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    15 October 2003, Volume 14 Issue 10
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    Articles
    Evaluation of ecological services of Populus simonii forest on Heerqin sandy land
    ZHANG Hua, LI Fengrui, ZHANG Tonghui, ZHAO Liya, YASUHITO Shirato
    2003, (10):  1591-1596. 
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    The main ecological services of the sand-fixed forest are windbreak, soil erosion control, and atmospheric dust retention.In this paper, the ecological services of Populus simonii forest were assessed by simultaneous measurements of wind speeds, daily amount of soil surface wind erosion, and amount of atmospheric dust deposition at different observation sites located within and outside the forestland.The results showed that compared with the control site (mobile sand dune), the daily mean wind velocity at 2 m height was reduced by 18.3, 31.6, 66.1, 66.0, 62.3 and 45.2% for the observation sites over the distances of 6 and 3H (Hmeant average tree height) from forest edge of the windward side, forest center, and observation sites over the distances of 0, 6 and 8H from forest edge of the leeward side, respectively.'The greatest reduction in daily mean wind velocity was occurred in both forest center and forest edge of the leeward side.There was a significant positive relationship between leaf area index of the forest and monthly declining index of mean wind speed.The monthly declining index of mean wind speed increased with increasing the forest leaf area index by a cubic function.The daily wind erosion rates of soil surface in observation sites at 6 and 3Hfrom forest edge of the windward side, forest center, and at 0, 6 and 8Hfrom forest edge of the leeward side were reduced by as much as 85.2 %～99.9 %, in comparison with the control site.The greatest reduction in daily wind erosion rate of soil surface occurred in forest edge of the leeward side, followed in decreasing order by forest center, 6 and 8Hfrom forest edge of the leeward side, 3 and 6Hfrom forest edge of the windward side.During the observation period, the daily mean dust deposition within the forestland was 13.2 kg·hm-2,compared with 9.9 kg·hm-2 outside the forestland, with a 33 % increase.All these results suggested that the poplar forest played an important role in reducing damaging winds, controlling wind erosion, and improving the local environment through increasing atmospheric dust deposition.
    Nutrient cycling in Castanea mollissima Bl forest at the Miyun Reservoir Watershed, Beijing
    LIU Shihai, YU Xinxiao, HU Chunhong, GAO Guoxiong
    2003, (10):  1597-1601. 
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    Studies on the nutrient cycling in Costariea moLLissima Bl forest at the Miyun reservoir watershed, Beijing, showed that the total biomass of the Castanea mollissima Bl stands at age 22 was 38638 kg· hm-2, and the biomass of their stem, branch, leaf, blossom, chestnut, seed capsule and root was 20160, 8430, 1429, 873, 1024, 800 and 5922 kg·hm-2, occupying 52.18%, 21.82%, 3.70%, 2.26%, 2.65%, 2.07%, 15.33% of the total biomass, respectively.The annual average growth amount of stem, branch, and root was 916, 383, and 269 kg·hm-2, respectively, and the total annual average growth amount was 5694 kg·hm-2.The nutrient contents in different organs of Castanea mollissima Bl stands showed that the Ncontent sequence was leaf>blossom > chestnut > seed capsule > branch > stem, Pcontent sequence was leaf > blossom > branch>stem > seed capsule > cheatnut, Kcontent sequence was chestnut > blossom > leaf > chestnut > branch>stem, Ca content sequence leaf > seed capsule > branch > stem > blossom > chestnut, and Mg content sequence was leaf > blossom > branch > chestnut > seed capsule > stem.The storage of N, P, K, Ca and Mg in Castanea mollissima Bl forest was 89.47, 17.34, 74.68, 105.49 and 28.40 kg·hm-2, respectively.The nutrient annual assimilation was 79.17 kg·hm-2, the total annual returning amount 106.55 kg·hm-2, and the annual retention amount was 11.25 kg·hm-2.Among of the total returning, atmospheric dry and wet deposition was 38.36 kg-hm, and the litter returning was 58.08 kg·hm2.The nutrient input was a little more than the output.The storage of the five nutrient elements in0～30 cm soil layer was 206427.59 kg·hm-2, and their storage amount in stands only occupied about 0.15% of the total storage in soil.The absorption coefficient of the stands was N>P>K>Ca> Mg, the utilization coefficient was K > N > Mg > P > Ca, and the cycling coefficient was K > N > P> Mg > Ca.The turnover period of the N, P, K, Ca and Mg was 4.34, 7.51, 3.31, 12.90 and 6.45 yr, respectively.
    Dissolved aluminum and organic carbon in soil solution under six tree stands in Lushan forest ecosystems
    WANG Lianfeng, PAN Genxing, SHI Shengli, ZHANG Lehua, HUANG Mingxing
    2003, (10):  1602-1606. 
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    Different depths of soils under 6 tree stands in Lushan Botany Garden were sampled and water-digested at room temperature.The dissolved aluminum and organic carbon were then determined by colorimetry, using 8-hydrox-ylquilin and TOC Analyzer, respectively.The results indicated that even derived from a naturally identical soil type, the test soils exhibited a diverse solution chemistry, regarding with the A1 speciation.The soil solutions under Japanese cedar, giant arborvitae and tea had lower pH values and higher contents of soluble aluminum than those under Giant dogwood, azalea and bamboo.Under giant arborvitae, the lowest pH and the highest content of total soluble aluminum and monomeric aluminum were found in soil solution.There was a significant correlation between soluble aluminum and DOC, which tended to depress the accumulation of toxic monomeric aluminum.The 6 tree stands could be grouped into 2 categories of solution chemistry, according to aluminum mobilization.
    Effects of rhizosphere acidification on phosphorus efficiency in clones of poplar
    ZHANG Huanchao, WANG Gaiping, XU Xizeng, XU Chengkai, HU Zhengyi
    2003, (10):  1607-1611. 
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    Effects of rhizosphere acidification on Pefficiency in different poplar clones were conducted by the method of soil culture in greenhouse.Potassium dihydrogen phosphate was applied to furnish 0, 40, 80, and 120 mg P2O5 kg-1.The experiment consisted of three replicatesof each treatment, with a pot of 40 kg soil in a randomized block.The results showed that high Pefficiency clones, such as S17, S19, and 105, could decrease their pHvalues in rhizosphere under P deficiency stress much stronger than clones 106, 797, 1-69, 1388, and 3244, which were low Pefficiency clones.The most decrement of pH for the former even accounted to 1.32 pHunits and the ratios of the decrements were over 10% in comparison with the pHvalues in bulk soil.Whereas for the latter less than0.21 pH units and 2.5% of the decreasing ratio respectively.In contrast to low P efficiency clones, high Pefficiency clones could acidify their rhizosphere through a kind of specific mechanism because the pH values in rhizosphere of high Pefficiency clones were gradually decreased corresponding with the intensity of Pdeficiency stress and vice versa.The amounts of available P in rhizosphere of clone S17, S19, and 105 reached 2.64, 3.27, and 3.28 mg穔g-1, respectively, obviously higher than those of the other five low P efficiency clones, which all were below 2.00 mg穔g-1 under Pdeficiency stress, and the summation percentages of available Pin rhizosphere were over 60% for all high Pefficiency clones, but less than 10% for low P efficiency clones.The amounts of P taken up by high P efficiency clones wore statistically greater than by low Pefficiency clones.Regression analysis also indicated that the increment of available Pin rhizosphere was closely correlated with the decrement of pHvalues in rhizosphere under Pdeficiency stress.This demonstrated the impact of rhizosphere acidification on availability of rhizosphere P, and identified that high Pefficiency clones could enhance their contents of available Pin rhizosphere, absorb more Pand thus grow better through rhizosphere acidification depended on deficiency stress.
    Residual of exogenous iodine in forest soils and its effect on some wild-vegetable plants
    GUI Xiaoyang, SANG Ying, SONG Jinfeng
    2003, (10):  1612-1616. 
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    To cultivate iodine-enriched forest vegetables in the mountainous regions of northeast China, a series of iodine application experiments were conducted.Iodine fertilizer (potassium iodide, KI) was added to the forest soils supporting a variety of wild-vegetable plants, with a dosage gradient of 1.00,3.33,10.00, 16.67 and 50.00 mg· kg-1.The results showed that iodine application was an effective approach to obtain iodine-rich vegetable materials, and the iodine contents in treated plants could be 2～40 times higher than control.But, the residual of added iodine in soil was generally not high, only occupying 40%～5% of the application dosage.The accumulation of iodine in plants did not consistently increase with the dosage, which tended to slow down when the application amount increased to 10.00 mg·kg-1.In a comprehensive consideration of soil iodine residual, plant iodine accumulation and application cost, the proper iodine dosage should be approximately 10 mg·kg-1.Soil conditions had significant influence on the efficiency of iodine application, and the cultivated lands should be chosen at fine-textured, fertile, and upper-sloped sites, while sandy soils and down-sloped sites were unfavorable to the preservation of added iodine and to plant absorption.
    Effect of soil fertility on chestnut stem diseases
    SHU Qinglong, XU Jianmin, XIAO Bin, DUAN Lin, ZHENG Hongbin, ZOU Yunding
    2003, (10):  1617-1621. 
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    Studies on the relationship between soil fertility and chestnut stem disease showed that in soil physical factors, the disease index in the chestnut orchards with clay soil and stone soil was higher than that with loam, sand loam and yellow-brown loam soil.It was increased with the increasing soil bulk density, and decreased with increasing soil depths.In soil chemical factors, the disease index negatively associated with the contents of organic matter and available phosphorus, and not with total nitrogen, Kand pHvalue.Based on the above factors and stepwise regression, five factors such as soil depth, bulk density, clay soil, organic matter and available phosphorus were regarded as important to the disease, and a linear multiple regression model that predicts the development level of the diseases was derived, which could assist in manageming the particular stand against chestnut stem diseases in Anhui Province.
    Energy value evaluation of dike-pond agro-ecological engineering modes
    LU Hongfang, PENG Shaolin, LAN Shengfang, CHEN Feipeng
    2003, (10):  1622-1626. 
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    In this paper, energy value analysis and new energy index for sustainable development (EISD) were used to evaluate three different dike-pond agro-ecological engineering modes in Sanshui city of Pearl River Delta in system and subsystem levels.The result showed that mode Ⅲ was the best in its sustainable development ability.The EISD of mode Ⅲ was 58.3% and 29.7% higher than that of modes Ⅰ and Ⅱ .With a higher economic benefit and higher environmental loading, the planting subsystem had the lowest sustainability.Although the economic benefit of stock raising subsystem was not high, its indirect benefit was higher.With a higher economic benefit and a lower environmental loading, fishing subsystem had the highest sustainability.
    Effects of sowing times on the spike differentiation of different wheat varieties under the climate of warm winter
    GAO Qinglu, XUE Xiang, WU Yu'e, RU Zhengang
    2003, (10):  1627-1631. 
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    Spike differentiation processes and freezing damage of three wheat varieties were studied by sowing in different stages.The results showed that under the condition of weather changing warm, the time of entering each stage of spike differentiation of wheat of strong spring variety was earlier than that of wheat of spring variety and semi-winter variety.Sowing times had more effects on durative time of the elongation stage, single-prism stage and two-prism stage of the spike differentiation.Under sowing early, the stronger the springness of wheat was, the quicker it developed, the higher spike differentiation phases it reached before winter, and the more serious freezing damage it suffered in wintering.According to this, the semi-winter varieties of wheat should he adopted first and arranged in pairs with spring varieties in wheat production, and the sowing times should not be too early as the weather becoming warm.
    Experimental study on crop photosynthesis, transpiration and high efficient water use
    WANG Huixiao, LIU Changming
    2003, (10):  1632-1636. 
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    It is well known that the development of water-saving agriculture is a strategic choice for getting rid of the crisis of water shortage.In this paper, the crop photosynthesis, transpiration, stomatic behavior, and their affecting factors were studied in view of increasing the crop water use efficiency.The experimental results showed that there was a parabola relationship between photosynthesis and transpiration.The transpiration at the maximum photosynthesis was a critical value, above which, transpiration was the luxurious part.The luxurious transpiration could be controlled without affecting photosynthetic production.It is possible that the measures for increasing stomatic resistance and preventing transpiration could save water, and improve photosynthesis and yield as well.The photosynthesis rate increased with photosynthetic active radiation, and the light saturation point for photosynthesis existed.The light saturation point of dry treatment was much lower than that of wet treatment, and the relationship between transpiration and radiation was linear.When the photosynthetic active radiation was bigger than 1000 μmol·m-2·s-1, some treatments could be carried out for decreasing transpiration and improving photosynthesis.
    Effect of triadimefon on cucumber seedlings growth and their resistance to chilling injury
    FENG Zhaozhong, WANG Jing, FENG Zongwei
    2003, (10):  1637-1640. 
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    Studies on the effects of different concentrations of triadimefon on cucumber seedlings growth and their resistance to chilling injury showed that 20～100 μmol·L-1 triadimefon inhibited the shoot or root length of cucumber seedlings, and increased their root weight or root/ shoot ratio and chlorophyll content significantly.After at low temperature for 3 days, a higher chlorophyll content, lower membrane relative permeability and higher SODactivity were observed in the leaves of cucumber seedlings soaked with 10～50 μmol·L-1 triadimefon.50 μmol· L-1 triadimefon could retard the accumulation of MDA at low temperature stress.It was also observed that 50 μmol·L-1 triadimefon enhanced the accumulation of praline at the first day of chilling treatment.However, higher concentrations(> 100 μmol ·L-1) of triadimefon were unfavorable for cucumber seedlings to defense a-gainst low temperature.It was thus concluded that triadimefon protected the cucumber seedlings against low temperature.
    Response of indica rice in two genie male-sterile lines to temperature and photoperiod
    CHEN Xiaorong, TIAN Zhentao, XUE Qingzhong
    2003, (10):  1641-1644. 
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    Investigations on the fertility conversion of two photoperiod-and temperature sensitive genie male-sterile lines Zheda 247S and Peiai 64s under natural conditions in Hangzhou showed that there was a little impact of photope-riod on their fertility expression, while temperature was the main factor.Among daily mean temperature, daily maximum temperature and daily minimum temperature, the last one had the most significant correlation with the fertility.The temperature sensitive stage of Zheda 247S and Peiai 64S was 318 and 621 days before heading, the critical temperature of their fertility conversion was 25.28 and 25.66 ℃, and the critical date was September 19th and September 25th, respectively.Compared to Peiai 64S, Zheda 247S had a more evident fertility conversion, its sterility was more complete and its self-setting percentage was higher at fertile stage, and the duration of the fertile stage was longer.Zheda 247S could be reproduced in Hangzhou.
    Effects of soil water stress and shading on growth characteristics of ginger
    XU Kun, ZOU Qi, ZHAO Yan
    2003, (10):  1645-1648. 
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    Water stress decreased the chlorophyll contents, stomatic density, and stomatic size of ginger leaves, and reduced the root activity and magnitude of bleeding sap of ginger roots.Under the same water contents, shading increased the root activity and the chlorophyll contents and stomatic size of upper cuticulae of ginger leaves, but decreased the stomatic density and size of their lower cuticulae.Water stress influenced the growth and yield of ginger significantly, but the effects of light intensity on ginger growth and yield were different under different water contents.Under normal water content, ginger grew better and yield was higher in natural sunlight, while under water stress, ginger grew better and yield was higher in shading.
    Effects of genotype and environment on wheat grain quality and protein components
    JING Qi, JIANG Dong, DAI Tingbo, CAO Weixing
    2003, (10):  1649-1653. 
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    The variations of grain qualities and protein components of 40 wheat (Triticum aestivum) varieties were studied at three sites in1998 and 1999.The results showed that there were significant differences among the genotypes in all the quality characters and protein components.The 40 wheat varieties were divided into 6 groups by comprehensive characters, which mainly included semi-hard and soft wheat in the experimental environment.The effects of environment were significant on grain test weight, sedimentation value, and on contents of wet gluten, protein, lysine and protein components, while contents of starch, amylose and gluten index were insensitive to environment.The rational proportion of glutenin to gliadin could be formed under proper environments.The effects of genotype Xenvironment were significant on grain quality, contents of glutenin and gliadin and the proportion of glutenin to gliadin, while not on globulin.Genotype and environment had more effects on flour protein content, gluten content, sedimentation value and 1000-kernel weight than genotype ? environment.The differences of protein components among genotypes and environments reflected the variation of grain baking quality in wheat.
    Articles
    Dynamic simulation of nitrogen application level effects on rice yield and optimization analysis of fertilizer supply in paddy
    YANG Jingping, JIANG Ning, CHEN Jie
    2003, (10):  1654-1660. 
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    Field and water tank plot experiments were conducted in Zhejiang Province in1999 to determine the effects of nitrogen application amount and times on rice growth and yield, and rice growth simulation model ORYZA-0 and nitrogen management module were used to establish a modified nitrogen effect-rice growth model.The simulated results presented a higher positive relationship with the measured results.According to the simulated and measured results, 160 kg·hm-2 was the economic nitrogen application amount for two rice varieties production, and the nitrogen application strategies were:l) <100 kg·hm-2 nitrogen fertilizer should be applied within35 days after transplanting; 2) when the nitrogen application level was between100～200 kg · hm-2, it should be applied within45 days after transplanting; 3) if the nitrogen application amount exceeded 200 kg·hm-2, it should be put into paddy field with in 60 days after transplanting;4) as the nitrogen application amount increased, the nitrogen supply at the later rice growth stage should be increased.As for the second cropping rice, the more times the nitrogen applied in the field, the more closeness the rice yield reached the APCUM curve(optimized nitrogen curve)suggested.But in real rice production, it is impossible for farmers to adopt more times of N applying, since labor and cost will increase.Based on the experimental parameters and real rice production situation, the reasonable nitrogen application under 160 kg·hm-2 levels for high yielding second cropping rice was split into 4 times with fraction0.2:0.3:0.3:0.2 at 5, 20, 3040 days after transplanting.The rice yield could reach 5916 kg·hm-2, resulted in a 3.12% increase as compared with the yield under actual fertilizer application amount and timing.
    Characteristics of phosphorus losses from slope field in red soil area under different cultivated ways
    YUAN Donghai, WANG Zhaoqian, CHEN Xin, GUO Xinbo, ZHANG Ruliang
    2003, (10):  1661-1664. 
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    A study on the properties of phosphorus loss under different cultivated ways was conducted in Lanxi Water and Soil Supervision Conservation Station of Zhejiang Province in2000.The results showed that the phosphorus lost mainly through bed load and runoff.Phosphorus lost through runoff accounted for 55.26% of total lost phosphorus in straight farming field, but in other farming field, phosphorus lost with runoff accounted for 67.59%～88.11% .Particle phosphorus was the major form of the lost phosphorus, which contributed to 57.79%～77.59% of total lost phosphorus.The runoff most phosphorus was available phosphorus.Comparing with the traditional cultivated ways in the local area(treatment 5,stright farming field), the alternative different cultivated ways reduced soil phosphorus loss by 40.73 %～84.70 %, the contour, contour dam and fallow had better effect on controlling loss of phosphorus than the contour ditch and contour grass strip.In a year of 2000 most of the lost phosphorus was occurred during May to August accounting for 89.15%～100% of total lost.
    Articles
    Seasonal variation of fixed ammonium content of paddy soils in Hunan Province and its bioavailability
    LIAO Jipei, Li Fayun, ZHANG Yangzhu, FENG Yuehua, HUANG Yunxiang
    2003, (10):  1665-1668. 
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    Three paddy soils with higher content of fixed ammonium in Hunan Province were used as test soils in pot experiment to study the seasonal variation of their fixed ammonium content and its bioavailability during rice growth period.The results showed that the fixed ammonium content in the paddy soils changed constantly during rice growth.Applying Nfertilizer and organic manure increased the fixed ammonium content, which was decreased through the Nuptake by rice plants.The recently fixed ammonium was almost fully available to rice, while the native fixed ammonium was partly available.The release of fixed ammonium during rice growth was newly alluvial sandy soil > purple clayey soil> alluvial sandy soil, and was greater at early growth stage than at later growth stage.
    Change of farmyard manure application in Shaanxi Province
    BAO Xuemei, ZHANG Fusuo, MA Wenqi, XU Wenhua
    2003, (10):  1669-1672. 
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    The change of farmyard manure (FYM) application in Shaanxi Province since 1986 was analyzed.The proportion of farmyard manure application to total nutrient decreased gradually with years, and was only 46.9% in 2000, which was reduced hy 23% compared to the figure in 1986.Soil fertility was gradually reduced, and potassium shortage appeared in farmlands of some regions.The farmyard manure were consumed mainly on grain crops in terms of overall amount of manure inputs, hut application rates of manure to fruit trees and vegetahlcs were higher than that of grain crops in terms of per unit area.Consumption of manure obviously increased in apple since middle of 1990's.The reason of the FYM consumption decrease was also analyzed, and some suggestions were made.
    Spatial variability of soil nutrients in cultivated surface soil of Sujiatun District, Shenyang City
    JIANG Yong, ZHANG Yuge, LIANG Wenju, WEN Dazhong, CHEN Wenbo
    2003, (10):  1673-1676. 
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    The spatial variability of organic matter (OM), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) in0～20 cm horizon in cultivated soils of Sujiatun District, Shenyang City were investigated using geostatistics and geographic information system (GIS).Data of each variable fitted normal distribution or normal distribution after log transformation, and a spherical model for semivariogram fitted all the variables.Semivariograms indicated that OM content strongly spatially dependent with the ratio of nugget to sill of 24.11 % .The contents of AN, AP and AK were moderately spatially dependent with the ratio of nugget to sill of 29.53%, 60.77% and 58.82%, respectively.The ranges of spatially dependent for OM, AN, AP and AK were 26.051, 28.293, 15.132 and 23.813 km, respectively.The spatial variability for OM and AN was fundamentally affected by structural factors such as soil formation factors, and that for AP and AK was by random factors such as fertilization.Kriging maps showed the spatial distributions of the four variables, which were useful in monitoring nutrient changes and providing quantitative support to decision and policy making for agriculture and environment management.
    Characteristics or zero point of charge of volcanic ash soils in Changbaishan and Wudalianchi
    ZHAO Lanpo, YANG Xueming, LIU Wei
    2003, (10):  1677-1680. 
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    The characteristics of the zero point of charge (ZPC) of volcanic ash soil profiles in Changbaishan and Wu-dalianchi was studied and discussed by means of potentiometric titration curves.The results showed that the two volcanic ash soils had not only a little variable charg, but also a little permanent charge.The clay fractions of the volcanic ash soils carried both variable and permanent charges.The ZPC of eeach layer in both soil profiles all lied in the acid side of titration curve, and increased with increasing soil depth.However, the ZPC displacements (σi) decreased with increasing soil depth.The ZPC of surface layer in both soil profiles was lower than that of the volcanic ash soils in foreign countries, but obviously higher than that of Loess soil in the Northwest and of black soil in the Northeast China.The variation of ZPC and Si was affected not only by the deposition of long-rang tropospheric eolian dust from the Asian continent, but also by the accumulation of soil organic matter.Their combined effect was the main reason to the decrease of ZPC and σi the increase of σi in Changbaishan and Wudalianchi volcanic ash soils.
    Effects of land use and management on soil quality of Heerqin sandy land
    SU Yongzhong, ZHAO Halin
    2003, (10):  1681-1686. 
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    The changes of soil physical, chemical and biological properties under different land use and management lasted for 14 years were investigated on the Heerqin sandy land.The results showed that among various land use systems marked differences exhibited in soil quality indicators, including soil particle composition, porosity distribution, bulk density, water-holding capacity, organic matter and nutrient contents, pH, and enzyme activities.Most of these soil quality indicators were the highest in the orchard intercropped with crops and perennial grass (agroforestry systems), intermediate in the well-management irrigated farmland, and the lowest in the less-management dry farmland.Compared to the primary grassland soil, although some soil properties, including porosity distribution, water-holding capacity, phosphorus content, and enzyme activities, were improved in the well-management systems, soil organic matter and nitrogen contents were significantly lower.It suggested that a long-term input of organic matter was needed for the restoration and reestablishment of soil carbon and nitrogen pools in the seriously degraded ecosystem.Inappropriate land use and management could rapidly worsen soil quality, and hence, from a perspective of soil resource conservation, a preferable way for preventing soil degradation and achieving sustainable land use should be to give up the cultivation of degraded dry farmlands, and to adopt more effective and appropriate soil management and cultivation practices.
    Theoretical and methodological research on the comprehensive development of agricultural model zone in waterlogged area
    TIAN Xiaohai, HUANG Yongping, HUANG Zhimin, LEI Weici, HIGATA Shugo
    2003, (10):  1687-1691. 
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    The searching for a proper land reclamation and utilization method adapted to the regional natural conditions and economical level is a prime subject in the waterlogged area of Southern China.Choosing a dish-like micro-zone, one of the typical waterlogged areas deprived from a reclaimed lake as the studying region, its biophysical characteristics and developmental models was investigated, aiming at making a comprehensive development plan to this area.The results showed that with the successive change in altitude across the sector of the land, the soil type, soil profile structure, underground water level, and soil temperature were characterized by five step divergence steps.The analysis on the site and area of the individual divergences showed that the low land was unsuitable for rice planting, and the land between upland and paddy should be increased for rotation and needed to be reclaimed better.After an engineering consolidation to the land, the original five divergence steps were rehabilitated into four steps, and a utilization model of "development in a step way" focused on comprehensively agricultural development and improvement in farming systems was developed, which leaded to a great advance in economic profit of this area.
    Application of geostatistical analysis in study of macrophytes community's pattern
    PAN Wenbin, DENG Hongbing, TANG Tao, CAI Qinghua
    2003, (10):  1692-1696. 
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    In this paper, the Log-log semivariogram and theoretical models of Geostatistics and fractal theory were applied to study the mosaic spatial pattern of macrophytes community and its different characters on different scales in littoral zone of the Baoan Lake, Hubei Province.The macrophytes in the littoral zone with a square area of 25600 m2, which was divided in to 1024 grids, were investigated, and the macrophytes species in every grid were recorded.If the species was discovered in the grid, the variable of the grid had a value of 1, otherwise, it was 0.The community had a value of the total species discovered in the grid.By the method, the sampling results of Vallisneria spiralis, Ceratophyllum oryzetorum, Myriophyllum spicatum and the community were made into four worksheets.With help of the software GS+ for Windows to treat these worksheets, we got their log-log semivariogram, isotropic model, anisotropic model, isotropic fractal dimension and anisotropic fractal dimension.According to the results of isotropic models, the exponential models of Vailisneria spiralis and Myrio-phyllum spicatum indicated their contagious distribution with a high proportion of spatial structure, which indicated that their distribution changed lesser at microscale.In their range of 48.6m and 34.2m respectively, they had a spatial autocorrelation.Isotropic models of Ceratophvllum oryzetorum and the community were linear, and their proportions of spatial structure were low, indicating their great change at microscale and their moderate contagious distribution.The isotropic fractal dimension and anisotropic fractal dimension results indicated the dominant pattern of Vallisneria spiralis in the direction of NE-SW, the dominant patterns of Myriophyilum spicatum and Ceratophyllum oryzetorum in the direction of N-S, and the community's dominant pattern in the direction of NW-SE.Compared with other analysis tools, the method had advantages in deciding whether the community components had a spatial autocorrelation and in quantitatively classifying the aggregation density.It provides us a new way to quantitatively describe the pattern of the macrophytes community.
    Impact of trawl fishing on fisheries population components in East China Sea
    FAN Wei, ZHOU Sufang, GUI Xuesen, CHENG Yanhong
    2003, (10):  1697-1700. 
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    Based on the recent 50 years two-boats trawl fishing data of some state-owned fisheries companies and recent 7 years single-boat fishing data of some areas in East China Sea, the trophic index (TI) and composition indexs of fishes of two-boats trawl and single-boat trawl were calculated and analyzed, which indicated that TIincreased before 1974 and decreased rapidly thereafter, while composition index decreased from the end of 1970s, but SD increased.The results of single-boat trawl also indicated that TIdecreased gradually.Long-term over-fishing of trawl was one of the main reasons of the change of fisheries population structure in East China Sea.All of these showed that there was an over-fishing in East China Sea, and the robust of fisheries population was lower.
    Articles
    Laboratory culture of Tetraselmis strains isolated from the coasts of China
    OUYANG Yexin, LUO Liming, HU Hongjun, ZHANG Chengwu, LI Yeguang
    2003, (10):  1701-1704. 
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    Tetraselmis is an important alga commonly used as live food in aquaculture.This paper reported the laboratory culture of its strains collected from the coasts of China, covering Guangdong, Zhejiang and Shandong Provinces.The separated strains of Tetraselmis for mono-species culture were isolated with capillary method, and their ax-enic cultures were obtained by inoculating them in plates with solid Marine Ⅲ medium (MⅢ).Modified Guil-lard & Ryther medium (MGM), M Ⅲ, and modified Marine Ⅲ medium (M Ⅲ M) were utilized for the liquid cultivation of Tetraselmis in 500 mLflasks.It was displayed that the average growth of Tetraselmis cultured in MⅢ M was the fastest at pH 7.0～8.0, and vitamin B12 addition to M Ⅲ M slightly increased the relative growth rate of Tetraselmis.Therefore, the modified Marine Ⅲ medium was effective to use as a large-scale culture medium for Tetraselmis in aquaculture.
    Behaviors time budget and daily rhythm of great bustard in breeding season
    ZHAO Jiang, GAO Wei, WANDongmei, WANG Haitao
    2003, (10):  1705-1709. 
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    The direct observation method was adopted to study the breeding behaviors time budget and daily rhythm of wild great bustard (Otis tarda) on the grassland of Southeast Keyouqianqi in Inner Mongolia Municipality during the period from April to July in 2000 and 2001.The results showed that the behaviors time budget of great bustard were regularly in some degree, and there exited differences between male and female.The behaviors changed with the changes of activity space, food conditions and breeding stages.During breeding prophase, great bustard spent its time mainly on feeding, relaxing, walking and observing, and the male and female spent 87% and 93% of the time on the 4 behaviors, respectively.The time budget and intensity of male and female changed greatly during the breeding anaphase.The great bustard had a daily rhythm on feeding, relaxing and displaying, and there were two peaks on feeding and displaying.The great bustard spent most time on relaxing.
    Structure and biodiversity of insect community on syconia fruits of Ficus racemosa in tropical rainforest of Xishuangbanna, China
    YANG Darong, PENG Yanqiong, ZHANG Guangming, SONG Qishi, GU Haiyan, WANG Qiuyan
    2003, (10):  1710-1714. 
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    Ficus racemosa is a keystone plant in tropical rainforest of Xishuangbanna, Yunnan.The structure, dynamic and biodiversity of insect community on its syconia fruits were investigated in different plots located in Menglun nature reserve, ravine rainforest in the botanical garden, and secondary forest by Luosuo River.The results showed that the total number of collected insects were 184 264, belonging to 5 order, 19 families, 36 genera, and 51 species.Hymenoptera was the most dominant group, accounted for 37.3 % of the total collected species.The pollinator of Ceratosolen fusciceps had huge individual quantities among Hymenoptera, and its successful pollination influenced the stability and development of F.racemosa population.In addition, the proportion of Lepidopter inspects was 31.4%, and the other 31.3% species belonged to Coleoptera, Homopter and Diptera.Through calculating diversity index, evenness index and richness of three plots, it showed that these three indexes were the highest in Menglun nature reserve, secondary in ravine rainforest, and low species diversity and richness in secondary forest by Luosuo River.The experimental results reported here showed that the insect species decreased, the individual number of common species increased, and special species reduced.
    Ecological study on small-middle size soil animals in a compound ecosystem of farmland, grassland and woodland in the grassland region of Songnen Plain
    WANG Haixia, YIN Xiuqin, ZHOU Daowei
    2003, (10):  1715-1718. 
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    Based on the method of selecting samples in field, the ecological characters of small-middle size soil animals communities were investigated in a compound ecosystem of farmland, grassland and woodland in the grassland region of Songnen Plain.The results showed that the dominant groups were Hypogastruridae, Actinedida, Gamasida and Oribatida; and the common groups were fsotomidae and Jassidae.From the comparison analysis of farmland, grassland and woodland, the diversity of small-middle size soil animals communities was the highest in grassland, and the habitat in grassland was superior to the other two.The number of individuals and groups of small-middle size soil animals was decreased with increasing soil depth, and the surface gathering was obvious.But, the characteristics of vertical distribution in the three subsystems were different.Using the principal component analysis, the correlations between soil environmental factors and small-middle size soil animals communities and those between climate factors and small-middle size soil animals communities were analyzed.The results showed that soil environmental factors were the dominant factors affecting small-middle size soil animals communities.
    Effects of AM fungi on potassium absorption of flue-cured tobacco LI Dengwu,
    LI Dengwu, WANG Dongmei, HE Xueli
    2003, (10):  1719-1722. 
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    The effects of AM fungus Glomus mosseae inoculation on the potassium absorption of flue-cured tobacco were studied with un-sterilized soil in a pot experiment.Potassium application and AM fungi inoculation had a significant influence on potassium accumulation and distribution, and the difference of potassium contents among different growth stages and different leaf positions was significant (P< 0.01).Different combinations of AM fungi inoculation and potassium application had an obvious influence on potassium content in tobacco leaf during the middle and later growth stage.AM fungi inoculation could enhance the potassium content of top, middle, and beneath position leaf, and hence, the content of potassium in leaf was increased, but that in stem was relatively lower.
    Articles
    Co-occurrence of soil fauna communities with changes in altitude on the northern slope of Changbai Mountain
    TONG Fuchun, JIN Zhedong, Wang Qingli, Xiao Yihua
    2003, (10):  1723-1728. 
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    The co-occurrence of soil fauna communities at different altitudes may reflect at some extent the relationships a-mong communities, their coexistence, and the replacement of species along the altitude gradient.The continuous or disjunctive distribution of different species along altitude gradient not only reflected the environment variation at altitude gradient, but also the biological and ecological spatiality as well as the adaptability of species.The northern slope of Changbai Moutain has not only a high diversity in soil fauna types and species, but also a high variation of diversity pattern along the altitude gradient, which is a perfect transect for the research of biodiversity and gradient patterns.From 550m to 2560m on the northern slope of Changbai Mountain, twenty-two plots were investigated with an interval of 100m in altitude.By using Jaccard index, the co-occurrence of soil fauna communities at different altitudes was analyzed.For the species of different life forms or for all the species as a whole, the co-occurrence of soil faunae between neighboring communities was the highest, except for that between different soil fauna types.The peak and valley values of the co-occurrence of soil fauna communities along altitude gradient were matched with their gradient patterns, and the co-occurrence of soil faunae at different layers or all of the soil fauna communities were decreased with increasing altitude difference.
    Biological characteristics and spatial distribution of Chorthippus dubius population on high mountain grassland
    LIU Changzhong, WANG Gang
    2003, (10):  1729-1731. 
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    Based on rearing observations and surveys in Ganjia High-Mountain Grassland, Xiahe County, Gansu Province, the occurrence period, ingestion capacity, spatial pattern, and dynamics of Chorthippus dubius were studied.The results showed that this grasshopper had only one generation in a year.Its eggs wintered in the soil, and in the next year, they began to hatch from the last ten days of May to the first ten days of June.The hatching peak took place from the middle ten days to the last ten days of June.The majority of the nymphs possessed 4 instars, and about 23% of them possessed 5 instars.The developmental duration of the nymphs underwent about 70 days, and the longevity of the adults lasted for 42 days.The ingestion capacity of the nymphs was 368.3 mg, and that of the adults was 743.8 mg.The spatial pattern of 1～2 instars belonged to an aggregated distribution, and that of 3～5 instars belonged to even and random distribution.
    Articles
    Effects of cruciferous vegetables on experimental population of diamondback moth Plutella xylostella
    LU Lihua, HE Yurong, PANG Xiongfei
    2003, (10):  1732-1734. 
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    The impact of four species of cruciferous vegetables on the experimental population of diamondback moth (DBM) Plutella xylastella was evaluated in the laboratory.The results showed that there was no significant difference in total fecundity and longevity of DBMfemale moths reared on different crucifers.The population increase index of DBM reared on flowering Chinese cabbage, Chinese kale, leaf mustard, and pak-choi was 41.0, 69.5, 38.2 and 52.4, respectively, and the natural death at larvae stage was the most important factor influencing the population increase of DBM.The relatively lower natural death rates of larvae on Chinese kale and pak-choi contributed a higher increasing potential of DBM populations.It was concluded that among four species crucifers, Chinese kale could provide the most suitable nutrients for the development and reproduction of DBM population, and thus, it was considered as the best host of DBM.However, although leaf mustard has been reported as one of the most preferable host for DBM adult oviposition, it was not as better as three other crucifers for DBM development due to the higher natural death rate of larvae.
    Effect of nitrogen fertilizer on pest population and cotton production
    GE Feng, LIU Xianghui, LI Hongda, MEN Xingyuan, SU Jianwei
    2003, (10):  1735-1738. 
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    Field experiments were conducted from 1999 to 2000 to assess the effect of nitrogen fertilization levels (0, 225 and 450 kg穐m-2) on the population dynamics of cotton bollworm (Helicoverpa armigera) and cotton aphid (Aphid gossypii), and on the numbers of cotton buds and bolls in North China.The population densities of cotton bollworm and cotton aphid increased with increasing nitrogen fertilization during1999 to 2000, but the differences between treatments were not significan(P>0.05).There were significant differences of cotton boll-worm populations and no significant differences of cotton aphid populations between years.Nitrogen fertilization at flower-bud stage decreased the loss of cotton buds and flowers and increased the number of effective bolls and cotton yield, but the decrement and increment did not get to significant level (P< 0.05).No obvious correlations of nitrogen levels with main pest abundance and cotton production were observed.
    Ecological distribution of macrofungi in Qingliang Mountain Natural Reserve, Anhui Province
    KE Lixia, YANG Chao
    2003, (10):  1739-1742. 
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    The north side of Qingliang Mountain Natural Reserveis is very rich of macrofungi resources.There are 160 species, belonging to 72 genera, 38 families, 10 orders and 2 classes, and distributing in the evergreen broadleaf forest, Pinus massoniana forest, evergreen-decidous mixed broadleaf forest, and Pinus taiwanensis forest.According to their economic value, these macrofungi may be grouped into two types: edible (72 species) and medicinal (55 species); and according their ecological habitat, they may be grouped into lignicolous (68 species), ento-mophilous (84 species), and ectomycorrhizal (21 species).Our study showed a certain regularity of their distribution, i.e., it varied with the ecological conditions of forests, tree species, soil types and altitude.Many economical macrofungi in this region could serve as one of the important natural resources, and had great potential usage on the edibility, medicinal and forestation.
    Effect of natural stress on genetic diversity of Frankia in Alnus nodules
    TANG Xiaomeng, DAI Yumei, XIONG Zhi, ZHANG Zhongze, ZHANG Chenggang
    2003, (10):  1743-1746. 
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    The genetic diversity of Frankia in the nodules of Alnus nepalensis growing in different habitats of Jizu and Wuliang Mountains in Yunnan Province was studied by rep-PCRtechnique.The results indicated that the Frankia had an abundant genetic diversity, which was varied with different zones, altitudes and slopes.More genotypes of Alnus-infective Frankia were found:at Jizu than at Wuliang Mountain.At the bottom of Jizu Mountain (2300 m), the Shannon-Weiner index was 0.90, and increased with raising altitude, up to 1.33 at the top (2700m).The genetic diversity of Frankia was more abundant along the southern slope than the northern slope.It was concluded that the diversity index was positively related to natural stresses which were one of the important factors producing and maintaining the genetic diversity of Frankia .
    Articles
    Effect of temperature on resistance of Pinus yunnanenensis to inoculation with Leptographium yunnanense, a pathogenic fungus associated with Tomicus piniperda
    LIAO Zhouyu, YE Hui, LU Jun, XIA Yuanlin
    2003, (10):  1747-1750. 
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    The study showed that temperature had an important effect both on the resistance of Pinus yunnanensis and on the growth and virulence of Leptographium yunnanense, a pathogenic fungus associated with Tomicus piniper-da attacking Pinus vunnanensis.which would result in the competence variation between them: at lower (< 10 ℃) and higher temperature(>30 ℃), the growth and virulence of L.yunnanmse were inhibited, while at 15 ℃～30 ℃, the resistance of Pinus yunnanensis was relatively weaker, indicating that in warmer climates, the growth and virulence of L.yunnanense were relatively strengthened, but the resistance of Pinus yunnanensis was relatively weakened.
    Effects of different nutritional resources on the longevity and parasitic ability of egg parasitoid Anagrus nila-parvatae
    ZHENG Xusong, YU Xiaoping, LU Zhongxian, CHEN Jianming, XU Hongxing
    2003, (10):  1751-1755. 
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    This paper dealt with the effects of honey, corn pollen, soybean flower, and honeydews excreted by Nila-paruatae lugens and Toya spp.on the longevity and parasitic ability of A.nilaparvatae.The results showed that the longevity of A.nilaparvatae was obviously extended, and its egg production on N.Lugens was significantly increased when fed with those nutrient-rich diets except the honeydew excreted by Toya spp.Corn pollen and the honeydew excreted by N.lugens worked only in the forms of pollen (water and honeydew) water.The longevity of N.lugens was not affected by its parasitic behaviors, but its survival rate was higher within 40～48 hours, and then decreased rapidly.About ten species of plant hopper, the host of Anagrus spp., were found in non-rice habitats, which provided shelter and afforded foods to the parasitoids of rice pests, and contributed to protecting the natural enemies and enhancing the biological control in the rice system.
    Transportation processes and rates of heavy metals in an artificial rainstorm runoff under different land use types
    LIANG Tao, WANG Hao, ZHANG Xiumei, ZHANG Shen, YU Kngxiu
    2003, (10):  1756-1760. 
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    Studies on the transportation and flux of various kinds of heavy metals in runoff and sediment of five typical land-use types in West Tiaoxi catchment showed that the losses of Cu (0.21 mg·m-2·min-1), Zn (0.45 mg·m-2· min-1), and Pb (0.15 mg·m-2·min-1) in mulberry and that of Cr (0.06 mg·m-2·min-1) in paddy field were larger in surface runoff, while their losses in pinery were very small.Suspended thin particles played the main role on transporting heavy metals in surface runoff under all kinds of land uses.The losses from runoff were much lower than that from sediment, which only occupied 0.1 %～4.9 %, and the loss rate of Cu from runoff and sediment was higher than that of Cr, Pb and Zn.
    Effects of cropping systems on nitrous oxide emissions from paddy soils during the rice-growing season
    XIONG Zhengqin, XING Guangxi, SHI Shulian, DU Lijuan
    2003, (10):  1761-1764. 
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    Cropping systems influence nitrous oxide (N2O) emissions from agricultural soils.Effects of 3 rice-based cropping systems on N2O emissions from paddy soils in pot experiment were investigated with closed chambers in triplicate.The results demonstrated that the seasonal N2O emission rate of the rice pot under rice-wheat cropping system was obviously higher than that of the early rice pot under double rice-wheat system, being 4.21 and 2.17 kg·hm-2, respectively.No distinct difference was observed between the seasonal average fluxes, which were 116.9 and 117.6 μg·m·2-h-1 respectively.Both of above mentioned seasonal average fluxes were greatly higher than that of the late rice pot under early rice-late rice-wheat cropping system and of rice pot under rice-flooding fallow system, being 67.0 and 42.1 μg·m-2·h-1 respectively.More than 91% of the seasonal emission was focused on the first half growing period both in the rice season in rice-wheat system and in the early rice season in double rice-wheat system in which the previous cropping was upland wheat.91% of the seasonal emission was focused on the water drainage period including the mid-season aeration and final drainage in the late rice season in double rice-wheat system in which the previous cropping was lowland rice.The results implied that cropping system and water status of previous cropping impacted N2O emission from paddy soil.
    Effects of pesticide-contamination on population size and denitrification activity of denitrifying bacteria in paddy soils
    CHEN Zhongyun, MIN Hang, WU Weixiang, CHEN Meichi, ZHANG Fudao, ZHAO Jianqiang
    2003, (10):  1765-1769. 
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    The effects of pesticide contamination on the population size and denitrification activity of denitrifying bacteria (DNB) were studied with three types of paddy soil (Huangsong paddy soil, red earth paddy soil and purple paddy soil) treated with carbofuran, carbendazim and butachlor for four weeks.The results showed that the population size of DNB in purple paddy soil, Huangsong paddy soil and red earth paddy soil varied in the range of 59.04 ×104～157.59×104, 42.89×104～108.97×104 and 32.14 × 104～75.30 × 104cfu·g-1 dried soil, respectively, which was positively related to the quantity of consumed nitrate in paddy soils.The population size and denitrification activity of DNB were increased by adding carbofuran (1 mg·kg-1 dried soil) or butachlor (1 mg·kg-1 dried soil), but decreased significantly by adding10 mg· kg-1 dried soil of butachlor, 5 mg· kg-1 dried soil of carbofuran, and 10 mg·kg-1 dried soil of carbendazim on 7th d, 14th d and 7th d, respectively.
    Use of methyl parathion (MP)-degrading strain DLL-E4(Pseudomonas sp) to remove MP residue on the surface of agricultural products
    LIU Zhi, ZHANG Xiaozhou, LI Shunpeng
    2003, (10):  1770-1774. 
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    In this paper, derivations from DLL-E4, including fermented liquid, its centrifuged (3000 ? g, 10min) supernatant, pellet extract with supersonic, crude enzyme(supernatant and pellet extract), detergent, and mixture of detergent and pellet extract, were used to degrade the MP residue on the surface of Chinese cabbage, tea and cucumber.The results showed that all of them were effective, with the best effect of 100% .Some constituents in the supernatant of fermented liquid could stimulate the enzymatic activity.For tea, the mixture of detergent and enzyme was more effective, but the opposite was found for the other two crops.In all treatments, crude enzyme and pellet extract had the best effect, and the rational added amount of enzyme was 2%, 5% and 10% for cucumber, Chinese cabbage and tea, respectively.Crude enzyme also could degrade methamidophos phoxim and chlorpyrifos.
    Effects of different arbuscular mycorrhizal fungi on Tagetes erecta growth and diesel degradation
    GENG Chunnü, LI Peijun, CHEN Suhua, ZHANG Hairong, HAN Guiyun
    2003, (10):  1775-1779. 
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    The effects of G.mosseae, G.geospora, G.constrictum and bacteria on diesel tolerance of Tagetes erecta were investigated under greenhouse conditions.The results showed that AM fungi could still develop mycorrhizal as-sosiations with mum when the diesel concentration was 5000 mg·kg-1.White mum was better than yellow mum in diesel tolerance, with 63.1% total biomass increased.The colonization rate of inoculating AM fungi treatment was 3.5%～29.9% higher than the control.G.mosseae and G.geospora were better strains, their biomass increasing 9.0% and 42.7% than the control, respectively, while the effect of inoculating mixed AM fungi was not obvious.Bacteria inhibited the colonization of arbuscular mycorrhizal fungi on white mum, but promoted the vegetative and reproductive growth of mycorrhizal mum.Among5 inoculation treatments, treatments of inoculating G.geospora and inoculating mixed AM fungi and bacteria were better, with 16.51% and 14.05% more diesel degradation rate than that of the control, respectively.
    Effects of BaP exposure on ultrastructures of hepatic cells of Boleophthalmus pectinirostris
    FENG Tao, ZHENG Weiyun, OUYANG Gaoliang, HONG Wanshu
    2003, (10):  1780-1782. 
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    The changes of ultrastructures of hepatic cells of Boleophthalmus pectinirostris were investigated after the fish were exposed under benzo (a) pyrene in different concentrations under experimental condition.The results showed that the organelles in hepatic cells of B.pectinirostris were damaged to different extents after the fish was exposed under lower concentration of BaP (0.5 mg稬-1) for up to 7 d, in which, mitochondria and endo-plasmic reticulum were the chief organelles affected by BaP exposure.While the fish was exposed under higher concentration of BaP (5 mg稬-1) for 2 h, almost all of the organelles including mitochondria and endoplasmic reticulum in hepatic cells of B.pectinirostr were affected by BaP exposure.The structures of liver cells were seriously damaged.It was demonstrated that BaP could produce multiorganalle lesions in hepatic cells of B.pectinirostris, and the severity extent of such lesions was dependent on the concentration level of BaP.
    Isolation and characteristics of PAHs-degrading strains
    ZHANG Jie, LIU Yongsheng, MENG Ling, SHAO Lidong, ZHANG Zhongze
    2003, (10):  1783-1786. 
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    The predominant indigenous microbial population and the strain ZL5 PAHS-degrading were obtained by selective enrichment culture from Liaohe viscous oil-contaminated field.The sequence analysis of 16s rDNA showed that strain ZL5 belonged to Sphingomonas sp.The microbial population and the strain could degrade phenanthrene well.95.28% and 69.24% of phenanthrene in the medium were degraded in 120hrs.However, the degradation of pyrene by the microbial population or by the strain was low.The degradation rate of phenanthrene or pyrene by the microbial population or the strain was greatly increased while glucose was used as an added substrate.The effect was closely related to the amount of glucose.If the concentration were too high, glucose would show inhibition effect on the degradation of PAHs.Therefore, it was necessary to control the amount of glucose while using glucose as an added substrate to increase degradation of phenanthrene or pyrene.
    Effects of rare earth elements on amino acid contents in earthworms
    HUA Rimao, ZHANG Zili, WU Xinan, ZHANG Dongchun, TAN Huarong
    2003, (10):  1787-1789. 
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    Rare earth elements are wide-used in China, but a few of studies were made on whether they had toxicity to soil fauna.In this paper, the filter paper contact method was used to study the influence of two rare earth elements on the dynamics of amino acids in earthworm body.The result showed that at low concentrations, the test rare earth elements increased the amino acid contents except proline, but decreased them at high concentrations.The amino acid contents began to increase at 400 mg· L-1, while decreased with time.Both of the two rare earth elements reduced the proline content, and behaved inhibition effect at the range of 100～1200 mg·L-1.
    Contributing factors and control strategies of pine wilt disease
    OUYANG Gecheng, ZHANG Runjie
    2003, (10):  1790-1794. 
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    There are several types of pine wilt diseases with inherent inter-relations.The diseases are closely related with the complex ecological system composed of local environment, pine trees, insect vectors, and pathogenic nematodes and some other microorganisms.Sustainable pest management based on ecology is a potential approach for pine wilt disease control.
    Global consequences and control strategies of biological invasion
    XIE Zongqiang, CHEN Zhigang, FAN Dayong, XIONG Gaoming
    2003, (10):  1795-1798. 
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    Biological invasion is a worldwide ecological phenomenon, but its mechanism is still not very clear.Invasive species give impacts on native species and ecosystems through competitions, predations, changing habitats, and dispersing diseases.They pose an increasing threat to the composition and structure of natural communities across the globe.Biological invasion has been greatly damaging the ecological and evolutionary integrity of natural e-cosystems, which will weaken the functions of the ecosystems and frequently cause natural disasters.Abetter understanding of the causes, patterns, predictability, consequences, and management options associated with this threat to biodiversity is necessary to guide managers, policy makers, researchers, and general publics.Biological invasion also causes huge economic losses, and 137 billion dollar losses per year from biological invasion were estimated in USA.Invasive diseases impair human health and kill thousands and thousands of people, and invasive bacteria lead to so serious social panic and turbulence that people could feel uneasy even when eating and sleeping.Biological invasion largely decreases global biodiversity, which will threaten the survival and development of our descendants.Three steps are used in prevention and control of biological invasions.Comprehensive quarantine is the most effective way to prevent exotic invasion by accident.Ecological evaluation and monitoring is helpful to avoid disasters from species introduction.Physical methods, chemical approaches and biological controls are used to eradicate and control the spread of invaded species.Before biological controls are chosen, risk analysis of controlling organism is needed.Ideally, there should be both pre-eradication assessment to tailor removal to avoid unwanted ecological effects and post-removal assessment of eradication effects on both the target organism and the invaded ecosystem.
    Articles
    Main mechanism and affecting factors of phytoremediation of organic contaminated soil
    LIN Daohui, ZHU Lizhong, GAO Yanzheng
    2003, (10):  1799-1803. 
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    In this paper, the main mechanisms of phytoremediation of organic contaminated soil, such as adsorption and degradation in rhizosphere, plant uptake, and transformation, and phytoremediation model were illuminated in detail, and their affecting factors, including properties of pollutants, plant species, soil properties, coexisted pollutants, and climate conditions were analyzed.The main topics that need further research were prospected, e.g., deepening the mechanism of phytoremediation, consummating phytoremediation models, approaching on the mechanism and appliance of microbe associated phytoremediation systems, building efficient surfactants enhancing phytoremediation systems, and strengthening the research on phytoremediation of combined organic pollution.
    Comparison of soil organic matter models
    GAO Lupeng, LIANG Wenju, JINAG Yong, WEN Dazhong
    2003, (10):  1804-1808. 
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    Soil organic matter is a soil carbon pool, and its content and dynamics is very important to global Ccycling, soil fertility, and soil quality.SOM models can simulate soil organic matter dynamics and predict its content, especially for which some of data are difficult or impossible to obtain by experiential hypotheses and existing data.Therefore, SOM models have become the most important quantitative means to study SOM decomposition and accumulation, and can help us to identify the mechanism about SOM dynamics.SOM models can also predict CO2 emission and plant growth, and evaluate agricultural management practices.Several SOM models, especially RothC model and CENTURY model, were summarized and analyzed in this paper.
    New quantificational indexes in modern study of soil organic matter
    WANG Jing, ZHANG Xudong, XIE Hongtu, ZHU Ping, JIANG Guimin
    2003, (10):  1809-1812. 
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    In modern study of soil organic matter, many new quantificational indexes and relevant testing methods, e.g., DOC, WSOC, HWC, ROC, MBC, MEN, PMC, PMN, Glu, Gla, Man, Mur,δ13C, and CPMI, came forth with deepening study.Because they are disorderly and unsystematic, it is necessary to clarify these indexes.This paper summarized their origin, concept, and testing method, which is of significance in the modern study of soil organic matter.
    Evaluation of ecological services of Populus simonii forest on Heerqin sandy land
    ZHANG Hua, LI Fengrui, ZHANG Tonghui, ZHAO Liya, YASUHITO Shirato
    2003, (10):  1591-1596. 
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    The main ecological services of the sand-fixed forest are windbreak, soil erosion control, and atmospheric dust retention.In this paper, the ecological services of Populus simonii forest were assessed by simultaneous measurements of wind speeds, daily amount of soil surface wind erosion, and amount of atmospheric dust deposition at different observation sites located within and outside the forestland.The results showed that compared with the control site (mobile sand dune), the daily mean wind velocity at 2 m height was reduced by 18.3, 31.6, 66.1, 66.0, 62.3 and 45.2% for the observation sites over the distances of 6 and 3H (Hmeant average tree height) from forest edge of the windward side, forest center, and observation sites over the distances of 0, 6 and 8H from forest edge of the leeward side, respectively.'The greatest reduction in daily mean wind velocity was occurred in both forest center and forest edge of the leeward side.There was a significant positive relationship between leaf area index of the forest and monthly declining index of mean wind speed.The monthly declining index of mean wind speed increased with increasing the forest leaf area index by a cubic function.The daily wind erosion rates of soil surface in observation sites at 6 and 3Hfrom forest edge of the windward side, forest center, and at 0, 6 and 8Hfrom forest edge of the leeward side were reduced by as much as 85.2 %～99.9 %, in comparison with the control site.The greatest reduction in daily wind erosion rate of soil surface occurred in forest edge of the leeward side, followed in decreasing order by forest center, 6 and 8Hfrom forest edge of the leeward side, 3 and 6Hfrom forest edge of the windward side.During the observation period, the daily mean dust deposition within the forestland was 13.2 kg·hm-2,compared with 9.9 kg·hm-2 outside the forestland, with a 33 % increase.All these results suggested that the poplar forest played an important role in reducing damaging winds, controlling wind erosion, and improving the local environment through increasing atmospheric dust deposition.
    Nutrient cycling in Castanea mollissima Bl forest at the Miyun Reservoir Watershed, Beijing
    LIU Shihai, YU Xinxiao, HU Chunhong, GAO Guoxiong
    2003, (10):  1597-1601. 
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    Studies on the nutrient cycling in Costariea moLLissima Bl forest at the Miyun reservoir watershed, Beijing, showed that the total biomass of the Castanea mollissima Bl stands at age 22 was 38638 kg· hm-2, and the biomass of their stem, branch, leaf, blossom, chestnut, seed capsule and root was 20160, 8430, 1429, 873, 1024, 800 and 5922 kg·hm-2, occupying 52.18%, 21.82%, 3.70%, 2.26%, 2.65%, 2.07%, 15.33% of the total biomass, respectively.The annual average growth amount of stem, branch, and root was 916, 383, and 269 kg·hm-2, respectively, and the total annual average growth amount was 5694 kg·hm-2.The nutrient contents in different organs of Castanea mollissima Bl stands showed that the Ncontent sequence was leaf>blossom > chestnut > seed capsule > branch > stem, Pcontent sequence was leaf > blossom > branch>stem > seed capsule > cheatnut, Kcontent sequence was chestnut > blossom > leaf > chestnut > branch>stem, Ca content sequence leaf > seed capsule > branch > stem > blossom > chestnut, and Mg content sequence was leaf > blossom > branch > chestnut > seed capsule > stem.The storage of N, P, K, Ca and Mg in Castanea mollissima Bl forest was 89.47, 17.34, 74.68, 105.49 and 28.40 kg·hm-2, respectively.The nutrient annual assimilation was 79.17 kg·hm-2, the total annual returning amount 106.55 kg·hm-2, and the annual retention amount was 11.25 kg·hm-2.Among of the total returning, atmospheric dry and wet deposition was 38.36 kg-hm, and the litter returning was 58.08 kg·hm2.The nutrient input was a little more than the output.The storage of the five nutrient elements in0～30 cm soil layer was 206427.59 kg·hm-2, and their storage amount in stands only occupied about 0.15% of the total storage in soil.The absorption coefficient of the stands was N>P>K>Ca> Mg, the utilization coefficient was K > N > Mg > P > Ca, and the cycling coefficient was K > N > P> Mg > Ca.The turnover period of the N, P, K, Ca and Mg was 4.34, 7.51, 3.31, 12.90 and 6.45 yr, respectively.
    Dissolved aluminum and organic carbon in soil solution under six tree stands in Lushan forest ecosystems
    WANG Lianfeng, PAN Genxing, SHI Shengli, ZHANG Lehua, HUANG Mingxing
    2003, (10):  1602-1606. 
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    Different depths of soils under 6 tree stands in Lushan Botany Garden were sampled and water-digested at room temperature.The dissolved aluminum and organic carbon were then determined by colorimetry, using 8-hydrox-ylquilin and TOC Analyzer, respectively.The results indicated that even derived from a naturally identical soil type, the test soils exhibited a diverse solution chemistry, regarding with the A1 speciation.The soil solutions under Japanese cedar, giant arborvitae and tea had lower pH values and higher contents of soluble aluminum than those under Giant dogwood, azalea and bamboo.Under giant arborvitae, the lowest pH and the highest content of total soluble aluminum and monomeric aluminum were found in soil solution.There was a significant correlation between soluble aluminum and DOC, which tended to depress the accumulation of toxic monomeric aluminum.The 6 tree stands could be grouped into 2 categories of solution chemistry, according to aluminum mobilization.
    Effects of rhizosphere acidification on phosphorus efficiency in clones of poplar
    ZHANG Huanchao, WANG Gaiping, XU Xizeng, XU Chengkai, HU Zhengyi
    2003, (10):  1607-1611. 
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    Effects of rhizosphere acidification on Pefficiency in different poplar clones were conducted by the method of soil culture in greenhouse.Potassium dihydrogen phosphate was applied to furnish 0, 40, 80, and 120 mg P2O5 kg-1.The experiment consisted of three replicatesof each treatment, with a pot of 40 kg soil in a randomized block.The results showed that high Pefficiency clones, such as S17, S19, and 105, could decrease their pHvalues in rhizosphere under P deficiency stress much stronger than clones 106, 797, 1-69, 1388, and 3244, which were low Pefficiency clones.The most decrement of pH for the former even accounted to 1.32 pHunits and the ratios of the decrements were over 10% in comparison with the pHvalues in bulk soil.Whereas for the latter less than0.21 pH units and 2.5% of the decreasing ratio respectively.In contrast to low P efficiency clones, high Pefficiency clones could acidify their rhizosphere through a kind of specific mechanism because the pH values in rhizosphere of high Pefficiency clones were gradually decreased corresponding with the intensity of Pdeficiency stress and vice versa.The amounts of available P in rhizosphere of clone S17, S19, and 105 reached 2.64, 3.27, and 3.28 mg穔g-1, respectively, obviously higher than those of the other five low P efficiency clones, which all were below 2.00 mg穔g-1 under Pdeficiency stress, and the summation percentages of available Pin rhizosphere were over 60% for all high Pefficiency clones, but less than 10% for low P efficiency clones.The amounts of P taken up by high P efficiency clones wore statistically greater than by low Pefficiency clones.Regression analysis also indicated that the increment of available Pin rhizosphere was closely correlated with the decrement of pHvalues in rhizosphere under Pdeficiency stress.This demonstrated the impact of rhizosphere acidification on availability of rhizosphere P, and identified that high Pefficiency clones could enhance their contents of available Pin rhizosphere, absorb more Pand thus grow better through rhizosphere acidification depended on deficiency stress.
    Residual of exogenous iodine in forest soils and its effect on some wild-vegetable plants
    GUI Xiaoyang, SANG Ying, SONG Jinfeng
    2003, (10):  1612-1616. 
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    To cultivate iodine-enriched forest vegetables in the mountainous regions of northeast China, a series of iodine application experiments were conducted.Iodine fertilizer (potassium iodide, KI) was added to the forest soils supporting a variety of wild-vegetable plants, with a dosage gradient of 1.00,3.33,10.00, 16.67 and 50.00 mg· kg-1.The results showed that iodine application was an effective approach to obtain iodine-rich vegetable materials, and the iodine contents in treated plants could be 2～40 times higher than control.But, the residual of added iodine in soil was generally not high, only occupying 40%～5% of the application dosage.The accumulation of iodine in plants did not consistently increase with the dosage, which tended to slow down when the application amount increased to 10.00 mg·kg-1.In a comprehensive consideration of soil iodine residual, plant iodine accumulation and application cost, the proper iodine dosage should be approximately 10 mg·kg-1.Soil conditions had significant influence on the efficiency of iodine application, and the cultivated lands should be chosen at fine-textured, fertile, and upper-sloped sites, while sandy soils and down-sloped sites were unfavorable to the preservation of added iodine and to plant absorption.
    Effect of soil fertility on chestnut stem diseases
    SHU Qinglong, XU Jianmin, XIAO Bin, DUAN Lin, ZHENG Hongbin, ZOU Yunding
    2003, (10):  1617-1621. 
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    Studies on the relationship between soil fertility and chestnut stem disease showed that in soil physical factors, the disease index in the chestnut orchards with clay soil and stone soil was higher than that with loam, sand loam and yellow-brown loam soil.It was increased with the increasing soil bulk density, and decreased with increasing soil depths.In soil chemical factors, the disease index negatively associated with the contents of organic matter and available phosphorus, and not with total nitrogen, Kand pHvalue.Based on the above factors and stepwise regression, five factors such as soil depth, bulk density, clay soil, organic matter and available phosphorus were regarded as important to the disease, and a linear multiple regression model that predicts the development level of the diseases was derived, which could assist in manageming the particular stand against chestnut stem diseases in Anhui Province.
    Energy value evaluation of dike-pond agro-ecological engineering modes
    LU Hongfang, PENG Shaolin, LAN Shengfang, CHEN Feipeng
    2003, (10):  1622-1626. 
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    In this paper, energy value analysis and new energy index for sustainable development (EISD) were used to evaluate three different dike-pond agro-ecological engineering modes in Sanshui city of Pearl River Delta in system and subsystem levels.The result showed that mode Ⅲ was the best in its sustainable development ability.The EISD of mode Ⅲ was 58.3% and 29.7% higher than that of modes Ⅰ and Ⅱ .With a higher economic benefit and higher environmental loading, the planting subsystem had the lowest sustainability.Although the economic benefit of stock raising subsystem was not high, its indirect benefit was higher.With a higher economic benefit and a lower environmental loading, fishing subsystem had the highest sustainability.
    Effects of sowing times on the spike differentiation of different wheat varieties under the climate of warm winter
    GAO Qinglu, XUE Xiang, WU Yu'e, RU Zhengang
    2003, (10):  1627-1631. 
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    Spike differentiation processes and freezing damage of three wheat varieties were studied by sowing in different stages.The results showed that under the condition of weather changing warm, the time of entering each stage of spike differentiation of wheat of strong spring variety was earlier than that of wheat of spring variety and semi-winter variety.Sowing times had more effects on durative time of the elongation stage, single-prism stage and two-prism stage of the spike differentiation.Under sowing early, the stronger the springness of wheat was, the quicker it developed, the higher spike differentiation phases it reached before winter, and the more serious freezing damage it suffered in wintering.According to this, the semi-winter varieties of wheat should he adopted first and arranged in pairs with spring varieties in wheat production, and the sowing times should not be too early as the weather becoming warm.
    Experimental study on crop photosynthesis, transpiration and high efficient water use
    WANG Huixiao, LIU Changming
    2003, (10):  1632-1636. 
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    It is well known that the development of water-saving agriculture is a strategic choice for getting rid of the crisis of water shortage.In this paper, the crop photosynthesis, transpiration, stomatic behavior, and their affecting factors were studied in view of increasing the crop water use efficiency.The experimental results showed that there was a parabola relationship between photosynthesis and transpiration.The transpiration at the maximum photosynthesis was a critical value, above which, transpiration was the luxurious part.The luxurious transpiration could be controlled without affecting photosynthetic production.It is possible that the measures for increasing stomatic resistance and preventing transpiration could save water, and improve photosynthesis and yield as well.The photosynthesis rate increased with photosynthetic active radiation, and the light saturation point for photosynthesis existed.The light saturation point of dry treatment was much lower than that of wet treatment, and the relationship between transpiration and radiation was linear.When the photosynthetic active radiation was bigger than 1000 μmol·m-2·s-1, some treatments could be carried out for decreasing transpiration and improving photosynthesis.
    Effect of triadimefon on cucumber seedlings growth and their resistance to chilling injury
    FENG Zhaozhong, WANG Jing, FENG Zongwei
    2003, (10):  1637-1640. 
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    Studies on the effects of different concentrations of triadimefon on cucumber seedlings growth and their resistance to chilling injury showed that 20～100 μmol·L-1 triadimefon inhibited the shoot or root length of cucumber seedlings, and increased their root weight or root/ shoot ratio and chlorophyll content significantly.After at low temperature for 3 days, a higher chlorophyll content, lower membrane relative permeability and higher SODactivity were observed in the leaves of cucumber seedlings soaked with 10～50 μmol·L-1 triadimefon.50 μmol· L-1 triadimefon could retard the accumulation of MDA at low temperature stress.It was also observed that 50 μmol·L-1 triadimefon enhanced the accumulation of praline at the first day of chilling treatment.However, higher concentrations(> 100 μmol ·L-1) of triadimefon were unfavorable for cucumber seedlings to defense a-gainst low temperature.It was thus concluded that triadimefon protected the cucumber seedlings against low temperature.
    Response of indica rice in two genie male-sterile lines to temperature and photoperiod
    CHEN Xiaorong, TIAN Zhentao, XUE Qingzhong
    2003, (10):  1641-1644. 
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    Investigations on the fertility conversion of two photoperiod-and temperature sensitive genie male-sterile lines Zheda 247S and Peiai 64s under natural conditions in Hangzhou showed that there was a little impact of photope-riod on their fertility expression, while temperature was the main factor.Among daily mean temperature, daily maximum temperature and daily minimum temperature, the last one had the most significant correlation with the fertility.The temperature sensitive stage of Zheda 247S and Peiai 64S was 318 and 621 days before heading, the critical temperature of their fertility conversion was 25.28 and 25.66 ℃, and the critical date was September 19th and September 25th, respectively.Compared to Peiai 64S, Zheda 247S had a more evident fertility conversion, its sterility was more complete and its self-setting percentage was higher at fertile stage, and the duration of the fertile stage was longer.Zheda 247S could be reproduced in Hangzhou.
    Effects of soil water stress and shading on growth characteristics of ginger
    XU Kun, ZOU Qi, ZHAO Yan
    2003, (10):  1645-1648. 
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    Water stress decreased the chlorophyll contents, stomatic density, and stomatic size of ginger leaves, and reduced the root activity and magnitude of bleeding sap of ginger roots.Under the same water contents, shading increased the root activity and the chlorophyll contents and stomatic size of upper cuticulae of ginger leaves, but decreased the stomatic density and size of their lower cuticulae.Water stress influenced the growth and yield of ginger significantly, but the effects of light intensity on ginger growth and yield were different under different water contents.Under normal water content, ginger grew better and yield was higher in natural sunlight, while under water stress, ginger grew better and yield was higher in shading.
    Effects of genotype and environment on wheat grain quality and protein components
    JING Qi, JIANG Dong, DAI Tingbo, CAO Weixing
    2003, (10):  1649-1653. 
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    The variations of grain qualities and protein components of 40 wheat (Triticum aestivum) varieties were studied at three sites in1998 and 1999.The results showed that there were significant differences among the genotypes in all the quality characters and protein components.The 40 wheat varieties were divided into 6 groups by comprehensive characters, which mainly included semi-hard and soft wheat in the experimental environment.The effects of environment were significant on grain test weight, sedimentation value, and on contents of wet gluten, protein, lysine and protein components, while contents of starch, amylose and gluten index were insensitive to environment.The rational proportion of glutenin to gliadin could be formed under proper environments.The effects of genotype Xenvironment were significant on grain quality, contents of glutenin and gliadin and the proportion of glutenin to gliadin, while not on globulin.Genotype and environment had more effects on flour protein content, gluten content, sedimentation value and 1000-kernel weight than genotype ? environment.The differences of protein components among genotypes and environments reflected the variation of grain baking quality in wheat.
    Articles
    Dynamic simulation of nitrogen application level effects on rice yield and optimization analysis of fertilizer supply in paddy
    YANG Jingping, JIANG Ning, CHEN Jie
    2003, (10):  1654-1660. 
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    Field and water tank plot experiments were conducted in Zhejiang Province in1999 to determine the effects of nitrogen application amount and times on rice growth and yield, and rice growth simulation model ORYZA-0 and nitrogen management module were used to establish a modified nitrogen effect-rice growth model.The simulated results presented a higher positive relationship with the measured results.According to the simulated and measured results, 160 kg·hm-2 was the economic nitrogen application amount for two rice varieties production, and the nitrogen application strategies were:l) <100 kg·hm-2 nitrogen fertilizer should be applied within35 days after transplanting; 2) when the nitrogen application level was between100～200 kg · hm-2, it should be applied within45 days after transplanting; 3) if the nitrogen application amount exceeded 200 kg·hm-2, it should be put into paddy field with in 60 days after transplanting;4) as the nitrogen application amount increased, the nitrogen supply at the later rice growth stage should be increased.As for the second cropping rice, the more times the nitrogen applied in the field, the more closeness the rice yield reached the APCUM curve(optimized nitrogen curve)suggested.But in real rice production, it is impossible for farmers to adopt more times of N applying, since labor and cost will increase.Based on the experimental parameters and real rice production situation, the reasonable nitrogen application under 160 kg·hm-2 levels for high yielding second cropping rice was split into 4 times with fraction0.2:0.3:0.3:0.2 at 5, 20, 3040 days after transplanting.The rice yield could reach 5916 kg·hm-2, resulted in a 3.12% increase as compared with the yield under actual fertilizer application amount and timing.
    Characteristics of phosphorus losses from slope field in red soil area under different cultivated ways
    YUAN Donghai, WANG Zhaoqian, CHEN Xin, GUO Xinbo, ZHANG Ruliang
    2003, (10):  1661-1664. 
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    A study on the properties of phosphorus loss under different cultivated ways was conducted in Lanxi Water and Soil Supervision Conservation Station of Zhejiang Province in2000.The results showed that the phosphorus lost mainly through bed load and runoff.Phosphorus lost through runoff accounted for 55.26% of total lost phosphorus in straight farming field, but in other farming field, phosphorus lost with runoff accounted for 67.59%～88.11% .Particle phosphorus was the major form of the lost phosphorus, which contributed to 57.79%～77.59% of total lost phosphorus.The runoff most phosphorus was available phosphorus.Comparing with the traditional cultivated ways in the local area(treatment 5,stright farming field), the alternative different cultivated ways reduced soil phosphorus loss by 40.73 %～84.70 %, the contour, contour dam and fallow had better effect on controlling loss of phosphorus than the contour ditch and contour grass strip.In a year of 2000 most of the lost phosphorus was occurred during May to August accounting for 89.15%～100% of total lost.
    Articles
    Seasonal variation of fixed ammonium content of paddy soils in Hunan Province and its bioavailability
    LIAO Jipei, Li Fayun, ZHANG Yangzhu, FENG Yuehua, HUANG Yunxiang
    2003, (10):  1665-1668. 
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    Three paddy soils with higher content of fixed ammonium in Hunan Province were used as test soils in pot experiment to study the seasonal variation of their fixed ammonium content and its bioavailability during rice growth period.The results showed that the fixed ammonium content in the paddy soils changed constantly during rice growth.Applying Nfertilizer and organic manure increased the fixed ammonium content, which was decreased through the Nuptake by rice plants.The recently fixed ammonium was almost fully available to rice, while the native fixed ammonium was partly available.The release of fixed ammonium during rice growth was newly alluvial sandy soil > purple clayey soil> alluvial sandy soil, and was greater at early growth stage than at later growth stage.
    Change of farmyard manure application in Shaanxi Province
    BAO Xuemei, ZHANG Fusuo, MA Wenqi, XU Wenhua
    2003, (10):  1669-1672. 
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    The change of farmyard manure (FYM) application in Shaanxi Province since 1986 was analyzed.The proportion of farmyard manure application to total nutrient decreased gradually with years, and was only 46.9% in 2000, which was reduced hy 23% compared to the figure in 1986.Soil fertility was gradually reduced, and potassium shortage appeared in farmlands of some regions.The farmyard manure were consumed mainly on grain crops in terms of overall amount of manure inputs, hut application rates of manure to fruit trees and vegetahlcs were higher than that of grain crops in terms of per unit area.Consumption of manure obviously increased in apple since middle of 1990's.The reason of the FYM consumption decrease was also analyzed, and some suggestions were made.
    Spatial variability of soil nutrients in cultivated surface soil of Sujiatun District, Shenyang City
    JIANG Yong, ZHANG Yuge, LIANG Wenju, WEN Dazhong, CHEN Wenbo
    2003, (10):  1673-1676. 
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    The spatial variability of organic matter (OM), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) in0～20 cm horizon in cultivated soils of Sujiatun District, Shenyang City were investigated using geostatistics and geographic information system (GIS).Data of each variable fitted normal distribution or normal distribution after log transformation, and a spherical model for semivariogram fitted all the variables.Semivariograms indicated that OM content strongly spatially dependent with the ratio of nugget to sill of 24.11 % .The contents of AN, AP and AK were moderately spatially dependent with the ratio of nugget to sill of 29.53%, 60.77% and 58.82%, respectively.The ranges of spatially dependent for OM, AN, AP and AK were 26.051, 28.293, 15.132 and 23.813 km, respectively.The spatial variability for OM and AN was fundamentally affected by structural factors such as soil formation factors, and that for AP and AK was by random factors such as fertilization.Kriging maps showed the spatial distributions of the four variables, which were useful in monitoring nutrient changes and providing quantitative support to decision and policy making for agriculture and environment management.
    Characteristics or zero point of charge of volcanic ash soils in Changbaishan and Wudalianchi
    ZHAO Lanpo, YANG Xueming, LIU Wei
    2003, (10):  1677-1680. 
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    The characteristics of the zero point of charge (ZPC) of volcanic ash soil profiles in Changbaishan and Wu-dalianchi was studied and discussed by means of potentiometric titration curves.The results showed that the two volcanic ash soils had not only a little variable charg, but also a little permanent charge.The clay fractions of the volcanic ash soils carried both variable and permanent charges.The ZPC of eeach layer in both soil profiles all lied in the acid side of titration curve, and increased with increasing soil depth.However, the ZPC displacements (σi) decreased with increasing soil depth.The ZPC of surface layer in both soil profiles was lower than that of the volcanic ash soils in foreign countries, but obviously higher than that of Loess soil in the Northwest and of black soil in the Northeast China.The variation of ZPC and Si was affected not only by the deposition of long-rang tropospheric eolian dust from the Asian continent, but also by the accumulation of soil organic matter.Their combined effect was the main reason to the decrease of ZPC and σi the increase of σi in Changbaishan and Wudalianchi volcanic ash soils.
    Effects of land use and management on soil quality of Heerqin sandy land
    SU Yongzhong, ZHAO Halin
    2003, (10):  1681-1686. 
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    The changes of soil physical, chemical and biological properties under different land use and management lasted for 14 years were investigated on the Heerqin sandy land.The results showed that among various land use systems marked differences exhibited in soil quality indicators, including soil particle composition, porosity distribution, bulk density, water-holding capacity, organic matter and nutrient contents, pH, and enzyme activities.Most of these soil quality indicators were the highest in the orchard intercropped with crops and perennial grass (agroforestry systems), intermediate in the well-management irrigated farmland, and the lowest in the less-management dry farmland.Compared to the primary grassland soil, although some soil properties, including porosity distribution, water-holding capacity, phosphorus content, and enzyme activities, were improved in the well-management systems, soil organic matter and nitrogen contents were significantly lower.It suggested that a long-term input of organic matter was needed for the restoration and reestablishment of soil carbon and nitrogen pools in the seriously degraded ecosystem.Inappropriate land use and management could rapidly worsen soil quality, and hence, from a perspective of soil resource conservation, a preferable way for preventing soil degradation and achieving sustainable land use should be to give up the cultivation of degraded dry farmlands, and to adopt more effective and appropriate soil management and cultivation practices.
    Theoretical and methodological research on the comprehensive development of agricultural model zone in waterlogged area
    TIAN Xiaohai, HUANG Yongping, HUANG Zhimin, LEI Weici, HIGATA Shugo
    2003, (10):  1687-1691. 
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    The searching for a proper land reclamation and utilization method adapted to the regional natural conditions and economical level is a prime subject in the waterlogged area of Southern China.Choosing a dish-like micro-zone, one of the typical waterlogged areas deprived from a reclaimed lake as the studying region, its biophysical characteristics and developmental models was investigated, aiming at making a comprehensive development plan to this area.The results showed that with the successive change in altitude across the sector of the land, the soil type, soil profile structure, underground water level, and soil temperature were characterized by five step divergence steps.The analysis on the site and area of the individual divergences showed that the low land was unsuitable for rice planting, and the land between upland and paddy should be increased for rotation and needed to be reclaimed better.After an engineering consolidation to the land, the original five divergence steps were rehabilitated into four steps, and a utilization model of "development in a step way" focused on comprehensively agricultural development and improvement in farming systems was developed, which leaded to a great advance in economic profit of this area.
    Application of geostatistical analysis in study of macrophytes community's pattern
    PAN Wenbin, DENG Hongbing, TANG Tao, CAI Qinghua
    2003, (10):  1692-1696. 
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    In this paper, the Log-log semivariogram and theoretical models of Geostatistics and fractal theory were applied to study the mosaic spatial pattern of macrophytes community and its different characters on different scales in littoral zone of the Baoan Lake, Hubei Province.The macrophytes in the littoral zone with a square area of 25600 m2, which was divided in to 1024 grids, were investigated, and the macrophytes species in every grid were recorded.If the species was discovered in the grid, the variable of the grid had a value of 1, otherwise, it was 0.The community had a value of the total species discovered in the grid.By the method, the sampling results of Vallisneria spiralis, Ceratophyllum oryzetorum, Myriophyllum spicatum and the community were made into four worksheets.With help of the software GS+ for Windows to treat these worksheets, we got their log-log semivariogram, isotropic model, anisotropic model, isotropic fractal dimension and anisotropic fractal dimension.According to the results of isotropic models, the exponential models of Vailisneria spiralis and Myrio-phyllum spicatum indicated their contagious distribution with a high proportion of spatial structure, which indicated that their distribution changed lesser at microscale.In their range of 48.6m and 34.2m respectively, they had a spatial autocorrelation.Isotropic models of Ceratophvllum oryzetorum and the community were linear, and their proportions of spatial structure were low, indicating their great change at microscale and their moderate contagious distribution.The isotropic fractal dimension and anisotropic fractal dimension results indicated the dominant pattern of Vallisneria spiralis in the direction of NE-SW, the dominant patterns of Myriophyilum spicatum and Ceratophyllum oryzetorum in the direction of N-S, and the community's dominant pattern in the direction of NW-SE.Compared with other analysis tools, the method had advantages in deciding whether the community components had a spatial autocorrelation and in quantitatively classifying the aggregation density.It provides us a new way to quantitatively describe the pattern of the macrophytes community.
    Impact of trawl fishing on fisheries population components in East China Sea
    FAN Wei, ZHOU Sufang, GUI Xuesen, CHENG Yanhong
    2003, (10):  1697-1700. 
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    Based on the recent 50 years two-boats trawl fishing data of some state-owned fisheries companies and recent 7 years single-boat fishing data of some areas in East China Sea, the trophic index (TI) and composition indexs of fishes of two-boats trawl and single-boat trawl were calculated and analyzed, which indicated that TIincreased before 1974 and decreased rapidly thereafter, while composition index decreased from the end of 1970s, but SD increased.The results of single-boat trawl also indicated that TIdecreased gradually.Long-term over-fishing of trawl was one of the main reasons of the change of fisheries population structure in East China Sea.All of these showed that there was an over-fishing in East China Sea, and the robust of fisheries population was lower.
    Articles
    Laboratory culture of Tetraselmis strains isolated from the coasts of China
    OUYANG Yexin, LUO Liming, HU Hongjun, ZHANG Chengwu, LI Yeguang
    2003, (10):  1701-1704. 
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    Tetraselmis is an important alga commonly used as live food in aquaculture.This paper reported the laboratory culture of its strains collected from the coasts of China, covering Guangdong, Zhejiang and Shandong Provinces.The separated strains of Tetraselmis for mono-species culture were isolated with capillary method, and their ax-enic cultures were obtained by inoculating them in plates with solid Marine Ⅲ medium (MⅢ).Modified Guil-lard & Ryther medium (MGM), M Ⅲ, and modified Marine Ⅲ medium (M Ⅲ M) were utilized for the liquid cultivation of Tetraselmis in 500 mLflasks.It was displayed that the average growth of Tetraselmis cultured in MⅢ M was the fastest at pH 7.0～8.0, and vitamin B12 addition to M Ⅲ M slightly increased the relative growth rate of Tetraselmis.Therefore, the modified Marine Ⅲ medium was effective to use as a large-scale culture medium for Tetraselmis in aquaculture.
    Behaviors time budget and daily rhythm of great bustard in breeding season
    ZHAO Jiang, GAO Wei, WANDongmei, WANG Haitao
    2003, (10):  1705-1709. 
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    The direct observation method was adopted to study the breeding behaviors time budget and daily rhythm of wild great bustard (Otis tarda) on the grassland of Southeast Keyouqianqi in Inner Mongolia Municipality during the period from April to July in 2000 and 2001.The results showed that the behaviors time budget of great bustard were regularly in some degree, and there exited differences between male and female.The behaviors changed with the changes of activity space, food conditions and breeding stages.During breeding prophase, great bustard spent its time mainly on feeding, relaxing, walking and observing, and the male and female spent 87% and 93% of the time on the 4 behaviors, respectively.The time budget and intensity of male and female changed greatly during the breeding anaphase.The great bustard had a daily rhythm on feeding, relaxing and displaying, and there were two peaks on feeding and displaying.The great bustard spent most time on relaxing.
    Structure and biodiversity of insect community on syconia fruits of Ficus racemosa in tropical rainforest of Xishuangbanna, China
    YANG Darong, PENG Yanqiong, ZHANG Guangming, SONG Qishi, GU Haiyan, WANG Qiuyan
    2003, (10):  1710-1714. 
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    Ficus racemosa is a keystone plant in tropical rainforest of Xishuangbanna, Yunnan.The structure, dynamic and biodiversity of insect community on its syconia fruits were investigated in different plots located in Menglun nature reserve, ravine rainforest in the botanical garden, and secondary forest by Luosuo River.The results showed that the total number of collected insects were 184 264, belonging to 5 order, 19 families, 36 genera, and 51 species.Hymenoptera was the most dominant group, accounted for 37.3 % of the total collected species.The pollinator of Ceratosolen fusciceps had huge individual quantities among Hymenoptera, and its successful pollination influenced the stability and development of F.racemosa population.In addition, the proportion of Lepidopter inspects was 31.4%, and the other 31.3% species belonged to Coleoptera, Homopter and Diptera.Through calculating diversity index, evenness index and richness of three plots, it showed that these three indexes were the highest in Menglun nature reserve, secondary in ravine rainforest, and low species diversity and richness in secondary forest by Luosuo River.The experimental results reported here showed that the insect species decreased, the individual number of common species increased, and special species reduced.
    Ecological study on small-middle size soil animals in a compound ecosystem of farmland, grassland and woodland in the grassland region of Songnen Plain
    WANG Haixia, YIN Xiuqin, ZHOU Daowei
    2003, (10):  1715-1718. 
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    Based on the method of selecting samples in field, the ecological characters of small-middle size soil animals communities were investigated in a compound ecosystem of farmland, grassland and woodland in the grassland region of Songnen Plain.The results showed that the dominant groups were Hypogastruridae, Actinedida, Gamasida and Oribatida; and the common groups were fsotomidae and Jassidae.From the comparison analysis of farmland, grassland and woodland, the diversity of small-middle size soil animals communities was the highest in grassland, and the habitat in grassland was superior to the other two.The number of individuals and groups of small-middle size soil animals was decreased with increasing soil depth, and the surface gathering was obvious.But, the characteristics of vertical distribution in the three subsystems were different.Using the principal component analysis, the correlations between soil environmental factors and small-middle size soil animals communities and those between climate factors and small-middle size soil animals communities were analyzed.The results showed that soil environmental factors were the dominant factors affecting small-middle size soil animals communities.
    Effects of AM fungi on potassium absorption of flue-cured tobacco LI Dengwu,
    LI Dengwu, WANG Dongmei, HE Xueli
    2003, (10):  1719-1722. 
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    The effects of AM fungus Glomus mosseae inoculation on the potassium absorption of flue-cured tobacco were studied with un-sterilized soil in a pot experiment.Potassium application and AM fungi inoculation had a significant influence on potassium accumulation and distribution, and the difference of potassium contents among different growth stages and different leaf positions was significant (P< 0.01).Different combinations of AM fungi inoculation and potassium application had an obvious influence on potassium content in tobacco leaf during the middle and later growth stage.AM fungi inoculation could enhance the potassium content of top, middle, and beneath position leaf, and hence, the content of potassium in leaf was increased, but that in stem was relatively lower.
    Articles
    Co-occurrence of soil fauna communities with changes in altitude on the northern slope of Changbai Mountain
    TONG Fuchun, JIN Zhedong, Wang Qingli, Xiao Yihua
    2003, (10):  1723-1728. 
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    The co-occurrence of soil fauna communities at different altitudes may reflect at some extent the relationships a-mong communities, their coexistence, and the replacement of species along the altitude gradient.The continuous or disjunctive distribution of different species along altitude gradient not only reflected the environment variation at altitude gradient, but also the biological and ecological spatiality as well as the adaptability of species.The northern slope of Changbai Moutain has not only a high diversity in soil fauna types and species, but also a high variation of diversity pattern along the altitude gradient, which is a perfect transect for the research of biodiversity and gradient patterns.From 550m to 2560m on the northern slope of Changbai Mountain, twenty-two plots were investigated with an interval of 100m in altitude.By using Jaccard index, the co-occurrence of soil fauna communities at different altitudes was analyzed.For the species of different life forms or for all the species as a whole, the co-occurrence of soil faunae between neighboring communities was the highest, except for that between different soil fauna types.The peak and valley values of the co-occurrence of soil fauna communities along altitude gradient were matched with their gradient patterns, and the co-occurrence of soil faunae at different layers or all of the soil fauna communities were decreased with increasing altitude difference.
    Biological characteristics and spatial distribution of Chorthippus dubius population on high mountain grassland
    LIU Changzhong, WANG Gang
    2003, (10):  1729-1731. 
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    Based on rearing observations and surveys in Ganjia High-Mountain Grassland, Xiahe County, Gansu Province, the occurrence period, ingestion capacity, spatial pattern, and dynamics of Chorthippus dubius were studied.The results showed that this grasshopper had only one generation in a year.Its eggs wintered in the soil, and in the next year, they began to hatch from the last ten days of May to the first ten days of June.The hatching peak took place from the middle ten days to the last ten days of June.The majority of the nymphs possessed 4 instars, and about 23% of them possessed 5 instars.The developmental duration of the nymphs underwent about 70 days, and the longevity of the adults lasted for 42 days.The ingestion capacity of the nymphs was 368.3 mg, and that of the adults was 743.8 mg.The spatial pattern of 1～2 instars belonged to an aggregated distribution, and that of 3～5 instars belonged to even and random distribution.
    Articles
    Effects of cruciferous vegetables on experimental population of diamondback moth Plutella xylostella
    LU Lihua, HE Yurong, PANG Xiongfei
    2003, (10):  1732-1734. 
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    The impact of four species of cruciferous vegetables on the experimental population of diamondback moth (DBM) Plutella xylastella was evaluated in the laboratory.The results showed that there was no significant difference in total fecundity and longevity of DBMfemale moths reared on different crucifers.The population increase index of DBM reared on flowering Chinese cabbage, Chinese kale, leaf mustard, and pak-choi was 41.0, 69.5, 38.2 and 52.4, respectively, and the natural death at larvae stage was the most important factor influencing the population increase of DBM.The relatively lower natural death rates of larvae on Chinese kale and pak-choi contributed a higher increasing potential of DBM populations.It was concluded that among four species crucifers, Chinese kale could provide the most suitable nutrients for the development and reproduction of DBM population, and thus, it was considered as the best host of DBM.However, although leaf mustard has been reported as one of the most preferable host for DBM adult oviposition, it was not as better as three other crucifers for DBM development due to the higher natural death rate of larvae.
    Effect of nitrogen fertilizer on pest population and cotton production
    GE Feng, LIU Xianghui, LI Hongda, MEN Xingyuan, SU Jianwei
    2003, (10):  1735-1738. 
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    Field experiments were conducted from 1999 to 2000 to assess the effect of nitrogen fertilization levels (0, 225 and 450 kg穐m-2) on the population dynamics of cotton bollworm (Helicoverpa armigera) and cotton aphid (Aphid gossypii), and on the numbers of cotton buds and bolls in North China.The population densities of cotton bollworm and cotton aphid increased with increasing nitrogen fertilization during1999 to 2000, but the differences between treatments were not significan(P>0.05).There were significant differences of cotton boll-worm populations and no significant differences of cotton aphid populations between years.Nitrogen fertilization at flower-bud stage decreased the loss of cotton buds and flowers and increased the number of effective bolls and cotton yield, but the decrement and increment did not get to significant level (P< 0.05).No obvious correlations of nitrogen levels with main pest abundance and cotton production were observed.
    Ecological distribution of macrofungi in Qingliang Mountain Natural Reserve, Anhui Province
    KE Lixia, YANG Chao
    2003, (10):  1739-1742. 
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    The north side of Qingliang Mountain Natural Reserveis is very rich of macrofungi resources.There are 160 species, belonging to 72 genera, 38 families, 10 orders and 2 classes, and distributing in the evergreen broadleaf forest, Pinus massoniana forest, evergreen-decidous mixed broadleaf forest, and Pinus taiwanensis forest.According to their economic value, these macrofungi may be grouped into two types: edible (72 species) and medicinal (55 species); and according their ecological habitat, they may be grouped into lignicolous (68 species), ento-mophilous (84 species), and ectomycorrhizal (21 species).Our study showed a certain regularity of their distribution, i.e., it varied with the ecological conditions of forests, tree species, soil types and altitude.Many economical macrofungi in this region could serve as one of the important natural resources, and had great potential usage on the edibility, medicinal and forestation.
    Effect of natural stress on genetic diversity of Frankia in Alnus nodules
    TANG Xiaomeng, DAI Yumei, XIONG Zhi, ZHANG Zhongze, ZHANG Chenggang
    2003, (10):  1743-1746. 
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    The genetic diversity of Frankia in the nodules of Alnus nepalensis growing in different habitats of Jizu and Wuliang Mountains in Yunnan Province was studied by rep-PCRtechnique.The results indicated that the Frankia had an abundant genetic diversity, which was varied with different zones, altitudes and slopes.More genotypes of Alnus-infective Frankia were found:at Jizu than at Wuliang Mountain.At the bottom of Jizu Mountain (2300 m), the Shannon-Weiner index was 0.90, and increased with raising altitude, up to 1.33 at the top (2700m).The genetic diversity of Frankia was more abundant along the southern slope than the northern slope.It was concluded that the diversity index was positively related to natural stresses which were one of the important factors producing and maintaining the genetic diversity of Frankia .
    Articles
    Effect of temperature on resistance of Pinus yunnanenensis to inoculation with Leptographium yunnanense, a pathogenic fungus associated with Tomicus piniperda
    LIAO Zhouyu, YE Hui, LU Jun, XIA Yuanlin
    2003, (10):  1747-1750. 
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    The study showed that temperature had an important effect both on the resistance of Pinus yunnanensis and on the growth and virulence of Leptographium yunnanense, a pathogenic fungus associated with Tomicus piniper-da attacking Pinus vunnanensis.which would result in the competence variation between them: at lower (< 10 ℃) and higher temperature(>30 ℃), the growth and virulence of L.yunnanmse were inhibited, while at 15 ℃～30 ℃, the resistance of Pinus yunnanensis was relatively weaker, indicating that in warmer climates, the growth and virulence of L.yunnanense were relatively strengthened, but the resistance of Pinus yunnanensis was relatively weakened.
    Effects of different nutritional resources on the longevity and parasitic ability of egg parasitoid Anagrus nila-parvatae
    ZHENG Xusong, YU Xiaoping, LU Zhongxian, CHEN Jianming, XU Hongxing
    2003, (10):  1751-1755. 
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    This paper dealt with the effects of honey, corn pollen, soybean flower, and honeydews excreted by Nila-paruatae lugens and Toya spp.on the longevity and parasitic ability of A.nilaparvatae.The results showed that the longevity of A.nilaparvatae was obviously extended, and its egg production on N.Lugens was significantly increased when fed with those nutrient-rich diets except the honeydew excreted by Toya spp.Corn pollen and the honeydew excreted by N.lugens worked only in the forms of pollen (water and honeydew) water.The longevity of N.lugens was not affected by its parasitic behaviors, but its survival rate was higher within 40～48 hours, and then decreased rapidly.About ten species of plant hopper, the host of Anagrus spp., were found in non-rice habitats, which provided shelter and afforded foods to the parasitoids of rice pests, and contributed to protecting the natural enemies and enhancing the biological control in the rice system.
    Transportation processes and rates of heavy metals in an artificial rainstorm runoff under different land use types
    LIANG Tao, WANG Hao, ZHANG Xiumei, ZHANG Shen, YU Kngxiu
    2003, (10):  1756-1760. 
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    Studies on the transportation and flux of various kinds of heavy metals in runoff and sediment of five typical land-use types in West Tiaoxi catchment showed that the losses of Cu (0.21 mg·m-2·min-1), Zn (0.45 mg·m-2· min-1), and Pb (0.15 mg·m-2·min-1) in mulberry and that of Cr (0.06 mg·m-2·min-1) in paddy field were larger in surface runoff, while their losses in pinery were very small.Suspended thin particles played the main role on transporting heavy metals in surface runoff under all kinds of land uses.The losses from runoff were much lower than that from sediment, which only occupied 0.1 %～4.9 %, and the loss rate of Cu from runoff and sediment was higher than that of Cr, Pb and Zn.
    Effects of cropping systems on nitrous oxide emissions from paddy soils during the rice-growing season
    XIONG Zhengqin, XING Guangxi, SHI Shulian, DU Lijuan
    2003, (10):  1761-1764. 
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    Cropping systems influence nitrous oxide (N2O) emissions from agricultural soils.Effects of 3 rice-based cropping systems on N2O emissions from paddy soils in pot experiment were investigated with closed chambers in triplicate.The results demonstrated that the seasonal N2O emission rate of the rice pot under rice-wheat cropping system was obviously higher than that of the early rice pot under double rice-wheat system, being 4.21 and 2.17 kg·hm-2, respectively.No distinct difference was observed between the seasonal average fluxes, which were 116.9 and 117.6 μg·m·2-h-1 respectively.Both of above mentioned seasonal average fluxes were greatly higher than that of the late rice pot under early rice-late rice-wheat cropping system and of rice pot under rice-flooding fallow system, being 67.0 and 42.1 μg·m-2·h-1 respectively.More than 91% of the seasonal emission was focused on the first half growing period both in the rice season in rice-wheat system and in the early rice season in double rice-wheat system in which the previous cropping was upland wheat.91% of the seasonal emission was focused on the water drainage period including the mid-season aeration and final drainage in the late rice season in double rice-wheat system in which the previous cropping was lowland rice.The results implied that cropping system and water status of previous cropping impacted N2O emission from paddy soil.
    Effects of pesticide-contamination on population size and denitrification activity of denitrifying bacteria in paddy soils
    CHEN Zhongyun, MIN Hang, WU Weixiang, CHEN Meichi, ZHANG Fudao, ZHAO Jianqiang
    2003, (10):  1765-1769. 
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    The effects of pesticide contamination on the population size and denitrification activity of denitrifying bacteria (DNB) were studied with three types of paddy soil (Huangsong paddy soil, red earth paddy soil and purple paddy soil) treated with carbofuran, carbendazim and butachlor for four weeks.The results showed that the population size of DNB in purple paddy soil, Huangsong paddy soil and red earth paddy soil varied in the range of 59.04 ×104～157.59×104, 42.89×104～108.97×104 and 32.14 × 104～75.30 × 104cfu·g-1 dried soil, respectively, which was positively related to the quantity of consumed nitrate in paddy soils.The population size and denitrification activity of DNB were increased by adding carbofuran (1 mg·kg-1 dried soil) or butachlor (1 mg·kg-1 dried soil), but decreased significantly by adding10 mg· kg-1 dried soil of butachlor, 5 mg· kg-1 dried soil of carbofuran, and 10 mg·kg-1 dried soil of carbendazim on 7th d, 14th d and 7th d, respectively.
    Use of methyl parathion (MP)-degrading strain DLL-E4(Pseudomonas sp) to remove MP residue on the surface of agricultural products
    LIU Zhi, ZHANG Xiaozhou, LI Shunpeng
    2003, (10):  1770-1774. 
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    In this paper, derivations from DLL-E4, including fermented liquid, its centrifuged (3000 ? g, 10min) supernatant, pellet extract with supersonic, crude enzyme(supernatant and pellet extract), detergent, and mixture of detergent and pellet extract, were used to degrade the MP residue on the surface of Chinese cabbage, tea and cucumber.The results showed that all of them were effective, with the best effect of 100% .Some constituents in the supernatant of fermented liquid could stimulate the enzymatic activity.For tea, the mixture of detergent and enzyme was more effective, but the opposite was found for the other two crops.In all treatments, crude enzyme and pellet extract had the best effect, and the rational added amount of enzyme was 2%, 5% and 10% for cucumber, Chinese cabbage and tea, respectively.Crude enzyme also could degrade methamidophos phoxim and chlorpyrifos.
    Effects of different arbuscular mycorrhizal fungi on Tagetes erecta growth and diesel degradation
    GENG Chunnü, LI Peijun, CHEN Suhua, ZHANG Hairong, HAN Guiyun
    2003, (10):  1775-1779. 
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    The effects of G.mosseae, G.geospora, G.constrictum and bacteria on diesel tolerance of Tagetes erecta were investigated under greenhouse conditions.The results showed that AM fungi could still develop mycorrhizal as-sosiations with mum when the diesel concentration was 5000 mg·kg-1.White mum was better than yellow mum in diesel tolerance, with 63.1% total biomass increased.The colonization rate of inoculating AM fungi treatment was 3.5%～29.9% higher than the control.G.mosseae and G.geospora were better strains, their biomass increasing 9.0% and 42.7% than the control, respectively, while the effect of inoculating mixed AM fungi was not obvious.Bacteria inhibited the colonization of arbuscular mycorrhizal fungi on white mum, but promoted the vegetative and reproductive growth of mycorrhizal mum.Among5 inoculation treatments, treatments of inoculating G.geospora and inoculating mixed AM fungi and bacteria were better, with 16.51% and 14.05% more diesel degradation rate than that of the control, respectively.
    Effects of BaP exposure on ultrastructures of hepatic cells of Boleophthalmus pectinirostris
    FENG Tao, ZHENG Weiyun, OUYANG Gaoliang, HONG Wanshu
    2003, (10):  1780-1782. 
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    The changes of ultrastructures of hepatic cells of Boleophthalmus pectinirostris were investigated after the fish were exposed under benzo (a) pyrene in different concentrations under experimental condition.The results showed that the organelles in hepatic cells of B.pectinirostris were damaged to different extents after the fish was exposed under lower concentration of BaP (0.5 mg稬-1) for up to 7 d, in which, mitochondria and endo-plasmic reticulum were the chief organelles affected by BaP exposure.While the fish was exposed under higher concentration of BaP (5 mg稬-1) for 2 h, almost all of the organelles including mitochondria and endoplasmic reticulum in hepatic cells of B.pectinirostr were affected by BaP exposure.The structures of liver cells were seriously damaged.It was demonstrated that BaP could produce multiorganalle lesions in hepatic cells of B.pectinirostris, and the severity extent of such lesions was dependent on the concentration level of BaP.
    Isolation and characteristics of PAHs-degrading strains
    ZHANG Jie, LIU Yongsheng, MENG Ling, SHAO Lidong, ZHANG Zhongze
    2003, (10):  1783-1786. 
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    The predominant indigenous microbial population and the strain ZL5 PAHS-degrading were obtained by selective enrichment culture from Liaohe viscous oil-contaminated field.The sequence analysis of 16s rDNA showed that strain ZL5 belonged to Sphingomonas sp.The microbial population and the strain could degrade phenanthrene well.95.28% and 69.24% of phenanthrene in the medium were degraded in 120hrs.However, the degradation of pyrene by the microbial population or by the strain was low.The degradation rate of phenanthrene or pyrene by the microbial population or the strain was greatly increased while glucose was used as an added substrate.The effect was closely related to the amount of glucose.If the concentration were too high, glucose would show inhibition effect on the degradation of PAHs.Therefore, it was necessary to control the amount of glucose while using glucose as an added substrate to increase degradation of phenanthrene or pyrene.
    Effects of rare earth elements on amino acid contents in earthworms
    HUA Rimao, ZHANG Zili, WU Xinan, ZHANG Dongchun, TAN Huarong
    2003, (10):  1787-1789. 
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    Rare earth elements are wide-used in China, but a few of studies were made on whether they had toxicity to soil fauna.In this paper, the filter paper contact method was used to study the influence of two rare earth elements on the dynamics of amino acids in earthworm body.The result showed that at low concentrations, the test rare earth elements increased the amino acid contents except proline, but decreased them at high concentrations.The amino acid contents began to increase at 400 mg· L-1, while decreased with time.Both of the two rare earth elements reduced the proline content, and behaved inhibition effect at the range of 100～1200 mg·L-1.
    Contributing factors and control strategies of pine wilt disease
    OUYANG Gecheng, ZHANG Runjie
    2003, (10):  1790-1794. 
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    There are several types of pine wilt diseases with inherent inter-relations.The diseases are closely related with the complex ecological system composed of local environment, pine trees, insect vectors, and pathogenic nematodes and some other microorganisms.Sustainable pest management based on ecology is a potential approach for pine wilt disease control.
    Global consequences and control strategies of biological invasion
    XIE Zongqiang, CHEN Zhigang, FAN Dayong, XIONG Gaoming
    2003, (10):  1795-1798. 
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    Biological invasion is a worldwide ecological phenomenon, but its mechanism is still not very clear.Invasive species give impacts on native species and ecosystems through competitions, predations, changing habitats, and dispersing diseases.They pose an increasing threat to the composition and structure of natural communities across the globe.Biological invasion has been greatly damaging the ecological and evolutionary integrity of natural e-cosystems, which will weaken the functions of the ecosystems and frequently cause natural disasters.Abetter understanding of the causes, patterns, predictability, consequences, and management options associated with this threat to biodiversity is necessary to guide managers, policy makers, researchers, and general publics.Biological invasion also causes huge economic losses, and 137 billion dollar losses per year from biological invasion were estimated in USA.Invasive diseases impair human health and kill thousands and thousands of people, and invasive bacteria lead to so serious social panic and turbulence that people could feel uneasy even when eating and sleeping.Biological invasion largely decreases global biodiversity, which will threaten the survival and development of our descendants.Three steps are used in prevention and control of biological invasions.Comprehensive quarantine is the most effective way to prevent exotic invasion by accident.Ecological evaluation and monitoring is helpful to avoid disasters from species introduction.Physical methods, chemical approaches and biological controls are used to eradicate and control the spread of invaded species.Before biological controls are chosen, risk analysis of controlling organism is needed.Ideally, there should be both pre-eradication assessment to tailor removal to avoid unwanted ecological effects and post-removal assessment of eradication effects on both the target organism and the invaded ecosystem.
    Articles
    Main mechanism and affecting factors of phytoremediation of organic contaminated soil
    LIN Daohui, ZHU Lizhong, GAO Yanzheng
    2003, (10):  1799-1803. 
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    In this paper, the main mechanisms of phytoremediation of organic contaminated soil, such as adsorption and degradation in rhizosphere, plant uptake, and transformation, and phytoremediation model were illuminated in detail, and their affecting factors, including properties of pollutants, plant species, soil properties, coexisted pollutants, and climate conditions were analyzed.The main topics that need further research were prospected, e.g., deepening the mechanism of phytoremediation, consummating phytoremediation models, approaching on the mechanism and appliance of microbe associated phytoremediation systems, building efficient surfactants enhancing phytoremediation systems, and strengthening the research on phytoremediation of combined organic pollution.
    Comparison of soil organic matter models
    GAO Lupeng, LIANG Wenju, JINAG Yong, WEN Dazhong
    2003, (10):  1804-1808. 
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    Soil organic matter is a soil carbon pool, and its content and dynamics is very important to global Ccycling, soil fertility, and soil quality.SOM models can simulate soil organic matter dynamics and predict its content, especially for which some of data are difficult or impossible to obtain by experiential hypotheses and existing data.Therefore, SOM models have become the most important quantitative means to study SOM decomposition and accumulation, and can help us to identify the mechanism about SOM dynamics.SOM models can also predict CO2 emission and plant growth, and evaluate agricultural management practices.Several SOM models, especially RothC model and CENTURY model, were summarized and analyzed in this paper.
    New quantificational indexes in modern study of soil organic matter
    WANG Jing, ZHANG Xudong, XIE Hongtu, ZHU Ping, JIANG Guimin
    2003, (10):  1809-1812. 
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    In modern study of soil organic matter, many new quantificational indexes and relevant testing methods, e.g., DOC, WSOC, HWC, ROC, MBC, MEN, PMC, PMN, Glu, Gla, Man, Mur,δ13C, and CPMI, came forth with deepening study.Because they are disorderly and unsystematic, it is necessary to clarify these indexes.This paper summarized their origin, concept, and testing method, which is of significance in the modern study of soil organic matter.