng
    2004, (5):  827-832. 
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    This paper studied the dynamics of ecological footprints(EF),degree of sustainable development and its tendency of Hexi oasis agricultural region in Gansu.The results showed that the EF displayed an increasing trend from 0.426 hm2 to 2.158 hm2 in 1949～2000,which was 0.693 hm2 in 1949～1970,1.029 hm2 in 1975～1980,and 2.288 hm2 in 1985～2000.The ecological capacity (EC)was also increased from 0.550 hm2 in 1949 to 1.762 hm2 in 2000.Comparing with EF,the EC increased at low speed,which reached 0.782 hm2 in 1949～1970 and 1.715 hm2 in 1975～2000.Meanwhile,the sustainable development of Hexi region maintained ecological remainder during 1949～1975.However,it emerged ecological deficit in 1980,and resumed in 1985.The sustainable development of Hexi region has been successive ecological deficit since 1991.The degree was keeping negative increment at acceleration,and got to -0258 hm2 in 1991～2000.These results showed that the regional economic development of Hexi region was far away from sustainable development,and was in no-sustainable state.
    Simulation of hydrological response to land-cover changes
    CHEN Junfeng, LI Xiubin
    2004, (5):  833-836. 
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    Hydrological modeling methodology had a quick development in recent years.In this article,a distributed hydrological model SWAT was used to simulate the rainfall-runoff relationship of the Suomo Basin under different land covers in order to evaluate the impact of land-cover changes on runoff,evapotransperation and peak flow.The results showed that if the land-cover changed from non-vegetation-cover to full-forest-cover scenarios,the runoff depth decreased,evaporation increased,while the reduced extent of runoff in dry season was less than that in rainy season,and in the first rainy season,the reduced extent of runoff was more than that in the second rainy season.With the same recurrent flood flow,the peak flow value under full-forest-cover scenario was 31.2% less than that under non-vegetation-cover scenario.The effect of land-cover between current cover and optimum cover on hydrology was small for large storm,and big for small storm events.
    Spatially explicit Landscape Model-LANDIS I.Mechanism
    XU Chonggang, HU Yuanman, CHANG Yu, LI Xiuzhen, BU Renchang, HE Hongshi
    2004, (5):  837-844. 
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    Spatially explicit landscape models are the models that spatially explicitly simulate the ecological processes at landscape scale on heterogeneous landscape.LANDIS is a spatially explicit landscape model of forest landscape disturbance,succession and management.By recording the absence/presence of species in terms of 10-yr age cohorts at site level,the semi-quantitative description of fire and windthrow disturbances,and the representation of age-cohorts by bit-wise array,it is possible for LANDIS to simulate the ecological processes at species,site and landscape level.We addressed in detail the approaches used in simulating seed dispersal,disturbances of fire and windthrow,and harvesting.The deficiencies of the model were also discussed to provide feedback for model development.
    Response of parasitic wasps of cotton bollworm to different cotton varieties with transgenic Bacillus thringienthsis genes
    YU Yueshu, YANG Yizhong, LU Yanhui
    2004, (5):  845-848. 
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    The relationship between the parasitic wasp population number of cotton bollworm (Helicoverpa armigera) and the varieties of cotton was studied by releasing and collecting the eggs and larvae of cotton bollworm on transgenic and non-transgenic cottons.The research results from2000 to 2003 showed that the parasitic rates of the eggs and larvae of cotton bollworm were notably lower in transgenic cotton field than in non-transgenic cotton field.At the same time,the effect of transgenic and non-transgenic cottons on the selection behavior of the parasitic wasp Microplitis mediatar of the larvae of cotton bollworm was studied by using “Y” olfactometer.The results showed that the selection response about the parasitic wasp Microplitis mediatar of cotton bollworm on non-transgenic cotton was prior to the transgenic cotton.
    Effect of insect pest on activated oxygen metabolism in lanceolate leaves of Populus euphratica under different water condition
    WAN Dongshi, LI Hongyu, ZHOU Gongke, LIANG Houguo, ZHANG Lixin
    2004, (5):  849-852. 
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    This paper studied the effect of insect pest on the activities of protective enzymes SOD and CAT and the contents of H2O2 and H2O2 in lanceolate leaves of Populus euphratica under different soil water conditions.The results showed that soil water deficiency did not increase SOD and CAT activities and H2O2 and H2O2 contents in lanceolate leaves,but under this condition,insect pest increased them.When soil water was abundance,insect pest couldn't increase the activities of SOD and CAT and the contents of H2O2 and H2O2 in lanceolate leaves.It's concluded that insect pest had an important role in death of Populus euphratica under soil water deficiency.
    Influence of temperature on insect-resistance of transgenic hybrid poplar 741.
    LIU Junxia, GAO Baojia, ZHANG Juhong, WANG Yongfang, WANG Jinmao
    2004, (5):  853-855. 
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    The study showed that the insect-resistance of transgenic hybrid poplar 741 was closely related with temperature.The total mortality and accumulative mortality of Gypsy moth (Lmantriadispar L.) larvae increased with increasing temperature,and the sensitivity of larvae to the clones of transgenic hybrid poplar 741 and temperature decreased gradually with the increasing instars.Temperature had a promotion to the development of larvae fed on CK.When the temperature was high,the development of larvae quickened,the development period shortened,and the weight increasing rate and the frass increasing quantity quickened,but the development rate of larvae fed on transgenic hybrid poplar 741 was not obvious with varied temperature.The regressive equation of temperature and Clostera anachoreta(Fabricius) mortality during 1998～2000 year indicated that high resistant and medium resistant clones' temperature-insect mortality curve presented an obvious regressive relation.
    Repellent effect of volatile oil from whitefly (Syngonium podophyllum) on aphids and its chemical constituents
    ZHOU Qiong, LIANG Guangwen, KONG Chuihua, HUANG Shoushan
    2004, (5):  856-858. 
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    The interference effect of volatile oil from whitefly (Syngonium podophyllum) on aptera aphid,guard aphid (Aphis gossypii),mustard aphid (Lipaphis erysimi) and red peach aphid (Myzus persicae) was studied by using four arms olfraetometes.The results showed that the volatile oil had distinct repelling effect.The staying periods of test aphids in test areas were obviously shorter than in control areas,and the selecting frequencies were less than the control,too.The volatile oil did not show repelling effect on red peach aphid at the test concentrations.The components of the volatile oil from S.podophyllum were analysed by GC-MS.43 constituents were identified.
    Behavioral and morphological indices for phase transformation of oriental migratory locust Locusta migratoria manilensis
    GUO Zhiyong, SHI Wangpeng, ZHANG Long, WANG Guilong
    2004, (5):  859-862. 
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    Based on the data obtained from laboratory and field experiments,this paper established the morphological and behavioral indices for phase solitaria (S) and phase gregaria (G) of oriental migratory locust Locusta migratoria manilensis.S-females and S-males jumped 1.4 times·min-1,and the frequency of turning was 1.3 times·min-1 for S-females and 1.4 times·min-1 for S-males.G-females and G-males jumped 1.6 times·min-1,and the frequency of turning was 1.6 times·min-1 for G-females and 1.5 times·min-1 for G-males.Both jumping and turning behaviours were significantly greater (P<0.05) for gregaria locusts than for solitairia locusts.These behavioral parameters of the frequency of locust jumping and turning can be used as “the behavioral indices for phase transformation".The F/C ratio and the E/F ratio might be used as the morphological indices for phase transformation of the gregaria and solitaria of Locusta migratoria manilensis.The F/C ratio goes up as the locust grows,but the F/C ratio of females from the 4th instar to adult is less than that of the male of the same instar and phase.Comparing with the F/C and E/F ratio of the male,those of the female exhibited significant difference in the same phase.The F/C ratio of the fourth instar,fifth instar and adults were 2.5,2.8 and 3.3 for S-females,and 2.6,2.9 and 3.5 for S-males.As for G-females and and G-males,the F/C ratio of the fourth instar,fifth instar and adults were 2.5,2.8,3.3 and 2.5,2.7,3.1,respectively.The E/F ratios of adults can be used as “the morphological phase indices for phase transformation".
    Production and properties of chitinase from Beauveria bassiana Bb174 in solid state fermentation
    ZHANG Jie, CAI Jingmin, WU Ke, JIN Shengxian, PAN Renrui, FAN Meizhen
    2004, (5):  863-866. 
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    This paper studied the chitinase production of Beauveria bassiana Bb174 under solid state fermentation condition.The optimal medium consisted of wheat bran and silkworm chrysalis at the ratio of 4:1,supplemented with 1 g peptone·L-1 as nitrogen source and some other mineral nutrients.The enzyme activity reached 126 units per gram dry medium after cultured for 2 days at 28 ℃ and natural pH by inoculated 3 ml spore suspension into this medium.The optimal temperature and pH for chintinase production were 40 ℃ and 5.0,respectively.The temperature to lose 50% activity of the enzyme was 48 ℃ after incubated at 30～70 ℃ for 1 h.The enzyme was stable at 30～40 ℃ and pH 4～6,and the Km and Vmax values were 0.52 mg·ml-1 and 0.7△E680·h-1,respectively.
    Effect of organic materials in controlling cucumber seedling diseases
    YUAN Fei, PENG Yu, ZHANG Chunlan, SHEN Qirong
    2004, (5):  867-870. 
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    In this work,pot experiments with organic materials were carried out to study the alleviation of Fusarim wilt and Rhizictonia wilt of cucumber and the changes of soil microorganism.The results showed that rice straw,pig feces and wood chip could alleviate Fusarium wilt and Rhizoctonia wilt of cucumber,and the effect of rice straw was most significant,followed by pig feces and wood chip.The amount of soil microbes was higher in organic materials treatments than in control. The total amount of actinomyces and epidhyte which can inhibit the growth of pathogen was the highest in rice straw treatment,followed by pig feces treatment.No significant change of soil microbial amount was found in wood chip treatment.
    Revulsive response of protein and enzyme activity of degradative Bacilluss strains by phenanthrene
    ZHONG Ming, ZHOU Qixing, XU Huaxia, WU Xiaodan, LI Yushuang
    2004, (5):  871-874. 
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    Three strains of Bacillus sp.BA11,BA19 and BA27,which can grow when phenanthrene is taken as the sole source of carbon and energy,were isolated from an oil-contaminated soil.Their crude extract was used to test the activities of polyphenol oxidase and catalase.The results demonstrated that all the three strains did not show a significant change in the activity of both enzymes when phenanthrene was lower than 200 mg稬-1 .Under different phenanthrene concentration,the enzyme activities of strains BA19,BA27 showed a higher stabilization than BA11.Using the SDS-PAGE contrasted the difference of proteins between the strains in normal medium and the strains growing on phenanthrene,the results showed that BA27 growing on phenanthrene synthesized a new protein with 27 000 dal of molecular weight.At the same time,the synthesis of some proteins was cancelled.We conjecture that the new protein induced by phenanthrene may be related to the ability of phenanthrene degradation and the stabilization of enzyme activity by the strain.
    Diversity and stability of arthropod assemblage in tea orchard
    CHEN Yigen, XIONG Jinjun, HUANG Mingdu, GU Dejiu
    2004, (5):  875-878. 
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    Two tea orchards,simplex tea orchard with weeds removed manually or by herbicides (STO) and complex tea orchard with the weed Hedyotis uncinella(CTO),each with an area of 0.4 hm2,were established in 1995 in Yingde Hongxing Tea Plantation,Guangdong Province.The primary eigenvalues,species richness index (R),assemblage diversity index (H'),evenness index (J) and species concentration index (C) of arthropod assemblage were employed and compared to assess the efficacy of STO and CTO on the diversity and stability of arthropod assemblage.Stability indexes Ss/Si and Sn/Sp and variation coefficient of diversity index ds/dm were utilized as well.The results demonstrated that the R of arthropod assemblage in CTO ranged from 4 to 8,with the highest of 7.7403,while that in STO varied mainly between 4 to 6.The average R of arthropod assemblage in CTO was 5.4672?0.3483,higher than that in STO (4.8809?0.3175).The H' of arthropod in CTO (3,8535?0.1232) was higher,in contrast to the value in STO (3.4654?0.1856).The J in CTO was higher,while the species concentration index (C) was lower,in comparison to STO.The stability indexes Ss/Si and Sn/Sp of CTO were greater than those of STO,while the ds/dm in CTO (0.1107) was lower than that in STO (0.1855).All these indicated that the diversity of arthropod assemblage was better preserved in CTO,and the arthropod assemblage in CTO was more stable.
    Genetic diversity of Fujian local duck populations in different ecological type
    XIAO Tianfang, ZHENG Xiancheng, WU Qiwen
    2004, (5):  879-882. 
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    A total of 40 short primers of arbitrary nucleotide sequence were used singly in polymerase chain reaction to amplify DNA fingerprints in pools of DNA representing seven duck populations from two ecological areas in Fujian Province.9 primers which discriminated between the breed-specific DNA pools were used further to amplify individual pool components.Shannon index was used to calculate the genetic diversity and its partition within and between the seven duck populations.The relationships between seven duck populations and ecological environment,and their variation patterns were studied by RAPD.The results showed that the genetic diversity in east Fujian (67.97%) was higher than that in west Fujian (59.05%).Genetic differentiation was estimated to be about 32.03% among populations of east Fujian,and about 40.95% among populations of west Fujian.The genetic distance index matrix and UPMGA dendrogram indicated that Liancheng white duck,Taining duck,Longyan duck and Sanming duck in west Fujian had closer genetic relationships,and Longhai Jinding duck and Putian black duck in east Fujian had the similarly.There were some evidences showing that relevance existed between the variation and the geographical position.
    Community diversity of entomogenous fungi in Dabie Mountains in Anhui
    WANG Sibao, LIU Jingnan, WANG Chengshu, FAN Meizhen, LI Zengzhi
    2004, (5):  883-887. 
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    The abundance,Shannon-Wiener's diversity index (H'),Pielou's evenness (E) and K-dominance curves were calculated for community diversity of entomogenous fungi in the Dabie Mountains.The results showed that the species number,diversity value,evenness and dominance were distinctly different among different habitats,altitudes,seasons and horizontals.These indexes reflected the community structure of entomogenous fungi,and revealed the relations among different entomogenous fungal communities.By means of Bray-Curtis Measure and UPGMA clustering analysis,entomogenous fungi were vertically distributed from lower altitude upwards into 3 belts,i.e.,warm humid low-mountains zone(alt.<900 m),cool humid mid-mountains zone(alt.900～1 200 m),and cold humid high-mountains zone(alt.>1 200 m).
    Acute toxicity and bio-concentration factor of three pesticides on Brachydanio rerio
    DING Zhonghai, YANG Yi, JIN Hongjun, SHAN Zhengjun, YU Hongxia, FENG Jianfang, ZHANG Xiaofeng, ZHOU Jiayan
    2004, (5):  888-890. 
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    The acute toxicity and bio-concentration factor of imidacloprid,triazophos and pyridaben were measured by using Brachydanio rerio as test organism.The 96 h LC50 value of these pesticides was 281.37 mg·L-1,8.37 mg·L-1 and 11.66 μg·L-1,respectively.The concentrations of pesticides and the exposure duration of 14 days for BCF tests were designed according to results of the acute toxicity tests and relevant guideline.At the exposure concentrations of 0.5 and 5 mg·L-1,the bio-concentration factor (BCF) of imidacloprid was 1.52 and 0.97,respectively; while at the exposure concentrations of 0.02 and 0.2 mg·L-1,that of triazophos was 9.00 and 8.45,respectively.For pyridaben,the BCF was respectively 5600 and 4920 at the exposure concentrations of 0.1 and 1μg·L-1 .
    Accumulation and translocation of lead in soil-crop system of green food production
    LI Liguang, HE Xingyuan, CAO Zhiqiang, CHEN Wei
    2004, (5):  891-894. 
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    In this paper,the accumulation and translocation of lead in soil-crop ecosystems were studied through fertilization with chemical fertilizer,manure and bio-fertilizer.The results showed that the soil total Pb content was decreased with soil depth.It was 11.14 and 9.37 mg·kg-1 in 0～15 and 15～30 cm after harvest,respectively.Rice root absorbed lead from soil,and transferred it to stem-leaf and grain.The Pb content in rice plant was root>stem and leaf>grain,which was increased with rice growth.The grains of 606-14 and Liao 294 contained 0.008 and 0.007 mg·kg-1 of Pb,respectively,which is under the standard of green food.Variance analysis indicated that the grain yield of different varieties had a significant variance,but no significant variance was found among different treatments.It could be summarized that manure or bio-fertilizer could be the substitute of chemical fertilizer in producing rice.
    Effect of arsenic on soil urease activity
    HE Wenxiang, MA Aisheng, WU Yongjun, ZHU Minge
    2004, (5):  895-898. 
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    By simulation method,this paper studied the urease activity in arsenic polluted soils.The results showed that arsenic could activate soil urease activity after added for one year.With arsenic addition,soil urease activity remarkably increased,and there existed a significantly positive correlation.The Vmax of soil urease increased with arsenic addition,while the Km of urease in high and low fertility soil was unchanged and slight increased,respectively.It is proved that As could accelerate the separating velocity of enzyme-urea complexes.This paper also illustrated that soil properties were important to study the relationship between soil enzyme and pollutants.
    Methods for studying soil microbial diversity
    ZHONG Wenhui, CAI Zucong
    2004, (5):  899-904. 
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    This paper gave a review on the main methods for studying soil microbial diversity.Traditionally,the analysis of soil microbial communities relied on culturing techniques,using a variety of culture media.However,only a small fraction of the soil microbial community has been cultured and isolated with this approach.Other methods such as Biolog GN analysis,phospholipids fatty acids analysis and nucleic acid-based analysis can be used to study and characterize soil microbes which currently cannot be cultured,and to get more and complete information about soil microbial community.
    Selectivity and influence of parasite plants on their hosts.
    HU Fei, KONG Chuihua
    2004, (5):  905-908. 
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    More and more studies have demonstrated that parasite plants have strong selectivity on their hosts,which is correlated with nutrients,secondary metabolites and hardship.It is beneficial to the growth and development of parasite plants under multiple hosts.Parasite plants can change the direction of photosynthate flow and influence the adjustable ability of leaf stomata on their hosts.The growth and development of these hosts are dramatically influenced.Furthermore,parasite plants are able to have strong impacts on biomass,composition diversity,and fluctuation of the community in which they occurred.An increasing number of studies showed that the interactions between parasitic plants and their hosts may compare with those between herbivores and plants.The influence of climate changing on the relationships between parasite plants and their hosts is at beginning.Recently,most of parasite plants have more economical values other than harmful weeds.Therefore,researches on the relationships between parasite plants and their hosts are of significance both in theoretical and practical aspects.
    Comprehensive assessment on sustainable development of livestock production
    SHI Guanghua, SUN Zhenjun, GAO Jixi
    2004, (5):  909-912. 
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    To assess the sustainable development of livestock production is not only helpful to learn about the present status of the livestock development,but also of great significance to predict the trend of the development of livestock husbandry and to stipulate the appropriate policies and laws in livestock husbandry.After summarizing and analyzing the present methods and theories adopted in the assessment of global sustainable development,and taking into account the characteristics of livestock production,the authors provided a new comprehensive assessment method and theory.