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    15 June 2005, Volume 16 Issue 6
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    Articles
    Effects of aspect on distribution pattern of Taxus chinensis population in Yele,Sichuan Province:An analysis based on patches information
    XU Xiao1,SU Zhixian2,YAN Xianchun1
    2005, 16(06):  985-990 . 
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    Employing GIS method and based on patches information,this paper studied the effects of aspect on the distribution pattern of Taxus chinensis population in Yele,Sichuan Province.The results showed that Taxus chinensis population mainly distributed on the aspects of northwest,northeast,east and north. These aspect patches were absolutely dominant on area,mean size,mean edge and the number of Taxus chinensis.There existed a significant correlation between aspect and Taxus chinensis distribution.Taxus chinensis distributed preferentially on north,northeast,northwest and east patches, then on west and southwest patches,and finally on flat and southeast patches. The distribution patterns of Taxus chinensis in Yele were clustering,except on south aspect patches.The intensity of clustering on north aspect patches was the highest,with the value of Clark-Evans (CE) index being 0.906.The intensity of clustering on northeast and northwest aspect patches was lower than that on north aspect patches,with the CE value 0.797 and 0.563,respectively.The CE values on the rest aspect patches were all not larger than 0.5.There existed a significant positive correlation between the intensity of clustering index,number of patches,total patch edge,and the number of Taxus chinensis distributed on the patches,with the value of correlation coefficient 0.936,0.735 and 0.802,respectively.There were no significant correlations among the intensity of clustering,patch area,mean patch size,mean patch edge,and mean shape index of aspect patches.
    Effects of Fargesia denudata density on its biomass distribution pattern
    WU Fuzhong1,3,WANG Kaiyun1,2，YANG Wanqin1,LU Yejiang1,3
    2005, 16(06):  991-995 . 
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    In this paper,the effects of Fargesia denudata density on its biomass distribution pattern were studied in the primitive Fargesia denudate, Picea purpurea forest from May to October,2003.The results showed that with increasing stem density,the total biomass,above-and below-ground biomass,net production,and average stem biomass of the bamboo were all increased,while the net increment of aboveground biomass decreased.The relationship between above-and below-ground biomass in the bamboo communities was also regulated by the stem density,with the correlation coefficient increased with the density.Except for the exponential period (July and August),the ratio of above-/below-ground biomass increased with the density,and the moderate density (140±7 stems·m-2) had the highest ratios of above-/below-ground biomass.The biomass distribution pattern of different organs depended on both stem density and growth period,and stem density played a significantly important role in the distribution pattern of bamboo biomass.
    Effects of Fargesia denudata density on soil nutrient pool
    LU Yejiang 1,3,WANG Kaiyun 1,2，YANG Wanqin 1,WU Fuzhong 1,3
    2005, 16(06):  996-1001 . 
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    This paper studied the nutrient storage and its dynamics in different soil layers under three densities of Fargesia denudata communities in Wanglang National Nature Reserve,aimed to understand the effects of F.denudata density on the storage and dynamics of soil nutrients.The results showed that F.denudata density had a significant effect on the total and available nutrient contents in 0～30 cm soil layer.The total and available P contents decreased significantly with the increasing F.denudata density (P<0.01), being 0.274 kg·m-2 and 1.72 g·m-2 at D1,0.222 kg·m-2 and 1.50 g·m-2 at D2,and 0.158 kg·m-2 and 1.10 g·m-2 at D3 sampling site,while the contents of total Ca and Mg increased with the increasing F.denudata density,being 2.64 and 1.70 kg·m-2 at D1,4.42 and 1.80 kg·m-2 at D2,and 4.85 and 2.12 kg·m-2 at D3 sampling site,respectively.The contents of both total and available N and K did not change significantly with F.denudata density.Soil total and available N were 1.10 and 45.15 kg·m-2 at D1,1.04 and 44.38 kg·m-2 at D2,and 1.06 and 42.02 kg·m-2 at D3,while soil total and available K were 3.19 and 39.62 kg·m-2 at D1,3.30 and 36.23 kg·m-2 at D2,and 3.19 and 37.18 kg·m-2 at D3,respectively.The total nutrient storage was in order of Ca>K>Mg>N>P,except a higher K storage than Ca under D1 community.The available N,P and K concentration in surface soil (0～10 cm) decreased significantly in July,and then increased slowly in the later growth season.In general,the change magnitude of available nutrients was greater in surface soil (L1) than in lower soil layers (L2 and L3),under higher F.denudata density (D3) than under lower F.denudata density,and for P than for N and K.The distribution pattern of nutrient storage in soil layers differed greatly from that of nutrient concentration,regardless of F.denudata densities.The contents of total N,P,K,Ca and Mg in L1 (0～10 cm) were lower than those in L2 (10～20 cm) and L3 (20～30 cm).The differences of nutrient contents among soil layers varied with F.denudata density,and particularly with bio?elements.The results suggested that the nutrient storage in soil under F.denudata community was related to F.denudata density,because the density affects the processes of nutrient cycling,such as nutrient absorption, return through litter,and activity of soil microorganisms.It could be concluded that the density of F.denudata communities affected the storage of soil P and Ca significantly,but that of soil Mg,N and K slightly.Soil total and available P contents decreased with the increasing F.denudata density,implying that soil P could be one of the main factors limiting the growth and succession of F.denudata community in these stands,and affecting the flowering and death of bamboo.
    Neural network grade program of natural forest protection
    LUO Chuanwen1,CHEN Yian1,HU Haiqing1,SHEN Hailong1,FAN Shaohui2
    2005, 16(06):  1002-1006 . 
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    In this paper,the implement steps of natural forest protection program grading (NFPPG) with neural network (NN) were summarized,and the concepts of program illustration,patch sign unification and regress,and inclining factor were set forth.Employing Arc/Info GIS,the tree species diversity and rarity,disturbance degree,protection of channel system,and classification management in Moershan National Forest Park were described,and,used as the input factors of NN,the relationships between NFPPG and above factors were analyzed.Through artificially determining training samples,the NFFPG of Moershan National Forest Park was built. Tested with all patches in the park,the generalization of NFFPG was satisfied. NFPPG took both the classification management and the protection of forest community types into account,as well as the ecological environments.The excitation function of NFPPG was not seriously saturated,indicating the leading effect of inclining factor on the network optimization.
    Seasonal dynamics of hyperin content in Acanthopanax senticosus at different habitats
    CAO Jianguo,ZU Yuangang,YANG Fengjian,ZHAO Zehai
    2005, 16(06):  1007-1010 . 
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    The study with HPLC technology showed that hyperin only existed in A.senticosus leaf,flower and fruit,and its content was higher in leaf and flower than in fruit.The hyperin content in A.senticosus leaf showed a distinct dynamic change with the rhythm of development.Its content in bud was about 0.013%,which increased gradually with bud development.In mid May,the hyperin content in young leaf reached the maximum (0.087%);while in mid August,it decreased rapidly,with the lowest content about 0.008%.At different habitats,the hyperin content in A.senticosus leaf had different seasonal rhythm,which was low in understory,being at most 0.15%,and high in forest gap and edge,with the contents of 0.42% and 0.65%, respectively. The same trend was found in A.senticosus flower and fruit.There was a significantly negative correlation between leaf area index (LAI) and hyperin content.
    Kinetic developmental genetics analysis of Hibiscus cannabinus plant height and stem diameter
    CHEN Youyu1,QI Jianmin1,LIN Lihui1,LIANG Kangjing1,ZHOU Ruiyang2,WU Jianmei1
    2005, 16(06):  1011-1016 . 
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    By using quantitative traits additive-dominance genetics model and developmental genetics model,this paper analyzed the developmental behaviors of gene expression for Hibiscus cannabinu plant height and stem diameter at its different growth stages.The results showed that at different growth stages,the unconditional and conditional genetics effects of plant height all showed dominance,while the additive effect was weak.No additive effect was found for stem diameter,but dominance effect was significant at each growth stage.Plant height and stem diameter all had active gene expression from July 28 to August 9,and from September 2 to September 14.There was no additive correlation between plant height and stem diameter,but positive dominance correlation was significant after August 21.The unconditional and conditional genetics effects of plant height and stem diameter were not completely the same.According to practice, conditional genetic analysis could indicate the gene expression more truly in the whole growth period.The ecological and genetics variation patterns of Hibiscus cannabinus plant height and stem diameter at different space-time growth stages implied by our research was of significance in Hibiscus cannabinus genetics and breeding in both theory and practice.
    Effects of stand condition improvement on surface soil nutrient losses of hilly land Dendrocalamus latiflorus plantations
    QIU Erfa1,CHEN Zhuomei2,ZHENG Yushang3,HONG Wei3,YU Zhida4
    2005, 16(06):  1017-1021 . 
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    A comparative study on the soil nutrient losses of hilly land shoot-used Dendrocalamus latiflorus plantations at the Nanjing stated-owned forest farm,Fujian Province showed that the losses of soil N,P and K under three treatments of stand condition improvement varied with season,and 90% or more of these losses appeared from April to September,with the order of overall ploughing>strip ploughing>control. There was no significant difference of N and P losses among the three treatments,while the K loss was markedly higher under overall ploughing than the control.
    Ecological effects of intercrops in comprehensive management patterns of hilly area plum orchard
    ZHANG Tie,HUANG Xianpeng,YANG Bin
    2005, 16(06):  1022-1025 . 
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    The study on the ecological effects of intercrops in four cropping patterns showed that with the increase of multiple cropping,the annual increase of soil organic matter,total N,total P and total K was 5%～20%,7%～40%,8%～70% and 15%～80%,respectively. Potato-soybean had the best benefit in soil and water conservation,followed by cole?peanut,potato?watermelon,and wheat. Compared with control,the average soil erosion module and runoff amount of 4 patterns were decreased by 44.19%,39.55%,38.24% and 37.56%,and 22.40%,9.28%,24.11% and 21.16%,respectively. Cole-peanut had the highest biomass,being averaged 100 276 kg·hm-2 annually,and the second was potato-watermelon,with an average of 73 692 kg·hm-2. Potato-watermelon had the highest productivity,which averaged 37 565 kg·hm-2 annually,and the second was potato-soybean,averaged 25 934 kg·hm-2. The efficiency of energy input was in order of cole-peanut,potato-watermelon,potato-soybean,and wheat,and the value was 2.96,2.08,2.01 and 0.96,respectively.
    Correlation of intersubspecific hybrid rice spikelet fertilization rate with temperature and related statistic model.L
    Chuangen1,ZOU Jiangshi1,HU Ning2,YAO Kemin2
    2005, 16(06):  1026-1032 . 
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    Using four types of rice,i.e.,indica?japonica hybrid,intermediate hybrid,indica and japonica cultivars as test materials,this paper studied the sensitivity of intersubspecific hybrid rice to climatic factors,and the correlations between spikelet fertilization rate (SFR) and daily meteorological factors during 2000 and 2001.The results showed that the SFR of intersubspecific hybrids was lower than that of indica and japonica cultivars.Among eleven meteorological factors,temperature was the key factor,and the mean temperature within five or seven days around panicle flower blooming affected the SFR significantly.A comprehensive model of SFR?temperature was established, with which,the fittest temperature and safe temperature for fertilization of intersubspecific hybrids was estimated to be 28.2～29.3 ℃ and 23.4～24.3 ℃,2.2 ℃ and 1.5 ℃ higher than those of indica and japonica cultivars, respectively.It was suggested that the safe heading date for planting intersubspecific hybrid should be moved up to the last ten-day of September to the first ten-day of October in southern China,the first ten-day of September in middle and lower reaches of Yangtze River Valley,and the last ten-day of August to the first ten-day of September in rice planting area between Yangtze and Huai River.
    Effects of applying L-methionine，L-phenylalanine and L-tryptophan on Zea mays growth and its nutrient uptake
    CHEN Mingchang, CHENG Bin, ZHANG Qiang, DING Yuchuan, YANG Zhiping, LIU Ping
    2005, 16(06):  1033-1037 . 
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    A pot experiment was conducted to evaluate the effects of applying L-methionine(L-MET), L-phenylalanine (L-PHE) and L-tryptophan (L-TRP) on the growth of Zea mays and its nutrient uptake, and to determine the optimal application rate of them. The results showed that L-MET, L-PHE and L-TRP could improve the shoot height, shoot and root dry weights, root activity, nitrate reductase and hydrogen peroxidase activities, and N, P, K and Zn uptake of corn. The optimal application rate of L-MET, L-PHE and L-TRP was 0.0185～0.185 mg·kg-1 soil,0.2 mg·kg-1 soil, and 0.03～0.3 mg·kg-1 soil, respectively, and L-PHE and L-TRP were superior to L-MET.
    SO2-caused oxidative stress and modulation of some signal molecules in wheat
    HAO Lin1,ZHANG Huiwen2,XU Xin1,TAO Siyuan1,YU Long1
    2005, 16(06):  1038-1042 . 
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    By adding different concentration SO2 to culture boxes,this paper studied the responses of wheat seedling's superoxide anion radical O2- and antioxidant enzymes to SO2.The results showed that when the concentration of SO2 was 10 and 40 μl·L-1,the O2- content and peroxidase (POD) and catalase(CAT) activities of wheat leaf were increased,while the activity of superoxide dismutase(SOD) was reduced.When the SO2 concentration was 50 μl·L-1, the activities of POD and CAT were decreased,with the top end leaves appeared necrosis,and more fungi multiplied on green leaves.Presoaking wheat seeds with 1 mmol·L-1 salicylic acid (SA) for 6 h or with 10 mmol·L-1 H2O2 for 12 h could efficiently alleviate the oxidative stress caused by SO2,with the O2- content decreased and the activities of test antioxidant enzymes increased.Under SO2 fumigation,ethylene significantly inhibited the activities of test enzymes,and promoted the O2- production rate.When applying SA and ethylene at the same time,SA could almost completely eliminate the influences of ethylene on O2- production and test enzyme activities.
    Effects of aluminum speciation on wheat root growth and its enzyme activity
    ZHU Xuezhu1,HUANG Yao1,3，ZONG Lianggang1,KONG Fanxiang2
    2005, 16(06):  1043-1046 . 
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    Aluminum speciation is recognized to associate with environmental pH.In this paper,the effects of aluminum speciation (Ala,Alb) on the growth,protein content,acid phosphatase (AP) activity of wheat root were studied by changing the pH of aluminum solutions.Two concentrations of total aluminum,25 μmol·L-1(T1) and 75 μmol·L-1(T2),were set up in the test solutions,and four levels of pH,4.0,4.5,5.0 and 5.5,were regulated for each solution.The results indicated that the growth of wheat root in T1 and T2 was strongly inhibited by low doses of Ala and Alb,while the changing trend of protein content and AP activity varied when exposed to different composition of active Al.When the Ala concentration was above 90% of the active Al concentration,the protein content was reduced while the AP activity was enhanced by Al at pH 4.0,but it was reverse at pH 5.0 when the concentration of Ala and Alb was below 10 μmol·L-1,respectively.
    Effects of excess Mn on photosynthesis characteristics in cucumber under different light intensity
    SHI Qinghua,ZHU Zhujun,YING Quansheng,QIAN Qiongqiu
    2005, 16(06):  1047-1050 . 
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    By a solution culture experiment,this paper studied the effects of excess Mn on the growth,chlorophyll content,chlorophyll fluorescence parameters and photosynthesis of cucumber under different light intensity.The results indicated that excess Mn inhibited plant growth,which was more obvious under high light intensity than under low light intensity.The primary maximum photochemical efficiency of PSII (Fv/Fm),quantum efficiency of noncyclic electron transport of PSII (ΦPSII ),and photochemical quenching (qP) were significantly decreased in excess Mn treatment under high light intensity, while no significant effects on Fv/Fm and qP were observed under low light intensity.Excess Mn,particularly under high light intensity,decreased net photosynthetic rate (Pn) and stomatal conductance (Gs).Excess Mn increased intracellular CO2 (Ci) under high light intensity and decreased Ci under low light intensity,while stomatal limitation value (Ls) was just reverse to Ci.It could be concluded that the decrease of Pn in excess Mn treatment was not resulted from stomatal limitation under high light intensity,but was true under low light intensity.
    Effects of daytime sub-high temperature on greenhouse tomato growth, development,yield and quality
    ZHANG Jie,LI Tianlai,XU Jing
    2005, 16(06):  1051-1055 . 
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    The study on the effects of daytime sub?high temperature (30 and 35 ℃) in spring and autumn on the growth,development,yield and quality of greenhouse tomato in northeast China showed that compared with the plant growing under feasible temperature 25 ℃,three days' daytime sub-high temperature increased the relative growth significantly,and made the plant spindling.Seven days or more sub-high temperature made the plant grow fast,with thinner leaves and presenility.Under sub-high temperature,the harvest time was earlier,the fruit weight and the 2nd and 3rd inflorescence lessened,the quality of fruit decreased,and the yield decreased significantly. Sub-high temperature had a strong influence on the normal growth and development of greenhouse tomato.The longer the plant suffered sub-high temperature from flower bud differentiation to fruit maturing,the worse the fruit quality,and the lower the yield would be.
    Effects of selenium on Chamaecrista rotundifolia growth,nutrient absorption and nitrogen-fixing ability
    WENG Boqi1,HUANG Dongfeng2,XIONG Dezhong3,YING Zhaoyang1,HUANG Yibin1,Luo Tao2
    2005, 16(06):  1056-1060 . 
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    In this paper,a field experiment was conducted on a red soil of South China to study the effects of applying selenium fertilizer on the growth,forage quality and nitrogen-fixing ability of Chamaecrista rotundifolia. The results showed that applying 75,150,225 and 300 g Se·hm-2 could increase the plant height,branch number,dry root weight and dry forage yield by 0.3%～6.2%,65.1%～79.5%,155%～252% and 30.6%～54.1%,respectively. The total nitrogen,total phosphorus and total potassium contents of plant were increased by 21.79%～41.46%,20.74%～34.67% and 34.3%～62.4%, respectively,and the raw protein,raw fat,raw fiber and amino acid contents were increased by 21.79%～41.46%,1.4%～89.6%,34.1%～56.6% and 6.33%～63.24%,respectively. Among the 4 doses,150 g Se·hm-2 was the most effective and suitable application amount. The selenium content in plant after applying 300 g Se·hm-2（S4） was 0.695 mg·kg-1,with an increase of 0.658 mg·kg-1 compared to no selenium fertilization. There was a significantly positive correlation between plant selenium content and applied selenium (R2=0.9666**). The root nodule weight,number and nitrogenase activity in treatment 150 g Se·hm-2（S2） were respectively 131.7%, 114.3% and 1 417.9% higher than those of no selenium fertilization. The correlation between applied selenium and nitrogenase activity was also significant (R2=0.9606*).
    Dissipation mechanism of excessive energy in umbilical orange under phosphorus deficiency and strong light stress
    CHEN Pingzhao,WANG Lei,DAI Xun,LIU Zhongrong,JIANG Bin,FAN Qinping
    2005, 16(06):  1061-1066 . 
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    The dissipation mechanism of excessive energy of umbilical orange under phosphorus deficiency and strong light stress was studied with solution culture method.The results showed that under phosphorus deficiency and strong light stress,the photosynthetic pigment content,net photosynthetic rate (Pn), photorespiration rate (Pr),maximum fluorescence (Fm), photochemical efficiency (Fv/Fm) and electron transmit rate (ETR) of umbilical orange were all declined,while original fluorescence (Fo) and Pr/Pn ratio were raised.The fast-phase (qNf) of non-photochemical quenching of chlorophyll fluorescence was decreased,while the middle-phase (qNm) and slow-phase (qNs) were increased.After treated with DTT, Fo turned higher,but qNm and qNs were much lower than the control(H2O),while qNf did not have any significant change. Phosphorus deficiency and strong light stress aggravated photoinhibition of photosynthesis, which in turn started up several dissipation mechanisms in umbilical orange leaf.
    Control effects of rice-duck farming and other weed management strategies on weed communities in paddy fields
    WEI Shouhui1,QIANG Sheng1,MA Bo1,WEI Jiguang1,CHEN Jianwei2,WU Jianqiang 2,XIE Tongzhou 2,SHEN Xiaokun 3
    2005, 16(06):  1067-1071 . 
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    By the methods of community ecology,field studies were conducted to evaluate the control effects of three weed management strategies,i.e.,rice-duck farming (RD),manual weeding (MW) and chemical weeding (CW),on the weed communities in paddy fields.The results showed that under rice-duck farming,the weed density in paddy fields decreased significantly,and the control effects on dominant weed species such as Monochoria vaginalis, Cyperus difformis,Sagittaria pygmaea were all above 95%,with an overall effect higher than CW and MW.Under RD,the species richness and Shannon-Wiener diversity indices decreased slightly,while Pielou community evenness indices increased markedly,indicating that the species composition of weed community was greatly improved,and the infestation of former dominant weed species was reduced.The structure of weed communities in paddy fields varied with different weed management strategies,e.g.,under RD,Lindernia procumbens,Cyperus difformis and Fimbristylis miliacea constituted the major weed community,and the Whittaker index was significant higher than that of CW,MW and CK,which indicated that rice-duck farming had a greater effect on the structure of the weed communities.The same conclusion could be drawn from Sorensen's similarity indices and cluster analysis with Sorensen's index as the distance measurement.
    Developing models on water?saving agriculture through rainwater harvesting for supplemental irrigation in northern China semiarid-region
    SUN Huimin1,CHENG Manjin2,ZHENG Dawei3,ZHANG Jianxin3
    2005, 16(06):  1072-1076 . 
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    Zhungeer of Inner Mongolia,an arsenic?bearing sandstone area of northern Loess Plateau,is one of the sites with most serious soil and water losses in China,while rainwater harvesting (RWH) for supplemental irrigation is the only approach to abate droughts in this region.In the ongoing water saving agriculture project,a national 863 project of China,Zhungeer was chosen as a demonstration zone of water-saving dryland agriculture through rainwater harvesting for supplemental irrigation in northern China semi-arid region.The traditional RWH and utilization lacks of holistic consideration,resulting in the blindness in engineering planning and production arrangement.Based on the analysis of the ecological,economic and societal conditions in the demonstration zone,this paper summarized the technological system of dryland cropping production centered on RWH for supplemental irrigation,and developed three models of RWH and highly effective crop-planting,RWH and ecological pasturing,and domestic RWH and economy.The water demand standards for integrative rainwater utilization in the demonstration zone were determined,and the ecological and socio-economic assessment on the three years implement effects of the models was conducted.
    Soil enzyme activities of limestone degraded ecosystem at its different restoration phases
    HE Yuejun1,2,ZHONG Zhangcheng1,LIU Jiming2,LIU Jinchun1,JIN Jing1, LI Qingyu1
    2005, 16(06):  1077-1081 . 
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    The study showed that there was no distinct descending of enzyme activities along the soil profile of limestone degraded ecosystem,which were enhanced with progressive succession,and varied with vegetation characteristics,soil types,and soil enzyme properties.On the whole,soil enzyme activities enhanced in order of herb < Cupressuss funebris high forest＜shrubbery,and under the same vegetation,limestone Cupressuss funebris high forest had higher soil enzyme activities than purple psammophytia.There was no significant correlation between soil enzyme activities and soil pH,while significant correlation was found between soil moisture content,soil total nitrogen content and soil enzyme activities,indicating that soil water and nutrient contents were the key factors of ecological restoration in this region.Different soil enzymes in the same vegetation-soil system as well as the same enzyme in the same soil type but at different restoration phases had different activities,so did for the same type vegetation but different soil type.
    Effects of environmental factors on Phyllotreta striolata dispersion
    GAO Zezheng1,2,WU Weijian1,CUI Zhixin3,LIANG Guangwen1
    2005, 16(06):  1082-1085 . 
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    Using marking recapture method,this paper studied the effects of host plants and climatic factors on the dispersion of Phyllotreta striolata adults.The results showed that the dispersion of the beetle was impelled by environment elements (τ≈1).Temperature and wind speed had significantly positive correlations with the dispersion of the beetle (P<0.05),while high temperature had a negative correlation.Wind orientation had a significant effect on the dispersion of the beetle,with the adults mostly flying against or vertically to the wind.Humidity contributed little to the dispersion (P>0.05). Host plant was one of the important factors affecting the dispersion of the beetle.Among the plants studied,flowering Chinese cabbage ranked first in capturing marked adults,followed by mustard and Chinese cabbage,while nearly no marked adults were captured on Chinese kale.
    Evaluation of nonhost plant ethanol extracts against Plutella xylostella population
    WEI Hui1,HOU Youming2,YANG Guang2,FU Jianwei1，YOU Minsheng2
    2005, 16(06):  1086-1089 . 
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    Through establishing experimental and natural population life tables,and by using the index of population trend (I) and interference index of population control (IIPC),this paper evaluated 8 kinds of nonhost plant ethanol extracts against experimental population of Plutella xylostella,and 3 kinds of these extracts and their mixture against Plutella xylostella natural population.The experimental population life table of DBM showed that the index of population trend (I) was 69.8964 in control,and decreased dramatically to 5.3702,4.4842,8.0945,11.1382,6.8937,6.1609,5.5199 and 9.8052,respectively in treatments of Zanthoxylum bungeanum,Eucalyptus tereticornis,Nicotiana tabacum,Broussonetia papyrifera,Bauhinia variegata, Duranta repens,Euphorbia hirta and Camellia oleifera ethanol extracts,while the corresponding IIPC was 0.0768,0.0642,0.1158,0.1594,0.0986,0.0881, 0.0790 and 0.1403,respectively.The natural population life tables of DBM showed that the index of population trend (I) was 21.6232 in control,and decreased dramatically to 5.1997,7.4160,7.3644 and 3.1399,respectively in treatments of the ethanol extracts of E.tereticornis,N.tabacum,C.oleifera and their mixture,while the corresponding IIPC was 0.2405,0.3695,0.3549 and 0.1608,respectively.All of these indicated that the test plant extracts could interfere the development of P.xylostella population significantly,and had the potential as an effective measure for controlling insect pest.
    Virulence of Sogatella furcifera field populations to rice varieties:A determination with electronic monitoring system
    SHEN Junhui1,LI Ping2,LIU Guangjie1
    2005, 16(06):  1090-1094 . 
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    With electronic monitoring system (EMS) and honeydew measurement,this paper determined the virulence of Sogatella furcifera field populations in Fuyang County of Zhejiang Province and Changfeng County of Anhui Province.The results showed that in the three EMS recording periods (2,4 and 6 h),the ratios of phloem ingestion duration to susceptible rice variety TN1 (check) and highly resistant variety RHT were relatively stable.Two hours duration was defined as the shortest period to detect the virulence of S.furcifera field population by EMS.The amounts of honeydew excreted by S.furcifera field population on rice varieties N22,ARC,ADR52 and ND in Fuyang County,which carried the dominant resistance gene Wbph1,Wbph2,Wbph3 and Wbph5,respectively,were not significantly different from each other,but significantly lower than that on TN1.The durations of phloem ingestion on ARC and ADR52 were not significantly different,but significantly shorter than that on TN1.For the field population in Changfeng County,the amounts of honeydew excreted by S.furcifera did not differ significantly on N22 and ARC or on ADR52 and ND,but the honeydew on the former two rice varieties was significantly more than that on the latter two.The duration of phloem ingestion on ADR52 (22.3 min·2 h-1) was significantly shorter than that on ARC(49.8 min·2 h-1).Therefore,the virulence of S.furcifera field population in Fuyang County had no changes,whereas in Changfeng County,the population showed a definite adaptation to N22 and ARC,displaying the trend of virulence shift.Electronic monitoring system provided a new means for rapidly and accurately detecting the virulence and monitoring its change of S.furcifera field population.
    Bioactivity of azadirachtin and its field efficiency against Spodoptera litura
    DAI Jianqing1，2,HUANG zhiwei1，2,DU Jiawei1
    2005, 16(06):  1095-1098 . 
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    In this paper,the effects of varying concentration azadirachtin on tobacco cutworm Spodoptera litura were investigated in both laboratory and field.The results showed that azadirachtin exhibited a wide range of bioactivities, including anti-feeding,growth inhibition,larval toxicity,and oviposition deterrent.This compound could significantly reduce pupal weight and pupation and eclosion rates.After treated with 12 μl·L-1 azadirachtin for 5 and 7 days,the third instar larvae only weighted 36.8% and 14.5% of the untreated ones,and their development took approximately 6 days longer, with a 27.79% pupation rate and a 37.23% emergence rate,significantly lower than the control by 85.66% and 82.11%,respectively.Azadirachtin was more efficient for the low instar larva than the old ones.Field experiments confirmed that after 7 days application,azadirachtin could effectively control Spodoptera litura,being more efficient than the chemistry pesticide,10% Chu-Jin SC.
    Effects of acetochlor and methamidophos on culturable fungal population and community structure in black soil
    LI Xinyu1,2,ZHANG Huiwen1,ZHANG Jing1,SU Zhencheng1,ZHANG Chenggang1
    2005, 16(06):  1099-1103 . 
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    By the methods of CFU and rDNA-PCR-DGGE,this paper studied the dynamic changes of culturable fungal populations,community structure,and population richness in black soil under stress of acetochlor and methamidophos.The results showed that the growth of fungi was promoted under lower concentration acetochlor (50 mg·kg-1),but long-standing inhibited under its higher concentration (250 mg·kg-1).250 mg·kg-1 methamidophos promoted the growth of culturable fungi intensively during 8-week period,resulting in 10 times increase in CFU of fungi than the control,while low concentration methamidophos (50 mg·kg-1) had no evident effect.The richness of culturable fungi in soil treated by medium and high concentration acetochlor was decreased irreversibly.Cluster analysis of fungal rDNA-PCR-DGGE fingerprints profile showed that acetochlor and methamidophos could change the culturable fungal community structure diversely,and the effect of methomidophos was more obvious.
    Prevention efficiency of Exserohilum monoceras with chemical herbicides against Echinochloa crus-galli in paddy field
    CHEN Yong1，2,NI Hanwen2,ZHANG Hongjun3,LI Xiaojing2,LI Jianqiang4
    2005, 16(06):  1104-1107 . 
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    This paper studied the impact of several herbicides on the conidium germination of Exserohilum monoceras strain X27 in petri dish,and the synergistic effects of the pathogen and chemical herbicide quinclorac or propanil against Echinochloa crus-galli in greenhouse.The prevention efficiency of the tank-mixture of pathogen and quinclorac was also evaluated in paddy field.The results showed that test herbicides except quinclorac and bensulfulfuron-methyl could inhibit conidium germination and hypha growth to different degree.A significant synergism was observed between the pathogen and quinclorac.Adding quinclorac could obviously increase the prevention efficiency against Echinochloa crus-galli.Under field condition,the single use of pathogen could only control about 60% of the weed,while the efficiency of pathogen-quinclorac mixture could reach 90%.
    Toxicological study of three veterinary drugs on Eisenia foetida
    QU Mengmeng1,XU Yun1,CHEN Haigang1,LI Zhaoli1,SUN Liwei1,XU Dijin1, KONG Zhiming1,SUGIURA Norio2
    2005, 16(06):  1108-1111 . 
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    By the methods of acute toxicity test and single cell gel electrophoresis (comet assay),this paper evaluated the toxicological effects of three veterinary drugs olaquindox,arsanilic acid and oxytetracycline on earthworm (Eisenia foetida) coelomocytes in vivo.The results of acute toxicity test showed that only the highest dose of olaquidox caused the death of some earthworms,and none of the test drugs had any effects on earthworm at their environmentally relevant concentrations.The comet assay indicated that arsanilic acid had no genotoxicity to earthworm,while olaquindox and oxytetracycline induced significant DNA damage in earthworm coelomocytes (P<0.01).
    Effects of bacteria?feeding nematode at its different density on bacterial number,bacterial activity and soil nitrogen mineralization
    MAO Xiaofang,LI Huixin,LONG Mei,HU Feng
    2005, 16(06):  1112-1116 . 
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    A gnotobiotic microcosm experiment was conducted to study the interactions between bacteria?feeding nematode Caenorhabditis elegans and bacterium Bacillus subtilis,and their effects on soil nitrogen mineralization at different Caenorhabditis elegans density.The results showed that the inoculation of the nematode stimulated the growth of the bacterium,and the increment was in order of 20>10>40 nematodes·g-1 dried soil.The interaction between Caenorhabditis elegans and Bacillus subtilis significantly enhanced soil respiration rate and soil invertase,urease and phosphatase activities,with no significant differences among three test nematode densities.The inoculation of bacterial?feeding nematode markedly increased soil NH4+-N and mineral N,suggesting that soil N mineralization was enhanced under the effect of the nematode.The increment of soil nitrogen mineralization at different nematode density was also in the same order mentioned above.
    Landscape health assessment on Ejin natural oasis
    CAO Yu1，OUYANG Hua1，XIAO Duning2
    2005, 16(06):  1117-1121 . 
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    Landscape scale ecosystem health research could not only provide a basis for integrating natural ecological processes and social economic values,but also provide an appreciated temporal and spatial scale in dealing with the issues of resources and environment.The Ejin natural oasis landscape is at the lower reach of Heihe river basin in the arid inland regions of northwestern China.Owing to the lack of sufficient water resource from the upper reaches of Heihe River,a series of ecological and environmental problems are getting more serious in the oasis in recent years.Based on the past decade landscape change of the Ejin natural oasis,this paper developed a landscape health indicators system including landscape change indicators, bio-physical indicators,eco?environmental indicators and social-economic indicators,and established the criteria and weightiness for assessment indicators.The landscape health index (LHI) was finally figured out as 0.3042 by using fuzzy comprehensive evaluation method,which showed that the health condition of Ejin natural oasis landscape was ranked to “severely ill level" in the landscape health assessment criteria system.The landscape health of Ejin natural oasis landscape today is much worse than in the past years,with a badly unsustainable developing trend.
    Measurement of terrestrial ecosystem service value in China
    HE Hao,PAN Yaozhong,ZHU Wenquan,LIU Xulong,ZHANG Qing,ZHU Xiufang
    2005, 16(06):  1122-1127 . 
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    With the measurement of net primary productivity and vegetation coverage fraction based on remote sensing data,the terrestrial ecosystem service value of China in 2000 was quantitatively estimated as 9.17×1012 yuan (RMB).The spatial distribution of the ecological service value showed a decreasing trend from southeast China to northwest China,which was consistent with the regional distribution of vegetation types.The service value varied with different vegetations,e.g.,forests had the highest service value of 18 789 yuan·hm-2,accounting for 40.80% of the total terrestrial ecosystem service value,and bushes and farmlands had a higher service value of 13 789 yuan·hm-2 and 13 054 yuan·hm-2,which was 10.79% and 24.23% of total value,respectively.The service value was also varied with different ecosystem functions,i.e.,gas regulation contributed the highest value of 45.16% to the total service value,and the contribution of soil conservation and water conservation was 28.83% and 14.44%,respectively.The integrated approach coupling ecology and remote sensing data provided a new method to measure the ecological service value,which could estimate the value objectively and spatial-explicitly.However,some uncertainties still existed in this approach,which should be improved in the future studies.
    Urbanization expanding process and its spatial characteristics in Changping District of Beijing,China
    ZHANG Feng,ZHANG Xinshi
    2005, 16(06):  1128-1132 . 
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    Urbanization is a massive and unplanned experiment that already affects large acreages worldwide,and has profound social and ecological consequences for both urban and rural residents.Therefore,to comprehensively quantify the urbanization process and to investigate its ecological consequences become the central issues in urban ecological studies.Combining urbanization expanding index with landscape metrics,this paper quantified the urbanization expanding process and the urbanization spatial characteristics in Changping District of Beijing.The results showed that there were three main urbanization models,i.e.,urban fringe belt?expending model,main transportation routes line-expending model,and satellite city panel-expending model.The urbanization expansion index showed that urbanization mainly took place during the period from 1989 to 1996,and the urban landscape metrics indicated that there were urban patches isolated expanding and new urban patches emerged from 1989 to 1996,mainly amalgamated expanding from 1996 to 2001 in urban fringe belt?expanding region.In transportation routes line-expanding region,the urban patches isolated expanding,amalgamated expanding and new urban patches emerging took place simultaneously,and mainly urban patches amalgamated expanding during the former period,and new urban patches constantly turning up around satellite city during the latter in satellite city panel-expanding region.This study showed that urbanization expansion integrating landscape metrics might reveal the urbanization expanding process and its spatial characteristics,and would be a good example for the application of landscape metrics.
    Attenuation of photosynthetically available radiation (PAR) in Meiliang Bay under different winds and waves
    ZHANG Yunlin1,2,QIN Boqiang1,CHEN Weimin1,HU Weiping1,GAO Guang1,ZHU Guangwei1，LUO Liancong1
    2005, 16(06):  1133-1137 . 
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    Based on the successive underwater irradiance measurement in situ from Jul.12 to 17 in 2003,the attenuation of photosynthetically available radiation (PAR) and euphotic depth in Meiliang Bay were analyzed under different winds and waves.The results showed that the downward PAR attenuation coefficients ranged from 2.63 to 4.7· m-1,with an average of 3.63±0.47·m-1,and the corresponding euphotic depth ranged from 0.98 to 1.75 m,with an average of 1.29±0.18 m,which demonstrated that phytoplankton and macrophyte could not grow below 1.5 m due to the lack of adequate solar radiation.The total suspended solids resulted from wind and wave increased the attenuation of light,with the downward attenuation coefficients of PAR being 2.63,3.72 and 4.37·m-1 under small,medium and large wind and wave,respectively.Significant linear correlations were found between transparence,PAR attenuation coefficient,euphotic depth and total suspended solid,especially inorganic suspended solid,while chlorophyll a was the most nonsignificant light attenuator.Multiple stepwise linear regressions showed that inorganic suspended solid was the most important light attenuator dominating the light attenuation in wind?exposed Meiliang Bay.
    Effects of Brachionus calyciflorus culture media filtrate on Microcystis aeruginosa,Scenedesmus obliquus and Chlorella vulgaris colony formation and growth
    YANG Zhou1,2,3,KONG Fanxiang1,SHI Xiaoli1,YANG Jiaxin3
    2005, 16(06):  1138-1141 . 
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    To examine the possible information transfer by chemicals between zooplankton and algae,this paper studied the effects of Brachionus calyciflorus culture media filtrate on the colony formation and growth of Microcystis aeruginosa,Scenedesmus obliquus and Chlorella vulgaris.The results showed that the test filtrate could significantly promote the colony formation and population growth of S.obliquus,while no significant effect was observed on M.aeruginosa and C.vulgaris.The induced colony formation of S.obliquus increased its resistance to grazing,and thus,reduced the risk of its being grazed,which could be viewed as a kind of inducing defense.The accelerated growth of C.vulgaris and the toxin production of M.aeruginosa could also be interpreted as a defense mechanism against grazing.It maybe concluded that M.aeruginosa,S.obliquus and C.vulgaris could adopt different ecological strategies to resist the potential grazing by rotifer B.calyciflorus, and thus,to keep their population on a certain scale.
    Effects of glyphosate on life history characteristics of freshwater rotifer Brachionus calyciflorus
    CHU Zhaoxia,XI Yilong,XU Xiaoping,GE Yali,DONG Lili,CHEN Fang
    2005, 16(06):  1142-1145 . 
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    The life table study on the life history characteristics of freshwater rotifer Brachionus calyciflorus under effects of different concentrations glyphosate showed that glyphosate had significant effects on the embryonic developmental time,duration of juvenile and reproductive periods,average lifespan,net reproductive rate,and intrinsic population increasing rate of the rotifer.The embryonic developmental time was significantly lengthened when exposed to 3 and 8 mg·L-1 glyphosate,the juvenile period began to be lengthened significantly when exposed to 3 mg·L-1 glyphosate,while the net reproductive rate and intrinsic population increasing rate decreased significantly when the rotifer was exposed to 8.00 and 10.50 mg·L-1 glyphosate,respectively.Among all the parameters,intrinsic population increasing rate was the most sensitive parameter which could be used in monitoring the effects of glyphosate on the life history characteristics of B.calyciflorus.
    Pollution ?ecological problems of old industrial and mining areas and future research prospects
    ZHOU Qixing
    2005, 16(06):  1146-1150 . 
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    Environmental pollution and its solicitation in ecological problems of old industrial and mining areas have become a worldwide technological puzzle restricting sustainable economic and social development.But,the definition and category of old industrial and mining areas is still disputed as an important concept.In this paper,the concept of old industrial and mining area was discussed in theory,and,proceeded with analyzing the complexity of current situation and environmental pollution problems of old industrial and mining areas in China,more keystone attention was paid to the secondary pollution problems from old industrial and mining areas as an important frontier of science.On the basis of expounding the complexity and characters of environmental pollution in old industrial and mining areas,it was suggested that as two key scientific problems in environmental sciences and ecology,the formation mechanisms and control technology of secondary pollution in old industrial and mining areas and the responses of new-type diseases to environmental pollution based on molecular ecotoxicology should be systematically studied on the national scale,and be an important component of environmental protection strategy in China in the future.
    Research advances on BVOCs emission from forest
    QIE Guangfa1，2,WANG Cheng1，2,PENG Zhenhua1，2
    2005, 16(06):  1151-1155 . 
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    BVOCs play an important role in atmospheric environmental quality,global tropospheric chemistry,and global carbon balance,while forest is the main sources of them.This paper summarized the seasonal and diurnal variations of BVOCs emission from forest and its affecting factors including habitat variation,environmental change,forest development phase and its physiological status,and exotic interference.The ecological significance of forest BVOCs emission was further discussed,and some suggestions were proposed on ecological healthcare forest resources exploitation and urban forest construction.
    Research advances in simulating regional crop growth under water stress by remote sensing
    ZHANG Li,WANG Shili,MA Yuping
    2005, 16(06):  1156-1162 . 
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    It is of practical significance to simulate the regional crop growth under water stress,especially at regional scale.Combined with remote sensing information,crop growth simulation model could provide an effective way to estimate the regional crop growth,development and yield formation under water stress.In this paper,related research methods and results were summarized,and some problems needed to be further studied and resolved were discussed.
    Effects of plant process on soil organic carbon concentration
    LI Hongbo1，SHI Kun1，Xu Deying2
    2005, 16(06):  1163-1168 . 
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    From the viewpoint of the globe and ecosystem,this paper reviewed the effects and the possible action mechanisms of plant process on soil organic carbon concentration.Plant process could affect the source and sink of soil organic carbon,which was likely related with ambient temperature,and forest process could be in favor of the accumulation of soil carbon.Future tasks in this field were put forward to reduce the CO2 concentration in atmosphere through controlling the respiration of soil surface layer and keeping ecosystem balance.It is crucial to make efforts in increasing plant biomass to enhance soil organic carbon storage.
    Research advance on lake ecosystem dynamic models
    LIU Yong,GUO Huaicheng,FAN Yingying,WANG Lijing
    2005, 16(06):  1169-1175 . 
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    Starting with the role of system analysis in lake ecosystem research,this paper summarized the tentative procedures and softwares for studying the dynamics of lake ecosystem.There are several main stages in modeling the dynamics of lake ecosystem,namely,problems identification,mathematical formulation,computation,validation,sensitive analysis,calibration,and verification.In the modeling,selecting temporal and spatial scales is essential but complex.Since 1960s,a rapid progress has been made in modeling the dynamics of lake ecosystem,being developed from simple zero?dimension models to complex ecological-aquatic-hydrodynamic ones,among which, exergy was applied popularly as an objective function in modeling.In this paper,LakeWeb and LEEDS (Lake Eutrophication,Effect,Dose,and Sensitivity model) were analyzed as examples.In China,the development of lake ecosystem dynamic models could be traced back to1980s,and most of them were focused on Lake Dianch,Lake Taihu,Lake Chaohu and Lake Donghu. Some softwares such as CE-QUAL-ICM,WASP,AQUATOX,PAMOLARE and CAEDYM were developed to simulate lake ecosystem dynamics,among which,CE-QUAL-ICM is more suitable for long and narrow water bodies.WASP consists of three parts,i.e.,DYNHYD,EUTRO,and TOXI.AQUATOX is an ecological risk model,and the parameters are mainly calibrated in U.S.A,which has limited its further application in China.The software ECOPATH for simulating the energy flows in lakes was also described in this paper.There are still many shortages in the lake ecosystem dynamic models,e.g.,the lack of sufficient monitoring data for validation,insufficient consideration of uncertainties and the role of bacteria,and inconsistent relationship with watershed changes.The uncertainties are mainly from the intrinsic uncertainties in aquatic ecosystem,in modeling,in parameters selection,and also in forecast and application.Setting up long-term monitoring and data sharing mechanism,using interpolation to make data more densely, introducing objective functions,dealing with uncertainties,and constructing watershed-lake ecosystem dynamic model could be the available ways for overcoming the shortages.
    Avian diversity in Wuhu City during summertime
    LI Yongmin,WU Xiaobing
    2005, 16(06):  1176-1179 . 
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    Urban avian diversity is an important part of city biodiversity,which plays an important role in ecological balance of cities.During the summertime in 2004, we studied three typical avian communities at the habitats of village and farmland,urban woodlot,and floodplain in the urban and suburban areas of Wuhu City.A total of 71 species were recorded,which belonged to 12 orders, 27 families.The analysis of diversity index showed that urban woodlot had the greatest avian species number and G?F index,village and farmland had the highest avian density,and floodplain had the highest Shannon?Wiener and Pielou indices due to low human disturbance and dense vegetation.It is important to keep the avian diversity of floodplain in Wuhu City.
    Toxic effects of 1,8-dihydroxyanthraquinone on Daphnia magna
    SUN Jingyan,HUANG Liping,QIAO Xianliang,YANG Xichuan,CHEN Jingwen
    2005, 16(06):  1180-1182 . 
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    The study on the acute,sublethal and chronic toxicity of 1,8-ihydroxyanthraquinone (1,8-dihAQ) to Daphnia magna showed that the 48 h LC50 was 0.37 mg·L-1,and the feeding behavior of Daphnia magna was severely affected by the compound.When exposed to 0.2 mg·L-1 of 1,8-dihAQ for 5 h,the filtration and ingestion rate of Daphnia magna was inhibited by 97%.Chronic toxicity test results indicated that the reproduction ability decreased dramatically after exposing to sublethal concentration of 1,8-dihAQ.It could be inferred that reproduction parameters and intrinsic rate of natural increase were the sensitive parameters in characterizing sublethal toxicity.The NOEC and LOEC values for reproduction parameters were also given.
    Effects of aspect on distribution pattern of Taxus chinensis population in Yele,Sichuan Province:An analysis based on patches information
    XU Xiao, SU Zhixian, YAN Xianchun
    2005, 16(6):  985-990. 
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    Employing GIS method and based on patches information,this paper studied the effects of aspect on the distribution pattern of Taxus chinensis population in Yele,Sichuan Province.The results showed that Taxus chinensis population mainly distributed on the aspects of northwest,northeast,east and north.These aspect patches were absolutely dominant on area,mean size,mean edge and the number of Taxus chinensis.There existed a significant correlation between aspect and Taxus chinensis distribution.Taxus chinensis distributed preferentially on north,northeast,northwest and east patches,then on west and southwest patches,and finally on flat and southeast patches.The distribution patterns of Taxus chinensis in Yele were clustering,except on south aspect patches.The intensity of clustering on north aspect patches was the highest,with the value of Clark-Evans (CE) index being 0.906.The intensity of clustering on northeast and northwest aspect patches was lower than that on north aspect patches,with the CE value 0.797 and 0.563,respectively.The CE values on the rest aspect patches were all not larger than 0.5.There existed a significant positive correlation between the intensity of clustering index,number of patches,total patch edge,and the number of Taxus chinensis distributed on the patches,with the value of correlation coefficient 0.936,0.735 and 0.802,respectively.There were no significant correlations among the intensity of clustering,patch area,mean patch size,mean patch edge,and mean shape index of aspect patches.
    Effects of Fargesia denudata density on its biomass distribution pattern
    WU Fuzhong, WANG Kaiyun, YANG Wanqin, LU Yejiang
    2005, 16(6):  991-995. 
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    In this paper,the effects of Fargesia denudata density on its biomass distribution pattern were studied in the primitive Fargesia denudata-Picea purpurea forest from May to October,2003.The results showed that with increasing stem density,the total biomass,above-and below-ground biomass,net production,and average stem biomass of the bamboo were all increased,while the net increment of aboveground biomass decreased.The relationship between above-and below-ground biomass in the bamboo communities was also regulated by the stem density,with the correlation coefficient increased with the density.Except for the exponential period (July and August),the ratio of above-/below-ground biomass increased with the density,and the moderate density (140?7 stems穖-2) had the highest ratios of above-/below-ground biomass.The biomass distribution pattern of different organs depended on both stem density and growth period,and stem density played a significantly important role in the distribution pattern of bamboo biomass.
    Effects of Fargesia denudata density on soil nutrient pool
    LU Yejiang, WANG Kaiyun, YANG Wanqin, WU Fuzhong
    2005, 16(6):  996-1001. 
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    This paper studied the nutrient storage and its dynamics in different soil layers under three densities of Fargesia denudata communities in Wanglang National Nature Reserve,aimed to understand the effects of F.denudata density on the storage and dynamics of soil nutrients.The results showed that F.denudata density had a significant effect on the total and available nutrient contents in 0～30 cm soil layer.The total and available P contents decreased significantly with the increasing F.denudata density (P<0.01),being 0.274 kg·m-2 and 1.72 g·m-2 at D1,0.222 kg·m-2 and 1.50 g·m-2 at D2,and 0.158 kg·m-2 and 1.10 g·m-2 at D3 sampling site,while the contents of total Ca and Mg increased with the increasing F.denudata density,being 2.64 and 1.70 kg·m-2 at D1,4.42 and 1.80 kg·m-2 at D2,and 4.85 and 2.12 kg·m-2 at D3 sampling site,respectively.The contents of both total and available N and K did not change significantly with F.denudata density.Soil total and available N were 1.10 and 45.15 kg·m-2 at D1,1.04 and 44.38 kg·m-2 at D2,and 1.06 and 42.02 kg·m-2 at D3,while soil total and available K were 3.19 and 39.62 kg·m-2 at D1,3.30 and 36.23 kg·m-2 at D2,and (3.19) and 37.18 kg·m-2 at D3,respectively.The total nutrient storage was in order of Ca>K>Mg>N>P,except a higher K storage than Ca under D1 community.The available N,P and K concentration in surface soil (0～10 cm) decreased significantly in July,and then increased slowly in the later growth season.In general,the change magnitude of available nutrients was greater in surface soil (L1) than in lower soil layers (L2 and L3),under higher F.denudata density (D3) than under lower F.denudata density,and for P than for N and K.The distribution pattern of nutrient storage in soil layers differed greatly from that of nutrient concentration,regardless of F.denudata densities.The contents of total N,P,K,Ca and Mg in L1 (0～10 cm) were lower than those in L2 (10～20 cm) and L3 (20～30 cm).The differences of nutrient contents among soil layers varied with F.denudata density,and particularly with bio-elements.The results suggested that the nutrient storage in soil under F.denudata community was related to F.denudata density,because the density affects the processes of nutrient cycling,such as nutrient absorption,return through litter,and activity of soil microorganisms.It could be concluded that the density of F.denudata communities affected the storage of soil P and Ca significantly,but that of soil Mg,N and K slightly.Soil total and available P contents decreased with the increasing F.denudata density,implying that soil P could be one of the main factors limiting the growth and succession of F.denudata community in these stands,and affecting the flowering and death of bamboo.
    Neural network grade program of natural forest protection
    LUO Chuanwen, CHEN Yian, HU Haiqing, SHEN Hailong, FAN Shaohui
    2005, 16(6):  1002-1006. 
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    In this paper,the implement steps of natural forest protection program grading (NFPPG) with neural network (NN) were summarized,and the concepts of program illustration,patch sign unification and regress,and inclining factor were set forth.Employing Arc/Info GIS,the tree species diversity and rarity,disturbance degree,protection of channel system,and classification management in Moershan National Forest Park were described,and,used as the input factors of NN,the relationships between NFPPG and above factors were analyzed.Through artificially determining training samples,the NFFPG of Moershan National Forest Park was built.Tested with all patches in the park,the generalization of NFFPG was satisfied.NFPPG took both the classification management and the protection of forest community types into account,as well as the ecological environments.The excitation function of NFPPG was not seriously saturated,indicating the leading effect of inclining factor on the network optimization.
    Seasonal dynamics of hyperin content in Acanthopanax senticosus at different habitats
    CAO Jianguo, ZU Yuangang, YANG Fengjian, ZHAO Zehai
    2005, 16(6):  1007-1010. 
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    The study with HPLC technology showed that hyperin only existed in A.senticosus leaf,flower and fruit,and its content was higher in leaf and flower than in fruit.The hyperin content in A.senticosus leaf showed a distinct dynamic change with the rhythm of development.Its content in bud was about 0.013%,which increased gradually with bud development.In mid May,the hyperin content in young leaf reached the maximum (0.087%);while in mid August,it decreased rapidly,with the lowest content about 0.008%.At different habitats,the hyperin content in A.senticosus leaf had different seasonal rhythm,which was low in understory,being at most (0.15%,)and high in forest gap and edge,with the contents of 0.42% and 0.65%,respectively.The same trend was found in A.senticosus flower and fruit.There was a significantly negative correlation between leaf area index (LAI) and hyperin content.
    Kinetic developmental genetics analysis of Hibiscus cannabinus plant height and stem diameter
    CHEN Youyu, QI Jianmin, LIN Lihui, LIANG Kangjing, ZHOU Ruiyang, WU Jianmei
    2005, 16(6):  1011-1016. 
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    By using quantitative traits additive-dominance genetics model and developmental genetics model,this paper analyzed the developmental behaviors of gene expression for Hibiscus cannabinu plant height and stem diameter at its different growth stages.The results showed that at different growth stages,the unconditional and conditional genetics effects of plant height all showed dominance,while the additive effect was weak.No additive effect was found for stem diameter,but dominance effect was significant at each growth stage.Plant height and stem diameter all had active gene expression from July 28 to August 9,and from September 2 to September 14.There was no additive correlation between plant height and stem diameter,but positive dominance correlation was significant after August 21.The unconditional and conditional genetics effects of plant height and stem diameter were not completely the same.According to practice,conditional genetic analysis could indicate the gene expression more truly in the whole growth period.The ecological and genetics variation patterns of Hibiscus cannabinus plant height and stem diameter at different space-time growth stages implied by our research was of significance in Hibiscus cannabinus genetics and breeding in both theory and practice.
    Effects of stand condition improvement on surface soil nutrient losses of hilly land Dendrocalamus latiflorus plantations
    QIU Erfa, CHEN Zhuomei, ZHENG Yushang, HONG Wei, YU Zhida
    2005, 16(6):  1017-1021. 
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    A comparative study on the soil nutrient losses of hilly land shoot-used Dendrocalamus latiflorus plantations at the Nanjing stated-owned forest farm,Fujian Province showed that the losses of soil N,P and K under three treatments of stand condition improvement varied with season,and 90% or more of these losses appeared from April to September,with the order of overall ploughing>strip ploughing>control. There was no significant difference of N and P losses among the three treatments,while the K loss was markedly higher under overall ploughing than the control.
    Ecological effects of intercrops in comprehensive management patterns of hilly area plum orchard
    ZHANG Tie, HUANG Xianpeng, YANG Bin
    2005, 16(6):  1022-1025. 
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    The study on the ecological effects of intercrops in four cropping patterns showed that with the increase of multiple cropping,the annual increase of soil organic matter,total N,total P and total K was 5%～20%,7%～40%,8%～70% and 15%～80%,respectively. Potato-soybean had the best benefit in soil and water conservation,followed by cole-peanut,potato-watermelon,and wheat. Compared with control,the average soil erosion module and runoff amount of 4 patterns were decreased by 44.19%,39.55%,38.24% and 37.56%,and 22.40%,(9.28%,)24.11% and 21.16%,respectively. Cole-peanut had the highest biomass,being averaged 100 276 kg·hm-2 annually,and the second was potato-watermelon,with an average of 73 692 kg·hm-2. Potato-watermelon had the highest productivity,which averaged 37 565 kg·hm-2 annually,and the second was potato-soybean,averaged 25 934 kg·hm-2. The efficiency of energy input was in order of cole-peanut,potato-watermelon,potato-soybean,and wheat,and the value was 2.96,2.08,2.01 and 0.96,respectively.
    Correlation of intersubspecific hybrid rice spikelet fertilization rate with temperature and related statistic model
    Lv Chuangen, ZOU Jiangshi, HU Ning, YAO Kemin
    2005, 16(6):  1026-1032. 
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    Using four types of rice,i.e.,indica-japonica hybrid,intermediate hybrid,indica and japonica cultivars as test materials,this paper studied the sensitivity of intersubspecific hybrid rice to climatic factors,and the correlations between spikelet fertilization rate (SFR) and daily meteorological factors during 2000 and 2001.The results showed that the SFR of intersubspecific hybrids was lower than that of indica and japonica cultivars.Among eleven meteorological factors,temperature was the key factor,and the mean temperature within five or seven days around panicle flower blooming affected the SFR significantly.A comprehensive model of SFR-temperature was established,with which,the fittest temperature and safe temperature for fertilization of intersubspecific hybrids was estimated to be 28.2～29.3 ℃ and 23.4～24.3 ℃,2.2 ℃ and 1.5 ℃ higher than those of indica and japonica cultivars,respectively.It was suggested that the safe heading date for planting intersubspecific hybrid should be moved up to the last ten-day of September to the first ten-day of October in southern China,the first ten-day of September in middle and lower reaches of Yangtze River Valley,and the last ten-day of August to the first ten-day of September in rice planting area between Yangtze and Huai River.
    Effects of applying L-methionine,L-phenylalanine and L-tryptophan on Zea mays growth and its nutrient uptake
    CHEN Mingchang, CHENG Bin, ZHANG Qiang, DING Yuchuan, YANG Zhiping, LIU Ping
    2005, 16(6):  1033-1037. 
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    A pot experiment was conducted to evaluate the effects of applying L-methionine(L-MET), L-phenylalanine (L-PHE) and L-tryptophan (L-TRP) on the growth of Zea mays and its nutrient uptake, and to determine the optimal application rate of them. The results showed that L-MET, L-PHE and L-TRP could improve the shoot height, shoot and root dry weights, root activity, nitrate reductase and hydrogen peroxidase activities, and N, P, K and Zn uptake of corn. The optimal application rate of L-MET, L- PHE and L-TRP was 0.0185～0.185 mg·kg-1 soil, 0.2 mg·kg-1 soil, and 0.03～0.3 mg·kg-1 soil, respectively, and L-PHE and L-TRP were superior to L-MET.
    SO2-caused oxidative stress and modulation of some signal molecules in wheat
    HAO Lin, ZHANG Huiwen, XU Xin, TAO Siyuan, YU Long
    2005, 16(6):  1038-1042. 
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    By adding different concentration SO2 to culture boxes,this paper studied the responses of wheat seedling's superoxide anion radical O2-· and antioxidant enzymes to SO2.The results showed that when the concentration of SO2 was 10 and 40 μl·L-1,the O2-· content and peroxidase (POD) and catalase(CAT) activities of wheat leaf were increased,while the activity of superoxide dismutase(SOD) was reduced.When the SO2 concentration was 50 μl·L-1,the activities of POD and CAT were decreased,with the top end leaves appeared necrosis,and more fungi multiplied on green leaves.Presoaking wheat seeds with 1 mmol·L-1 salicylic acid (SA) for 6 h or with 10 mmol·L-1 H2O2 for 12 h could efficiently alleviate the oxidative stress caused by SO2,with the O2-· content decreased and the activities of test antioxidant enzymes increased.Under SO2 fumigation,ethylene significantly inhibited the activities of test enzymes,and promoted the O2-· production rate.When applying SA and ethylene at the same time,SA could almost completely eliminate the influences of ethylene on O2-· production and test enzyme activities.
    Effects of aluminum speciation on wheat root growth and its enzyme activity
    ZHU Xuezhu, HUANG Yao, ZONG Lianggang, KONG Fanxiang
    2005, 16(6):  1043-1046. 
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    Aluminum speciation is recognized to associate with environmental pH.In this paper,the effects of aluminum speciation (Ala,Alb) on the growth,protein content,acid phosphatase (AP) activity of wheat root were studied by changing the pH of aluminum solutions.Two concentrations of total aluminum,25 μmol·L-1 (T1) and 75 μmol·L-1 (T2),were set up in the test solutions,and four levels of pH,4.0,4.5,5.0 and 5.5,were regulated for each solution.The results indicated that the growth of wheat root in T1 and T2 was strongly inhibited by low doses of Ala and Alb,while the changing trend of protein content and AP activity varied when exposed to different composition of active Al.When the Ala concentration was above 90% of the active Al concentration,the protein content was reduced while the AP activity was enhanced by Al at pH 4.0,but it was reverse at pH 5.0 when the concentration of Ala and Alb was below 10 μmol·L-1,respectively.
    Effects of excess Mn on photosynthesis characteristics in cucumber under different light intensity
    SHI Qinghua, ZHU Zhujun, YING Quansheng, QIAN Qiongqiu
    2005, 16(6):  1047-1050. 
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    By a solution culture experiment,this paper studied the effects of excess Mn on the growth,chlorophyll content,chlorophyll fluorescence parameters and photosynthesis of cucumber under different light intensity.The results indicated that excess Mn inhibited plant growth,which was more obvious under high light intensity than under low light intensity.The primary maximum photochemical efficiency of PSII (Fv/Fm),quantum efficiency of non-cyclic electron transport of PSII (ΦPSII),and photochemical quenching (qP) were significantly decreased in excess Mn treatment under high light intensity,while no significant effects on Fv/Fm and qP were observed under low light intensity.Excess Mn,particularly under high light intensity,decreased net photosynthetic rate (Pn) and stomatal conductance (Gs).Excess Mn increased intracellular CO2 (Ci) under high light intensity and decreased Ci under low light intensity,while stomatal limitation value (Ls) was just reverse to Ci.It could be concluded that the decrease of Pn in excess Mn treatment was not resulted from stomatal limitation under high light intensity,but was true under low light intensity.
    Effects of daytime sub-high temperature on greenhouse tomato growth,development,yield and quality
    ZHANG Jie, LI Tianlai, XU Jing
    2005, 16(6):  1051-1055. 
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    The study on the effects of daytime sub-high temperature (30 and 35 ℃) in spring and autumn on the growth,development,yield and quality of greenhouse tomato in northeast China showed that compared with the plant growing under feasible temperature 25 ℃,three days' daytime sub-high temperature increased the relative growth significantly,and made the plant spindling.Seven days or more sub-high temperature made the plant grow fast,with thinner leaves and presenility.Under sub-high temperature,the harvest time was earlier,the fruit weight and the 2nd and 3rd inflorescence lessened,the quality of fruit decreased,and the yield decreased significantly.Sub-high temperature had a strong influence on the normal growth and development of greenhouse tomato.The longer the plant suffered sub-high temperature from flower bud differentiation to fruit maturing,the worse the fruit quality,and the lower the yield would be.
    Effects of selenium on Chamaecrista rotundifolia growth,nutrient absorption and nitrogen-fixing ability
    WENG Boqi, HUANG Dongfeng, XIONG Dezhong, YING Zhaoyang, HUANG Yibin, Luo Tao
    2005, 16(6):  1056-1060. 
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    In this paper,a field experiment was conducted on a red soil of South China to study the effects of applying selenium fertilizer on the growth,forage quality and nitrogen-fixing ability of Chamaecrista rotundifolia. The results showed that applying 75,150,225 and 300 g Se·hm-2 could increase the plant height,branch number,dry root weight and dry forage yield by 0.3%～6.2%,65.1%～79.5%,155%～252% and 30.6%～54.1%,respectively. The total nitrogen,total phosphorus and total potassium contents of plant were increased by 21.79%～41.46%,20.74%～34.67% and 34.3%～62.4%,respectively,and the raw protein,raw fat,raw fiber and amino acid contents were increased by 21.79%～41.46%,1.4%～89.6%,34.1%～56.6% and 6.33%～63.24%,respectively. Among the 4 doses,150 g Se·hm-2 was the most effective and suitable application amount. The selenium content in plant after applying 300 g Se·hm-2(S4) was 0.695 mg·kg-1,with an increase of 0.658 mg·kg-1 compared to no selenium fertilization. There was a significantly positive correlation between plant selenium content and applied selenium (R2=0.9666**). The root nodule weight,number and nitrogenase activity in treatment 150 g Se·hm-2(S2) were respectively 131.7%,114.3% and 1 417.9% higher than those of no selenium fertilization. The correlation between applied selenium and nitrogenase activity was also significant (R2=0.9606*).
    Dissipation mechanism of excessive energy in umbilical orange under phosphorus deficiency and strong light stress
    CHEN Pingzhao, WANG Lei, DAI Xun, LIU Zhongrong, JIANG Bin, FAN Qinping
    2005, 16(6):  1061-1066. 
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    The dissipation mechanism of excessive energy of umbilical orange under phosphorus deficiency and strong light stress was studied with solution culture method.The results showed that under phosphorus deficiency and strong light stress,the photosynthetic pigment content,net photosynthetic rate (Pn),photorespiration rate (Pr),maximum fluorescence (Fm),photochemical efficiency (Fv/Fm) and electron transmit rate (ETR) of umbilical orange were all declined,while original fluorescence (Fo) and Pr/Pn ratio were raised.The fast-phase (qNf) of non-photochemical quenching of chlorophyll fluorescence was decreased,while the middle-phase (qNm) and slow-phase (qNs) were increased.After treated with DTT,Fo turned higher,but qNm and qNs were much lower than the control (H2O),while qNf did not have any significant change.Phosphorus deficiency and strong light stress aggravated photoinhibition of photosynthesis,which in turn started up several dissipation mechanisms in umbilical orange leaf.
    Control effects of rice-duck farming and other weed management strategies on weed communities in paddy fields
    WEI Shouhui, QIANG Sheng, MA Bo, WEI Jiguang, CHEN Jianwei, WU Jianqiang, XIE Tongzhou, SHEN Xiaokun
    2005, 16(6):  1067-1071. 
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    By the methods of community ecology,field studies were conducted to evaluate the control effects of three weed management strategies,i.e.,rice-duck farming (RD),manual weeding (MW) and chemical weeding (CW),on the weed communities in paddy fields.The results showed that under rice-duck farming,the weed density in paddy fields decreased significantly,and the control effects on dominant weed species such as Monochoria vaginalis,Cyperus difformis,Sagittaria pygmaea were all above 95%,with an overall effect higher than CW and MW.Under RD,the species richness and Shannon-Wiener diversity indices decreased slightly,while Pielou community evenness indices increased markedly,indicating that the species composition of weed community was greatly improved,and the infestation of former dominant weed species was reduced.The structure of weed communities in paddy fields varied with different weed management strategies,e.g.,under RD,Lindernia procumbens,Cyperus difformis and Fimbristylis miliacea constituted the major weed community,and the Whittaker index was significant higher than that of CW,MW and CK,which indicated that rice-duck farming had a greater effect on the structure of the weed communities.The same conclusion could be drawn from Sorensen's similarity indices and cluster analysis with Sorensen's index as the distance measurement.
    Developing models on water-saving agriculture through rainwater harvesting for supplemental irrigation in northern China semi-arid region
    SUN Huimin, CHENG Manjin, ZHENG Dawei, ZHANG Jianxin
    2005, 16(6):  1072-1076. 
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    Zhungeer of Inner Mongolia,an arsenic-bearing sandstone area of northern Loess Plateau,is one of the sites with most serious soil and water losses in China,while rainwater harvesting (RWH) for supplemental irrigation is the only approach to abate droughts in this region.In the ongoing water saving agriculture project,a national 863 project of China,Zhungeer was chosen as a demonstration zone of water-saving dryland agriculture through rainwater harvesting for supplemental irrigation in northern China semi-arid region.The traditional RWH and utilization lacks of holistic consideration,resulting in the blindness in engineering planning and production arrangement.Based on the analysis of the ecological,economic and societal conditions in the demonstration zone,this paper summarized the technological system of dryland cropping production centered on RWH for supplemental irrigation,and developed three models of RWH and highly effective crop-planting,RWH and ecological pasturing,and domestic RWH and economy.The water demand standards for integrative rainwater utilization in the demonstration zone were determined,and the ecological and socio-economic assessment on the three years implement effects of the models was conducted.
    Soil enzyme activities of limestone degraded ecosystem at its different restoration phases
    HE Yuejun, ZHONG Zhangcheng, LIU Jiming, LIU Jinchun, JIN Jing, LI Qingyu
    2005, 16(6):  1077-1081. 
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    The study showed that there was no distinct descending of enzyme activities along the soil profile of limestone degraded ecosystem,which were enhanced with progressive succession,and varied with vegetation characteristics,soil types,and soil enzyme properties.On the whole,soil enzyme activities enhanced in order of herb < Cupressuss funebris high forest<shrubbery,and under the same vegetation,limestone Cupressuss funebris high forest had higher soil enzyme activities than purple psammophytia.There was no significant correlation between soil enzyme activities and soil pH,while significant correlation was found between soil moisture content,soil total nitrogen content and soil enzyme activities,indicating that soil water and nutrient contents were the key factors of ecological restoration in this region.Different soil enzymes in the same vegetation-soil system as well as the same enzyme in the same soil type but at different restoration phases had different activities,so did for the same type vegetation but different soil type.
    Effects of environmental factors on Phyllotreta striolata dispersion
    GAO Zezheng, WU Weijian, CUI Zhixin, LIANG Guangwen
    2005, 16(6):  1082-1085. 
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    Using marking recapture method,this paper studied the effects of host plants and climatic factors on the dispersion of Phyllotreta striolata adults.The results showed that the dispersion of the beetle was impelled by environment elements (τ≈1).Temperature and wind speed had significantly positive correlations with the dispersion of the beetle (P<0.05),while high temperature had a negative correlation.Wind orientation had a significant effect on the dispersion of the beetle,with the adults mostly flying against or vertically to the wind.Humidity contributed little to the dispersion (P>0.05).Host plant was one of the important factors affecting the dispersion of the beetle.Among the plants studied,flowering Chinese cabbage ranked first in capturing marked adults,followed by mustard and Chinese cabbage,while nearly no marked adults were captured on Chinese kale.
    Evaluation of non-host plant ethanol extracts against Plutella xylostella population
    WEI Hui, HOU Youming, YANG Guang, FU Jianwei, YOU Minsheng
    2005, 16(6):  1086-1089. 
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    Through establishing experimental and natural population life tables,and by using the index of population trend (I) and interference index of population control (IIPC),this paper evaluated 8 kinds of non-host plant ethanol extracts against experimental population of Plutella xylostella,and 3 kinds of these extracts and their mixture against Plutella xylostella natural population.The experimental population life table of DBM showed that the index of population trend (I) was 69.8964 in control,and decreased dramatically to 5.3702,4.4842,8.0945,(11.1382),6.8937,6.1609,5.5199 and 9.8052,respectively in treatments of Zanthoxylum bungeanum,Eucalyptus tereticornis,Nicotiana tabacum,Broussonetia papyrifera,Bauhinia variegata,Duranta repens,Euphorbia hirta and Camellia oleifera ethanol extracts,while the corresponding IIPC was 0.0768,0.0642,0.1158,0.1594,0.0986,0.0881,0.0790 and 0.1403,respectively.The natural population life tables of DBM showed that the index of population trend (I) was 21.6232 in control,and decreased dramatically to 5.1997,(7.4160),7.3644 and 3.1399,respectively in treatments of the ethanol extracts of E.tereticornis,N.tabacum,C.oleifera and their mixture,while the corresponding IIPC was 0.2405,0.3695,0.3549 and 0.1608,respectively.All of these indicated that the test plant extracts could interfere the development of P.xylostella population significantly,and had the potential as an effective measure for controlling insect pest.
    Virulence of Sogatella furcifera field populations to rice varieties:A determination with electronic monitoring system
    SHEN Junhui, LI Ping, LIU Guangjie
    2005, 16(6):  1090-1094. 
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    With electronic monitoring system (EMS) and honeydew measurement,this paper determined the virulence of Sogatella furcifera field populations in Fuyang County of Zhejiang Province and Changfeng County of Anhui Province.The results showed that in the three EMS recording periods (2,4 and 6 h),the ratios of phloem ingestion duration to susceptible rice variety TN1 (check) and highly resistant variety RHT were relatively stable.Two hours duration was defined as the shortest period to detect the virulence of S.furcifera field population by EMS.The amounts of honeydew excreted by S.furcifera field population on rice varieties N22,ARC,ADR52 and ND in Fuyang County,which carried the dominant resistance gene Wbph1,Wbph2,Wbph3 and Wbph5,respectively,were not significantly different from each other,but significantly lower than that on TN1.The durations of phloem ingestion on ARC and ADR52 were not significantly different,but significantly shorter than that on TN1.For the field population in Changfeng County,the amounts of honeydew excreted by S.furcifera did not differ significantly on N22 and ARC or on ADR52 and ND,but the honeydew on the former two rice varieties was significantly more than that on the latter two.The duration of phloem ingestion on ADR52 (22.3 min?2 h-1) was significantly shorter than that on ARC (49.8 min?2 h-1).Therefore,the virulence of S.furcifera field population in Fuyang County had no changes,whereas in Changfeng County,the population showed a definite adaptation to N22 and ARC,displaying the trend of virulence shift.Electronic monitoring system provided a new means for rapidly and accurately detecting the virulence and monitoring its change of S.furcifera field population.
    Bioactivity of azadirachtin and its field efficiency against Spodoptera litura
    DAI Jianqing, HUANG zhiwei, DU Jiawei
    2005, 16(6):  1095-1098. 
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    In this paper,the effects of varying concentration azadirachtin on tobacco cutworm Spodoptera litura were investigated in both laboratory and field.The results showed that azadirachtin exhibited a wide range of bioactivities,including anti-feeding,growth inhibition,larval toxicity,and oviposition deterrent.This compound could significantly reduce pupal weight and pupation and eclosion rates.After treated with 12 μl·L-1 azadirachtin for 5 and 7 days,the third instar larvae only weighted 36.8% and 14.5% of the untreated ones,and their development took approximately 6 days longer,with a 27.79% pupation rate and a 37.23% emergence rate,significantly lower than the control by 85.66% and 82.11%,respectively.Azadirachtin was more efficient for the low instar larva than the old ones.Field experiments confirmed that after 7 days application,azadirachtin could effectively control Spodoptera litura,being more efficient than the chemistry pesticide,10% Chu-Jin SC.
    Effects of acetochlor and methamidophos on culturable fungal population and community structure in black soil
    LI Xinyu, ZHANG Huiwen, ZHANG Jing, SU Zhencheng, ZHANG Chenggang
    2005, 16(6):  1099-1103. 
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    By the methods of CFU and rDNA-PCR-DGGE,this paper studied the dynamic changes of culturable fungal populations,community structure,and population richness in black soil under stress of acetochlor and methamidophos.The results showed that the growth of fungi was promoted under lower concentration acetochlor (50 mg穔g-1),but long-standing inhibited under its higher concentration (250 mg穔g-1).250 mg穔g-1 methamidophos promoted the growth of culturable fungi intensively during 8-week period,resulting in 10 times increase in CFU of fungi than the control,while low concentration methamidophos (50 mg穔g-1) had no evident effect.The richness of culturable fungi in soil treated by medium and high concentration acetochlor was decreased irreversibly.Cluster analysis of fungal rDNA-PCR-DGGE fingerprints profile showed that acetochlor and methamidophos could change the culturable fungal community structure diversely,and the effect of methomidophos was more obvious.
    Prevention efficiency of Exserohilum monoceras with chemical herbicides against Echinochloa crus-galli in paddy field
    CHEN Yong, NI Hanwen, ZHANG Hongjun, LI Xiaojing, LI Jianqiang
    2005, 16(6):  1104-1107. 
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    This paper studied the impact of several herbicides on the conidium germination of Exserohilum monoceras strain X27 in petri dish,and the synergistic effects of the pathogen and chemical herbicide quinclorac or propanil against Echinochloa crus-galli in greenhouse.The prevention efficiency of the tank-mixture of pathogen and quinclorac was also evaluated in paddy field.The results showed that test herbicides except quinclorac and bensulfulfuron-methyl could inhibit conidium germination and hypha growth to different degree.A significant synergism was observed between the pathogen and quinclorac.Adding quinclorac could obviously increase the prevention efficiency against Echinochloa crus-galli.Under field condition,the single use of pathogen could only control about 60% of the weed,while the efficiency of pathogen-quinclorac mixture could reach 90%.
    Toxicological study of three veterinary drugs on Eisenia foetida
    QU Mengmeng, XU Yun, CHEN Haigang, LI Zhaoli, SUN Liwei, XU Dijin, KONG Zhiming, SUGIURA Norio
    2005, 16(6):  1108-1111. 
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    By the methods of acute toxicity test and single cell gel electrophoresis (comet assay),this paper evaluated the toxicological effects of three veterinary drugs olaquindox,arsanilic acid and oxytetracycline on earthworm (Eisenia foetida) coelomocytes in vivo.The results of acute toxicity test showed that only the highest dose of olaquidox caused the death of some earthworms,and none of the test drugs had any effects on earthworm at their environmentally relevant concentrations.The comet assay indicated that arsanilic acid had no genotoxicity to earthworm,while olaquindox and oxytetracycline induced significant DNA damage in earthworm coelomocytes (P<0.01).
    Effects of bacteria-feeding nematode at its different density on bacterial number,bacterial activity and soil nitrogen mineralization
    MAO Xiaofang, LI Huixin, LONG Mei, HU Feng
    2005, 16(6):  1112-1116. 
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    A gnotobiotic microcosm experiment was conducted to study the interactions between bacteria-feeding nematode Caenorhabditis elegans and bacterium Bacillus subtilis,and their effects on soil nitrogen mineralization at different Caenorhabditis elegans density.The results showed that the inoculation of the nematode stimulated the growth of the bacterium,and the increment was in order of 20>10>40 nematodes穏-1 dried soil.The interaction between Caenorhabditis elegans and Bacillus subtilis significantly enhanced soil respiration rate and soil invertase,urease and phosphatase activities,with no significant differences among three test nematode densities.The inoculation of bacterial-feeding nematode markedly increased soil NH4+-N and mineral N,suggesting that soil N mineralization was enhanced under the effect of the nematode.The increment of soil nitrogen mineralization at different nematode density was also in the same order mentioned above.
    Landscape health assessment on Ejin natural oasis
    CAO Yu, OUYANG Hua, XIAO Duning
    2005, 16(6):  1117-1121. 
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    Landscape scale ecosystem health research could not only provide a basis for integrating natural ecological processes and social economic values,but also provide an appreciated temporal and spatial scale in dealing with the issues of resources and environment.The Ejin natural oasis landscape is at the lower reach of Heihe river basin in the arid inland regions of northwestern China.Owing to the lack of sufficient water resource from the upper reaches of Heihe River,a series of ecological and environmental problems are getting more serious in the oasis in recent years.Based on the past decade landscape change of the Ejin natural oasis,this paper developed a landscape health indicators system including landscape change indicators,bio-physical indicators,eco-environmental indicators and social-economic indicators,and established the criteria and weightiness for assessment indicators.The landscape health index (LHI) was finally figured out as 0.3042 by using fuzzy comprehensive evaluation method,which showed that the health condition of Ejin natural oasis landscape was ranked to "severely ill level" in the landscape health assessment criteria system.The landscape health of Ejin natural oasis landscape today is much worse than in the past years,with a badly unsustainable developing trend.
    Measurement of terrestrial ecosystem service value in China
    HE Hao, PAN Yaozhong, ZHU Wenquan, LIU Xulong, ZHANG Qing, ZHU Xiufang
    2005, 16(6):  1122-1127. 
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    With the measurement of net primary productivity and vegetation coverage fraction based on remote sensing data,the terrestrial ecosystem service value of China in 2000 was quantitatively estimated as 9.17?1012 yuan (RMB).The spatial distribution of the ecological service value showed a decreasing trend from southeast China to northwest China,which was consistent with the regional distribution of vegetation types.The service value varied with different vegetations,e.g.,forests had the highest service value of 18 789 yuan穐m-2,accounting for (40.80%) of the total terrestrial ecosystem service value,and bushes and farmlands had a higher service value of 13 789 yuan穐m-2 and 13 054 yuan穐m-2,which was 10.79% and 24.23% of total value,respectively.The service value was also varied with different ecosystem functions,i.e.,gas regulation contributed the highest value of 45.16% to the total service value,and the contribution of soil conservation and water conservation was (28.83%) and 14.44%,respectively.The integrated approach coupling ecology and remote sensing data provided a new method to measure the ecological service value,which could estimate the value objectively and spatial-explicitly.However,some uncertainties still existed in this approach,which should be improved in the future studies.
    Urbanization expanding process and its spatial characteristics in Changping District of Beijing,China
    ZHANG Feng, ZHANG Xinshi
    2005, 16(6):  1128-1132. 
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    Urbanization is a massive and unplanned experiment that already affects large acreages worldwide,and has profound social and ecological consequences for both urban and rural residents.Therefore,to comprehensively quantify the urbanization process and to investigate its ecological consequences become the central issues in urban ecological studies.Combining urbanization expanding index with landscape metrics,this paper quantified the urbanization expanding process and the urbanization spatial characteristics in Changping District of Beijing.The results showed that there were three main urbanization models,i.e.,urban fringe belt-expending model,main transportation routes line-expending model,and satellite city panel-expending model.The urbanization expansion index showed that urbanization mainly took place during the period from 1989 to 1996,and the urban landscape metrics indicated that there were urban patches isolated expanding and new urban patches emerged from 1989 to 1996,mainly amalgamated expanding from 1996 to 2001 in urban fringe belt-expanding region.In transportation routes line-expanding region,the urban patches isolated expanding,amalgamated expanding and new urban patches emerging took place simultaneously,and mainly urban patches amalgamated expanding during the former period,and new urban patches constantly turning up around satellite city during the latter in satellite city panel-expanding region.This study showed that urbanization expansion integrating landscape metrics might reveal the urbanization expanding process and its spatial characteristics,and would be a good example for the application of landscape metrics.
    Attenuation of photosynthetically available radiation (PAR) in Meiliang Bay under different winds and waves
    ZHANG Yunlin, QIN Boqiang, CHEN Weimin, HU Weiping, GAO Guang, ZHU Guangwei, LUO Liancong
    2005, 16(6):  1133-1137. 
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    Based on the successive underwater irradiance measurement in situ from Jul.12 to 17 in 2003,the attenuation of photosynthetically available radiation (PAR) and euphotic depth in Meiliang Bay were analyzed under different winds and waves.The results showed that the downward PAR attenuation coefficients ranged from 2.63 to 4.7穖-1,with an average of 3.63?0.47穖-1,and the corresponding euphotic depth ranged from 0.98 to 1.75 m,with an average of 1.29?0.18 m,which demonstrated that phytoplankton and macrophyte could not grow below 1.5 m due to the lack of adequate solar radiation.The total suspended solids resulted from wind and wave increased the attenuation of light,with the downward attenuation coefficients of PAR being 2.63,3.72 and 4.37穖-1 under small,medium and large wind and wave,respectively.Significant linear correlations were found between transparence,PAR attenuation coefficient,euphotic depth and total suspended solid,especially inorganic suspended solid,while chlorophyll a was the most nonsignificant light attenuator.Multiple stepwise linear regressions showed that inorganic suspended solid was the most important light attenuator dominating the light attenuation in wind-exposed Meiliang Bay.
    Effects of Brachionus calyciflorus culture media filtrate on Microcystis aeruginosa,Scenedesmus obliquus and Chlorella vulgaris colony formation and growth
    YANG Zhou, KONG Fanxiang, SHI Xiaoli, YANG Jiaxin
    2005, 16(6):  1138-1141. 
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    To examine the possible information transfer by chemicals between zooplankton and algae,this paper studied the effects of Brachionus calyciflorus culture media filtrate on the colony formation and growth of Microcystis aeruginosa,Scenedesmus obliquus and Chlorella vulgaris.The results showed that the test filtrate could significantly promote the colony formation and population growth of S.obliquus,while no significant effect was observed on M.aeruginosa and C.vulgaris.The induced colony formation of S.obliquus increased its resistance to grazing,and thus,reduced the risk of its being grazed,which could be viewed as a kind of inducing defense.The accelerated growth of C.vulgaris and the toxin production of M.aeruginosa could also be interpreted as a defense mechanism against grazing.It maybe concluded that M.aeruginosa,S.obliquus and C.vulgaris could adopt different ecological strategies to resist the potential grazing by rotifer B.calyciflorus,and thus,to keep their population on a certain scale.
    Effects of glyphosate on life history characteristics of freshwater rotifer Brachionus calyciflorus
    CHU Zhaoxia, XI Yilong, XU Xiaoping, GE Yali, DONG Lili, CHEN Fang
    2005, 16(6):  1142-1145. 
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    The life table study on the life history characteristics of freshwater rotifer Brachionus calyciflorus under effects of different concentrations glyphosate showed that glyphosate had significant effects on the embryonic developmental time,duration of juvenile and reproductive periods,average lifespan,net reproductive rate,and intrinsic population increasing rate of the rotifer.The embryonic developmental time was significantly lengthened when exposed to 3 and 8 mg稬-1 glyphosate,the juvenile period began to be lengthened significantly when exposed to 3 mg稬-1 glyphosate,while the net reproductive rate and intrinsic population increasing rate decreased significantly when the rotifer was exposed to 8.00 and 10.50 mg稬-1 glyphosate,respectively.Among all the parameters,intrinsic population increasing rate was the most sensitive parameter which could be used in monitoring the effects of glyphosate on the life history characteristics of B.calyciflorus.
    Pollution-ecological problems of old industrial and mining areas and future research prospects
    ZHOU Qixing
    2005, 16(6):  1146-1150. 
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    Environmental pollution and its solicitation in ecological problems of old industrial and mining areas have become a worldwide technological puzzle restricting sustainable economic and social development.But,the definition and category of old industrial and mining areas is still disputed as an important concept.In this paper,the concept of old industrial and mining area was discussed in theory,and,proceeded with analyzing the complexity of current situation and environmental pollution problems of old industrial and mining areas in China,more keystone attention was paid to the secondary pollution problems from old industrial and mining areas as an important frontier of science.On the basis of expounding the complexity and characters of environmental pollution in old industrial and mining areas,it was suggested that as two key scientific problems in environmental sciences and ecology,the formation mechanisms and control technology of secondary pollution in old industrial and mining areas and the responses of new-type diseases to environmental pollution based on molecular ecotoxicology should be systematically studied on the national scale,and be an important component of environmental protection strategy in China in the future.
    Research advances on BVOCs emission from forest
    QIE Guangfa, WANG Cheng, PENG Zhenhua
    2005, 16(6):  1151-1155. 
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    BVOCs play an important role in atmospheric environmental quality,global tropospheric chemistry,and global carbon balance,while forest is the main sources of them.This paper summarized the seasonal and diurnal variations of BVOCs emission from forest and its affecting factors including habitat variation,environmental change,forest development phase and its physiological status,and exotic interference.The ecological significance of forest BVOCs emission was further discussed,and some suggestions were proposed on ecological healthcare forest resources exploitation and urban forest construction.
    Research advances in simulating regional crop growth under water stress by remote sensing
    ZHANG Li, WANG Shili, MA Yuping
    2005, 16(6):  1156-1162. 
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    It is of practical significance to simulate the regional crop growth under water stress,especially at regional scale.Combined with remote sensing information,crop growth simulation model could provide an effective way to estimate the regional crop growth,development and yield formation under water stress.In this paper,related research methods and results were summarized,and some problems needed to be further studied and resolved were discussed.
    Effects of plant process on soil organic carbon concentration
    LI Hongbo, SHI Kun, Xu Deying
    2005, 16(6):  1163-1168. 
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    From the viewpoint of the globe and ecosystem,this paper reviewed the effects and the possible action mechanisms of plant process on soil organic carbon concentration.Plant process could affect the source and sink of soil organic carbon,which was likely related with ambient temperature,and forest process could be in favor of the accumulation of soil carbon.Future tasks in this field were put forward to reduce the CO2 concentration in atmosphere through controlling the respiration of soil surface layer and keeping ecosystem balance.It is crucial to make efforts in increasing plant biomass to enhance soil organic carbon storage.
    Research advance on lake ecosystem dynamic models
    LIU Yong, GUO Huaicheng, FAN Yingying, WANG Lijing
    2005, 16(6):  1169-1175. 
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    Starting with the role of system analysis in lake ecosystem research,this paper summarized the tentative procedures and softwares for studying the dynamics of lake ecosystem.There are several main stages in modeling the dynamics of lake ecosystem,namely,problems identification,mathematical formulation,computation,validation,sensitive analysis,calibration,and verification.In the modeling,selecting temporal and spatial scales is essential but complex.Since 1960s,a rapid progress has been made in modeling the dynamics of lake ecosystem,being developed from simple zero-dimension models to complex ecological-aquatic-hydrodynamic ones,among which,exergy was applied popularly as an objective function in modeling.In this paper,LakeWeb and LEEDS (Lake Eutrophication,Effect,Dose,and Sensitivity model) were analyzed as examples.In China,the development of lake ecosystem dynamic models could be traced back to1980s,and most of them were focused on Lake Dianch,Lake Taihu,Lake Chaohu and Lake Donghu.Some softwares such as CE-QUAL-ICM,WASP,AQUATOX,PAMOLARE and CAEDYM were developed to simulate lake ecosystem dynamics,among which,CE-QUAL-ICM is more suitable for long and narrow water bodies.WASP consists of three parts,i.e.,DYNHYD,EUTRO,and TOXI.AQUATOX is an ecological risk model,and the parameters are mainly calibrated in U.S.A,which has limited its further application in China.The software ECOPATH for simulating the energy flows in lakes was also described in this paper.There are still many shortages in the lake ecosystem dynamic models,e.g.,the lack of sufficient monitoring data for validation,insufficient consideration of uncertainties and the role of bacteria,and inconsistent relationship with watershed changes.The uncertainties are mainly from the intrinsic uncertainties in aquatic ecosystem,in modeling,in parameters selection,and also in forecast and application.Setting up long-term monitoring and data sharing mechanism,using interpolation to make data more densely,introducing objective functions,dealing with uncertainties,and constructing watershed-lake ecosystem dynamic model could be the available ways for overcoming the shortages.
    Avian diversity in Wuhu City during summertime
    LI Yongmin, WU Xiaobing
    2005, 16(6):  1176-1179. 
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    Urban avian diversity is an important part of city biodiversity,which plays an important role in ecological balance of cities.During the summertime in 2004,we studied three typical avian communities at the habitats of village and farmland,urban woodlot,and floodplain in the urban and suburban areas of Wuhu City.A total of 71 species were recorded,which belonged to 12 orders,27 families.The analysis of diversity index showed that urban woodlot had the greatest avian species number and G-F index,village and farmland had the highest avian density,and floodplain had the highest Shannon-Wiener and Pielou indices due to low human disturbance and dense vegetation.It is important to keep the avian diversity of floodplain in Wuhu City.
    Toxic effects of 1,8-dihydroxyanthraquinone on Daphnia magna
    SUN Jingyan, HUANG Liping, QIAO Xianliang, YANG Xichuan, CHEN Jingwen
    2005, 16(6):  1180-1182. 
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    The study on the acute,sublethal and chronic toxicity of 1,8-dihydroxyanthraquinone (1,8-dihAQ) to Daphnia magna showed that the 48 h LC50 was 0.37 mg稬-1,and the feeding behavior of Daphnia magna was severely affected by the compound.When exposed to 0.2 mg稬-1 of 1,8-dihAQ for 5 h,the filtration and ingestion rate of Daphnia magna was inhibited by 97%.Chronic toxicity test results indicated that the reproduction ability decreased dramatically after exposing to sublethal concentration of 1,8-dihAQ.It could be inferred that reproduction parameters and intrinsic rate of natural increase were the sensitive parameters in characterizing sublethal toxicity.The NOEC and LOEC values for reproduction parameters were also given.