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    15 December 2005, Volume 16 Issue 12
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    Articles
    Productivity and species diversity of artificial broad-leaved Korean pine forests in eastern Liaoning mountainous areas
    YU Lizhong, ZHU Jiaojun, SHI Jianwei, YU Shuiqiang, WANG Zuomei, LU Zhengmao, DING Guoquan
    2005, 16(12):  2225-2230. 
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    An investigation in the typical plots of 20-yr artificial broad-leaved Korean pine forests in eastern Liaoning mountainous areas showed that the productivity of mixed forests Pinus koraiensis-Betula platyphylla,P.koraiensis-Alnus tinctoria,and P.koraiensis-Fraxinus mandshurica was 6.529,4.966 and 5.682 t·hm-2·yr-1,respectively,much higher than that of pure Korean pine forest (3.812 t·hm-2·yr-1),while mixed forests P.koraiensis-Kalopanax septemlobus and P.koraiensis-Tilia amurensis had a productivity of 2.945 and 2.84 t·hm-2·yr-1,respectively,lower than that of pure Korean pine forest.The plant species diversities of arbor,shrub and herb layers of artificial broad-leaved Korean pine forests were all higher than those of pure Korean pine forests.The plant species number in pure Korean pine forests only accounted for 42%～52% of artificial broad-leaved Korean pine forests,and the tree number of vegetation only accounted for 11%～37% of mixed forests.These results suggested that artificial broad-leaved Korean pine forests could provide the chances for the succession of secondary forest systems to regional climax,but it would take a long time to reach the climax.
    Niche characteristics of dominant populations of Sophora davidii community in loess gully region
    LI Dengwu, ZHANG Wenhui, REN Zhengzheng
    2005, 16(12):  2231-2235. 
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    Based on field investigation data and employing Levin and niche proportional similarity formulae,this paper calculated the niche breadth,niche proportional similarity,and niche overlap of 13 dominant species of Sophora davidii community in loess gully region.The results showed that the niche breadth of the dominant populations of Sophora davidii community decreased in order of Sophora davidii(0.964),Artemisia giraldii(0.775),Artemisia gmelinii(0.664),Themeda triandra var.japonica(0.508),Polygala tenuifolia(0.485),Setaria viridis(0.399),Cynodon dactylon(0.393),Bothriochloa ischaemum(0.327),Lespedeza davurica(0.321),Stipa bungeana(0.472),Periploca sepium(0.292),Clematis fruticosa(0.251),and Cleistogenes squarrosa(0.234).The niche proportional similarity between Sophora davidii and other species was 0.21～0.76,while the niche overlap was not high,which meant that there was no severe competition between them.It could be concluded that Sophora davidii was the dominant population in the community,with most resources utilization and most adaptability to the ecosystem.
    Correlation between gap structure and tree diversity of mixed-broad-leaved Korean pine forests in northeast China
    ZHAO Xiuhai, ZHANG Chunyu, ZHENG Jingming
    2005, 16(12):  2236-2240. 
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    This paper studied the regeneration of tree species in the gaps of broad-leaved Korean pine forest,with the tree diversity in gaps and under closed canopy compared,and the relationship between biodiversity and gap structure analyzed.The results indicated that there was a significant difference between tree species diversity in gaps and under canopy (P<0.01).In regeneration layer,the biodiversity in terms of Shannon-Wiener,evenness,and abundance indices was higher in gap community than under forest canopy,while the dominance of certain species in terms of Simpson's dominance index was increased from gaps to closed canopy (P<0.01).The biodiversity of succession layer in gaps and under closed canopy had an opposite trend.Tree species diversity of different layers reacted differently to the change of gap size class,e.g.,Shannon-Wiener and abundance indices were higher,but Simpson's dominance index was the lowest in the succession layer of medium-size gap(100～250 m2) in broad-leaved Korean pine forest of Changbai Mountain.The Shannon-Wiener index and evenness index reached the highest in the size of ≥250 m2 and <100 m2,and reached the lowest in the size of 200～250 m2 in regeneration layer.Simpson's dominance index reached the highest in the size of 200～250 m2.On the whole,tree species of different layers reacted differently to the change of gap size class,and the gap size class with more seedlings was not corresponding to the size class containing more medium-size trees.With gaps aging,tree diversity indices in the two layers behaved reciprocally.
    Drought resistibility of main tree species in water conservation forest of Qilian Moutains
    DANG Hongzhong, ZHOU Zefu, ZHAO Yusen
    2005, 16(12):  2241-2247. 
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    With P-V techniques,this paper determined and analyzed the water parameters of main tree species in the water conservation forest of Qilian Moutains.The results showed that the test water parameters varied with tree species,reflecting the complicacy of the drought-resistance mechanism of trees.Among 10 parameters,|φπ100 -φπ0 |,RCV,ROWC0 and εmax could reflect most information of drought resistibility.Based on their drought resistibility,the test tree species could be classified into 4 groups,i.e.,high drought resistibility(Picea crassifolia and Rhododendron thymifolium),sub-high drought resistibility(Sabina przewalskii,Rhododendron anthopogonoides,Rhododendron capitatum and Rhododendron przewalskii),low drought resistibility(Populus cathyana),and inferior drought resistibility(Potentilla fruticosa,Spiraea salicifoliaand Betula albosinensis).The relationships between predawn leaf water potential and soil water content could be well modeled by hyperbola function,power function or exponent function.Meanwhile,the test tree species could be also grouped as high potential delay dehydration species (Betula albosinensis and Rhododendron przewalskii),sub-high potential delay dehydration species(Picea crassifolia,Rhododendron thymifolium and Rhododendron capitatum),inferior potential tolerance species(Sabina przewalskii),and low potential tolerance species(Potentilla fruticosa,Spiraea salicifolia and Rhododendron anthopogonoides),based on their drought-resistance mechanism.
    Carbon storage and its dynamics of forest vegetations in Heilongjiang Province
    JIAO Yan, HU Haiqing
    2005, 16(12):  2248-2252. 
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    Forest is the leading sink of carbon on the earth,while the forest resources of Heilongjiang Province take an important position in China.Based on the national forest inventory data from 1973 to 2003,the carbon storage of forests in Heilongjiang Province was estimated by the linear relationship between stand biomass and volume.The results showed that the total carbon storage of forests in 1973～1976,1977～1981,1985～1988,1989～1993,1994～1998 and 1999～2003 was 7.916×108,5.413×108,5.661×108,5.880×108,6.216×108 and 6.011×108 t,respectively,with an increasing trend since 1977,indicating that the forests in this Province played a role as a sink of atmospheric carbon dioxide,and this functioning was strengthened during the last 20 years.If the current forest is managed well,it would become a huge potential carbon sink in the future.
    A comparison of various correction methods for calculating carbon flux above tropical seasonal rainforest
    ZHANG Yiping, DOU Junxia, SUN Xiaomin, ZHAO Shuangju, SONG Qinghai, YU Guirui
    2005, 16(12):  2253-2258. 
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    In this paper,various correction methods were compared,based on the observation data of the CO2 and water fluxes above the canopy of a tropical seasonal rainforest in Xishuangbanna during 1～9 March,2003.The results showed that it was necessary to correct the observation data when calculating the carbon flux,though various correction methods contributed differently to the results.For daytime data,WPL made the most important contribution,while sonic temperature correction did the least.t test indicated that no significant difference was found between the carbon fluxes corrected by WPL and the standard values.Cluster analysis showed that triple-rotation correction was helpful to improve the precision of the data.For nighttime data,it was the triple-rotation correction that made the most important contribution,and sonic temperature correction also did the least.There existed significant differences between the carbon fluxes corrected by WPL,planar-fit correction and their combination and the standard values,while the differences between the carbon fluxes corrected by double-or triple-rotation and the standard values were not significant.Cluster analysis showed that the data corrected orderly by coordinate axes-rotated correction and WPL would be propitious to improve the precision.The results would provide a basis for calculating the fluxes within tropical rainforest in the future,and supply reference to the fluxes calculation for other areas.
    Effects of forest harvesting on river runoff in Xiaoxing′anling
    ZHU Daoguang, CAI Tijiu, YAO Yuefeng, JU Cunyong
    2005, 16(12):  2259-2262. 
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    By the method of runoff determination in large basin combined with contrast experiment in small watershed,and based on the runoff and forest resources data in past 35 years,this paper studied the serial changes of river runoff in Xiaoxinganling after forest harvesting.The results showed that the river flow was increased in the early 10 years after forest harvesting,but decreased gradually with the growth and crown closure of artificial larch forest,tended towards or even lower than the level before harvesting.The river runoff had a close correlation with annual rainfall and the areas of forest harvesting and regeneration.Significant positive correlation was observed between annual flow and forest harvesting area,which resulted in the increase of river runoff after forest harvesting.Forest harvesting could also significantly increase the peak flood and snowmelt runoff.There was a negative correlation between regenerated forest area and annual flow,and thus,forest regeneration would decrease annual flow.
    Roles of bryophyte in nutrient cycling in dark coniferous forest of Changbai Mountains
    HAO Zhanqing, YE Ji, JIANG Ping, LIN Fei
    2005, 16(12):  2263-2266. 
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    This paper measured the nutrient contents of five main bryophytes in the dark coniferous forest of Changbai Mountains,and estimated their values per unit area.The results showed that bryophyte had a nitrogen content 54.371 kg·hm-2,being 12.22% of total nitrogen content of arbor,shrub and herb,and its potassium and phosphorous content was 12.042 kg·hm-2 and 31.679 kg·hm-2,occupying 5.63% and 70.57% of the total,respectively.The phosphorous content of bryophyte was higher than that of arbor,and 2.4 and 792 times as much as that of herb and shrub,respectively,indicating that bryophyte was an important phosphorous pool.Soil nitrogen and potassium content under different coverage of bryophyte had little difference,while soil phosphorous content was significantly different.The soil with no bryophyte coverage had the highest phosphorous content (0.419±0.023 g·kg-1),while that with 80%～100% bryophyte coverage had the lowest one (0.346±0.017 g·kg-1),suggesting that soil phosphorous content was decreased with increasing bryophyte coverage.
    Landscape diversity and stability of Korean pine broad-leaved forest in Xiaoxing'anling forest region
    WANG Lihai, MENG Chun
    2005, 16(12):  2267-2270. 
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    Taking the Dongfanghong Forestry Farm of Dailing Forestry Bureau in Heilongjiang Province as the study area,and based on the GIS information and the analysis of current forest management measures,a landscape dynamic model was established,which indicated that the indexes of landscape classification at the first and second levels were rather low,due to the forest covered about 91% of the whole study area.The dominance index of forest cover was increased from 0.611 to 0.692 during the period from 1985 to 1993,and that of climax forest community was increased by 70%.During the years of 2 041～2 049,the Korean pine broad-leaved forest would become the climax forest community in this area,with an area around 13 120～13 242 hm2 if taking selective cutting as the prevailing harvesting method.
    Dynamics of soil erosion at upper reaches of Minjiang River based on GIS
    HE Xingyuan, HU Zhibin, LI Yuehui, HU Yuanman
    2005, 16(12):  2271-2278. 
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    Based on TM and ETM imagines,and employing GIS technique and empirical Revised Universal Soil Loss Equation (RUSLE) model,this paper studied the dynamics of soil erosion at the upper reaches of Minjiang River during three typical periods,with the main affecting factors analyzed.The results showed that the soil erosion area was increased by 1.28%,1.84% and 1.70% in 1986,1995 and 2000,respectively.The average erosion modulus was increased from 832.64 t穔m-2穣r-1 in 1986 to 1 048.74 t穔m-2穣r-1 in 1995 and reached 1 362.11 t穔m-2穣r-1 in 2000,and soil loss was mainly of slight and light erosion,companying with a small quantity of middling erosion.The area of soil erosion was small,and the degree was light.There was a significant correlation between slope and soil loss,which mainly happened in the regions with a slope larger than 25?,and accounted for 93.65%,93.81% and 92.71% of the total erosion in 1986,1995 and 2000,respectively.As for the altitude,middling,semi-high and high mountains and dry valley were liable to soil erosion,which accounted for 98.21%,97.63% and 99.27% of the total erosion in 1986,1995 and 2000,respectively.Different vegetation had a significant effect on soil erosion,and shrub and newly restored forest were the main erosion area.Excessive depasture not only resulted in the degradation of pasture,but also led to slight soil erosion.Land use type and soil type also contributed to soil loss,among which,dry-cinnamon soil and calcic gray-cinnamon soil were the most dangerous ones needing more protection.Soil loss was also linearly increased with increasing population and households,which suggested that the increase of population and households was the driving factor for soil loss increase in this area.
    Estimation of China soil organic carbon storage and density based on 1:1000000 soil database
    YU Dongsheng, SHI Xuezheng, SUN Weixia, WANG Hongjie, LIU Qinghua, ZHAO Yongcun
    2005, 16(12):  2279-2283. 
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    Based on 1: 1 000 000 soil database,and employing the methods of spatial expression,this paper estimated the soil organic carbon storage (SOCS) and density (SOCD) of China.The database consists of 1: 1 000 000 digital soil map,soil profile attribution database,and soil reference system.The digital soil map contained 926 soil mapping units,690 soil families,and 94 000 or more polygons,while the soil profile attribution database collected 7 292 soil profiles,including 81 attribution fields.The SOCDs of soil profiles were calculated and linked to the soil polygons in the digital soil map by the method of “GIS linkage based on soil type",resulting in a vector map of 1: 1 000 000 China SOCD.The SOCS of the country or of a soil could be estimated by summing up the SOCS of all polygons or the polygons of a soil,and their SOCD were the SOCS of them derived by their areas.The estimated SOCS and SOCD of the country was 89.14 Pg (1 Pg=1015 g) and 9.60 kg·m-2,respectively,covered all the soils with a total area of 928.10×104 km2,which might be considered closest to the real value.
    Regional ecosecurity pattern in urban area based on land use analysis:A case study in Lanzhou
    FANG Shubo, XIAO Duning, AN Shuqing
    2005, 16(12):  2284-2290. 
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    Mid-scale regional ecosecurity,which takes practical ecosecurity issues as its priority,should be viewed as the core of the multi-scale concept of ecosecurity.For urban area,a special region taking ecological infrastructure as its core mission,the construction of regional ecosecurity pattern may provide a good chance to realize its sustainable development.Based on land use analysis,a qualitative and quantitative research on the landscape pattern,ecovalue evaluation,and driving force analysis of social economy could provide an effective approach to construct the ecosecurity pattern in urban area.This study showed that in Lanzhou,the ecosecurity pattern consisted of three parts,i.e.,eco-safeguarding system,eco-buffering system and eco-percolating system,among which,eco-buffering system was the decisive part determining ecosecurity pattern construction.The quantitative analysis of urban spatial expansion pattern was taken as the decisive function to determine the security level of the ecosecurity pattern,which was divided into low,middle and high levels.
    Application of 3S techniques in ecological landscape planning of Harbin suburb
    FAN Wenyi, GONG Wenfeng, LIU Dandan, ZHOU Hongze, ZHU Ning
    2005, 16(12):  2291-2295. 
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    With the image data (SPOT),soil utilization map (1:50 000) and other related materials of Harbin,and under the support of GIS,RS and GPS techniques,this paper obtained the landscape pattern of Harbin suburb and the Digital Elevation Model (DEM) of Harbin.Indices including mean patch area,landscape dominance,mean slope,mean altitude,and fragmentation degree were selected and synthetically analyzed,with the ecological landscape planning made by DEM model.The results showed that 3S techniques could help to decide typical landscape types.The landscape type database was established,and the landscape type thematic map was generated,with land use status and landscape distribution,physiognomy,and land use types combined.The ecological landscape planning was described in large scale with the image data and DEM combined,and the landscape structure of Harbin suburb was reflected directly with the ecological landscape planning and DEM combined,which improved the ecological function in this region,and provided scientific bases to the healthy development in urban-rural integration area.
    Effects of land use structure change on regional ecological health-Taking Shapingba County of Chongqing as an example
    WANG Cheng, WEI Chaofu, GAO Ming, LUO Guanglian, JIANG Wei
    2005, 16(12):  2296-2300. 
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    Land resource is the carrier for the exchange of matter,energy and information flows,while the change velocity and the intensity of land use has strong effects on the ecological processes such as matter circulation,energy flow,and biologic diversity.Land use structure change will alter the type,area,and spatial distribution of ecosystem,and in the meantime,result in the changes of regional ecological health.Employing the principles and methods of landscape ecology,and through endowing relative ecological value to land use type,this paper analyzed the characteristics of recent 10 years land use change in Shapingba County of Chongqing,and discussed the effects of land use change on regional ecological health,aimed to provide scientific references for land use planning and sustainable land resource utilization.The results indicated that transformation often occurred among different land use types,and the land use structure in each transformation phase differed quite obviously.Under different land use structure,there was a great disparity in relative ecological value of sub-ecosystems,which played various roles in regional ecological health.In general,the regional relative ecological value embodied both increase and decrease.In the future,the relative ecological value of sub-ecosystem would represent three tendencies,i.e.,increase first and decrease then,continuous decrease,and continuous increase.The situation of regional ecological health would gradually become better.
    Quantitative estimation of vegetation coverage in Mu Us sandy land based on RS and GIS
    CAI Tijiu, JU Cunyong, YAO Yuefeng
    2005, 16(12):  2301-2305. 
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    On the basis of oriented field investigation data and corresponding RS and GIS information,and by the method of ridge estimation,this paper studied the estimation model of vegetation coverage and its affecting factors in Yijinholo County of northeast Mu Us sandy land.The results showed that the vegetation coverage was affected by NDVI,and closely linked with such RS and GIS information as,TM7,TM2,TM4/3 and gradient.Ridge estimation method could obviously improve the limitation of Least Square method,eliminate the adverse effects caused by existing complex estimation relation towards uncoiling undetermined parameter among the variables,and improve the estimate precision.The vegetation coverage estimation model taking pixel as unit was established,and its test precision could reach 98.7%.In addition,a regional vegetation coverage GIS was established,which could realize the inquiry,regeneration,and drawing of any spot (pixel) or any land unit of vegetation coverage automatically.
    Utilization of compressed Chinese fir thinning wood
    CHEN Ruiying, WEI Ping, LIU Jinghong
    2005, 16(12):  2306-2310. 
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    With Chinese fir thinnings as raw material,and through measuring the physical-mechanical indices of its compressed wood,observing the variation of its microstructure and using IR analysis,an optimized technique of compressing Chinese fir thinnings was established.The technique was: compression ratio 50%～60%,thickness after compression 20 mm,moisture content before compression 50%,compressing time 20～30 minutes,and hot compressing temperature 180～200 ℃.CH,an environmentally friendly cooking additive,had positive effects on softening the wood.During compressing,only the cells of fast-growing Chinese fir were extruded,their cavity became smaller,while the cell wall was not destroyed.The thickness reversion ratio of compressed wood was 2.68%,and its size stability and mechanical quality were as good as hardwoods (Betula luminifera).
    Module structure and growth pattern of Stipa baicalansis clone in Songnen Plain of China
    YANG Yunfei, ZHANG Baotian
    2005, 16(12):  2311-2315. 
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    By the method of digging up whole tiller tuft,this paper quantitatively analyzed the module structure and growth pattern of Stipa baicalansis clone under the cultural conditions in the Songnen Plain of Northeast China.The results showed that after two growth seasons of vegetative reproduction,the tuft size of the clone in its growth stopping period at the end of September was 9.4?3.24 cm,and the total number of the clonal modules was 161.5?85.2,among which,the individuals of reproductive and vegetative tillers were 14.6?11.48 and 146.9?78.70,occupying 9.25% and 90.75% of the total,respectively.The total biomass of the clonal modules was 53.8?34.22 g,and the biomass of reproductive and vegetative tillers was 25.0?20.34 g and 28.8?19.43 g,occupying 43.75% and 56.25% of the total,respectively.With the increase of tuft size,the number of different modules was in a linear isogony growth,while their biomass was in an power allometry growth.There was a significant (P<0.05) or very significant (P<0.01) power positive correlation between the biomass of different modules and the number and total biomass of clonal modules.The mean productivity of unit reproductive tiller was about ten times higher than that of unit vegetative tiller,and the phenotype plasticity of the number and biomass of reproductive tiller was larger than that of vegetative tiller.
    Changes of biomass allocation of Artemisia frigida population in grazing-induced retrogressive communities
    WANG Jing, YANG Chi, WANG Tiejuan
    2005, 16(12):  2316-2320. 
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    The study showed that under the disturbance of grazing,the biomass of Artemisia frigida leaves,stems,roots and total plant were increased with increasing retrogressive degree,and that of roots was increased more.The biomass of inflorescences and fruits was increased in light retrogressive community while decreased rapidly in mid retrogressive community,and no reproductive model was observed in heavy retrogressive community.With the increase of retrogressive degree,biomass allocation changed.The allocation to roots increased,but that to sexual reproduction decreased,which was badly inhibited in heavy retrogressive community,accompanying with the change of reproduction pattern.As for the dynamics of resource allocation,the resource was prior to allocate to aboveground portion,especially to photosynthesis organ from early to mid growth period,and allocate to sexual reproduction or reserve organ from mid to late growth period,with the increase of retrogressive degree.The alternation of reproductive pattern was the key that A.frigida population resisted grazing and became the established species in heavy retrogressive community.The change pattern of resource allocation made the allocation harmonious between the growth,resistance and reproduction,and was the substantial base that A.frigida population became the constructive species in heavy retrogressive community.
    Degradation process and plant diversity of alfalfa grassland in North Loess Plateau of China
    LI Yuyuan, SHAO Ming'an
    2005, 16(12):  2321-2327. 
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    Vegetation recovery and reconstruction is the key of ecosystem restoration in the North Loess Plateau.With the Liudaogou catchment of Shenmu County,Shaanxi Province as test area,this paper studied the dynamics of the plant diversity of artificial alfalfa (Medicago sativa) grassland during its degradation process.The results showed that the degradation process of the grassland could be divided into three stages,i.e.,artificial alfalfa grassland stage (1～6 yrs),transitional stage from artificial to natural grassland (6～10 yrs),and secondary natural grassland stage dominated by Stipa bungeana (>10 yrs).In the whole degradation process from 1-to 30-yrs,32 species belonging to 13 families and 28 genera were found,of which,90% appeared in the initial 6-yrs.The dynamics of accumulatively appeared family,genus,and species in the vegetation succession process were well described by logarithmic function.During the process of community succession,the species richness (Gleason index and Margalef index),plant diversity (Shannon-Wiener index),and Pielou evenness index were changed with a similar tendency,i.e.,increased more rapidly at the first stage,and the climax phase appeared in the second stage.The plant diversity and evenness decreased slightly,and gradually became stable later.Planting alfalfa could markedly accelerate the natural vegetation succession process in the forest-steppe ecotone of Loess Plateau,mainly due to the intensive soil water consumption of artificial grassland,which accelerated the process of soil aridification.To develop artificial grasslands in the Loess Plateau is an optimal joint between accelerating natural vegetation recovery and increasing farmers'income by stockbreeding,and is also a favorable paradigm both for the ecological and for the economic benefits in the eco-environmental construction in West China.
    Responses of Medicago sativa and Astragalus adsurgens seedlings growth and water use to soil moisture regime
    XU Bingcheng, SHAN Lun, LI Fengmin
    2005, 16(12):  2328-2332. 
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    In the semi-arid area of Loess Plateau,seasonal drought often occurs during the vegetative stage of grass plants,leading to the subsequent serious reduction of their yield.Aimed to study the responses of the seedlings growth and water use of two perennial leguminous grasses Medicago sativa and Astragalus adsurgens to different soil moisture regimes,a pot experiment was installed with five treatments,i.e.,adequate water supply (HW),moderate water stress (LW),soil drying gradually from HW (DHW) and LW (DLW),and refilling water to LW after soil drying from LW (RWL).The results showed that under HW,the seedlings of both M.sativa and A.adsurgens had the highest biomass and transpiration water use efficiency (TWUE),and M.sativa had a significantly higher biomass than A.adsurgens (P<0.05).When the soil moisture content declined,M.sativa had a higher reduction rate in biomass and TWUE than A.adsurgens,and after the soil moisture regime changed from LW and DLW to RWL,the biomass of M.sativa and A.adsurgens was reduced by 47.8% and 27.9%,respectively,as compared to LW (P<0.05).At the same time,the root/shoot ratio (R/S) of M.sativa and its water consumption per unit root increased significantly,while the TWUE decreased significantly(P<0.05); but for A.adsurgens,its R/S decreased significantly (P<0.05),while the TWUE and the water consumption per unit root had no significant change.
    Effects of different cutting system on main typical steppe populations in Inner Mongolia
    BAO Qinghai, BAOYIN Togeto, ZHONG Yankai, SUN Wei, LIU Meiling
    2005, 16(12):  2333-2338. 
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    Twelve main typical steppe populations in Inner Mongolia were selected to investigate the effects of different cutting system on their aboveground standing biomass.The results showed that the test populations could be categorized into 3 groups,i.e.,1) group with decreasing biomass,which included Leymus chinensis,Agropyron michnoi,Caragana microphylla and Carex korshinskyi,with L.chinensis and C.microphylla as the representatives.The average aboveground standing biomass of L.chinensis was decreased by 63.37%,64.96%,45.64% and 34.18% after 2 cuttings a year,1 cutting a year,1 year cutting and 1 year resting,and 2 years cutting and 1 year resting,while that of C.microphylla decreased by 81.79%,63.33%,40.29% and 26.30%,respectively,compared with the control; 2) group with increasing biomass,which included Koeleria cristata,Artemisia scoparia,A.frigida,and Salsola collina,and K.cristata and A.frigida were the representatives.The biomass of K.cristata was increased by 94.84%,287.79%,132.86% and 211.74%,while that of A.frigida was increased by 193.02%,210.47%,154.65% and 160.47%,respectively.The biomass increase of K.cristata and A.frigida was derived from their population changes,while that of A.scoparia and S.collina was come from the decrease of community densities and the more suitable conditions for seed germination; 3) group with fluctuated biomass,which included Stipa grandis,Achnatherum sibiricum,Artemisia commutata and Serratula centauroides,and the change patterns of their biomass were between those of the former 2 groups.
    Matter production and storage of Leymus chinensis clonal populations in restoration succession process of flooded meadow in Songnen Plain of China
    LI Haiyan, YANG Yunfei
    2005, 16(12):  2339-2343. 
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    In this paper,the tiller matter production and the rhizome matter storage of Leymus chinensis clonal populations in the patches with radius of 0.5,1,3,5 and 10 m were studied in the restoration succession process of flooded meadow in Songnen Plain.The results indicated that in each patch,1 and 2 age classes had the most tiller matter production,while in the patches except in the center of 10 m patch,the rhizome matter storage of 1 age class was predominant.The proportion of the matter production and storage increased with increasing patch radius.On the whole,young tillers and rhizomes had vigorous matter productivity and storage capacity.From the center to the edge of each patch,the matter production and storage were consistent with the trend of patch expansion,and the variation of tiller matter productivity and rhizome matter storage capacity was the biggest at the edge of each patch.The matter production and storage strategies of L.chinensis clonal population modules settled the matter basis for population expansion and progressive succession of community in the restoration succession process of flooded meadow.
    Effects of soil surface mulching on solar greenhouse grafted and own-rooted cucumber growth and soil environment
    ZHAI Sheng, LIANG Yinli, WANG Juyuan
    2005, 16(12):  2344-2348. 
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    The study on the effects of different soil surface mulching models,including wheat straw mulching(WS),plastic film mulching(PF),and wheat straw plus plastic film mulching(WP),on the growth of solar greenhouse grafted and own-rooted cucumber and on soil environment showed that soil surface mulching not only increased the individuals of pistillate flower,improved its differentiation and development,shortened fruit-developing period,increased fruit weight,reduced fruit malformation percentage,but also raised total yield.Among the test mulching models,WP was better than WS and PF,and the effects were superior on grafted than on own-rooted cucumber.Soil surface mulching also had considerable effects on soil environment,but the effects varied with different modules.For example,under field condition,the diurnal change of soil temperature was a single-peak curve,with its peak higher and appeared at 14:30 in 5 cm and 10 cm soil depth,but lower and appeared later in deeper soil layers.In this study,WS lowered the maximum soil temperature and raised the minimum soil temperature,making soil temperature quite stable,while PF raised the maximum soil temperature much higher and enhanced the minimum soil temperature less than WS and WP,making the largest variation range of soil temperature.WP played a role of raising soil temperature and kept it stable.Similar to the diurnal change of soil temperature at 5 cm and 10 cm depth,that of soil respiration rate was also a single-peak curve.The soil respiration rate in all treatments was significantly higher than that of CK,and WP had a higher soil respiration rate than PF and WS.There was a significant positive correlation between soil respiration rate and soil temperature at 5 cm and 10 cm depth.By the end of the experiment,soil bulk density at the depth of 0～20 cm was measured,which was significantly lower in WS and WP than in CK and PF.The difference in soil bulk density was gradually inconspicuous with soil layer deepened.
    Root system hydraulic conductivity of different genotype maize and its relationship with root anatomy
    WANG Zhoufeng, ZHANG Suiqi, LIU Xiaofang
    2005, 16(12):  2349-2352. 
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    Under solution culture condition and by using pressure chamber techniques,this paper studied the difference of root system hydraulic conductivity (Lpr) of different genotype maize at the level of individual root,and its relationship with root anatomy.The results showed that the Lpr of root system was different with different genotype,and there existed heterosis in F1 generation.Under normal culture condition,the root with wider vessels had higher Lpr and drought resistance; while under water deficit,there was a significantly negative correlation between the width of root vessel and the Lpr and drought resistance.Under both normal and deficient water supply,there was a negative correlation between the ratio of cortex to root diameter and the Lpr and drought resistance,suggesting that root cortex was the placement with the greatest resistance to the liquid water flow in plant.
    Effects of water stress on protective enzyme activities and lipid peroxidation in Phellodendron amurense seedlings
    LI Xia, YAN Xiufeng, YU Tao
    2005, 16(12):  2353-2356. 
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    This paper studied the effects of water stress on the dynamic variations of malondialdehyde (MDA) and free proline contents,and of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT) activities in Phellodendron amurense seedlings.The results showed that after treated with light drought,heavy drought and waterlogging for 40 days,the MDA content in corktree seedlings was significantly higher,being 2.49,2.37 and 4.12 times of the control,respectively,but after treated for 80 days,there was no significant difference among the three treatments.The free proline content had no obvious variation under waterlogging and in the control,but increased after 40 days of light and heavy drought while declined after 80 days of drought stresses,with the increment being higher under heavy drought than under light drought.No regularity was found for the dynamic variations of SOD,POD and CAT activities,but they were significantly higher under heavy drought than under light drought,waterlogging,and the control.
    Community structure of entomogenous fungi in Beauveria-inoculated Masson's pine forest
    WANG Bin, DING Degui, FAN Meizhen, LI Zengzhi
    2005, 16(12):  2357-2360. 
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    The study on the community structure of entomogenous fungi in a Masson's pine forest having been inoculated with Beauveria bassiana for many years showed that there were 4 genus and 7 species of entomogenous fungi,among which,B.bassiana was the dominant species,occupying 63.22% of the total,followed by Paecilomyces (25.86%),Metarhizium (9.20%) and Verticillum (1.72%).In terms of insect host diversity,the Brillouin index and evenness index were 3.564 and 2.315,and 0.814 and 0.865 for B.bassiana and P.cateniannulatus,and 1.471 and 0.862,and 0.963 and 1.000 for P.farinosus and V.lecanii,respectively,while M.flavoviride,M.anisopliae,and P.fumosoroseus had lower diversity and evenness.The diversity index of insect hosts infected by B.bassiana showed a temporal variation,i.e.,higher in spring and autumn,and lower in summer,which reflected the seasonal dynamics of B.bassiana population.
    Antifeeding effects of crude lantadene from Lantana camara on Plutella xylostella and Spodoptera litura larvae
    DONG Yizhi, ZHANG Maoxin, LING Bing
    2005, 16(12):  2361-2364. 
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    In this study,crude lantadene was extracted from Lantanacamara leaves,and its antifeeding effects on Plutella xylostella and Spodoptera litura larvae were tested.In no-choice test,crude lantadene at 1.6 mg穖l-1 concentration had antifeeding effects on the 2nd instar P.xylostella larvae and 1st instar S.litura larvae,with the antifeeding rate being 62.4% and 33.1%,respectively within 48 h.In choice test,even a low concentration (0.4 mg穖l-1) crude lantadene still had anti-feeding effects on the 2nd instar P.xylostella larvae,and the antifeeding rate at 0.4,0.8 and 1.6 mg穖l-1 concentration was 52.7%,55.5% and 78.9%,respectively.Crude lantadene only at 1.6 mg穖l-1 concentration had anti-feeding effects on the 1st instar S.litura larvae,and the antifeeding rate was 33.0%.For the 2nd instar S.litura larvae,crude lantadene had no antifeeding effects both in no-choice and in choice test.
    Effects of management level on community characteristics of arthropod and on population numbers of target insect pest and its natural enemies in graperies
    LI Changgen, ZOU Yunding, BI Shoudong, WU Houchang, CHEN Xiangyang, LI Fen, ZHOU Xiazhi, LIN Xuefei
    2005, 16(12):  2365-2368. 
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    In this paper,an investigation on the grape tree and ground vegetation was conducted in two graperies with intensive and extensive management,aimed to study the effects of different management level on the community characteristics of arthropod,and the population numbers of target pest Halticinae chalybca (Illiger) and its natural enemies Erigonidium graminicolum and Tetragnathidae.The results showed that between the two graperies,the individual number,concentration value,evenness,and Hill diversity index of arthropod community had no significant difference,but its species number and abundance was significantly different (P<0.05).The species number of arthropod on the grape trees in intensive management grapery was not significantly different from that in extensive management grapery,while on the ground vegetation,it was significantly different (P<0.05).There was a little difference in the population numbers of H.chalybca and its natural enemies on the trees and ground vegetations of the two graperies.
    Effects of temperature on Brontispa longissima population growth
    ZHONG Yihai, LI Hong, LIU Kui, WEN Haibo, JIN Qi'an, PENG Zhengqiang
    2005, 16(12):  2369-2372. 
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    The study on the development,survival and reproduction of Brontispa longissima at 5 different temperature (16,20,24,28,32 ℃) showed that the threshold temperature and effective accumulative temperature for the whole generations of Brontispa longissima were 11.08 ℃ and 966.22 ℃,respectively,and 4～5 generations could occur in a year in Danzhou,Hainan Province.One generation had the highest survival rate (92.5%) at 28 ℃,but failed to survive at 32 ℃.Brontispa longissima reared at 28 ℃ had the greatest intrinsic increasing rate (rm=0.0260),finite increasing capacity (λ=1.0263),and population trend index (I=50.8).The shortest mean generation time (123.1 d) and population doubling time (26.7 d) were obtained at 20 ℃ and 28 ℃,respectively.The temperature from 24 ℃ to 28 ℃ was suitable for the development and reproduction of Brontispa longissima.
    Changes of key enzyme activities in rice cultivars with different photooxidation-tolerance during grain-filling stage in early and late seasons
    CHEN Dongmei, LIN Wenxiong, LIANG Yiyuan, GUO Yuchun, LIANG Kangjing
    2005, 16(12):  2373-2378. 
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    Four rice cultivars with different photooxidation-tolerance characteristics during grain-filling stage in early and late seasons were selected to uncover the physiological and biochemical mechanisms of the correlation between rice photooxidation-tolerance and grain quality.The results showed that the parameters mean grain-filling rate (Gmean),time arrived to maximum grain-filling rate (Tmax.G),and 100-grain weight at the maximum grain-filling rate (Wmax.G) were relatively stable for the varieties adaptable to high light intensity,while on the contrary for those sensitive to photooxidation.The ADP glucose pyrophosphorylase and starch synthase activities of the varieties adaptable to high light intensity after grain-filling peaks had a less difference between early and late seasons than those sensitive to photooxidation,and the relative enzyme activities in the varieties adaptable to high light intensity changed coequally in early and late seasons.
    Allelopathic effects of invasive weed Solidago canadensis on native plants
    MEI Lingxiao, CHEN Xin, TANG Jianjun
    2005, 16(12):  2379-2382. 
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    With growth chamber method,this paper studied the allelopathic potential of invasive weed Solidago canadensis on native plant species.Different concentration S.canadensis root and rhizome extracts were examined,and the test plants were Trifolium repens,Trifolium pretense,Medicago lupulina,Lolium perenne,Suaeda glauca,Plantago virginica,Kummerowia stipulacea,Festuca arundinacea,Ageratum conyzoides,Portulaca oleracea,and Amaranthus spinosus.The results showed that the allelopathic inhibitory effect of the extracts from both S.canadensis root and rhizome was enhanced with increasing concentration,and rhizome extracts had a higher effect than root extracts.At the lowest concentration(1:60),root extract had little effect on the seed germination and seedling growth of T.repens,but rhizome extract could inhibit the germination of all test plants though the inhibitory effect varied with different species.The inhibition was the greatest for grass,followed by forb and legume.1:60(m:m)rhizome extract had similar effects on seed germination and radicel growth,but for outgrowth,the extract could inhibit Kummerowia stipulacea,Amaranthus spinosus and Festuca arundinacea,had no significant impact on Lolium perenne,Plantago virginica,Ageratum conyzoides,Portulaca oleracea and Amaranthus spinosus,and stimulated Trifolium repens,Trifolium pretense and Medicago lupulina.
    Chemical components of root exudates from allelopathic rice accession PI312777 seedlings
    HE Haibin, CHEN Xiangxu, LIN Ruiyu, LIN Wenxiong, HE Huaqin, JIA Xiaoli, XIONG Jun, SHEN Lihua, LIANG Yiyuan
    2005, 16(12):  2383-2388. 
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    In this study,allelopathic rice accession PI312777 seedlings were grown on a paddy soil under near natural condition,and their root exudates were collected by using circulation method,with the solution collected from no seedlings-planted soil as the control.The ether extracts of the root exudates and soil solution were detected by GC-MS,and identified with the mass spectral database of NIST and WILEY Library.The results showed that there were 36 compounds in the rice root exudates,including 9 terpenoids (peak area 10.97%),8 phenols or quinones (5.87%),6 esters (10.68%),3 aldehydes or ketones (1.44%),4 heterocycles (68.04%),2 alcohols (1.23%),2 ethers (0.57%),and 2 others (1.20%).A distinctly similar structure was observed among the terpenoids and among the phenols or quinones.In the soil solution,39 compounds were detected,and 7 of them were the same of the root exudates.The difference of the compounds in rice root exudates and soil solution,and the possible allelopathic mechanisms of these compounds were discussed in this paper.
    Phytate-phosphorus uptake and utilization by transgenic tobacco carrying Bacillus subtilis phytase gene
    KONG Fanli, LIN Wenliang, YAN Xiaolong, LIAO Hong
    2005, 16(12):  2389-2393. 
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    Phytate is the major form of organic phosphorus in soil.Elevating the phytase activity in transgenic plants may be an effective approach to promote their phytate-phosphorus utilization,but little is known about the applied conditions.In this study,several transgenic tobacco lines carrying Bacillus subtilis phytase gene were compared with wild-type tobacco,in terms of their ability in acquiring phosphorus from phytate in sterilized agar,sand and soil.In sterilized agar,transgenic tobacco plants were more efficient in phytate-phosphorus uptake and utilization,and their biomass and total phosphorus content were 3.6～10.7 and 2.2～4.6 fold of the wild-type's,respectively.In sand and soil systems,however,there were no significant differences in biomass and total phosphorus content between the trsansgenic and wild-type tobacco plants.These results indicated that Bacillus phytase transgene could only improve the phytate-phosphorus uptake by transgenic plants under sterilized condition,and its effectiveness might be limited under natural conditions because of microbial decomposition and mineral fixation.Therefore,further research is needed to understand the limiting factors on the functions of the transgene.
    Chemical components and antimicrobial activity of essential oils in Cunninghamia lanceolata heartwood
    YE Zhou, LIN Wenxiong, CHEN Wei, YU Xintuo
    2005, 16(12):  2394-2398. 
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    In this study,the essential oils in Cunninghamia lanceolata heartwood were water-steam distilled,and their chemical components were analyzed by column chromatography and GC-MS,with their antimicrobial activity tested.The results showed that the essential oils content was 1.794～2.076 (w/w),and 47 peaks were separated.27 compounds,accounted for 99% of crude essential oils,were identified.The essential oils had an obvious antimicrobial activity against Escherichia coli,Staphylococcus aureus,Bacillus sabtills and Salmonella typhi,and cedrol,occupying 76.27% of essential oils,was the major component with antimicrobial activity.
    Screening of a phenanthrene-degrading bacterium and its degradation conditions
    ZHOU Le, SHENG Xiafang, ZHANG Shijin, LIU Jing
    2005, 16(12):  2399-2402. 
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    Several PAHs-degrading bacteria were isolated from the soil near a petrochemicals factory,and one strain F10a identified as B.sphaericus was chosen for use.The study on the phenanthrene-degradation potential of the strain and its affecting factors showed that at 28 ℃,the degradation rate of phenanthrene (50 mg·L-1) was 98.12% after 27 hours rotary culture,and 98.47% after 84 hours static culture.F10a had a good phenanthrene-degradation capability when the pH was 4,6 and 8,but its growth was inhibited when pH was 10.Cr2+ was toxic to the strain,Cu2+ could delay the degradation of phenanthrene,while Zn2+ and Pb2+ had no significant effects.The degradation rate of phenanthrene (200 mg·L-1) was 99.6% after 84 hours rotary culture.A significant positive relationship was found between bacterial growth and phenanthrene degradation.
    Adsorption behavior of cadmium in phaeozem and burozem
    GUO Guanlin, ZHOU Qixing
    2005, 16(12):  2403-2408. 
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    The study on the thermodynamics and kinetics of Cd2+ adsorption in phaeozem and burozem showed that within the test range,Cd2+ adsorption was increased with its increasing initial concentration,and phaeozem had a much higher Cd2+ adsorption capacity than burozem.When the Cd2+ concentration in adsorption equilibrium was 20 mg·kg-1,the amount of adsorbed Cd2+ was 1 485.2 mg·kg-1 in phaeozem,but 700.6 mg·kg-1 in burozem.The adsorption isotherm of Cd2+ in the two soils could significantly conform to Langmuir,Freundlich and Henry equations,while Temkin equation was not applicable to describe the isothermal adsorption process of Cd2+ in phaeozem and burozem.The maximum adsorption of Cd2+ in phaeozem and burozem was 5 939.3 and 2 790 mg·kg-1,respectively,according to Langmuir formulation.The Cd2+ adsorption in test soils was a rapid reaction,with 90% of Cd2+ adsorption in the first 2 min and reached equilibrium in 15～30 min.First-order dynamic equation was the optimal model to describe the kinetics of Cd2+ adsorption,while the other models in point were Elovich and Two-constant equations.The adsorption rate of Cd2+ in test soils was increased with its increasing initial concentration,but decreased with its increasing adsorbed amount.Under low concentrations of Cd2+,the decrease of its adsorption rate with time was more quickly in phaeozem than in burozem.
    Dynamic variation of landfill gas production under different landfill treatment
    LIU Yuqiang, WANG Qi, HUANG Qifei, YANG Yufei, DONG Lu
    2005, 16(12):  2409-2412. 
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    Based on the landfill principles,large scale installations of anaerobic and semi-aerobic landfills were established,with the concentrations of CH4,O2 and CO2 detected regularly.The results showed that the average CH4 concentration in semi-aerobic and anaerobic landfill installations was 7%～13% and 35%～50%,respectively,indicating the better effect of semi-aerobic landfill in reducing CH4 production.The CH4 and O2 concentrations in the two landfill installations all presented obvious spatial layer effect,i.e.,under-layer > middle layer> upper layer for CH4,while upper layer > middle level > under-layer for O2.
    Effects of copper pollution on Trifolium repens growth and soil enzyme activities
    CHU Ling, WANG Youbao, DING Jiahong, LI Zheng, LIU Dengyi
    2005, 16(12):  2413-2417. 
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    The study with pot experiment showed that with increasing Cu concentration,soil urease,invertase,catalase and polyphenol oxidase activities decreased gradually.There was a significant correlation between Cu concentration and soil enzyme activities,with the correlated degree followed the order of invertase>polyphenol oxidase>urease>catalase.Under a fixed Cu concentration,soil enzyme activities changed with time,and the changes were different between high and low Cu concentrations,being increased slightly under low Cu concentration (<500 mg·kg-1),but decreased gradually as Cu concentration increased (500～3 000 mg·kg-1).Statistical analysis indicated that within the range of test Cu concentrations,the activities of test soil enzymes were significantly different among different Cu concentration (P<0.01),which was accorded with the seedlings growth status.Soil pH was decreased,while electric conductivity was increased with increasing Cu concentration (500～3 000 mg·kg-1),but they were increased with time under a fixed Cu concentration,with significant difference among different Cu concentration (P<0.01).Soil pH and electric conductivity were highly related to soil enzyme activities,with the order of polyphenol oxidase>invertase>catalase>urease.The test soil enzyme activities could be used as the indices of soil environment quality.
    Chemical forms of heavy metals in the soils and plants of copper tailings yard
    WANG Youbao, ZHANG Li, SHEN Zhangjun, LI Jing, LIU Dengyi
    2005, 16(12):  2418-2422. 
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    The study on the chemical forms of heavy metals in the soils and plants at the copper tailings yard in Tongling City indicated that the soils were extremely poor,with organic mater content being 2.6～5.8 g·kg-1,only 1/15 of the control,while their Cu,Cd,Pb and Zn contents were higher than the control,with Cu 809.30～1 395.54 mg·kg-1 and Cd 3.25～6.35 mg·kg-1,as 30～60 times as those of the control.The heavy metals contents in Zoysia japonica and Trifolium pratense had a significantly positive correlation with the contents of their exchangeable and organic forms in soils,a significantly or very significantly negative correlation with the forms of Fe-Mn oxides and carbonate,and no correlation with residual form.The main forms of Cu,Zn and Pb in Z.japonica and T.pratense were HAC-and HCl-extractable,and residual.The NaCl-extractable Zn content in the roots,stems and leaves of Z.japonica and T.pratense occupied a higher proportion,while NaCl-extractable Cd was the main form of Cd in both of the plants,not only in their roots but also in their leaves.
    Filtering capacity of Anodonta woodiana and its feeding selectivity on phytoplankton
    WU Qinglong, CHEN Yuwei, LIU Zhengwen
    2005, 16(12):  2423-2427. 
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    Lake eutrophication associated with algal bloom has become a major environmental challenge in China.Filter feeding organisms,e.g.,silver carp,bighead carp,and zebra mussel,have been widely used to manipulate water environment through their top-down effects.The bivalve Anodonta woodiana is widely distributed across China,and has been used for bio-manipulation of some water bodies.In situ experiments were performed in a bay of Lake Dianchi and its surrounding ponds to study the filtering capacity and the filter feeding rate of Anodonta woodiana in these aguatic habitats,and to determine the controlling factors.The results showed that there was a relationship between filtration rate and total suspended substances measured in laboratory during August and September 2001 when the water temperature was 20±2 ℃,which was expressed as y=4 380.41 e-0.0184x (R2=0.621,P<0.05) based on at least squares analyses.The filtration rate was strongly related to the body weight by measuring in laboratory over 24 hours during August 2001 when the water temperature was 20±2 ℃.At least squares analyses gave the equation y=2 904.16+12 076.24e-0.0034x (R2=0.9825,P=<0.05).A slight variation of filtration rate was found over 24 hours,which could be explained by the bivalves' adaptation to the experimental circumstances rather than the daily change of its filtration feeding.In general,the filtration capacity of natural Anodonta woodiana population in the water bodies was very limited,as a result of its small population size.No significant selective feeding on algae was found by contrasting the relative abundance of algae in the habitats and the guts of Anodonta woodiana.The feeding selectivity on algae was neither correlated with the size of algae,nor with the initial abundance of algae in water column.
    Fisheries biology of Nemipterus bathybius and its optimum catchable size in northern South China Sea
    WANG Xuehui, QIU Yongsong, DU Feiyan
    2005, 16(12):  2428-2434. 
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    Based on the investigation data in 1997～1999 and 1964～1965,this paper studied the population structure,stock density distribution and its seasonal variation,growth and mortality,as well as the feeding behaviour of Nemipterus bathybius (Snyber) in northern South China Sea.The results indicated that the body length of the samples was 4.2～21.5 cm,and body weight was 2.9～ 241 g,with the length of 9.6～14.0 cm and weight of 27～59 g as predominant.The stock density was the highest (9.92 kg·km-2) in spring and the lowest (5.53 kg·km-2) in summer,and had an obvious zonal distribution.Catch rate increased with the water depth in 60～150 m water zone.Macrura,fishes and cephalopods were the main foods of Nemipterus bathybius.The growth parameters of von Bertalanffy formula estimated with ELEFANⅠin FiSATⅡpackage were L∞=22.39 cm,k=0.44 a-1, and t0=-0.63 a.The natural mortality calculated with Pauly's empirical equation was M=0.94,and the total mortality estimated by length-converted catch curve was Z=2.65.Assessment with Beverton-Holt model indicated that the optimum catchable age and body length were 1.1 a and 12 cm,respectively.The stock was over-exploited,mainly due to the capture of under-size juveniles.It was suggested that the legal body length of Nemipterus bathybiu at its first capture in northern South China Sea should be 12 cm.
    Oxygen consumption and ammonia-N excretion rates of Coelomactra antiquata
    MENG Xueping, DONG Zhiguo, CHENG Hanliang, LI Xiaoying, LI Jiale
    2005, 16(12):  2435-2438. 
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    With laboratory experiments,this paper studied the oxygen consumption rate (OCR) and ammonia-N excretion rate (NR) of Coelomactra antiquata at different levels of dissolved oxygen (DO) and water temperature.The results indicated that at 25 ℃ and 3.11±0.15 mg DO·L-1,C.antiquate had a comparatively stable OCR and NR,which maintained at 0.74±0.05 mg·g-1·h-1 and 2.56±0.05 μmol·g-1·h-1,respectively.When DO was lower than 3.11±0.15 mg·L-1,the metabolism of C.antiquate became abnormal,and its OCR was decreased with decreasing DO until suffocate,with a suffocate point 1.22±0.06 mg·L-1 at 25 ℃.The NR also declined with decreasing DO,which ceased later than oxygen consumption.There was a quadratic linear relationship between OCR and water temperature (OCR=-0.0027T2+0.1367T-0.9557,R2=0.9724).When water temperature was 25.3 ℃,the OCR arrived to its maximum value 0.77 mg·g-1·h-1.The O/N ratio at optimal temperature (15～20 ℃) was higher than that at low (10 ℃) and high temperature (25 ℃ and 30 ℃).To maintain its standard metabolism,C.antiquata consumed more fat under fit condition,while more protein under stress.
    Ecological misunderstanding,integrative approach,and potential industries in circular economy transition
    WANG Rusong
    2005, 16(12):  2439-2446. 
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    Based on the Social-Economic-Natural Complex Ecosystem theory,this paper questioned 8 kinds of misunderstandings in current planning,incubation,development,and management of circular economy,which had led to either ultra-right or ultra-left actions in ecological and economic development.Rather than concentrated only on the 3-r micro-principles of “reduce-reuse-recycle”,thise paper suggested 3-R macro-principles of “Rethinking-Reform-Refunction” for circular economy development.Nine kinds of eco-integrative strategies in industrial transition were put forward,i.e.,food web-based horizontal/parallel coupling,life cycle-oriented vertical/serial coupling,functional service rather than products-oriented production,flexible and adaptive structure,ecosystem-based regional coupling,social integrity,comprehensive capacity building,employment enhancement,and respecting human dignity.Ten promising potential eco-industries in China's near-future circular economy development were proposed,such as the transition of traditional chemical fertilizer and pesticide industry to a new kind of industrial complex for agro-ecosystem management.
    Ecological carrying capacity and Chongming Island's ecological construction
    WANG Kaiyun, ZOU Chunjing, KONG Zhenghong, WANG Tianhou, CHEN Xiaoyong
    2005, 16(12):  2447-2453. 
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    This paper overviewed the goals of Chongming Island's ecological construction and its background,analyzed the current eco-economic status and constraints of the Island,and put forward some scientific issues on its ecological construction.It was suggested that for the resources-saving and sustainable development of the Island,the researches on its ecological construction should be based on its ecological carrying capacity,fully take the regional characteristics into consideration,and refer the successful development modes at home and abroad.The carrying capacity study should ground on systemic and dynamic views,give a thorough evaluation of the Island's present carrying capacity,simulate its possible changes,and forecast its demands and risks.Operable countermeasures to promote the Island's carrying capacity should be worked out,new industry structure,population scale,and optimized distribution projects conforming to regional carrying capacity should be formulated,and effective ecological security alarming and control system should be built,with the aim of providing suggestions and strategic evidences for the decision-making of economic development and sustainable environmental resources use of the region.
    Research advances in the effects of elevated atmospheric carbon dioxide and ozone on biogenic VOCs emission
    LI Dewen, SHI Yi, HE Xingyuan
    2005, 16(12):  2454-2458. 
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    The increasing concentrations of CO2 and O3 in the troposphere have become a focus of both the domestic and foreign researchers,and the emissions of biogenic volatile organic compounds (BVOCs) can be affected by the change of concentrations.The BVOCs with high chemical reactivity may affect the chemical compositions of lower atmosphere,and promote photochemistry air pollution.At one time,the greenhouse effect and global environment changes will be influenced by the BVOCs.The effects of single and joint action of CO2 and O3 on the emitting characteristics of biogenic volatile organic compounds (BVOCs) were summarized and further researches on this field,especially that of trees in urban areas under the condition of multiple environmental stresses were perspected in this paper.
    Sprouting ecology of woody plants:A research review
    YAN Enrong, WANG Xihua, SHI Jiayue, WANG Xibo, WANG Liangyan
    2005, 16(12):  2459-2464. 
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    Sprouting is an efficient regeneration means of woody plants to regain their biomass loss after disturbances.This paper reviewed the biological characteristics of sprouting,and its consequences on woody plants individual life history,dynamics of population and community,and biogeography.Many achievements have been obtained on the researches of sprouting strategy and its relationships with disturbances,but less is known about the ecological significances of sprouting,and especially,its effects on the structure and dynamics of woody plants population and community.As in China,both the basic and the applied research of sprouting ecology and vegetation restoration should be strengthened.
    Gene flow and its ecological risks of transgenic oilseed rape (Brassica napus)
    TANG Guixiang, SONG Wenjian, ZHOU Weijun
    2005, 16(12):  2465-2468. 
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    Transgenic oilseed rape Brassica napus,one of the first genetically modified crops,has now been released to commercial use in Canada and Australia.As a cross-pollinating crop,its natural crossing rate is 30%,and it is liable to cross with other Brassica species.The ecological risk of transgenic oilseed rape has been concerned by the scientists all over the world.There are two ways for the pollens flow of transgenic oilseed rape,one takes place between transgenic oilseed rape and other related wild species,and the other occurs between transgenic and non-transgenic oilseed rape.The gene may flow to other related wild species,but it is unlikely to get hybrids in field.Because the gene can really flow to the conventional oilseed rape,it is necessary to have a sufficient isolation distance in cultivating transgenic oilseed rape.
    Potential effects of Bt transgenic rice on soil micro-ecosystem
    WANG Zhonghua
    2005, 16(12):  2469-2472. 
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    With the increasing commercial use of genetically modified crops (GMCs),it is quite important to assess their potential ecological risk.The likelihood of genes dispersal from GMCs to related wild species,the tolerance of insects to insect-resistant GMCs,and the potential impact of GMCs on biodiversity have been extensively investigated.This article reviewed the potential ecological risk assessment of transgenic Bt rice-expressed products,including the persistence characteristics of Bt insecticidal crystal proteins in soil,and their effects on soil culturable microbial flora and soil enzyme activities,which could provide useful information for related researches.
    Life table of natural Bemisia tabaci population on cucumber plants in different seasons
    SHEN Binbin, CHEN Chao, REN Shunxiang
    2005, 16(12):  2473-2475. 
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    The study showed that in the early growth stage of cucumber in spring,the predation on Bemisia tabaci egg was the key factor for controlling B.tabaci population,and the exclusion index of population control was 1.7333.In the late growth stage of cucumber in spring,summer and autumn,the predation on B.tabaci elder nymph was the critical factor for controlling B.tabaci population,and the exclusion index of population control was 4.5372,4.0429 and 7.9021,respectively.From spring to autumn,the index of population development trend was decreased from 21.0610 to 5.8523,because of the increasing controlling effect of the predators,and the exclusion index of population control was from 4.0560 to 17.8662.
    Effects of pine wood nematode on propagation of its carrying bacteria
    LIN Feng, ZHAO Boguang
    2005, 16(12):  2476-2478. 
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    In this paper,the aseptic eggs of Bursaphelenchus xylophilus were obtained after treated with 30% H2O2,and cultured with Pinus thunbergii callus.Ten B.xylophilus-carrying bacterial strains directly isolated from diseased P.thugbergii and P.massoniana in six epidemic provinces i.e.,GcM6-2A Pseudomonas putida,GcM6-1A P.putida,ZpB1-2A P.putida,HeM2A Pseudomonas sp.,HeM1A Pseudomonas sp.,HeM142B Pseudomonas sp.,GcM1-3A P.cepacia and HM3 Pantoeu sp.,ZpB4-2B Staphylococcus sciuri and ZpB2-3A Enterobacter amnigenus,were collected,and the effects of axenic B.xylophilus (ABx) on their propagation were studied.The results showed that pine wood nematode (PWN) promoted the propagation of 7 bacterial strains in Pseudomonas and 1 bacterial strain in Pantoeu sp.,including Pseudomonas putida,P.putida,P.putida,Pseudomonas sp.,Pseudomonas sp.,Pseudomonas sp.,P.cepacia and Pantoeu sp.,but inhibited Staphylococcus sciuri and Enterobacter amnigenus,which could explain the phenomenon that Pseudomonas was the prevailing genus of the bacteria carried by PWN,and might provide essential nutrition to the bacteria.The close relationship between PWN and bacterial strains in Pseudomonas might account for the pine wood nematode disease.