Loading...
Welcome to Chinese Journal of Applied Ecology! Today is Jun. 2, 2025 Share:

Table of Content

    15 February 2005, Volume 16 Issue 2
    Previous Issue    Next Issue
    Articles
    Sabina przewalskii community structure in the upper reaches of Minjiang River
    CHEN Wennian,WU Ning,LUO Peng
    2005, 16(02):  197-202 . 
    Asbtract ( 1362 )   PDF (581KB) ( 97 )  
    In this paper,the physiognomy and the structure of Sabina przewalskii community were studied by sample plot method.The results showed that in the life spectrum of the community,hemicryptophyte was dominated,but therophytes also occurred frequently,which presented some features of temperate vegetation.The vertical structure of the community was quite simple,consisting of tree layer,shrub layer and herb layer,and there were no interstratum plants and ground layer.Sabina przewalskii was the only species in the tree layer.In fruticose stratum,the important value of Spiraea alpina was 153.3,ranking the first; while in herb layer,the important value of Carex caespifosa ranked the first,amounting to 36.8.Among the three plot groups on different slopes,spiny-shrubs such as Berberis wilsonae and Caragana erinacea grown on small slope were more than those on bigger slope,so did unpalatable grasses such as Pedicularis axillaries and Artemisia tauguticat,which mainly owed to retrogressive succession caused by frequently grazing.The age and height structures of Sabina przewalskii population indicated a declining trend,and the community would develop retrogressively if disturbances (e.g.,grazing) could not be reduced.The disturbance caused by livestock was more obvious in the plot group on small slope than on bigger slope,and livestock mainly destroyed seedlings and small trees,which made tree population be impossible to regenerate.The coverage of upper layers had a notable impact on the lower layers,and there wasn't any correlation between coverage and diversity index (ShannonWiener Index) ineach layer.
    Relationships between net primary production and nitrogen cycling in Chinese forest ecosystems
    ZHOU Caiping,OUYANG Hua,SONG Minghua
    2005, 16(02):  203-206 . 
    Asbtract ( 1389 )   PDF (371KB) ( 118 )  
    In order to better understand the relationships between net primary production (NPP) of forest ecosystem and nitrogen cycling,we studied and analyzed the relationships between NPP,litter nitrogen,plant nitrogen retention,and soil net nitrogen mineralization rate in Chinese forest ecosystems.The results indicated that NPP was linearly and positively related to litter nitrogen,plant nitrogen retention and soil net nitrogen mineralization rate,with the most correlation with soil net nitrogen mineralization rate (R2=0.74，n=37),and the next with plant nitrogen retention (R2=0.60，n=37).
    Spatial distribution pattern of Larix chinensis population in Taibai Mt.
    ZHANG Wenhui1，2,WANG Yanping1,KANG Yongxiang1,LIU Xiangjun2
    2005, 16(02):  207-212 . 
    Asbtract ( 1415 )   PDF (516KB) ( 100 )  
    Larix chinensis is an endangered species only distributed in Qinling Mountains of China.It has a concentrated distribution in Taibai Mt.,and plays an important role in environmental protection in the high altitude.After an investigation on fifteen 400 m2 plots,a comparative study on the spatial distribution pattern of L.chinensis population and its dynamics was made by the tests of discrete distribution pattern and aggregation intensity.The results showed that at different sampling areas,L.chinensis populations all performed the pattern of clustering distribution.As the sampling area increased,the congregating intensity of L.chinensis population appeared the pattern of high→low→high,but the highest congregation occurred in the areas of 100 m2 and 25 m2.The clustering intensity went down from low to high altitude,and the area with the highest clustering intensity occurred on that of 25 m2 in low altitude,150 m2 in middle altitude,and 100 m2 in higher altitude.The clustering intensity in shade slope was higher than that in sunny slope,and the area with the highest clustering intensity was 100 m2 on shade slope,and 150 m2 on sunny slope.With the population age increased, the distribution pattern had a trend from clustering to random,the clustering intensity decreased somewhat,and the area with the highest clustering intensity was 150 m2 in young or old stages,and 100 m2 in middle stage.The distribution pattern of L.chinensis population was related to its ecological characteristics,community composition,and environmental factors.In situ conservation should be strengthened in the future.In lower altitude or on shade slope,the measurements of thinning no-aim in tree and shrub species should be taken; while in higher altitude area or sunny slope,thinning shrub species in patch form would be better for L.chinensis populations block renovating.The fostering area for L.chinensis populations should be suit to the area with the highest clustering intensity of populations.
    Alleviation effect of exogenous Ca,P and N on the growth of Chinese fir seedlings under Al stress
    ZHANG Fan1,2,LUO Chengde1,ZAHNG Jian1
    2005, 16(02):  213-217 . 
    Asbtract ( 1652 )   PDF (452KB) ( 77 )  
    In this study,three month-old seedlings of Chinese fir (Cunninghamia laceolata ) were grown in solution culture with 1mmol·L-1 Al at pH 4.0 for 80 days to evaluate the effects of varying concentrations of Ca,P,and NH4+-N or NO3--N in solution on their growth.The morphological indexes (fresh weight, dry weight,shoot length,root length and relative elongation ratio) and physiological indexes (MDA content and POD activity) were submitted to statistical analysis and compared.The results indicated that the seedlings weight or shoot length had a significantly positive correlation with the molar ratio of solution Ca/Al.The MDA content and POD activity decreased with the increasing molar ratio of Ca/Al,and Ca/Al≥2.8 was the critical ratio.Similar to Ca/Al,high P/Al molar ratio also had an obvious effect on the growth of Chinese fir seedlings under Al stress,and P/Al≥4.5 was the critical ratio.The growth of Chinese fir seedlings was improved by increased NH4+-N supply, but the effect was less obvious than Ca and P.Solution NH4+-N/Al≥4.7 was the critical molar ratio.Solution NO3--N could mitigate some adverse effects of Al on Chinese fir seedlings growth,but no regular effects were found with the change of solution NO3--N/Al molar ratio.
    Effects of exogenous nitric oxide on photosynthetic characteristics of poplar leaves under water stress
    WANG Miao1,LI Qiurong2,FU Shilei1,DONG Baili1
    2005, 16(02):  218-222 . 
    Asbtract ( 1149 )   PDF (515KB) ( 168 )  
    Nitric oxide (NO) is an active molecule involved in many biological pathways, but its effects on photosynthesis of tree leaves have not been established yet.This paper studied the effects of exogenous NO,sodium nitroprusside (SNP),on the water status,photosynthesis and scavenging enzyme activities in poplar leaves.Different levels of SNP treatments had remarkable effects on the water content of leaves,which increased with increasing SNP levels.When the SNP level exceeded 500 μmol·L-1,differences in leaf water content were no longer significant between different SNP treatments.Exogenous NO increased the photosynthesis rate,photochemical efficiency of PSII Fv/Fm,and Fm/Fo and Fv/Fo ratios,and the effects decreased with increasing duration of water stress.The SOD and POD activities in poplar leaves were higher in 1 hour water stress treatment than in 3 h treatment. Treating with SNP could markedly increase POD activity,but SOD activity did not change much.POD and SOD activities increased initially,and then decreased with increasing SNP levels.The results indicated that exogenous NO delayed the accumulation of active oxygen by increasing POD and SOD activities,and thereby,alleviated the effects of water stress on photosynthetic organization of poplar leaves.
    Relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing
    SONG Huixing1,2,SU Zhixian2,PENG Yuanying1
    2005, 16(02):  223-226 . 
    Asbtract ( 1722 )   PDF (346KB) ( 105 )  
    Based on the analyses of soil physical and chemical properties,this paper studied the relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing.The results showed that the values of integrated soil fertility index of Pinus massoniana, Cunninghamia lanceolata,deciduous oak,Camellia sinensis and evergreen broad-leaved forest soils were 0.1256,0.2085,0.3514,0.2479 and 0.9329,respectively, implying that soil development had a close relation to plant community succession.
    Spatial distribution pattern and fractal analysis ofLarix chinensis populations in Qinling Mountain
    GUO Hua,WANG Xiaoan,XIAO Yaping
    2005, 16(02):  227-232 . 
    Asbtract ( 1817 )   PDF (544KB) ( 109 )  
    In this paper,the fractal characters of Larix chinensis populations in Qinling Mountain were studied by contiguous grid quadrate sampling method and by boxing-counting dimension and information dimension.The results showed that the high boxing-counting dimension (1.8087) and information dimension (1.7931) reflected a higher spatial occupational degree of L.chinensis populations.Judged by the dispersal index and Morisita's pattern index,L.chinensis populations clumped at three different age stages (0～25,25～50 and over 50 years).From Greig-Smiths'mean variance analysis,the figure of pattern scale showed that L.chinensis populations clumped in 128 m2 and 512 m2,and the different age groups clumped in different scales.The pattern intensities decreased with increasing age,and tended to reduce with increasing area when detected by Kershaw's PI index.The spatial pattern characters of L.chinensis populations may be their responses to environmental factors.
    Experience model for self-thinning process of even-aged pure stands
    WU Chengzhen,HONG Wei,YAN Shujun
    2005, 16(02):  233-237 . 
    Asbtract ( 1617 )   PDF (482KB) ( 51 )  
    Based on the famous-3/2 power rule and generalized Schumacher growth equation,a mathematical model for the density change of even-aged pure stands with time during self-thinning process was presented,and the genetic algorithms was used to fit this nonlinear model.With the collected data from Populus tremula var. davidiana,Pinus yunnanensis and Cunninghamia lanceolata even-aged pure stands,the new model was verified and compared with other models.The results showed that the new model could fit observed data very well,and was very useful in practice.The surplus square,mean relative error,mean absolute error and surplus standard deviation of the new model were all smaller than those of other models,indicating its good qualification in describing stand density change during self-thinning process and its useness in studying forest self-thinning rules.The study also showed that genetic algorithms could give a better global convergence,and be used to estimate the parameters of nonlinear models in ecology,biology and forestry.
    Effects of urease and nitrification inhibitors on alleviating the oxidation and leaching of soil urea's hydrolyzed product ammonium
    CHEN Zhenhua1,2,CHEN Lijun1,WU Zhijie1
    2005, 16(02):  238-242 . 
    Asbtract ( 1460 )   PDF (419KB) ( 98 )  
    With simulation test of insitu soil column,this paper studied the effects of urease inhibitor hydroquinone (HQ),nitrification inhibitors coated calcium carbide (ECC) and dicyandiamide (DCD),and their different combinations on the persistence,oxidation,and leaching of soil urea's hydrolyzed product ammonium.The results showed that compared with other treatments,the combination of HQ and DCD could effectively inhibit the oxidation of the ammonium,and make it as exchangeable form reserve in soil in a larger amount and a longer period.The inhibition of this oxidation not only decreased the accumulation of oxidized product NO3- in soil,but also decreased the potential of NO3- leaching,making the NO3- only leach to 5～10 cm in depth,and the leached amount significantly decreased.
    Simulation of nitrogen mineralization and immobilization of crop straw during it s initial decomposition in soil
    HU Xiyuan1,Kuehne R.F2
    2005, 16(02):  243-248 . 
    Asbtract ( 1080 )   PDF (508KB) ( 131 )  
    The nitrogen (N) transformation of crop straw during its initial decomposition in soil was simulated by Modelmaker software.A good fit was obtained between the simulated and measured data of 6 variables,including the amount of soil ammonium N,nitrate N,microbial biomass N and their15N atom %.The simulation results indicated that the main N form immobilized by soil microbes was ammonium,while the immobilization of nitrate was very small.N mineralization occurred dominantly in crop straw but very small in humus.The N mineralization of crop straw could be better described by first order than zero order kinetics.N re-mineralization occurred later than N immobilization. The assumptions on the absence of N re-mineralization or the simultaneous presence of re-mineralization and immobilization during straw decomposition led to a serious error in calculating the gross N mineralization and immobilization; while no consideration of nitrification and volatilization losses led to a low estimation of gross N mineralization.The occurrence of net N mineralization or net N immobilization depended not only on the C/N of straw,but also on the duration of straw decomposition.
    Shortterm changes of pH value and Al activity in acid soils after urea fertilization
    ZENG Qingru,LIAO Bohan,JIANG Zhaohui,ZHOU Xihong,TANG Can,ZHONG Ning
    2005, 16(02):  249-252 . 
    Asbtract ( 1312 )   PDF (371KB) ( 126 )  
    Acidic soils are widely distributed in South China,and their acidity is the major environmental stress factor limiting the growth of most crops.It is well known that soil Al solubilized at low pH is a main toxic factor for plant growth.Our study with three acidic soils showed that soil pH increased quickly,while soil exchangeable Al decreased sharply with the increasing concentrations of applied urea.The time-course experiment revealed that the increase of soil pH was short-lived,with a subsequently slow drop after reached its maximum. Urea fertilization caused a drastic change of soil pH during 2～4 weeks of the experimental period.There was a negative relationship between soil pH and soil exchangeable Al.Biological toxicity test demonstrated that applying urea to acidic soils could obviously decrease the aluminum toxicity of maize in a short-term period.
    Effects of fertilization on soil active organic carbon under Phyllostachys praecox stand
    JIANG Peikun,XU Qiufang
    2005, 16(02):  253-256 . 
    Asbtract ( 1162 )   PDF (411KB) ( 53 )  
    In this paper,fertilization experiment was conducted on Phyllostachys praecox stand to study the effects of different heavy application of chemical fertilizers and manure on soil active organic carbon pool.The results showed that compared with only applying chemical fertilizers,the combined application of chemical fertilizers and manure significantly increased the contents of soil total organic carbon (TOC),watersoluble organic carbon (WSOC),microbial biomass carbon (MBC) and mineralized carbon (MC) as well as the ratios of WSOC/TOC,MGC/TOC and MC/TOC (P<0.01 or P<0.05).With the decreasing application rate of manure,soil TOC,WSOC,MBC and MBC/TOC decreased significantly (P<0.05),and when the application rate of manure was decreased by 50%,soil TOC,WSOC,MBC and MBC/TOC decreased by 10.75%,12.02%,30.94% and 22.61%,respectively.In the treatments of only applying chemical fertilizers,soil WSOC,MBC and MBC/TOC decreased obviously when the application rate of fertilizer nitrogen exceeded 1009.5 kg·hm-2·yr-1.There were significant correlations between soil TOC,WSOC,MBC and MC (P<0.01 or P<0.05),among which,MBC and MBC/TOC could be used as the quality indications of soil carbon pool under Phyllostachys praecox stand.
    Several infection factors of Pseudoperonospora cubensis
    SHI Yanxia1,LI Baoju1,LIU Xuemin2
    2005, 16(02):  257-261 . 
    Asbtract ( 1047 )   PDF (451KB) ( 149 )  
    The study on the effects of temperature and humidity on the pathogenicity of Pseudoperonospora cubensis showed that the optimum temperature for the occurrence of cucumber downy mildew was 25～35 ℃.An alternation of 15/35 ℃ was the most propitious to the infection of Pseudoperonospora cubensis, while the high temperature above 35 ℃ could kill the pathogens.2 hours humid was enough for infection.Pseudoperonospora cubensis stored at -20 ℃ for 10 months and dried for 7 days could still infect cucumber.The infected cucumber leaves could continuously produce sporangium,with its quantity gradually decreased with time.The quantity of sporangium produced in vivo was more than that in vitro.
    Productivity of crop-fruit ecological agriculture in middle-south Loess Plateau
    WU Faqi1,ZHOU Zhengli2，LIU Haibin1
    2005, 16(02):  262-266 . 
    Asbtract ( 1317 )   PDF (415KB) ( 53 )  
    With the Xipo,Feimahe and Nangou villages as test objects,the productive characteristics of crop-fruit ecological agriculture in the middle-south Loess Plateau were investigated.The results showed that the biomass productivity of a plant was different with its organs,the highest for grain or fruit,and followed by stem,leaf and root.In the crop-fruit ecological agriculture,the higher ratio the crop subsystem,the higher productivity its biomass,the lower economic productivity and lower economic value was; while the fruit subsystem was on the contrary.The productivity of livestock farming subsystem was in a lower level,which restricted the increase of the total ecosystem's productivity.Based on these results,a countermeasure of increasing the ecosystem productivity was put forward.
    Effects of exogenous Ca on some physiological characteristics of tomato (Lycopersicon esculentum) seedlings with different Ca sensitivity
    DONG Caixia1,3,ZHOU Jianmin1,ZHAO Shijie2,WANG Huoyan1
    2005, 16(02):  267-272 . 
    Asbtract ( 1588 )   PDF (545KB) ( 102 )  
    Two tomato (Lycopersicon esculentum) cultivars with different Ca sensitivity were used to study the effects of exogenous Ca on their root activity,CaM content,chlorophyll a/b ratio,and reactive oxygenscavenging enzymes' activities under different Ca concentrations in nutrient solution.The results showed that the root activity and CaM content of two cultivars increased with increasing Ca concentrations in the nutrient solution.The root activity and chlorophyll a/b ratio of Cainsensitive cultivar Jiangshuyihao were higher than those of Ca－sensitive L402 under extreme low Ca stress (1 and 4 mg·L-1),while lower than those of L402 when sufficient Ca was applied (100 mg·L-1),indicating that Jiangshuyihao had a greater capability to bear the nutrient and light stress under low Ca stress.The SOD activity of Ca－insensitive cultivar Jiangshuyihao under 1 and 4 mg·L-1 Ca was higher than that of L402,while the activities of POD and CAT of L402 were consistently higher than that of Jiangshuyihao under test Ca concentrations in the nutrient solution.Comparing with 100 mg·L-1 Ca in solution,4 mg·L-1 Ca led to an increase of CAT and POD activities and a decrease of SOD activity in the two cultivars,but the variation of SOD activity was greater in L402 than in Jiangshuyihao,indicating that the system of defence enzymes in Ca-insensitive cultivar played a key role when suffered from Ca stress.
    Physiological characteristics of nitrogen nutrition and stress-resistance of film-mulched rice in various ecological regions of Zhejiang Province
    LU Xinghua1,WU Lianghuan1,ZHENG Zhaisheng2,KONG Xiangjun2,ZHANG Fusuo3
    2005, 16(02):  273-278 . 
    Asbtract ( 1282 )   PDF (548KB) ( 88 )  
    The study showed that different ecological environment and cultivation system in various ecological regions of Zhejiang Province resulted in some different physiological characteristics of nitrogen nutrition and stressresistance,especially in theaspect of NO3--N and NH4+-N concentrations, between film-mulched and conventional flooded rice.Owing to the heat stress in Hangjiahu plain,the NO3--N concentration of film-mulched rice decreased to some extent,but NH4+-N concentration increased markedly at tillering,jointing and booting stages,compared to conventional flooded rice.In Jinqu basin,the NO3--N concentration of film-mulched rice at booting stage was higher,while the NH4+-N concentration in its roots was notably lower than those of conventional flooded rice,with NH4+-N concentration in its basal stems and leaves somewhat increased.Generally,the glutamine synthetase(GS) and nitrate reductase (NR) activities in film-mulched rice leaves were enhanced at booting stage,while malondiadehyde (MDA),soluble sugar (SS) and proline(Pro) concentrations had little changes.In conclusion,film-mulched cultivation was beneficial to the rice growth and its high yielding.
    Gradient distribution of soil nitrogen and its response to climate change along the Northeast China Transect
    WANG Shuping1，2,ZHOU Guangsheng1,GAO Suhua3,GUO Jianping3
    2005, 16(02):  279-283 . 
    Asbtract ( 1551 )   PDF (412KB) ( 122 )  
    Terrestrial transect is an important and effective method for global change study.The Northeast China Transect (NECT),which is assigned along the latitude 43°30＇N in the midlatitude of temperate zone and located at 112°～130°30＇E and 42～46° N,is one of the fifteen global transects recognized by IGBP.It is about 1 600 km in length and 300 km in width.The NECT is mainly driven by precipitation,and becomes an effective platform of global change study in China.Based on the field survey in 2001 and a simulated experiment,this paper analyzed the gradient distribution of soil nitrogen and its response to climate change along the Transect.The results indicated that soil total and available nitrogen in NECT were significantly related to longitude,with a correlation coefficient being 0.695(P<0.001) and 0.636 (P<0.001),respectively,and had a similar horizontal distribution with soil organic carbon.Soil available nitrogen content in the NECT was decreased from east to west,and could be one of factors restricting plant growth.The decreasing rate of soil total and available nitrogen from topsoil to subsoil was different with ecosystems along the NECT.Soil total and available nitrogen contents had a close linear relationship with soil pH,total and labile carbon,total and available phosphorus,total sulphur,total and available zinc,available potassium,available manganese,bulk density,water holding capacity,and total porosity.They also had a significant linear relationship with precipitation,the correlation coefficient being 0.682(P<0.001) and 0688(P<0.001),respectively.The shortterm simulated experiment showed that doubled ambient CO2 concentration and soil moisture regime had no significant effects on soil total and available nitrogen,the variation coefficients being 5.55% and 3.84%,respectively.
    Wave-type time series variation of the correlation between NDVI and climatic factors
    BI Xiaoli,WANG Hui,GE Jianping
    2005, 16(02):  284-288 . 
    Asbtract ( 1272 )   PDF (411KB) ( 100 )  
    Based on the 1992～1996 data of 1km monthly NDVI and those of the monthly precipitation and mean temperature collected by 400 standard meteorological stations in China,this paper analyzed the temporal and spatial dynamic changes of the correlation between NDVI and climatic factors in different climate districts of this country.The results showed that there was a significant correlation between monthly precipitations and NDVI.The wavetype time series model could simulate well the temporal dynamic changes of the correlation between NDVI and climatic factors,and the simulated results of the correlation between NDVI and precipitation was better than that between NDVI and temperature.The correlation coefficients (R2) were 0.91 and 0.86,respectively for the whole country.
    Fragmentation process of wetland landscape in watersheds of Sanjiang Plain,China
    LIU Hongyu,L Xianguo,ZHANG Shikui,YANG Qing
    2005, 16(02):  289-295 . 
    Asbtract ( 1441 )   PDF (1555KB) ( 116 )  
    The Sanjiang Plain is the largest fresh water wetland distribution area in China and the center of waterfowls breeding and habitat area in Asia,but over the past 50 years,more than 73% of its wetland had lost because of agricultural development,and as a result,the wetland biodiversity declines dramatically,and the remnant wetlands are in a very fragment state.Based on historical maps,remote sensing data and GIS techniques,this paper selected two watersheds to analyze their wetland landscape fragmentation process during 1950～2000.It was indicated that land reclamation resulted in a decrease of 98% wetland corridors in Qixing River,90% in Naoli River,87% in the middle reach of Bielahong River,and 94% in the lower reach of Bielahong River;The amount of isolated wetlands in watershed increased dramatically; The maximum patch areas of wetland decreased by 92.6% in Naoli River watershed and 746% in Bielahong River watershed,and the mean wetland patch area in the two watersheds decreased by 99%.Before 1983,the wetland landscape was in an extensive area distribution state (the index of patch density was <0.1),but after 1983,it fragmented dramatically,with the index of patch density larger than 1.5.The shape fragmentation indices of wetland decreased from 1950 to 2000,indicating a very big change in wetland patch shapes in the watersheds.The area fragmentation indices of wetland also increased from 1950 to 2000,especially after 1983,showing that the wetlands were in a serious fragmentation state.The wetland landscape fragmentation changed from a landmass and island model to a satellite model,and finally to a completely isolated model,which indicated the great changes in spatial structure of wetland in the Sanjiang Plain.
    Land cover classification in Xianghai Nature Reserve
    HAN Min1,CHENG Lei1,TANG Xiaoliang1,WANG Jiaohe2
    2005, 16(02):  296-300 . 
    Asbtract ( 1426 )   PDF (2725KB) ( 90 )  
    This paper discussed the application of Fuzzy ARTMAP neural network in land cover classification in Xianghai Nature Reserve.The structure and algorithm of Fuzzy ARTMAP neural network were described in detail,and an automatic adjustment method of vigilance parameter was put forward to solve the problem of searching the optimum value in the selection of vigilance parameter. The results showed that the automatic adjustment method could adjust network parameter automatically,and improve the running speed of network.In comparing with maximum likelihood classification method and traditional Fuzzy ARTMAP neural network,the Fuzzy ARTMAP neural network with the functioning of automatic adjustment depended less on samples and had higher accuracy,and thus,could effectively make the classification of TM image covering Xianghai Nature Reserve.It's shown from the classification that in the Xianghai Nature Reserve,farmland covered large area while grassland and marsh were facing degradation,and hence,corresponding countermeasures should be taken to improve the eco-environment of this Reserve.
    Structural characteristics and heterogeneity analysis of yard-greenbelts in Shenyang city
    DAI Baoqing1，2,XIAO Duning1,WANG Yan1，3,JI Kai2
    2005, 16(02):  301-306 . 
    Asbtract ( 1431 )   PDF (556KB) ( 120 )  
    The analysis of the landscape and pattern of yard-greenbelts in Shenyang city indicated that residential greenbelt had the highest green path number,occupying 32.2% of all greenbelt types,but the virescence situation in residential area was the worst because its greenbelt ratio was only 19.5% in average.The average area of all yards was 4.04 hm2,with an average greenbelt of 0.93 hm2,and the green belt ratio was 23% in average that was lower than the standard established by the government.About 62.7% of all yards were lower than 15% in virescence,and 30% of them had a <13.3% of virescence.Micro-green patch was dominant (over 70%) in Shenyang yardgreenbelts. Landscape diversity index of residential areas was the highest, while that of hospital and army units was the lowest.The dominant degrees of all yardgreenbelt types in the researched 7 districts of the city were obviously different.The dominance of factory greenbelt in Yuhong district was 31.23 times of that in Heping district.The evenness indexes were also very different,the highest in residential greenbelt and the lowest in army unit.The highest fragmentation degree was in residential greenbelt and the lowest in army unit.The fragmentation degrees of old districts,especially in Shenhe district were more serious than the new districts.
    Characteristics,dynamics and niche of insect community in plum orchard
    HUANG Baohong1,ZOU Yunding2,BI Shoudong2,LI Hengkui1,ZHU Qiaoli1
    2005, 16(02):  307-312 . 
    Asbtract ( 1320 )   PDF (598KB) ( 107 )  
    The insect community in plum orchard was investigated on organization level and temporal-spatial niche.The results showed that the insect community was abundant,which included 6 orders,23 families.The individuals of species, diversity indices,and evenness increased with time.Myzus persicae and Asiaarposina sasokii had the widest spatial niche breadth,while Didesmococcus koreauus borchs had the widest temporal niche breadth. Among the natural enemies,Chilocorus rubidus had the widest both temporal and spatial niche breadth.The niche of Chicocorus rubidus and Didesmococcus koreauus overlapped larger than that of the others,which indicated their synchrony in temporal dimension and their similarity in spatial dimension.As the dominant natural enemies,the two populations should be protected and utilized to control plum pest.
    Suppressive effects of non-preferable plant alcohol extracts on diamondback moth Plutella xylostella population
    XIAN Jidong,LIANG Guangwen,SHEN Shuping,PANG Xiongfei
    2005, 16(02):  313-316 . 
    Asbtract ( 1628 )   PDF (342KB) ( 66 )  
    In this paper,a life table and an interference index of population control (IIPC) were used to evaluate the effects of spraying the alcohol extracts of non-preferable plants on the dynamics of diamondback moth Plutella xylostella) population.The results showed that the alcohol extracts of Eupatorium odoratum，Lantana camara and Wedelia chinensis were available to protect kidney bean from Plutella xylostella infestation.Their IIPC were 0.110,0.136 and 0.165,and the efficacies of controlling P.xylostella were 89.0%，86.4% and 83.5%,respectively,compared with control.
    Scanning electron microscopic observations of Monochamus alternatus antennal sensilla and their electroantennographic responses
    WANG Sibao1,2,ZHOU Hongchun1,MIAO Xuexia1,FAN Meizhen2, LI Zengzhi2, SI Shengli1,HUANG Yongping1
    2005, 16(02):  317-322 . 
    Asbtract ( 1300 )   PDF (1821KB) ( 164 )  
    With scanning electron microscope (SEM),this paper observed the shape, category,amount and distribution of the main antenna sensilla of adult Monochamus alternatus,and tested their electroantennographic (EAG) responses to the main volatiles of Pinus spp..There were seven types of antennal sensilla,i.e.,sensilla trichoid,sensilla basiconica,sensilla digitlike,sensilla rod-like,sensillabottle-like,sensilla bud-like and sensilla chaetica, among which,sensilla trichoid and sensilla basiconica were the most abundant on the antenna surface,and each of them could be divided into three subtypes.Two subtypes of sensilla digit-like could also be observed.The Ⅱ and Ⅲ subtypes of sensilla trichoid and I and Ⅱ subtypes of sensilla basiconica had deep longitudinal grooves on their surface,the typical characteristics of olfactory receptor.The comparison of the EAG response of different parts of Monochamus alternatus antennae to α-Pinene showed that each volatile and their compounds could provoke significant EAG responses of both females and males.The doseresponse test showed that there was a certain rule in the EAG responses of M.alternatus.
    Selection behavior of Cuscuta japonica on their hosts
    HU Fei1,KONG Chuihua1,2,ZHANG Chaoxian3,LIANG Wenju2, WANG Peng2
    2005, 16(02):  323-327 . 
    Asbtract ( 1313 )   PDF (1648KB) ( 109 )  
    A field investigation on the selection behavior of Cuscuta japonica on their hosts showed that among the test plant communities,the number of coiling, the time of haustorium occurring,and the rate of coiling of C.japonica on hosts followed the order of B.papyrifera,W.chinensis,I.cairica,and L.camara; but the length of the elongation of C.japonica growing tips from coiling to haustorium occurring was with the order of L.camara,I.cairica,W.chinensis,and B.papyrifera. Furthermore,the growing tips of C.japonica coiled 3 circles in left direction on all selected hosts in 12 hrs,but grew away after contacting PVC rods within 24 hrs.The host diversity of C.japonic was beneficial to the survival of both C.japonica and its hosts.The selection behavior of C.japonica on their hosts had no correlation with the total N contents of different hosts.It could be postulated that the secondary metabolites of hosts made a contribution to the selection behavior of C.japonica on their hosts.
    Cu and Zn pollution and soil enzyme activities in sewage irrigation area near smeltery
    WANG Guanglin1,2,WANG Lilong1,WANG Yupeng1,LIU Dengyi1
    2005, 16(02):  328-332 . 
    Asbtract ( 1376 )   PDF (451KB) ( 65 )  
    This paper studied the Cu and Zn status in soil and rice plant as well as the soil enzyme activities in the sewage irrigation area near a smeltery.The results showed that the soils near the smeltery were polluted.The soil total and extractable Cu contents at the distance of 100 m were 182.45 and 81.91 mg·kg-1,respectively,9.3 and 34 times higher than the control.The Cu concentration in different parts of rice was in order of root>leaf and stem> grain,while the Zn concentration was in order of leaf and stem>root>grain.Zn was more mobile than Cu which was likely to accumulate in rice root.It was considered that root could act as a barrier which retarded the upwards transport of Cu and protected the above ground parts of rice from toxication. The Cu contents of rice stem and leaf had a significant correlation with soil Cu contents in the sewage irrigation area.Among the three test enzymes,urease was the most sensitive one to Cu,and its activity had a significant correlation with soil Cu content.Therefore,it is feasible to use soil urease activity as an indicator of soil Cu pollution in sewage irrigation area near the smeltery.
    Effects of acid rain on nitrogen content in the water body of Wenzhou Sanyang wetland
    ZHANG Xiufeng,HE Wenshan,LU Jianjian
    2005, 16(02):  333-336 . 
    Asbtract ( 1215 )   PDF (368KB) ( 71 )  
    In order to understand the effects of acid rain on the nitrogen (N) content in the water body of Wenzhou Sanyang wetland,this paper measured the concentrations of different N forms in the wetland,of which,NH4+-N was 2.90～10.75 mg·L-1,average in 5.38 mg·L-1; NO3--N was 0.16～0.44 mg·L-1, average in 0.31 mg·L-1;and total was 34.04～63.20 mg·L-1,average in 55.75 mg·L-1.The pH value was 6.1～6.5,average in 6.4.The measurement of the N input from precipitation in the past two years and its proportion to the existed N in the water body of the wetland showed that the input of NH4+-N,NO3--N and total N was 2.48×104～2.86×104 kg,2.87～4.96×104 kg and 5.35×104～7.82×104 kg,and its proportion was 56～64%,11.21～19.38 times and 12%～17%,respectively.The N amount directly to the wetland water body was 0.72×104～0.84×104 kg,0.83×104～1.44×104 kg and 1.55×104～2.27×104,and its proportion was 16%～19%，3.24～5.63 times and 3%～5%.The results indicated that acid rain was one of the main sources of pollutant nitrogen which aggravated the water pollution of the Sanyang wetland.
    Physiological responses of Ceratophyllum demersum under different nutritional conditions
    WANG Jun,GU Yufei,Zhu Zengyin,WU Bin,YIN Daqiang
    2005, 16(02):  337-340 . 
    Asbtract ( 1172 )   PDF (331KB) ( 368 )  
    With static experiments,this paper investigated the protein and chlorophyll contents,and the peroxidase (POD) and superoxide dismutase (SOD ) activities of Ceratophyllum demersum cultured in meso-,eutro- and hypertrophic and Hoagland's solutions.The results showed that the changes of total N (TN) and total P (TP) concentrations in nutrient solutions had an obvious effect on the biosynthesis of C.demersum.When the concentrations of TN and TP were less than 1　mg·L-1 and 0.1 mg·L-1,respectively,the protein and chlorophyll contents of plant declined.The plant from eutrophic solution had higher SOD and POD activities.It was indicated that C.demersum was more preferable to eutropic condition (1 mg TN·L-1 and 0.1 mg TP·L-1),and the raised concentration of nutrients (e.g.,hypertrophic and Hoagland's solutions) was a stress to C.demersum and could affect its hardiness physiology.
    Effects of Dipterocarpaceae on arbuscular mycorrhizal fungi
    SHI Zhaoyong1,2,MENG Xiangxia2,CHEN Yinglong1,LIU Runjin2
    2005, 16(02):  341-344 . 
    Asbtract ( 1360 )   PDF (339KB) ( 110 )  
    An investigation was carried out on the colonization percentage,spore density,relative abundance,occurrence frequency,and species richness of arbuscular mycorrhizal (AM) fungi on 4 species of Dipterocarpaceae trees grown both in natural forests in Yunnan and Hainan Provinces and in greenhouse pots.The results showed that all dipterocarp species were able to form AM,the colonization rates ranged from 30.6% to 45.3%,37% on average.Hopea hainanensis (Dipterocarpacea) seedlings without AM fungal colonization were cultivated in pots with soil collected from Dipterocarpacea rhizosphere,and harvested a year later.The colonization rate of the seedlings ranged from 10.6% to 20.3%,14.2% on average,indicating the significant effect of host plants on AM fungi frequency.The relative abundance of Glomu,Acaulospora and Gigaspora also varied with host plants.It was concluded that the dominant AM fungi in the rhizospheric soil of dipterocarp plants were Acculospora spp.and Glomus spp.Using the same species of Dipterocarpacea as host plants might promote the growth and development of AM fungi,and increase the AM diversity.
    A comprehensive quantitative assessment model for arid area's basin water-soil environment quality
    SONG Songbai,CAI Huanjie
    2005, 16(02):  345-349 . 
    Asbtract ( 1579 )   PDF (427KB) ( 117 )  
    The existing assessment models for water-soil environment quality are usually established on the relationships between assessment indicators and their assessment criteria.Such kinds of models are varied with regional scale,and always need a mass of calculation work.This paper tried to find a general assessment model based on a given water-soil quality assessment criteria.In this process,stochastic technology was used to simulate enough assessment indictor series,and then,assessment model was built up by using artificial neural network to assess these series.This model could reduce work load,and needn't construct functional relations between assessment indicators and their criteria and calculate weigh value.A case study in a basin with the highest level of water resources utilization showed that the model was practical and convenient,and could be used in basin water-soil quality assessment.
    Correlation analysis on the damage of Mikania micrantha to plant communities in Neilingdind Island of Guandong Province,China
    ZHOU Xianye1,WANG Bosun2,LI Mingguang2,LIAO Wenbo2,ZHOU Yunlong1, ZAN Qijie3,WANG Yongjun3
    2005, 16(02):  350-354 . 
    Asbtract ( 1370 )   PDF (426KB) ( 82 )  
    The analysis showed that 58 species of trees,short-trees and shrubs in Neilingding Island of Guangdong Province were damaged byM.micrantha,of which,woody trees accounted for 67%.Short-trees and sunny shrubs were damaged most seriously,followed by the communities with low canopy density consisted of only 2 dominant species,and those with high canopy density consisted of 5 or 6 dominant species.The coverage of M.micrantha mainly related to the vertical structure of plant communities.The taller the community height and the more the synusia,the lesser was the coverage of M.micrantha.The damaging ratio mainly related to species diversity and community density.The higher the species diversity and community density, the lower the damaging ratio was.The damaging degree mainly related to the coverage of other liana.The more the coverage of other liana,the higher was the damaging degree of M.micrantha.
    Effects of ecological environment in Qinba Mountains on hair trace element contents of local inhabitants
    GAO Yunfang，ZHANG Xiaoyan，ZHANG Fuchang
    2005, 16(02):  355-359 . 
    Asbtract ( 1693 )   PDF (417KB) ( 81 )  
    Determinations of Zn,Fe,Ca,Cu,Mg,Al,Se,Mn,Cr and Pb contents in the hairs of 136 children aged 0～13 and of 22 adults in the Qinba Mountains showed that the contents of test trace elements except Mg were abnormal in different degrees.The Al,Mn and Cr contents were highly excessive,their mean values being 2.04,1.67 and 2.07 times as the highest value of normal range,and the people excessive in three elements occupied 83.54%,77.85% and 72.78%,respectively.On the other hand,Zn and Se contents were in shortage,with the mean values being only 91.96%and 68.33% of the lowest value of normal range,and the people deficient in Zn and Se occupied 69.62% and 79.11%,respectively.Based on the local environmental geochemistry,this paper analyzed the possible causes of this abnormal status in trace elements and its harm.
    Ecological restoration and reconstruction of degraded lakeside zone ecosystem
    YAN Changzhou1,2，JIN Xiangcan2，ZHAO Jingzhu1，YE Chun2，WANG Zhongqiong2
    2005, 16(02):  360-364 . 
    Asbtract ( 1444 )   PDF (503KB) ( 137 )  
    As a kind of aquatic-terrestrial ecotone,lakeside zone plays an important role in the lake basin ecosystem,and has high ecological,social and economic values.Its functions include lake buffer,conservation of biological diversities and special habitats,dike protection from soil erosion,and economic and esthetics values.The main factors inducing lakeside zone degradation are the anthropogenic activities that caused the converse succession of communities and the decline of ecological function.The theoretical basis of ecological restoration and reconstruction of degraded lakeside zone is restoration ecology; while the technologies are of three types,i.e.,habitat restoration and reconstruction,species restoration and reconstruction,and structural and functional restoration.A three-year case study on the ecosystem restoration and reconstruction of degraded lakeside zone of Erhai Lake in Yunnan Province showed that the aquatic macrophytes were restored,purifying function was distinct,algae were restrained,and the component and individuals of zooplankton were changed.In a word,the biological diversity and stability in the degraded lakesidezone ecosystem increased after the restoration and reconstruction.
    Research advance in response of forest seedling regeneration to light environmental heterogeneity
    CHEN Shengbin,SONG Aiqin,LI Zhenji
    2005, 16(02):  365-370 . 
    Asbtract ( 1678 )   PDF (639KB) ( 157 )  
    Based on the analysis of characteristics of forest light environmental heterogeneity, this paper reviewed the research advance in the response of forest seedlings to light environmental heterogeneity from the aspects of photosynthesis,thermal dissipation,biomass accumulation and distribution, morphological traits,germination,and population dynamics,and discussed the ecological significance of different responses of seedling regeneration to light environmental heterogeneity in forest biodiversity maintenance,forest succession,and revegetation.Some suggestions for future research in this field were put forward.
    Research advances in catalytic kinetics of soil oxidoreductase
    ZHANG Lili1,2,CHEN Lijun1,ZHANG Yulan1,2,WU Zhijie1
    2005, 16(02):  371-374 . 
    Asbtract ( 1117 )   PDF (452KB) ( 58 )  
    Soil oxidoreductase is a group of enzymes catalyzing many important soil biochemical reactions and concerning with the transformation of soil organic matter,formation of humic substance,and dynamics of soil fertility.The catalytic kinetics of oxidoreductase can illuminate its catalytic characteristics, substantial properties,and response to environmental changes.This paper summarized the research advance of its kinetics,and proposed some comments in understanding its action mechanism and in regulating its catalytic processes.
    Redundancy theory and its application in agro-ecosystem management
    HAN Mingchun1,WU Jianjun1,WANG Fen2
    2005, 16(02):  375-378 . 
    Asbtract ( 1807 )   PDF (425KB) ( 175 )  
    Redundancy theory is an ecological theory developed in 1990s.This paper gave a brief introduction on the concept of redundancy,its hypothesis and redundancy degree,and briefly reviewed the research advances in redundancy theory and in the methodologies about species redundancy,layer redundancy,gene redundancy,and growth redundancy.A hypothesis of optimal growth redundancy degree (OGRD) was proposed,i.e.,under certain cultivation and management conditions,there existed a growth redundancy degree corresponding to the highest crop yield,and a high yield would be obtained if OGRD could be achieved through the regulation of management practices.The hypothesis was tested by using the data from high-yielding rice cultivation cases.
    Research advance on environmental exposure and ecotoxicological effects of polybrominated diphenyl ethers (PBDEs)
    SUN Fuhong,ZHOU Qixing
    2005, 16(02):  379-384 . 
    Asbtract ( 1299 )   PDF (594KB) ( 149 )  
    Polybrominated diphenyl ethers (PBDEs) are a group of new type organic pollutants with significant ecological risk.As flame retardants,they have been increasingly added to industrial products,and thus,resulted in more and more extensive pollution of air,water,sediment and soil as well as their relevant ecosystems.In view of the new environmental problem and based on limited available data,this paper approached the anthropogenic sources of PBDEs and their pathways of environmental exposure,and gave the possible occurrence and concentration of PBDEs in several living organisms and different human tissues.The toxic effects and ecological influences of PBDEs acting on animals and human beings,and their potential biological accumulation and magnification in ecosystems were analyzed in the aspects of hypothyroid,neurotoxicity,and reproductive and developmental toxicity,and the pivots of further researches on environmental exposure,ecological effects and human health influences of PBDEs were thus suggested.
    Application of microsatellite DNA in molecular ecology and strategies for loci isolation
    XUE Hui,WU Xiaobing,YAN Peng
    2005, 16(02):  385-389 . 
    Asbtract ( 1316 )   PDF (491KB) ( 166 )  
    Microsatellite DNA has been widely used as a good genetic marker in molecular ecology.This paper reviewed its application in molecular population biology,molecular environmental genetics,and molecular adaptation.The isolation of the loci is the basis of microsatellite DNA genetic analysis. Compared with the traditional isolation method by genomic library,some novel approaches carried out recently,such as enrichment library,PIMA and FIASCO,are more efficient and timesaving.The details and compare-analysis of these approaches were introduced,which would offer good choices for researches on molecular ecology.
    Effects of no-tillage plus inter-planting and remaining straw on the field on cropland eco-environment and wheat growth
    LIU Shiping,ZHANG Hongcheng,DAI Qigen,HUO Zhongyang,XU Ke,RUAN Huifang
    2005, 16(02):  393-396 . 
    Asbtract ( 1189 )   PDF (391KB) ( 172 )  
    The studies showed that under no-tillage plus inter-planting rice and wheat, the height of rice stubble remained on the field significantly affected light transmission rate,with an optimal height of 20～30 cm.No-tillage and strawremaining decreased soil temperature at noon in sunny days,but slightly increased it in the morning and evening,led to a less diurnal difference of soil temperature.The average diurnal soil temperature under no-tillage was higher in cloudy but lower in sunny days.Under no-tillage and strawremaining, both the bulk density and the penetration resistance of topsoil increased,but no apparent adverse effect of them was observed on wheat growth.Under no-tillage,soil water content was higher under drought condition,and soil permeability after irrigation was better,which was propitious to the wheat growth.Straw-remaining significantly inhibited weeds,but led to the decrease of basic seedlings and enhanced the damage of freezing.Under no-tillage plus inter-planting,the individuals of effective ears decreased,while the kilo-grain weight increased.The grain yield was slightly but not significantly low under no-tillage plus inter-planting.
    Sabina przewalskii community structure in the upper reaches of Minjiang River
    CHEN Wennian, WU Ning, LUO Peng
    2005, 16(2):  198-202. 
    Asbtract ( 1379 )   PDF (312KB) ( 356 )  
    In this paper,the physiognomy and the structure of Sabina przewalskii community were studied by sample plot method.The results showed that in the life spectrum of the community,hemicryptophyte was dominated,but therophytes also occurred frequently,which presented some features of temperate vegetation.The vertical structure of the community was quite simple,consisting of tree layer,shrub layer and herb layer,and there were no interstratum plants and ground layer.Sabina przewalskii was the only species in the tree layer.In fruticose stratum,the important value of Spiraea alpina was 153.3,ranking the first; while in herb layer,the important value of Carex caespifosa ranked the first,amounting to 36.8.Among the three plot groups on different slopes,spiny-shrubs such as Berberis wilsonae and Caragana erinacea grown on small slope were more than those on bigger slope,so did unpalatable grasses such as Pedicularis axillaries and Artemisia tauguticat,which mainly owed to retrogressive succession caused by frequently grazing.The age and height structures of Sabina przewalskii population indicated a declining trend,and the community would develop retrogressively if disturbances (e.g.,grazing) could not be reduced.The disturbance caused by livestock was more obvious in the plot group on small slope than on bigger slope,and livestock mainly destroyed seedlings and small trees,which made tree population be impossible to regenerate.The coverage of upper layers had a notable impact on the lower layers,and there wasn't any correlation between coverage and diversity index (Shannon-Wiener Index) in each layer.
    Relationships between net primary production and nitrogen cycling in Chinese forest ecosystems
    ZHOU Caiping, OUYANG Hua, SONG Minghua
    2005, 16(2):  203-206. 
    Asbtract ( 1723 )   PDF (800KB) ( 487 )  
    In order to better understand the relationships between net primary production (NPP) of forest ecosystem and nitrogen cycling,we studied and analyzed the relationships between NPP,litter nitrogen,plant nitrogen retention,and soil net nitrogen mineralization rate in Chinese forest ecosystems.The results indicated that NPP was linearly and positively related to litter nitrogen,plant nitrogen retention and soil net nitrogen mineralization rate,with the most correlation with soil net nitrogen mineralization rate (R2=0.74,n=37),and the next with plant nitrogen retention (R2=0.60,n=37).
    Spatial distribution pattern of Larix chinensis population in Taibai Mt
    ZHANG Wenhui, WANG Yanping, KANG Yongxiang, LIU Xiangjun
    2005, 16(2):  207-212. 
    Asbtract ( 1465 )   PDF (798KB) ( 682 )  
    Larix chinensis is an endangered species only distributed in Qinling Mountains of China.It has a concentrated distribution in Taibai Mt.,and plays an important role in environmental protection in the high altitude.After an investigation on fifteen 400m2 plots,a comparative study on the spatial distribution pattern of L.chinensis population and its dynamics was made by the tests of discrete distribution pattern and aggregation intensity.The results showed that at different sampling areas,L.chinensis populations all performed the pattern of clustering distribution.As the sampling area increased,the congregating intensity of L.chinensis population appeared the pattern of high→low→high,but the highest congregation occurred in the areas of 100m2 and 25m2.The clustering intensity went down from low to high altitude,and the area with the highest clustering intensity occurred on that of 25m2 in low altitude,150m2 in middle altitude,and 100m2 in higher altitude.The clustering intensity in shade slope was higher than that in sunny slope,and the area with the highest clustering intensity was 100m2 on shade slope,and 150m2 on sunny slope.With the population age increased,the distribution pattern had a trend from clustering to random,the clustering intensity decreased somewhat,and the area with the highest clustering intensity was 150m2 in young or old stages,and 100m2 in middle stage.The distribution pattern of L.chinensis population was related to its ecological characteristics,community composition,and environmental factors.In situ conservation should be strengthened in the future.In lower altitude or on shade slope,the measurements of thinning no-aim in tree and shrub species should be taken; while in higher altitude area or sunny slope,thinning shrub species in patch form would be better for L.chinensis populations block renovating.The fostering area for L.chinensis populations should be suit to the area with the highest clustering intensity of populations.
    Alleviation effect of exogenous Ca,P and N on the growth of Chinese fir seedlings under Al stress
    ZHANG Fan, LUO Chengde, ZAHNG Jian
    2005, 16(2):  213-217. 
    Asbtract ( 1593 )   PDF (626KB) ( 543 )  
    In this study,three month-old seedlings of Chinese fir (Cunninghamia laceolata) were grown in solution culture with 1mmol·L-1 Al at pH 4.0 for 80 days to evaluate the effects of varying concentrations of Ca,P,and NH4+-N or NO3--N in solution on their growth.The morphological indexes (fresh weight,dry weight,shoot length,root length and relative elongation ratio) and physiological indexes (MDA content and POD activity) were submitted to statistical analysis and compared.The results indicated that the seedlings weight or shoot length had a significantly positive correlation with the molar ratio of solution Ca/Al.The MDA content and POD activity decreased with the increasing molar ratio of Ca/Al,and Ca/Al≥2.8 was the critical ratio.Similar to Ca/Al,high P/Al molar ratio also had an obvious effect on the growth of Chinese fir seedlings under Al stress,and P/Al≥4.5 was the critical ratio.The growth of Chinese fir seedlings was improved by increased NH4+-N supply,but the effect was less obvious than Ca and P.Solution NH4+-N/Al≥4.7 was the critical molar ratio.Solution NO3--N could mitigate some adverse effects of Al on Chinese fir seedlings growth,but no regular effects were found with the change of solution NO3--N/Al molar ratio.
    Effects of exogenous nitric oxide on photosynthetic characteristics of poplar leaves under water stress
    WANG Miao, LI Qiurong, FU Shilei, DONG Baili
    2005, 16(2):  218-222. 
    Asbtract ( 1558 )   PDF (777KB) ( 470 )  
    Nitric oxide (NO) is an active molecule involved in many biological pathways,but its effects on photosynthesis of tree leaves have not been established yet.This paper studied the effects of exogenous NO,sodium nitroprusside (SNP),on the water status,photosynthesis and scavenging enzyme activities in poplar leaves.Different levels of SNP treatments had remarkable effects on the water content of leaves,which increased with increasing SNP levels.When the SNP level exceeded 500 μmol·L-1,differences in leaf water content were no longer significant between different SNP treatments.Exogenous NO increased the photosynthesis rate,photochemical efficiency of PSII Fv/Fm,and Fm/Fo and Fv/Fo ratios,and the effects decreased with increasing duration of water stress.The SOD and POD activities in poplar leaves were higher in 1 hour water stress treatment than in 3 h treatment.Treating with SNP could markedly increase POD activity,but SOD activity did not change much.POD and SOD activities increased initially,and then decreased with increasing SNP levels.The results indicated that exogenous NO delayed the accumulation of active oxygen by increasing POD and SOD activities,and thereby,alleviated the effects of water stress on photosynthetic organization of poplar leaves.
    Relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing
    SONG Huixing, SU Zhixian, PENG Yuanying
    2005, 16(2):  223-226. 
    Asbtract ( 1689 )   PDF (248KB) ( 350 )  
    Based on the analyses of soil physical and chemical properties,this paper studied the relationship between plant community succession and fertility variation of mountain yellow soil in east Chongqing.The results showed that the values of integrated soil fertility index of Pinus massoniana,Cunninghamia lanceolata,deciduous oak,Camellia sinensis and evergreen broad-leaved forest soils were 0.1256,0.2085,0.3514,0.2479 and 0.9329,respectively,implying that soil development had a close relation to plant community succession.
    Spatial distribution pattern and fractal analysis of Larix chinensis populations in Qinling Mountain
    GUO Hua, WANG Xiaoan, XIAO Yaping
    2005, 16(2):  227-232. 
    Asbtract ( 1724 )   PDF (633KB) ( 827 )  
    In this paper,the fractal characters of Larix chinensis populations in Qinling Mountain were studied by contiguous grid quadrate sampling method and by boxing-counting dimension and information dimension.The results showed that the high boxing-counting dimension (1.8087) and information dimension (1.7931) reflected a higher spatial occupational degree of L.chinensis populations.Judged by the dispersal index and Morisita's pattern index,L.chinensis populations clumped at three different age stages (0～25,25～50 and over 50 years).From Greig-Smiths'mean variance analysis,the figure of pattern scale showed that L.chinensis populations clumped in 128m2 and 512m2,and the different age groups clumped in different scales.The pattern intensities decreased with increasing age,and tended to reduce with increasing area when detected by Kershaw's PI index.The spatial pattern characters of L.chinensis populations may be their responses to environmental factors.
    Experience model for self-thinning process of even-aged pure stands
    WU Chengzhen, HONG Wei, YAN Shujun
    2005, 16(2):  233-237. 
    Asbtract ( 1656 )   PDF (270KB) ( 502 )  
    Based on the famous-3/2 power rule and generalized Schumacher growth equation,a mathematical model for the density change of even-aged pure stands with time during self-thinning process was presented,and the genetic algorithms was used to fit this nonlinear model.With the collected data from Populus tremula var.davidiana,Pinus yunnanensis and Cunninghamia lanceolata even-aged pure stands,the new model was verified and compared with other models.The results showed that the new model could fit observed data very well,and was very useful in practice.The surplus square,mean relative error,mean absolute error and surplus standard deviation of the new model were all smaller than those of other models,indicating its good qualification in describing stand density change during self-thinning process and its useness in studying forest self-thinning rules.The study also showed that genetic algorithms could give a better global convergence,and be used to estimate the parameters of nonlinear models in ecology,biology and forestry.
    Effects of urease and nitrification inhibitors on alleviating the oxidation and leaching of soil urea's hydrolyzed product ammonium
    CHEN Zhenhua, CHEN Lijun, WU Zhijie
    2005, 16(2):  238-242. 
    Asbtract ( 1606 )   PDF (583KB) ( 589 )  
    With simulation test of in-situ soil column,this paper studied the effects of urease inhibitor hydroquinone (HQ),nitrification inhibitors coated calcium carbide (ECC) and dicyandiamide (DCD),and their different combinations on the persistence,oxidation,and leaching of soil urea's hydrolyzed product ammonium.The results showed that compared with other treatments,the combination of HQ and DCD could effectively inhibit the oxidation of the ammonium,and make it as exchangeable form reserve in soil in a larger amount and a longer period.The inhibition of this oxidation not only decreased the accumulation of oxidized product NO3-in soil,but also decreased the potential of NO3-leaching,making the NO3-only leach to 5～10 cm in depth,and the leached amount significantly decreased.
    Simulation of nitrogen mineralization and immobilization of crop straw during its initial decomposition in soil
    HU Xiyuan, Kuehne R.F.
    2005, 16(2):  243-248. 
    Asbtract ( 1623 )   PDF (371KB) ( 500 )  
    The nitrogen (N) transformation of crop straw during its initial decomposition in soil was simulated by Modelmaker software.A good fit was obtained between the simulated and measured data of 6 variables,including the amount of soil ammonium N,nitrate N,microbial biomass N and their 15N atom %.The simulation results indicated that the main N form immobilized by soil microbes was ammonium,while the immobilization of nitrate was very small.N mineralization occurred dominantly in crop straw but very small in humus.The N mineralization of crop straw could be better described by first order than zero order kinetics.N re-mineralization occurred later than N immobilization.The assumptions on the absence of N re-mineralization or the simultaneous presence of re-mineralization and immobilization during straw decomposition led to a serious error in calculating the gross N mineralization and immobilization; while no consideration of nitrification and volatilization losses led to a low estimation of gross N mineralization.The occurrence of net N mineralization or net N immobilization depended not only on the C/N of straw,but also on the duration of straw decomposition.
    Short-term changes of pH value and Al activity in acid soils after urea fertilization
    ZENG Qingru, LIAO Bohan, JIANG Zhaohui, ZHOU Xihong, TANG Can, ZHONG Ning
    2005, 16(2):  249-252. 
    Asbtract ( 1589 )   PDF (583KB) ( 614 )  
    Acidic soils are widely distributed in South China,and their acidity is the major environmental stress factor limiting the growth of most crops.It is well known that soil Al solubilized at low pH is a main toxic factor for plant growth.Our study with three acidic soils showed that soil pH increased quickly,while soil exchangeable Al decreased sharply with the increasing concentrations of applied urea.The time-course experiment revealed that the increase of soil pH was short-lived,with a subsequently slow drop after reached its maximum.Urea fertilization caused a drastic change of soil pH during 2～4 weeks of the experimental period.There was a negative relationship between soil pH and soil exchangeable Al.Biological toxicity test demonstrated that applying urea to acidic soils could obviously decrease the aluminum toxicity of maize in a short-term period.
    Effects of fertilization on soil active organic carbon under Phyllostachys praecox stand
    JIANG Peikun, XU Qiufang
    2005, 16(2):  253-256. 
    Asbtract ( 1451 )   PDF (618KB) ( 554 )  
    In this paper,fertilization experiment was conducted on Phyllostachys praecox stand to study the effects of different heavy application of chemical fertilizers and manure on soil active organic carbon pool.The results showed that compared with only applying chemical fertilizers,the combined application of chemical fertilizers and manure significantly increased the contents of soil total organic carbon (TOC),water-soluble organic carbon (WSOC),microbial biomass carbon (MBC) and mineralized carbon (MC) as well as the ratios of WSOC/TOC,MGC/TOC and MC/TOC (P<0.01 or P<0.05).With the decreasing application rate of manure,soil TOC,WSOC,MBC and MBC/TOC decreased significantly (P<0.05),and when the application rate of manure was decreased by 50%,soil TOC,WSOC,MBC and MBC/TOC decreased by 10.75%,12.02%,30.94% and 22.61%,respectively.In the treatments of only applying chemical fertilizers,soil WSOC,MBC and MBC/TOC decreased obviously when the application rate of fertilizer nitrogen exceeded 1009.5 kg穐m-2 穣r-1.There were significant correlations between soil TOC,WSOC,MBC and MC (P<0.01 or P<0.05),among which,MBC and MBC/TOC could be used as the quality indications of soil carbon pool under Phyllostachys praecox stand.
    Several infection factors of Pseudoperonospora cubensis
    SHI Yanxia, LI Baoju, LIU Xuemin
    2005, 16(2):  257-261. 
    Asbtract ( 1471 )   PDF (283KB) ( 317 )  
    The study on the effects of temperature and humidity on the pathogenicity of Pseudoperonospora cubensis showed that the optimum temperature for the occurrence of cucumber downy mildew was 25～35 ℃.An alternation of 15/35 ℃ was the most propitious to the infection of Pseudoperonospora cubensis,while the high temperature above 35 ℃ could kill the pathogens.2 hours humid was enough for infection.Pseudoperonospora cubensis stored at-20 ℃ for 10 months and dried for 7 days could still infect cucumber.The infected cucumber leaves could continuously produce sporangium,with its quantity gradually decreased with time.The quantity of sporangium produced in vivo was more than that in vitro.
    Productivity of crop-fruit ecological agriculture in middle-south Loess Plateau
    WU Faqi, ZHOU Zhengli, LIU Haibin
    2005, 16(2):  262-266. 
    Asbtract ( 1646 )   PDF (256KB) ( 509 )  
    With the Xipo,Feimahe and Nangou villages as test objects,the productive characteristics of crop-fruit ecological agriculture in the middle-south Loess Plateau were investigated.The results showed that the biomass productivity of a plant was different with its organs,the highest for grain or fruit,and followed by stem,leaf and root.In the crop-fruit ecological agriculture,the higher ratio the crop subsystem,the higher productivity its biomass,the lower economic productivity and lower economic value was; while the fruit subsystem was on the contrary.The productivity of livestock farming subsystem was in a lower level,which restricted the increase of the total ecosystem's productivity.Based on these results,a countermeasure of increasing the ecosystem productivity was put forward.
    Effects of exogenous Ca on some physiological characteristics of tomato (Lycopersicon esculentum) seedlings with different Ca sensitivity
    DONG Caixia, ZHOU Jianmin, ZHAO Shijie, WANG Huoyan
    2005, 16(2):  267-272. 
    Asbtract ( 1549 )   PDF (306KB) ( 521 )  
    Two tomato (Lycopersicon esculentum) cultivars with different Ca sensitivity were used to study the effects of exogenous Ca on their root activity,CaM content,chlorophyll a/b ratio,and reactive oxygen-scavenging enzymes' activities under different Ca concentrations in nutrient solution.The results showed that the root activity and CaM content of two cultivars increased with increasing Ca concentrations in the nutrient solution.The root activity and chlorophyll a/b ratio of Ca-insensitive cultivar Jiangshuyihao were higher than those of Ca-sensitive L-402 under extreme low Ca stress (1 and 4 mg稬-1),while lower than those of L-402 when sufficient Ca was applied (100 mg稬-1),indicating that Jiangshuyihao had a greater capability to bear the nutrient and light stress under low Ca stress.The SOD activity of Ca-insensitive cultivar Jiangshuyihao under 1 and 4 mg稬-1 Ca was higher than that of L-402,while the activities of POD and CAT of L-402 were consistently higher than that of Jiangshuyihao under test Ca concentrations in the nutrient solution.Comparing with 100 mg稬-1 Ca in solution,4 mg稬-1 Ca led to an increase of CAT and POD activities and a decrease of SOD activity in the two cultivars,but the variation of SOD activity was greater in L-402 than in Jiangshuyihao,indicating that the system of defence enzymes in Ca-insensitive cultivar played a key role when suffered from Ca stress.
    Physiological characteristics of nitrogen nutrition and stress-resistance of film-mulched rice in various ecological regions of Zhejiang Province
    LU Xinghua, WU Lianghuan, ZHENG Zhaisheng, KONG Xiangjun, ZHANG Fusuo
    2005, 16(2):  273-278. 
    Asbtract ( 1491 )   PDF (867KB) ( 369 )  
    The study showed that different ecological environment and cultivation system in various ecological regions of Zhejiang Province resulted in some different physiological characteristics of nitrogen nutrition and stress-resistance,especially in the aspect of NO3--N and NH4+-N concentrations,between film-mulched and conventional flooded rice.Owing to the heat stress in Hangjiahu plain,the NO3--N concentration of film-mulched rice decreased to some extent,but NH4+-N concentration increased markedly at tillering,jointing and booting stages,compared to conventional flooded rice.In Jinqu basin,the NO3--N concentration of film-mulched rice at booting stage was higher,while the NH4+-N concentration in its roots was notably lower than those of conventional flooded rice,with NH4+-N concentration in its basal stems and leaves somewhat increased.Generally,the glutamine synthetase(GS) and nitrate reductase (NR) activities in film-mulched rice leaves were enhanced at booting stage,while malondiadehyde (MDA),soluble sugar (SS) and proline(Pro) concentrations had little changes.In conclusion,film-mulched cultivation was beneficial to the rice growth and its high yielding.
    Gradient distribution of soil nitrogen and its response to climate change along the Northeast China Transect
    WANG Shuping, ZHOU Guangsheng, GAO Suhua, GUO Jianping
    2005, 16(2):  279-283. 
    Asbtract ( 1696 )   PDF (660KB) ( 449 )  
    Terrestrial transect is an important and effective method for global change study.The Northeast China Transect (NECT),which is assigned along the latitude 43°30'N in the mid-latitude of temperate zone and located at 112°～130°30'E and 42～46° N,is one of the fifteen global transects recognized by IGBP.It is about 1 600 km in length and 300 km in width.The NECT is mainly driven by precipitation,and becomes an effective platform of global change study in China.Based on the field survey in 2001 and a simulated experiment,this paper analyzed the gradient distribution of soil nitrogen and its response to climate change along the Transect.The results indicated that soil total and available nitrogen in NECT were significantly related to longitude,with a correlation coefficient being 0.695(P<0.001) and 0.636 (P<0.001),respectively,and had a similar horizontal distribution with soil organic carbon.Soil available nitrogen content in the NECT was decreased from east to west,and could be one of factors restricting plant growth.The decreasing rate of soil total and available nitrogen from topsoil to subsoil was different with ecosystems along the NECT.Soil total and available nitrogen contents had a close linear relationship with soil pH,total and labile carbon,total and available phosphorus,total sulphur,total and available zinc,available potassium,available manganese,bulk density,water holding capacity,and total porosity.They also had a significant linear relationship with precipitation,the correlation coefficient being 0.682(P<0.001) and 0.688(P<0.001),respectively.The short-term simulated experiment showed that doubled ambient CO2 concentration and soil moisture regime had no significant effects on soil total and available nitrogen,the variation coefficients being 5.55% and 3.84%,respectively.
    Wave-type time series variation of the correlation between NDVI and climatic factors
    BI Xiaoli, WANG Hui, GE Jianping
    2005, 16(2):  284-288. 
    Asbtract ( 1813 )   PDF (829KB) ( 398 )  
    Based on the 1992～1996 data of 1km monthly NDVI and those of the monthly precipitation and mean temperature collected by 400 standard meteorological stations in China,this paper analyzed the temporal and spatial dynamic changes of the correlation between NDVI and climatic factors in different climate districts of this country.The results showed that there was a significant correlation between monthly precipitations and NDVI.The wave-type time series model could simulate well the temporal dynamic changes of the correlation between NDVI and climatic factors,and the simulated results of the correlation between NDVI and precipitation was better than that between NDVI and temperature.The correlation coefficients (R2) were 0.91 and 0.86,respectively for the whole country.
    Fragmentation process of wetland landscape in watersheds of Sanjiang Plain,China
    LIU Hongyu, L? Xianguo, ZHANG Shikui, YANG Qing
    2005, 16(2):  289-295. 
    Asbtract ( 1472 )   PDF (208KB) ( 434 )  
    The Sanjiang Plain is the largest fresh water wetland distribution area in China and the center of waterfowls breeding and habitat area in Asia,but over the past 50 years,more than 73% of its wetland had lost because of agricultural development,and as a result,the wetland biodiversity declines dramatically,and the remnant wetlands are in a very fragment state.Based on historical maps,remote sensing data and GIS techniques,this paper selected two watersheds to analyze their wetland landscape fragmentation process during 1950～2000.It was indicated that land reclamation resulted in a decrease of 98% wetland corridors in Qixing River,90% in Naoli River,87% in the middle reach of Bielahong River,and 94% in the lower reach of Bielahong River;The amount of isolated wetlands in watershed increased dramatically;The maximum patch areas of wetland decreased by 92.6% in Naoli River watershed and 74.6% in Bielahong River watershed,and the mean wetland patch area in the two watersheds decreased by 99%.Before 1983,the wetland landscape was in an extensive area distribution state (the index of patch density was <0.1),but after 1983,it fragmented dramatically,with the index of patch density larger than 1.5.The shape fragmentation indices of wetland decreased from 1950 to 2000,indicating a very big change in wetland patch shapes in the watersheds.The area fragmentation indices of wetland also increased from 1950 to 2000,especially after 1983,showing that the wetlands were in a serious fragmentation state.The wetland landscape fragmentation changed from a landmass and island model to a satellite model,and finally to a completely isolated model,which indicated the great changes in spatial structure of wetland in the Sanjiang Plain.
    Land cover classification in Xianghai Nature Reserve
    HAN Min, CHENG Lei, TANG Xiaoliang, WANG Jiaohe
    2005, 16(2):  296-300. 
    Asbtract ( 1510 )   PDF (946KB) ( 452 )  
    This paper discussed the application of Fuzzy ARTMAP neural network in land cover classification in Xianghai Nature Reserve.The structure and algorithm of Fuzzy ARTMAP neural network were described in detail,and an automatic adjustment method of vigilance parameter was put forward to solve the problem of searching the optimum value in the selection of vigilance parameter.The results showed that the automatic adjustment method could adjust network parameter automatically,and improve the running speed of network.In comparing with maximum likelihood classification method and traditional Fuzzy ARTMAP neural network,the Fuzzy ARTMAP neural network with the functioning of automatic adjustment depended less on samples and had higher accuracy,and thus,could effectively make the classification of TM image covering Xianghai Nature Reserve.It's shown from the classification that in the Xianghai Nature Reserve,farmland covered large area while grassland and marsh were facing degradation,and hence,corresponding countermeasures should be taken to improve the eco-environment of this Reserve.
    Structural characteristics and heterogeneity analysis of yard-greenbelts in Shenyang city
    DAI Baoqing, XIAO Duning, WANG Yan, JI Kai
    2005, 16(2):  301-306. 
    Asbtract ( 1692 )   PDF (752KB) ( 836 )  
    The analysis of the landscape and pattern of yard-greenbelts in Shenyang city indicated that residential greenbelt had the highest green path number,occupying 32.2% of all greenbelt types,but the virescence situation in residential area was the worst because its greenbelt ratio was only 19.5% in average.The average area of all yards was 4.04 hm2,with an average greenbelt of 0.93 hm2,and the green belt ratio was 23% in average that was lower than the standard established by the government.About 62.7% of all yards were lower than 15% in virescence,and 30% of them had a <13.3% of virescence.Micro-green patch was dominant (over 70%) in Shenyang yard-greenbelts.Landscape diversity index of residential areas was the highest,while that of hospital and army units was the lowest.The dominant degrees of all yard-greenbelt types in the researched 7 districts of the city were obviously different.The dominance of factory greenbelt in Yuhong district was 31.23 times of that in Heping district.The evenness indexes were also very different,the highest in residential greenbelt and the lowest in army unit.The highest fragmentation degree was in residential greenbelt and the lowest in army unit.The fragmentation degrees of old districts,especially in Shenhe district were more serious than the new districts.
    Characteristics,dynamics and niche of insect community in plum orchard
    HUANG Baohong, ZOU Yunding, BI Shoudong, LI Hengkui, ZHU Qiaoli
    2005, 16(2):  307-312. 
    Asbtract ( 1616 )   PDF (313KB) ( 445 )  
    The insect community in plum orchard was investigated on organization level and temporal-spatial niche.The results showed that the insect community was abundant,which included 6 orders,23 families.The individuals of species,diversity indices,and evenness increased with time.Myzus persicae and Asiaarposina sasokii had the widest spatial niche breadth,while Didesmococcus koreauus borchs had the widest temporal niche breadth.Among the natural enemies,Chilocorus rubidus had the widest both temporal and spatial niche breadth.The niche of Chicocorus rubidus and Didesmococcus koreauus overlapped larger than that of the others,which indicated their synchrony in temporal dimension and their similarity in spatial dimension.As the dominant natural enemies,the two populations should be protected and utilized to control plum pest.
    Suppressive effects of non-preferable plant alcohol extracts on diamondback moth Plutella xylostella population
    XIAN Jidong, LIANG Guangwen, SHEN Shuping, PANG Xiongfei
    2005, 16(2):  313-316. 
    Asbtract ( 1515 )   PDF (210KB) ( 471 )  
    In this paper,a life table and an interference index of population control (IIPC) were used to evaluate the effects of spraying the alcohol extracts of non-preferable plants on the dynamics of diamondback moth Plutella xylostella) population.The results showed that the alcohol extracts of Eupatorium odoratum,Lantana camara and Wedelia chinensis were available to protect kidney bean from Plutella xylostella infestation.Their IIPC were 0.110,0.136 and 0.165,and the efficacies of controlling P.xylostella were 89.0%,86.4% and 83.5%,respectively,compared with control.
    Scanning electron microscopic observations of Monochamus alternatus antennal sensilla and their electroantennographic responses
    WANG Sibao, ZHOU Hongchun, MIAO Xuexia, FAN Meizhen, LI Zengzhi, SI Shengli, HUANG Yongping
    2005, 16(2):  317-322. 
    Asbtract ( 1719 )   PDF (883KB) ( 891 )  
    With scanning electron microscope (SEM),this paper observed the shape,category,amount and distribution of the main antenna sensilla of adult Monochamus alternatus,and tested their electroantennographic (EAG) responses to the main volatiles of Pinus spp..There were seven types of antennal sensilla,i.e.,sensilla trichoid,sensilla basiconica,sensilla digit-like,sensilla rod-like,sensilla bottle-like,sensilla bud-like and sensilla chaetica,among which,sensilla trichoid and sensilla basiconica were the most abundant on the antenna surface,and each of them could be divided into three subtypes.Two subtypes of sensilla digit-like could also be observed.The Ⅱ and Ⅲ subtypes of sensilla trichoid and I and Ⅱ subtypes of sensilla basiconica had deep longitudinal grooves on their surface,the typical characteristics of olfactory receptor.The comparison of the EAG response of different parts of Monochamus alternatus antennae to α-Pinene showed that each volatile and their compounds could provoke significant EAG responses of both females and males.The dose-response test showed that there was a certain rule in the EAG responses of M.alternatus.
    Selection behavior of Cuscuta japonica on their hosts
    HU Fei, KONG Chuihua, ZHANG Chaoxian, LIANG Wenju, WANG Peng
    2005, 16(2):  323-327. 
    Asbtract ( 1624 )   PDF (561KB) ( 497 )  
    A field investigation on the selection behavior of Cuscuta japonica on their hosts showed that among the test plant communities,the number of coiling,the time of haustorium occurring,and the rate of coiling of C.japonica on hosts followed the order of B.papyrifera,W.chinensis,I.cairica,and L.camara; but the length of the elongation of C.japonica growing tips from coiling to haustorium occurring was with the order of L.camara,I.cairica,W.chinensis,and B.papyrifera.Furthermore,the growing tips of C.japonica coiled 3 circles in left direction on all selected hosts in 12 hrs,but grew away after contacting PVC rods within 24 hrs.The host diversity of C.japonic was beneficial to the survival of both C.japonica and its hosts.The selection behavior of C.japonica on their hosts had no correlation with the total N contents of different hosts.It could be postulated that the secondary metabolites of hosts made a contribution to the selection behavior of C.japonica on their hosts.
    Cu and Zn pollution and soil enzyme activities in sewage irrigation area near smeltery
    WANG Guanglin, WANG Lilong, WANG Yupeng, LIU Dengyi
    2005, 16(2):  328-332. 
    Asbtract ( 1482 )   PDF (722KB) ( 510 )  
    This paper studied the Cu and Zn status in soil and rice plant as well as the soil enzyme activities in the sewage irrigation area near a smeltery.The results showed that the soils near the smeltery were polluted.The soil total and extractable Cu contents at the distance of 100 m were 182.45 and 81.91 mg穔g-1,respectively,9.3 and 34 times higher than the control.The Cu concentration in different parts of rice was in order of root>leaf and stem>grain,while the Zn concentration was in order of leaf and stem>root>grain.Zn was more mobile than Cu which was likely to accumulate in rice root.It was considered that root could act as a barrier which retarded the upwards transport of Cu and protected the above ground parts of rice from toxication.The Cu contents of rice stem and leaf had a significant correlation with soil Cu contents in the sewage irrigation area.Among the three test enzymes,urease was the most sensitive one to Cu,and its activity had a significant correlation with soil Cu content.Therefore,it is feasible to use soil urease activity as an indicator of soil Cu pollution in sewage irrigation area near the smeltery.
    Effects of acid rain on nitrogen content in the water body of Wenzhou Sanyang wetland
    ZHANG Xiufeng, HE Wenshan, LU Jianjian
    2005, 16(2):  333-336. 
    Asbtract ( 1545 )   PDF (570KB) ( 473 )  
    In order to understand the effects of acid rain on the nitrogen (N) content in the water body of Wenzhou Sanyang wetland,this paper measured the concentrations of different N forms in the wetland,of which,NH4+-N was 2.90～10.75 mg·L-1,average in 5.38 mg·L-1; NO3--N was 0.16～0.44 mg·L-1,average in 0.31 mg·L-1;and total was 34.04～63.20 mg·L-1,average in 55.75 mg·L-1.The pH value was 6.1～6.5,average in 6.4.The measurement of the N input from precipitation in the past two years and its proportion to the existed N in the water body of the wetland showed that the input of NH4+-N,NO3--N and total N was 2.48×104～2.86×104 kg,2.87～4.96×104 kg and 5.35×104～7.82×104 kg,and its proportion was 56～64%,11.21～19.38 times and 12%～17%,respectively.The N amount directly to the wetland water body was 0.72×104～0.84×104 kg,0.83×104～1.44×104 kg and 1.55×104～2.27×104,and its proportion was 16%～19%,3.24～5.63 times and 3%～5%.The results indicated that acid rain was one of the main sources of pollutant nitrogen which aggravated the water pollution of the Sanyang wetland.
    Physiological responses of Ceratophyllum demersum under different nutritional conditions
    WANG Jun, GU Yufei, Zhu Zengyin, WU Bin, YIN Daqiang
    2005, 16(2):  337-340. 
    Asbtract ( 1651 )   PDF (508KB) ( 516 )  
    With static experiments,this paper investigated the protein and chlorophyll contents,and the peroxidase (POD) and superoxide dismutase (SOD) activities of Ceratophyllum demersum cultured in meso-,eutro-and hypertrophic and Hoagland's solutions.The results showed that the changes of total N (TN) and total P (TP) concentrations in nutrient solutions had an obvious effect on the biosynthesis of C.demersum.When the concentrations of TN and TP were less than 1 mg稬-1 and 0.1 mg稬-1,respectively,the protein and chlorophyll contents of plant declined.The plant from eutrophic solution had higher SOD and POD activities.It was indicated that C.demersum was more preferable to eutropic condition (1 mg TN稬-1 and 0.1 mg TP稬-1),and the raised concentration of nutrients (e.g.,hypertrophic and Hoagland's solutions) was a stress to C.demersum and could affect its hardiness physiology.
    Effects of Dipterocarpaceae on arbuscular mycorrhizal fungi
    SHI Zhaoyong, MENG Xiangxia, CHEN Yinglong, LIU Runjin
    2005, 16(2):  341-344. 
    Asbtract ( 1487 )   PDF (626KB) ( 433 )  
    An investigation was carried out on the colonization percentage,spore density,relative abundance,occurrence frequency,and species richness of arbuscular mycorrhizal (AM) fungi on 4 species of Dipterocarpaceae trees grown both in natural forests in Yunnan and Hainan Provinces and in greenhouse pots.The results showed that all dipterocarp species were able to form AM,the colonization rates ranged from 30.6% to 45.3%,37% on average.Hopea hainanensis (Dipterocarpacea) seedlings without AM fungal colonization were cultivated in pots with soil collected from Dipterocarpacea rhizosphere,and harvested a year later.The colonization rate of the seedlings ranged from 10.6% to 20.3%,14.2% on average,indicating the significant effect of host plants on AM fungi frequency.The relative abundance of Glomu,Acaulospora and Gigaspora also varied with host plants.It was concluded that the dominant AM fungi in the rhizospheric soil of dipterocarp plants were Acaulospora spp.and Glomus spp.Using the same species of Dipterocarpacea as host plants might promote the growth and development of AM fungi,and increase the AM diversity.
    A comprehensive quantitative assessment model for arid area's basin water-soil environment quality
    SONG Songbai, CAI Huanjie
    2005, 16(2):  345-349. 
    Asbtract ( 1427 )   PDF (265KB) ( 364 )  
    The existing assessment models for water-soil environment quality are usually established on the relationships between assessment indicators and their assessment criteria.Such kinds of models are varied with regional scale,and always need a mass of calculation work.This paper tried to find a general assessment model based on a given water-soil quality assessment criteria.In this process,stochastic technology was used to simulate enough assessment indictor series,and then,assessment model was built up by using artificial neural network to assess these series.This model could reduce work load,and needn't construct functional relations between assessment indicators and their criteria and calculate weigh value.A case study in a basin with the highest level of water resources utilization showed that the model was practical and convenient,and could be used in basin water-soil quality assessment.
    Correlation analysis on the damage of Mikania micrantha to plant communities in Neilingdind Island of Guandong Province,China
    ZHOU Xianye, WANG Bosun, LI Mingguang, LIAO Wenbo, ZHOU Yunlong, ZAN Qijie, WANG Yongjun
    2005, 16(2):  350-354. 
    Asbtract ( 1508 )   PDF (265KB) ( 362 )  
    The analysis showed that 58 species of trees,short-trees and shrubs in Neilingding Island of Guangdong Province were damaged by M.micrantha,of which,woody trees accounted for 67%.Short-trees and sunny shrubs were damaged most seriously,followed by the communities with low canopy density consisted of only 2 dominant species,and those with high canopy density consisted of 5 or 6 dominant species.The coverage of M.micrantha mainly related to the vertical structure of plant communities.The taller the community height and the more the synusia,the lesser was the coverage of M.micrantha.The damaging ratio mainly related to species diversity and community density.The higher the species diversity and community density,the lower the damaging ratio was.The damaging degree mainly related to the coverage of other liana.The more the coverage of other liana,the higher was the damaging degree of M.micrantha.
    Effects of ecological environment in Qinba Mountains on hair trace element contents of local inhabitants
    GAO Yunfang, ZHANG Xiaoyan, ZHANG Fuchang
    2005, 16(2):  355-359. 
    Asbtract ( 1492 )   PDF (328KB) ( 374 )  
    Determinations of Zn,Fe,Ca,Cu,Mg,Al,Se,Mn,Cr and Pb contents in the hairs of 136 children aged 0～13 and of 22 adults in the Qinba Mountains showed that the contents of test trace elements except Mg were abnormal in different degrees.The Al,Mn and Cr contents were highly excessive,their mean values being 2.04,1.67 and 2.07 times as the highest value of normal range,and the people excessive in three elements occupied 83.54%,77.85% and 72.78%,respectively.On the other hand,Zn and Se contents were in shortage,with the mean values being only 91.96%and 68.33% of the lowest value of normal range,and the people deficient in Zn and Se occupied 69.62% and 79.11%,respectively.Based on the local environmental geochemistry,this paper analyzed the possible causes of this abnormal status in trace elements and its harm.
    Ecological restoration and reconstruction of degraded lakeside zone ecosystem
    YAN Changzhou, JIN Xiangcan, ZHAO Jingzhu, YE Chun, WANG Zhongqiong
    2005, 16(2):  360-364. 
    Asbtract ( 1670 )   PDF (772KB) ( 1016 )  
    As a kind of aquatic-terrestrial ecotone,lakeside zone plays an important role in the lake basin ecosystem,and has high ecological,social and economic values.Its functions include lake buffer,conservation of biological diversities and special habitats,dike protection from soil erosion,and economic and esthetics values.The main factors inducing lakeside zone degradation are the anthropogenic activities that caused the converse succession of communities and the decline of ecological function.The theoretical basis of ecological restoration and reconstruction of degraded lakeside zone is restoration ecology; while the technologies are of three types,i.e.,habitat restoration and reconstruction,species restoration and reconstruction,and structural and functional restoration.A three-year case study on the ecosystem restoration and reconstruction of degraded lakeside zone of Erhai Lake in Yunnan Province showed that the aquatic macrophytes were restored,purifying function was distinct,algae were restrained,and the component and individuals of zooplankton were changed.In a word,the biological diversity and stability in the degraded lakeside-zone ecosystem increased after the restoration and reconstruction.
    Research advance in response of forest seedling regeneration to light environmental heterogeneity
    CHEN Shengbin, SONG Aiqin, LI Zhenji
    2005, 16(2):  365-370. 
    Asbtract ( 1691 )   PDF (816KB) ( 780 )  
    Based on the analysis of characteristics of forest light environmental heterogeneity,this paper reviewed the research advance in the response of forest seedlings to light environmental heterogeneity from the aspects of photosynthesis,thermal dissipation,biomass accumulation and distribution,morphological traits,germination,and population dynamics,and discussed the ecological significance of different responses of seedling regeneration to light environmental heterogeneity in forest biodiversity maintenance,forest succession,and revegetation.Some suggestions for future research in this field were put forward.
    Research advances in catalytic kinetics of soil oxidoreductase
    ZHANG Lili, CHEN Lijun, ZHANG Yulan, WU Zhijie
    2005, 16(2):  371-374. 
    Asbtract ( 1621 )   PDF (129KB) ( 791 )  
    Soil oxidoreductase is a group of enzymes catalyzing many important soil biochemical reactions and concerning with the transformation of soil organic matter,formation of humic substance,and dynamics of soil fertility.The catalytic kinetics of oxidoreductase can illuminate its catalytic characteristics,substantial properties,and response to environmental changes.This paper summarized the research advance of its kinetics,and proposed some comments in understanding its action mechanism and in regulating its catalytic processes.
    Redundancy theory and its application in agro-ecosystem management
    HAN Mingchun, WU Jianjun, WANG Fen
    2005, 16(2):  375-378. 
    Asbtract ( 2075 )   PDF (227KB) ( 685 )  
    Redundancy theory is an ecological theory developed in 1990s.This paper gave a brief introduction on the concept of redundancy,its hypothesis and redundancy degree,and briefly reviewed the research advances in redundancy theory and in the methodologies about species redundancy,layer redundancy,gene redundancy,and growth redundancy.A hypothesis of optimal growth redundancy degree (OGRD) was proposed,i.e.,under certain cultivation and management conditions,there existed a growth redundancy degree corresponding to the highest crop yield,and a high yield would be obtained if OGRD could be achieved through the regulation of management practices.The hypothesis was tested by using the data from high-yielding rice cultivation cases.
    Research advance on environmental exposure and ecotoxicological effects of polybrominated diphenyl ethers (PBDEs)
    SUN Fuhong, ZHOU Qixing
    2005, 16(2):  379-384. 
    Asbtract ( 1766 )   PDF (1195KB) ( 726 )  
    Polybrominated diphenyl ethers (PBDEs) are a group of new type organic pollutants with significant ecological risk.As flame retardants,they have been increasingly added to industrial products,and thus,resulted in more and more extensive pollution of air,water,sediment and soil as well as their relevant ecosystems.In view of the new environmental problem and based on limited available data,this paper approached the anthropogenic sources of PBDEs and their pathways of environmental exposure,and gave the possible occurrence and concentration of PBDEs in several living organisms and different human tissues.The toxic effects and ecological influences of PBDEs acting on animals and human beings,and their potential biological accumulation and magnification in ecosystems were analyzed in the aspects of hypothyroid,neurotoxicity,and reproductive and developmental toxicity,and the pivots of further researches on environmental exposure,ecological effects and human health influences of PBDEs were thus suggested.
    Application of microsatellite DNA in molecular ecology and strategies for loci isolation
    XUE Hui, WU Xiaobing, YAN Peng
    2005, 16(2):  385-389. 
    Asbtract ( 1515 )   PDF (691KB) ( 915 )  
    Microsatellite DNA has been widely used as a good genetic marker in molecular ecology.This paper reviewed its application in molecular population biology,molecular environmental genetics,and molecular adaptation.The isolation of the loci is the basis of microsatellite DNA genetic analysis.Compared with the traditional isolation method by genomic library,some novel approaches carried out recently,such as enrichment library,PIMA and FIASCO,are more efficient and timesaving.The details and compare-analysis of these approaches were introduced,which would offer good choices for researches on molecular ecology.
    Mercury concentration and its distribution in Nycticorax nycticorax and Chinese Ardeola bacchus fledglings at Huangpu District of Guangzhou City,China
    ZOU Fasheng, YANG Qiongfang, LI Yanhong, CUI Kunyan
    2005, 16(2):  390-392. 
    Asbtract ( 1466 )   PDF (199KB) ( 331 )  
    In this study,live fledglings of Nycticorax nycticorax and Ardeola bacchus at the Huangpu District of Guangzhou City were collected,and their primary feather,breast feather,tail feather,liver,chest muscle and egg shell were sampled for mercury determination.The results showed that these two heron species had a very similar distribution pattern of mercury concentration in their tissues and organs,i.e.,tail feather > breast and primary feather > liver > chest muscle > egg shell.Ardeola bacchus had higher levels of mercury in all its tissues than Nycticorax nycticorax.There were significant interspecific differences in mercury level for breast feather and primary feather.Because the collection of breast feather is easier and not harmful to birds,it is better to use it rather than primary or tail feather to monitor environmental pollution.The mercury level in breast feather was ten times higher than that in liver,lower than that in tail feather,but not significantly different to that in primary feather.The mercury concentrations in the tissues of Nycticorax nycticorax and Ardeola bacchus from Huangpu District of Guangzhou were similar to those from the suburbs of Chengdu,Sichuan Province,but lower than those from Taihu Lake,Jiangsu Province and higher than those from Hong Kong.
    Effects of no-tillage plus inter-planting and remaining straw on the field on cropland eco-environment and wheat growth
    LIU Shiping, ZHANG Hongcheng, DAI Qigen, HUO Zhongyang, XU Ke, RUAN Huifang
    2005, 16(2):  393-396. 
    Asbtract ( 1475 )   PDF (766KB) ( 735 )  
    The studies showed that under no-tillage plus inter-planting rice and wheat,the height of rice stubble remained on the field significantly affected light transmission rate,with an optimal height of 20～30 cm.No-tillage and straw-remaining decreased soil temperature at noon in sunny days,but slightly increased it in the morning and evening,led to a less diurnal difference of soil temperature.The average diurnal soil temperature under no-tillage was higher in cloudy but lower in sunny days.Under no-tillage and straw-remaining,both the bulk density and the penetration resistance of topsoil increased,but no apparent adverse effect of them was observed on wheat growth.Under no-tillage,soil water content was higher under drought condition,and soil permeability after irrigation was better,which was propitious to the wheat growth.Straw-remaining significantly inhibited weeds,but led to the decrease of basic seedlings and enhanced the damage of freezing.Under no-tillage plus inter-planting,the individuals of effective ears decreased,while the kilo-grain weight increased.The grain yield was slightly but not significantly low under no-tillage plus inter-planting.