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Table of Content

    10 July 2005, Volume 24 Issue 07
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    Analysis of vegetation index sensitivity to soil moisture in Northern China
    ZHANG Qiang, XIAO Fengjin, NIU Haishan, DONG Wenjie
    2005, (7):  715-718. 
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    Soil moisture had severe influence on vegetation index.Using normalized difference of vegetation index (NDVI) derived from 8km NOAA/AVHRR data,the soil moisture of surface layer of 0～10 cm and deeper layer of 10～20 cm from 1981 to 1998 was obtained from meteorological stations,and the vegetation index sensitivity to soil moisture in Northern China was studied.The result showed that the average soil moisture as a whole had a trend of decrease in Northeastern and Northern China,while a trend of increase in Northwestern China.The responses of vegetation index to soil moisture had evident differences in different sub-regions.The sensitivity of vegetation index to soil moisture was the strongest in Northwestern China,followed by Northern China and Northeastern China.This trend was also fit for deeper layer soil moisture,but only the extent was lower than that for surface layer soil moisture.The sensitivity was also reflected in various seasons.In spring,soil moisture had strong influence on vegetation index in Northern China (P<0.05),then Northwestern China and Northeastern China,orderly.In summer and autumn,the correlations were significant at the 0.05 level,while in winter the correlation between vegetation index and soil moisture was not obvious in all of the three regions.
    Leaf development stability of Platanus acerifolia under urban environmental stress and its implication for environmental indicator
    ZHANG Hao, WANG Xiangrong
    2005, (7):  719-723. 
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    The development stability indices including leaf width based fluctuating asymmetry (FA1) and lateral vein length based directional asymmetry(RDA1) of Platanus acerifolia were studied,with all the leaves sampled from 14 sites categorized with different urban environmental stress levels(UESL) in Shanghai city.The stomatal density and stomatal length were investigated as the subsidiary indices to test the availability of developmental stability indices as the indicator under the stressful environment.The results showed that there was significant difference between FA1 and RDA1 under different environmental stresses during the 3 sampling periods.Between FA1 and UESL,a significant negative correlation was derived,i.e.,FA1=0.029-0.0009UESL+0.0003UESL2(r=0.7665,P=0.0014),while similar trend was not found between RDA1 and UESL.The significant correlations between FA1 and leaf stomatal length and stomatal density implied that they could be used as indicators for urban stress levels at small scale.RDA1 was possibly the normal parameter during leaf development but unsuitable to be as the indicator of urban stresses.
    Soil seed banks of Achnatherum splendens steppes in the Qinghai Lake area
    ZHOU Guoying, CHEN Guichen, WANG Shunzhong, HAN Youji
    2005, (7):  724-728. 
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    The study was conducted in the sheep breeding pasture-land of Sanjiao in Qinghai Province,which was located on the northern bank of Qinghai Lake.The germinated seed accumulation,density,amount,diversity of Achnatherum splendens communities,soil seed banks,and relationship between the vegetation and soil seed banks were studied and compared within and out of the fence.The results showed that the germination trend of soil seed banks was similar within and out of the fence,while the seed accumulation was different.The average density of germinationant seed within and out of the fence was 3660 seeds穖-2 and 2460 seeds穖-2.The number of seed accumulation was between 103 and 104 seeds穖-2.Diversity indices of soil seed banks within and out of the fence were significantly different.Richness indices R1 and R2 within and out of the fence were 17 and 13,3.693 and 2.832,respectively.The change of diversity indices was the same as richness indices.Evenness indices E1 within and out of the fence were 0.812 and 0.857 respectively.The community composition within and out of the fence was significantly different.The diversity index change of vegetation was the same as the soil seed banks.
    Effects of stocking rate and grazing time of yaks on soil nutrient contents in Kobrecia parva alpine meadow
    DONG Quanmin, ZHAO Xinquan, MA Yushou, LI Qingyun, WANG Qiji, SHI Jianjun
    2005, (7):  729-735. 
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    The results of grazing trial about yaks for two years showed that in summer,contents of different soil stratums and average contents of 0～20cm stratum for organic matter (OM),organic carbon (OC),total nitrogen (TN),total phosphorus (TP) and available phosphorus (AP) were negatively correlated with stocking rate with a linear regressive relationship,while it was quadratic regression between contents of available nitrogen (AN) and stocking rate.In winter,contents of different soil stratums and average contents of 0～20cm stratum for OM,OC,TN were negatively correlated with stocking rate linearly,while those of TP,AP and AN were quadratically correlated with stocking rate.In summer pasture,with the increase of stocking rate,contents of AN for different stratums decreased with depth.When stocking rate was 1.07,1.08 and 1.22 heads·hm-2 respectively,contents of AN for 0～5 cm,5～10 cm and 10～20 cm in sequence reached the minimum value.In winter pasture,contents of TP,AP and AN for 0～5 cm,5～10 cm and 10～20 cm,respectively reached the maximum value when stocking rate was 0.81,0.78 and 1.00 heads·hm-2,1.03,1.09 and 1.03 heads·hm-2,and 1.36,1.35 and 1.30 heads·hm-2,respectively.In addition,in summer pasture,average contents of AN for 0～20 cm soil stratum reached the minimum value when stocking rate was 1.07 heads·hm-2,while contents of TP,AP and AN were the maximum at 0.90,0.83 and 1.21 heads·hm-2 respectively in winter pasture.
    Functional responses of Pediobius foveolatus to Henosepilachna vigintioctopunctata
    WANG Guohong, TU Xiaoyun
    2005, (7):  736-740. 
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    Functional responses of Pediobius foveolatus to Henosepilachna vigintioctopunctata were studied in this paper.The results showed that the functional responses of P.foveolatus to host larval density of H.vigintioctopunctata could be described very well by Holling disc equation Ⅱ at all test temperatures.The maximum values of searching rate of Pediobius foveolatus to H.vigintioctopunctata in Solanum melongena groups and Solanum nigrum groups were 1.85 and 1.94,respectively.On the branches of Solanum melongena,Solanum nigrum,Physalis alkekengi var.francletii and Lycopersicon esculentum,the maximum interfering coefficients in the groups of Physalis alkekengi var.francletii and L.esculentum were 0.50 and 0.28,respectively.P.foveolatus did not parasized the 1st lavae,the values of searching rate in the 4th group were the maximum,followed by the 3rd and 2nd groups.The searching rate in the Avermectin group was the maximum,followed by the Bt and Celangulin groups.The searching rates in Dichlorovos and Cypermethrin groups decreased sharply compared with the others,while the handling time increased relatively.
    Simulation experiment of RCM and crop model combination and its uncertainty assessment
    XIONG Wei, XU Yinlong, LIN Erda, TIAN Zhan
    2005, (7):  741-746. 
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    Combining RCM-PRECIS (Resolution 50 km?50 km) regional climate model with the CERES crop model validated and calibrated with field experiment and observed weather data,impacts of climate change on agriculture and the uncertainty of the method were estimated in this paper.The results showed that compared with GCMs,RCM combined with the crop model could omit the intercurrent process of stochastic weather generator and decrease the assessment uncertainty.Site scale simulation indicated that the method was effective in plain areas,while not so good in mountain areas,which could be improved greatly if the weather data were validated with the observed data.Applied at regional scale simulation,the method could reflect the yield distribution effectively.But uncertainty increased due to limitation of spatial data.
    Ecological variation of wheat grain protein components and its relationships with N translocation
    JING Qi, DAI Tingbo, JIANG Dong, CAO Weixing
    2005, (7):  747-750. 
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    Wheat grain protein and protein components play a key role on grain-processing quality such as dough rheology and food cooking.The formations of protein components are in sequence and closely related to N accumulation and translocation after anthesis in wheat.Three wheat cultivars differing in grain protein contents grown at two different ecological sites were used to study the variations of protein and protein component contents.Significant genotype differences in protein and protein component contents were found among three wheat cultivars of the two eco-sites.There was a increase of crude protein content in wheat at Xuzhou signifiantly higher than that at Nanjing,which was resulted from the increase of albumin and glutenin contents.N accumulation and translocation after anthesis at Xuzhou were higher than that at Nanjing,while N assimilation after anthesis was higher at Nanjing than at Xuzhou.The contents of albumin,gliadinin and glutenin had soundly positive relationships with protein content and N translocation after anthesis.There were similar temporal shape of development rate after anthesis,but the highest rate appeared later at Nanjing than at Xuzhou.High development rate hampered the formation of albumin and glutenin in wheat at Nanjing,which led to a lower total grain protein in wheat at Nanjing than that at Xuzhou.
    Climatic warming-drying trend in Northeastern China during the last 44 years and its effects
    SUN Fenghua, YANG Suying, CHEN Pengshi
    2005, (7):  751-755,762. 
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    Northeastern China is one of the areas mostly influenced by global change and has particular climate characteristics. According to the data from 1949, climate changes, including climate jumps and climatic warming-drying trend, during the last 44 years were analyzed with the methods of Yamamoto check and climate trend coefficient. Possible effects of this change on eco-environment were discussed. The results showed that the climate in the area trended to become warming-drying, with seasonal and regional differences. It was more obvious in summer and autumn and in sensitive areas such as Sanjiang Plain and Horqin sandy land. Eco-environment problems resulted from the climate change should be recognized.
    Gray analysis on responses of desert/grassland biome transition zone to global warming-A case of the desert/grassland biome transition zone in New Mexico
    LIU Qinpu, LIN Zhenshan
    2005, (7):  756-762. 
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    Ecosystems on the earth exhited different responses to global warming.Biome transition zones or ecotones are considered to be particularly sensitive areas to climate changes.Sevilleta desert/grassland biome transition zone in New Mexico,USA is an important region for testing species' responses to changing environmental conditions.In this paper,changes of density,pattern and change trend of the two dominant plants,Bouteloua eriopoda and B.gracilis,in Sevilleta ecotone were studied with gray analysis method.The results showed that the density of Bouteloua eriopoda coming from deserts increased and that of B.gracilis from grassland decreased from 1989 to 1998,with the ratio between the density of B.eriopoda and that of B.gracilis over 1,and still increasing.The maximum temperature was the key factor among precipitation,temperature and humidity which contributed to the changes.The trend that the desert species B.eriopoda would strongly dominate in the mixed community indicated that Sevilleta ecotone would probably be replaced by desert grassland with global warming continuing.
    Assessment of annual variation for ecosystem health at Meiliang Bay,Lake Taihu
    HU Zhixin, HU Weiping, ZHANG Fabing, ZHONG Chunni
    2005, (7):  763-767. 
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    Ecosystem health is a new field in ecology and environmental management.Lake ecosystem health contains the capability of supplying services for people and maintaining its function and restoration.Assessment of lake ecosystem health is the basis of lake environmental management and ecosystem control.Exergy(Ex),structural exergy(Ex(st)) and ecological buffer capacity(β) were applied to the ecosystem health assessment of annual variation at Meiliang Bay ecosystem.The health state of Meiliang Bay ecosystem in 2001 decreased as the following order: March to April,January to February,November to December,September to October,May to June,and then July to August,which was similar to those estimated by trophic state index(TSI) and diversity index(DI).Therefore it is feasible to use exergy,structural exergy and ecological buffer capacity to evaluate the health state of lake ecosystem.
    On the absorptive characteristics of Microcystis and Scenedesmus
    WU Shengcai, ZHANG yunlin, CHEN Weimin
    2005, (7):  768-772. 
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    The diffuse attenuation coefficient (Kd) of 6 densities of Microcystis and Scenedesmus cell media were measured in simulative column indoor.The specific absorption coefficient (SAC) and the contribution of cell to total Kd were calculated after testing the content of chla.The absorption coefficient of dissolved organic carbon (DOC) was derived from the conversion of absorbance value in spectrophotometer.The result indicated that the spectrum characteristic of 2 kinds of algal cell in higher densities was similar and the Kd at 3 higher density of both algae had the same trend.The contribution to Kd was 84.95% (Microcystis) and 88.15% (Scenedesmus), respectively.Their mean SAC in 3 higher densities demonstrated parallel spectrum property.There were two obvious peaks in 380～500nm and 660～690nm with the corresponding peak values 0.1118,0.0413(m2·mg-1chla) at 435 nm and 0.075,0.032(m2·mg-1chla) at 670 nm.Scenedesmus cell has much higher SAC than Microcystis cell.The mean SAC of 3 densities of Scenedesmus in 340～800 nm was 0.0573(m2·mg-1 chla),while that of Microcystis was 0.0234(m2·mg-1 chla).The ecological significance of the differences and the potential utilization in remote sensing monitoring were discussed.
    Comparison of ecological characteristics between Gongping Reservoir and Xinhu Lake,Guangdong Province
    LIN Shaojun, GU Jiguang, WEI Peng, HAN Boping
    2005, (7):  773-779. 
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    Based on sampling and analysis of ecological Characteristics,we compared the physical factors,nutrients and phytoplankton structure of Gongping Reservoir and Xing Lake,which were similar in trophic level and water depth.The results suggested that there were significant differences in ecological processes between the reservoir and the lake,which was mainly attributed to the difference in hydrodynamics.The water retention time at Gongping Reservoir was half of that at Xing Lake,and the water column of Gongping Reservoir was well mixed over the year,while Xing Lake was stratified in summer.The nutrient concentration in Gongping Reservoir,which was affected mostly by watershed inputs,was higher in flooding season than in dry season, with highest value occurred in July.However,in Xing Lake,affected mostly by inter-cycle,the nutrient concentrations were high near the end of the dry season,but fell in July and the concentration of TP went up when the stratification disappear.The difference of retention time also resulted in different dominant phytoplankton groups.Xing Lake was dominated by Cyanobacteria for its longer retention time and steady water column,while Gongping Reservoir was dominated by Bacillariophyta.
    Character of zooplankton community and its variation in the water near the Yangtze River estuary
    XU Zhaoli
    2005, (7):  780-784. 
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    Based on the data of 8 voyages' investigation in May and August from 2000 to 2003 in the fisheries water near the Yangtze River estuary,this paper dealt with the variation trend of species composition and diversity of zooplankton.The results showed that species number of Heteropoda,Chaetognatha and Copepods in August was higher than that in May.The force of warm current enhanced with the enforcing Yangtze River freshwater in August.At the converge of different water current,isoline of species number and diversity of zooplankton were closely arranged.The rich species brought by warm current in August increased the species number and diversity value in August and were higher than those in May.Salinity was the most important environmental factor affecting community character of zooplankton in the water near the Yangtze River estuary.
    Assessment of the water quality using protozoan communities during low water period in Baiyangdian Lake
    LI Fengchao, SHEN Yunfen, LIU Cunqi, GUAN Yueqiang, SU Yanping, JIA Hong
    2005, (7):  785-789. 
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    The water level of Baiyangdian Lake has been under lowstand state for 5 years.The current water quality of the lake was evaluated using protozoan communities,which were collected by PFU (Polyurethane Foam Unite) artificial subtracts.The results showed that Baiyangdian Lake was still affected by waste water of Fuhe River.The internal source pollution of Baiyangdian Lake had a strong impact on the protozoan communities.The colonization species of protozoa decreased,with the abundance increased by 1.28 times at four sampling plots.Compared with the data of the middle 1990s,the effect of internal pollution sources on Baiyangdian Lake was more serious.
    Vertical landscape ecology of eco-agricultural tourism in the hilly area
    YAN Xianchun, SU Zhixian, XU Xiao, PENG Zhengsong, TANG Xiaoping, LUO Fuyan
    2005, (7):  790-794. 
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    Based on the landforms in the hilly area of suburbs,the landscape of eco-agricultural tourism should be designed according to the degrees of slope and contour line of hills in order to develop a water-conserving forest on the tops,a peach tree covering on the upper slope section,a loquats tree covering in the middle slope section,a covering of special fruit trees and melons and vegetables on the lower slope section,and a special water area at the bottom.The model of vertical eco-landscape could bring in efficiency of landscape and ecology.In the experimental area,the vegetation coverage was increased and the biodiversity was restored.The landscape forests helped to lower the air and soil temperature,and the daily temperature changes decreased while the relative humidity increased.The good effects increased in the order of crops field,water-conserving forest and fruit tree forest.Wildly growing-grass and man-planted herbage in orchards could improve the relative humidity in the air,reduce air and soil temperature,lower the daily changes of temperature and conserve water and soil.
    Comparison of the quantity of normal flora in digestive tracks betweeol SPF and ordinary chicken
    LIU Hongjie, CHENG Liangui, NIU Zhongxiang, WANG Jianchang, NING Haiqiang
    2005, (7):  795-798. 
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    Qualitative and quantitive investigations wasere carried out on the intestinal bacterial community in SPF and ordinary chicken.Nine kinds of dominant intestinal bacteria were selected and counted on various selective media.The results showed that when comparing SPF with ordinary chicken,significant differences were found in the number of clostridium,eubacterium,staphylococcus and escherichia coli in crop (P<0.01),staphylococcus(P<0.05) in proventriculus,bacteroides (P<0.01) in ileum,lactobacillus (P<0.05) in caecum,and bifidobacterium and lactobacillus (P<0.05) in rectum.
    Silviculture of Mongolian pine (Pinus sylvestris var.mongolica) plantations on sandy land
    KANG Hongzhang, ZHU Jiaojun, XU Meiling
    2005, (7):  799-806. 
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    Sustainable forest management is directly related to silvicultual activities.Achievements of afforestation in China are world famous,while,with the development of afforestation,some worrying events have turned out.For example,the monoculture of pure stands has caused gradual decrease of stand growth,and led to the loss of biological diversity,disequilibrium of forest ecosystem and the occurrence of disasters.As a valuable conifer tree species,Mongolian pine (Pinus sylvestris var.mongolica) has become a major tree species and been broadly introduced to sandy land in the arid and semi-arid area of northern,northwestern and northeastern China.However,the plantations of Mongolian pine on sandy land have declined in different degrees since early 1990s.In order to achieve sustainable forest management,it is important and significant to review and discuss the silvicultual activities of Mongolian pine plantations.Based on a wide range of literature collection on Mongolian pine,the research development on silviculture of Mongolian pine were summarized,which included the reason of low survival rate of afforestation and the techniques to improve it,the production of seed,the management of stand density,cultivation pattern,thinning and regeneration etc.Some problems to be solved were put forward and the suggestions were given.
    Application of ordination and GLM/GAM in the research of the relationship between plant species and environment
    ZHU Yuan, KANG Muyi
    2005, (7):  807-811. 
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    Ordination and GLM/GAM are both important methods to explore the relationship between plant species and environment.Generally,ordination methods,based on linear model,are suitable for dealing with the vegetation within a comparatively short environmental gradient,while those based on unimodal model are more suitable for tackling with the vegetation distributing along a longer gradient.PCA,CA/RA series and CCA series are the most commonly used ordination methods.Involving the environmental data in the analysis,CCA series could demonstrate the relationship between plant species and environment clearly.After modification,DCCA and PCCA are considered to be ideal ordination methods at present.Essentially,General Linear Model (GLM) and General Additive Modal (GAM) were using the high power polynomials of environmental variables to fit the response of plant species to environment.So,the models for delineating the relationship between species and environment have been enhanced through the introduction of GLM and GAM in recent years.GLM is basically driven by model,while GAM is more driven by data.In comparison,ordination can obtain the main environmental gradient and provide the general information of species assembling and plant community in the study area.GLM and GAM have advantages in probing deeply into the relationship between plant species and environment.In practice,the two kinds of methods can yield better results when used in combination.
    Maternal effect and its role in population regulation of small mammals
    ZHANG Zhiqiang, WANG Dehua
    2005, (7):  812-816. 
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    Maternal effect refers to parental phenotypes having a direct influence on their offspring phenotype.It is a phenotypic response of maternal offspring to different environmental conditions and an important source of evolutionary dynamics.It might be related to the population cycles of some small mammals.This paper introduced the development of the concept of maternal effect and the factors of nutrition and non-nutrition which influenced its performance.We focused on the role of photoperiod and hormone manipulation.At the population level,some measurement indexes were reviewed and the average individual mass was considered to be a proper candidate as the reflection of population mass.The main content of senescence-maternal effect hypothesis was summarized and its relationship with population dynamics was explicated.For small mammals,some evidences of both experimental manipulation and field studies showed that the changes of maternal mass might played an important role in periodical population fluctuations.The hypothesis focused on individual heterogeneity and highlighted the changes of physiology among individuals.It proposed that the changes of maternal mass miqht affect the reproduction and survival of its offspring and this effect could last for 2 to 3 generations.Maternal effect combined with the senescence effect could interpret the phenomenon of population cycles in some small mammals.The evolutionary and adaptive implications of maternal effects were also discussed.
    Analysis on driving force of China's cultivated land loss
    YAN Yan, ZHAO Jingzhu, WANG Yanchun, LUO Qishan
    2005, (7):  817-822. 
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    The conflict between population and cultivated land resources is a big hindrance to China's sustainable development.Persistent increase of the population and decrease of cultivated land have become a potential and thremendous treat to national food security and sustainable development.The analysis of data from the national-wide land survey (1996) and annual land-use change survey showed that the situation of cultivated land resources in China was under great tension.Cultivated land possession per capita was very scanty.General quality of cultivated land was poor,and productive capacity was low.Spatial distribution of cultivated land was uneven.Exploitable and feasible land resources to reclaim were scarse.Direct causes of cultivated land decrease included the return to pasture form cultivated land,the adjustment of agriculture structure,construction and natural hazards,among which,construction and natural hazards were the most dangerous menaces causirg permancent cultivated land loss.From the view of society-economic-nature complexity ecosystem,the driving mechanism and relationships among driving factors,such as population,society,economy,natural environment and policy were discussed,with the future cultivated land situation primarily predicted.Advices to improve cultivated land conservancy,food security and sustainable development were put forward.
    Sustainable management of regional ecosystem-A case study of Qingdao City
    XIE Hualin, LI Bo, WANG Chuansheng, LIU Hui, ZHU Wenjiao
    2005, (7):  823-827. 
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    Along with the acceleration of globalization,regional urbanization and modernization should be quickened and possibility of conflict between urbanization and ecological environment wight be objectively in existence.So we should scientifically understand the character of regional ecosystem,rationally manage regional ecosystem and confirm its direction.In this paper,Qingdao ecosystem was analyzed with some correlative theories of ecosystem management.An ecological safe system of integrality with rational structure and self-contained function was constructed between city and rural area,which was consisted of four sections.The first was the main eco-zone,including the vegetation of forest,grass and the mountain.The second was the controlling keystone zone,including river,lake,and reservoir etc.The third was the ecological corridor in the city,which was made up of green corridor,blue corridor and blue coastline in the city.The fourth was the non-controlling section,which was mainly consisted of huge cropland.Some countermeasures of sustainable use and management for regional ecosystem were put forward:maintaining and strengthening the regional holistic pattern of the mountain and water;protecting and resuming the regional wet ecosystem;pushing industrial ecology with circulation;integrating environmental space with open arms;sustainably using resources; and actualizing biodiversity protection plans for the city.
    Application of phospholipid fatty acid (PLFA) analysis in microbial ecology
    CHEN Zhenxiang, YU Xin, XIA Mingfang, DAI Zhaoxia, SUN Cheng
    2005, (7):  828-832. 
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    Phospholipid fatty acid (PLFA) analysis,based on modern biochemical techniques,is widely used in the research of microbial ecology nowadays.It shows many advantages over the conventional culturing methods such as accurate,quantitative,simple in operation,as well as no strict requirements for the microbial physiological status and sample conservation duration.The information provided by PLFA can present all the viable members of the microbial community.This paper reviewed the principles and applications of PLFA in the research of microbial ecology,including the biomass in the microbial community,the community structure and function and their changes,the indication of certain microbial species or genus,and the nutritional status.
    Relieving effects of different organic acids on wheat seedling under lead stress
    LI Xuemei, ZHANG Lihong, TAO Siyuan, HE Xingyuan
    2005, (7):  833-836. 
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    Relieving effects of different organic acids on wheat seedling under lead stress were studied in this paper.The results showed that low concentration of oxalic acid and acetic acid could increase the content of chlorophyll,enhance the activities of SOD,CAT and POD,and decrease the content of MDA,while high concentration of oxalic acid,acetic acid and citric acid had no apparent relieving effects.Acetic acid could reduce active absorbing area of roots while citric acid could increase roots activity.Among the tested organic acids,oxalic acid had the strongest relieving effect.
    A preliminary study on mangrove and aquaculture system
    SHE Zhongming, LIN Junxiong, PENG Yougui, CHEN Guizhu
    2005, (7):  837-840. 
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    In order to study the effect of planting mangrove in the fishponds on improving cultural water quality,reducing fish diseases and increasing the yield,three mangrove plants,Sonneratia caseolaris,Kandelia candel and Ageiceras corniculatum,were planted in different fishponds with three planting-aquatic breeding combinations of 45:55,30:70 and 15:85,respectively. The results showed that water quality of all fishponds planted with mangrove plants was improved at different degrees,and the water quality in the pond planted A.corniculatum with the combination of 45:55 was the best,where fishes grew most rapidly.
    Energy analysis of ecological benefit in mangrove wetland—Case study of the Nineteenth Chong mangrove wetland in Nansha
    ZHAO Xinsheng, CUI Baoshan, YANG Zhifeng
    2005, (7):  841-844. 
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    The energy and material flux in addition to ecological benefits in the Nineteenth Chong mangrove wetland in Nansha of Panyu district,Guangzhou City were analyzed quantificationally with the energy analysis method of ecological economy system.The results showed that nummary value of the mangrove was $ 1.88?104 in 2002,$ 22.78?104 and $ 12.00?104 for waterfowl and aquatic product,respectively.The total eergy input of wetland system was 17.96?1016sej,unrenewable 9.44?1016sej,while the total output was 31.28?1016sej.The energy analytical figures and tables indicated that the integrated rate of input/output of the mangrove wetland is reasonable with low input ($ 10.49?104) but high output ($ 42.82?104).Related suggestions were put forward.
    Indicative function of dioxygenase activities on the degradation of phenanthrene by bacteria
    XU Huaxia, LI Peijun, GONG Zongqiang, LIU Wan, ZHONG Ming, CHEN Suhua
    2005, (7):  845-847. 
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    Experiments on degradation of phenanthrene by two species of petroleum-degrading bacteria and the change of dioxygenase activities were carried out.The results indicated that when the phenanthrene concentration was 100 mg稬-1, phenanthrenee degradation was the highest.When the phenanthrene concentration was higher than 100 mg稬-1,the degradation decreased.There was a significant correlation between phenanthrene degradation and dioxygenase activities when the phenanthrene concentration ranged from 50 to 250 mg稬-1.The dioxygenase activities could be used as an effective assessment index of phenanthrene degradation process and intensity.
    Methodology assessment of urban ecological security-A case study of Beijing
    ZHOU Wenhua, WANG Rusong
    2005, (7):  848-852. 
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    Ecological security is defined as the goal of stakeholders to create a condition where the physical surroundings of a community provide for the needs of its inhabitants without diminishing its natural stock.Recently,the study of ecological security is mainly on the national and regional levels,and focus on landscape orientation comparison.The study of urban ecological security is little,but it is the basis and core of national and regional ecological security.This paper analyzed and referenced the methodology of regional ecological security assessment,taking Beijing as an example.The ecological security situations and trends at time scale (1996～2002) were analyzed,with suggestions on the management of urban ecological security.