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Table of Content

    10 December 2006, Volume 25 Issue 12
    Articles
    Effects of cultivation mode, nitrogen fertilization, and cultivar on winter whea t canopy parameters and grain yields in sub-humid area
    REN Shujie1,2,4;LI Shiqing2,3;WANG Quanjiu2;LI Shengxiu3
    2006, 25(12):  1449-1454 . 
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    A field experiment was conducted on the Earth-Cumulic-Orthic Anthrosols in south Loess Plateau to investigate the effects of nitrogen fertilization, cultivar,and cultivation mode on the leaf area index (LAI), diffuse non-interceptance (DIFN), and grain yield of winter wheat. The results showed that during the growth period, LAI increased first and decreased then, which was the highest in flowering but the lowest in maturing stage. Nitrogen fertilization improved the LAI sign ificantly. DIFN had a change pattern reverse to LAI. There were significant diff erences in LAI and DIFN among cultivars. The LAI under plastic-film mulching fo r whole growth period (PFMW) and plastic-film mulching for 150d (PFMD) was significantly higher than that under other three cultivation modes, while DIFN was in reverse. Nitrogen fertilization increased grain yield significantly. The grain yield under PFMW, PFMD, and rainfall harvest cultivation was higher than that under other two cultivation modes, but from the viewpoints of grain yield, canopy parameters, and soil quality, PFMW and PFMD were better than the other three cultivation modes.
    Phenological analysis of main tree species in Shenyang urban forest
    HU Jianbo1,2; XU Wenduo1;CHEN Wei1;HE Xingyuan1;WEN Hua1
    2006, 25(12):  1455-1459 . 
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    Phenological scheme of urban greening tree species is an important research content in urban horticulture. In this paper, the phenological table of 29 main trees in Shenyang urban forest was drawn based on six year observation, and their phenological phenomena were clustered into sprouting-leaf expanding, leaf coloring, leaf falling, and flowering-fruiting. According to the time of leaf coloring and flowering, which was most considered in horticulture, the main tree species in Shenyang urban forest were clustered into several groups, which could be helpful for the tree species selection and composing, and their benefit evaluation of urban forest.
    Spatial distribution and ecological adaptability of wetland vegetation in Yellow River Delta along a water table depth gradient
    TAN Xuejie;ZHAO Xinsheng
    2006, 25(12):  1460-1464 . 
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    The study with fuzzy set ordination (FSO) showed that in the National Nature Res erve in Yellow River Delta, there was a greater difference in plant habitat and vegetation type along a water table depth gradient. At the place with 40 cm to -30 cm water table depth,a transitional belt from water body to land,xerophiles and hydrophytes coexisted, plant species were most abundant, and vegetation cove rage was the largest. At the place of -30 cm to -50 cm water table depth, soil s a linization and alkalization had the highest degree because of the lower ground w ater level, while at the place with <-50 cm water table depth, soil surface was relatively dry, salinization and alkalization had a lower degree, and drought-tolerant vegetation took dominant place. Water table depth gradient had significa nt effects on soil moisture and air condition and soil physical, chemical and biological processes, and accordingly, affected the spatial distribution and ecological characters of the vegetations in the test region.
    Comparison of two evaluation methods on wild animal habitat suitability: A case study of Ailuropoda melanoleuca in Daxiangling Mountains
    ZHANG Wenguang1,2,3;TANG Zhonghai2; QI Dunwu2;HU Yuanman1; HU Jinchu2;BAI Dan4
    2006, 25(12):  1465-1469 . 
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    In this paper, landscape elements evaluation (method I) and principle components analysis (method II) were used to evaluate the habitat suitability of giant panda (Ailuropoda melanoleuca) in Daxiangling Mountains. With method I, the moderate suitable, suitable, and most suitable areas occupied 94.62, 45.46, and 0.21 km2, accounting for 4.17%, 2.00%, and 0.01% of the total area, while with method II, the moderate suitable and suitable areas occupied 623.03 and 170.27 km2, accounting for 27.49% and 7.51% of the total area, respectively. Both of the two methods could be used to evaluate the habitat of A. melanoleuca in Daxiangling Mountains, but there was a greater difference between the results. Method I needed less money and manpower, but the result was not very accurate, because fewer factors were considered in the evaluation process, which led to the more contribution of one factor to the whole evaluation. Method II needed more money and manpower, and it was very difficult to collect all the necessary data to reach 95% of a ccumulated contribution. These two methods should be integrated together to decrease the error in the evaluation of wild animal habitat suitability.
    Effects of grazing intensity on plant diversity and aboveground biomass of Stipa baicalensis grassland
    YANG Dianlin1;HAN Guodong2;HU Yuegao3;Wuyungerle1
    2006, 25(12):  1470-1475 . 
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    The study on the plant diversity and aboveground biomass of Stipa baicalensis grassland under different grazing intensity showed that with increasing intensity of grazing, the plant cluster of S. baicalensis population fragmented and miniaturized; while Leymus chinensis had stronger capability in enduring grazing, and its aboveground biomass was the highest under moderate grazing. The primary biomass of the grassland community decreased with increasing grazing intensity. Under higher grazing intensity, the weeds worse for feeding and with higher capability in enduring grazing increased. When the grazing intensity increased continuously, the population would be replaced by the weeds. The stability of the grassland population also decreased with increasing grazing intensity, but the effects on the population diversity, aboveground biomass, and stability were not synchronous and symmetry. There was a rapid and intensive response of the primary biomass of the grassland community to grazing disturbance.
    Gradient analysis of landscape pattern of Pingliang City in Jinghe River basin under effects of urbanization
    WANG Hui;ZHOU Rui;BI Xiaoli;CHEN Baoyu;GE Jianping
    2006, 25(12):  1476-1480 . 
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    With the combination of gradient analysis based on GIS and quantitative analysis of landscape elements, this paper studied the urbanized spatial pattern of Pingliang City in Jinghe River basin. Several landscape indices in landscape-and class level were calculated in Fragstats along a 30 km long and 3 km wide transect with a moving window based on a 1∶100 000 land use remote sense image. The re s ults showed that under the effects of urbanization, the landscape along the rural-urban transition of Pingliang City was compositionally diverse, geometrically complex, and ecologically fragmented. The spatial patterns of different land us e types were not uniform along the gradient, and the landscape process affected by human activities depended on the land use pattern and its type.
    Effects of Cu pollution on Medicago lupulina L. seedlings growth and active oxygen metabolism
    CHU Ling1,2;JIN Song1,2;WU Xuefeng1,2;LIU Dengyi1,2
    2006, 25(12):  1481-1485 . 
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    The study with pot experiment showed that low concentrations of Cu (<500 mg·kg -1) had no obvious inhibitory effects on the seedlings growth of Medicago lupulina L., while in adverse, could promote it. The leaf electric conductivity increased slightly, and the plant fresh and dry weights as well as the leaf soluble protein and pigments contents all reached their highest values at 500 mg Cu·kg-1.In the meantime, leaf MDA content decreased,superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities slightly increased, and protective enzy me system still kept in balance. However, definite negative effects of Cu were o bserved with the increase of Cu concentration (500—3000 mg·kg-1). Compared with the control,the plant fresh and dry weights as well as the leaf soluble protein and pigments contents decreased drastically, and leaf electric conductivity and malondialdehyde (MDA) content increased rapidly. Meanwhile, the POD activity increased obviously while SOD and CAT activities decreased markedly, which indicated that the active oxygen metabolism system was destroyed, and the balance of protective enzyme system was broken.
    Change patterns of leaf area index (LAI) of Pinus tabulaeformis and Platyc ladus orientalis plantations in Beijing
    WANG Xiqun1;MA Lüyi1;ZHANG Yongfu2
    2006, 25(12):  1486-1489 . 
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    Leaf area index (LAI) is an important parameter in plant population structure research, and of significance in the estimation of stand quality. The large scope LAI obtained by optical measurement and remote sensing needs to be validated by actual survey. With Pinus tabulaeformis and Platycladus orientalis plant ations in the State Shisanling Forest Farm of Beijing as test objects, and using the LAI data obtained by Digital Plant Canopy Imager (CI-110) and field survey,this paper analyzed the relationship between effective LAI (LAIe) and actual LAI (LAIa).The results showed that the LAIe/LAIa ratio ofP. tabulaeformis plantation was 35.52%~36.36%, and that of P. orientalisplantation was 14.60%~16.72%. Because the canopy openness of test plantations ranged from 0.5 to 0.8, which accorded with the requirement of non-commercial forest m anagement, the LAI of P. tabulaeformis and P. orientalis plantations was appropriate to be used as an important gist in their quality control.
    Species diversity of wild vascular plants in Longjiao Mountain forest area
    WANG Yinggang1;ZHU Yuen1;ZHANG Qiuhua1;ZHANG Feng2
    2006, 25(12):  1490-1494 . 
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    Based on the investigation data of 216 sampling plots, and by using Shannon-Wiener and S¢rensen indices, this paper analyzed the spatial distribution pattern of wild vascular plant species diversity in Longjiao Mountain forest area.The results showed that the species diversity was lower in arbor layer, but higher in shrub layer and herb layer.The species diversity decreased gradually with increasing altitude.There was a certain difference of the wild vascular plant species diversity on different slope direction, with the sequence of north slope>east and west slope>south slope. Slope direction and altitude were the main factors affecting the spatial distribution pattern of wild vascular plant species diversity in the area.Slope direction also affected the species composition of the wild vascular plants, with the most obvious difference between north and south slope, and the least one between east and west slope. On this aspect, the effect of altitude was not so obvious.
    Resources and chorology of Lactic acid bacteria in milk and dairy products of Inner Mongolia
    LI Shaoying1;WU Ni2;LI Peifeng2;DONG Guicheng1;TIAN Jianjun1
    2006, 25(12):  1495-1499 . 
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    In this paper,752samples of fresh milk and dairy products were collected from519 households in different pastoral areas of Inner Mongolia, and the lactobacillus in the samples was isolated, with its biological properties studied. A total of 765 strains were identified, belonging to 28 species and subspecies of Lactobacellus,2 species of Bifidobacterium,9 species of Enterococcus,3species and subspecies ofLactococcus,1 species of Streptococcus,6 species and subspecies of Leuconostoc,and 1 species of Pediococcus, which indicated that in the milk and dairy products of Inner Mongolia, there widely spread many kinds of lactobacillus. Some strains had high adaptability to environmental temperature and pH, and even, some of them had stronger capability of using melezitose, melibiose and raffinose, etc as carbon source.
    Oxidizable organic carbon in soils originated from different parent rocks
    ZHOU Wei1;ZHOU Yunchao1;ZHOU Xihui1;LI Jin2
    2006, 25(12):  1500-1507 . 
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    By using KMnO4-oxidation method, this paper determined the oxidizable organic carbon content in soils originated from eight parent rocks. The results showed that the content of soil oxidizable organic carbon differed significantly with different parent rocks. Soil oxidizable organic carbon had a significant negative correlation with soil available phosphorus, total nitrogen, available potassium,sand,and silt,a significant positive correlation with soil bulk density,and no relationship with soil organic matter, available nitrogen, pH, coarse sand,fine sand,clay,and gravel.
    Physiological responses of sweet potato callus to drought and salt stress
    WANG Lanlan1,2;ZHANG Lijun2;CHEN Gui2;LI Xuemei1
    2006, 25(12):  1508-1514 . 
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    With sweet potato"Lu Xuan 1"as test material, this paper studied the effects of drought- and salt stress on the callus soluble protein, soluble sugar and proline contents and SOD activity, aimed to understand the physiological mechanisms of sweet potato in resisting osmotic stress at cell level, and to analyze the difference of callus responses to drought- and salt stress. The results showed that soluble protein content had a slow increase under drought stress, and increased markedly at the early and middle stages of slight and moderate salt stress but decreased then, suggesting that Na+ was likely to promote the synthesis of soluble protein under short period salt stress. MDA content was markedly lower und er severe drought stress than under severe salt stress, while SOD activity was i n adverse, indicating that the increase of cytoplasm membrane permeability was resulted from the lipid peroxidation under salt stress and the dehydration by PEG-6000 under drought stress. Under severe drought stress, soluble sugar content had a fast increase within a short period of time and decreased then, while proline content increased fast at the middle and later stages of this stress, indicating that proline could probably compensate the decrease of sugar content.
    Yield performance of winter wheat and summer maize intercropped with young poplar
    DAI Xiaoqin1;GUO Xingqiang1;LI Peng1;SHAN Shuangsheng2;XIE Guanghui1
    2006, 25(12):  1515-1519 . 
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    A filed experiment of intercropping winter wheat and summer maize with young poplars was conducted to study the effects of poplar on crop yield and yield-forming factors. The results showed that compared with monoculture,intercropping with 1-2 years old poplar somewhat increased the wheat yield but decreased the maize yield by 31.3%-33.7%, while intercropping with 3-4 years old poplar decrease d the wheat and maize yield by 36.9%-42.5% and 80.8%-87.4%, respectively. Among the yield-forming factors of winter wheat, ear number was the main one affected by poplar,and thus, more attention should be paid to the water and fertilizer management at the tillering stage of wheat. For summer maize, the main affec ted yield-forming factor was from grain number to ear number with the growth of poplar, and thereby, it was necessary to ensure the resources supply at the elongation-silking stage of maize,and to strengthen the management of poplar after its 2-3 years growth.It was suggested that in the practice of agro-forestry,an integral consideration must be made on the biological characteristics and reasonable management of tree species and crops.
    Predatory behavior and meal habit of Lacerta vivipara
    ZHAO Wenge;DONG Bingjun;LIU Peng;LIU Zhitao
    2006, 25(12):  1520-1523 . 
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    With direct observation and stomach dissection, this paper studied the predatorybehavior and meal habit of Lacerta vivipara. The results showed that the predatory behavior of L. vivipara included searching for, before attacking, at tacking, executing, swallowing, and cleaning after eating. During the period fro m June to October,L. vivipara preferred insects and spiders. The kind and quantity of the preys that L. vivipara ate varied from month to month. Among the preys, those of 1-10 mm length were ingested with the highest amount. The natural diet ofL. vivipara was significantly related to the composition of in vertebrates in the environment, and the overlap of food niche was higher between male and female but lower between adult and young L. vivipara.
    Foraging behavior and dietary preference of Wuxue goats on karst shrubby grassland of West Hunan
    LIANG Liang;ZHANG Daigui;XU Jian;DENG Tao;TANG Yonghong;LIU Zhixiao
    2006, 25(12):  1524-1527 . 
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    The study on the foraging behavior and dietary preference of Wuxue goats on kars t shrubby grassland of West Hunan Province showed that the duration of different foraging behaviors was in the order of ingestion>wandering>resting and rumina tion>standing>drinking. The foraging behaviors except standing were significantly different in their durations before noon, at noon, and after noon, e.g., ingestion presented a “V” curve, while resting and rumination presented a parabola. The duration of wandering was significantly longer before noon than at noon a nd after noon, and that of drinking was significantly longer after noon than bef ore noon and at noon. Wuxue goats preferred to ingest Broussonetia kazinoki,Indigfera psendotictria and Lonicera japonica, etc., and more preference was to wood plants and lianas than to herbs. The majority of the plants that Wuxue goats i ngested were the preference species, but the main food of the goats was not always the preferred plants due to the different distribution and availability of the plants.
    Drought resistance of Elaeagnus mollis seedlings
    LIU Rentao;BI Runcheng;REN Jia
    2006, 25(12):  1528-1531 . 
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    The study with pot experiment showed that under light(30%-35%)and medium(45% -50%) soil water stress, Elaeagnus mollis seedlings leaves had a smaller decrease of water and chlorophyll contents, higher water potential, and lower MDA content. The seedlings could grow normally, and presented the typical physiological characters of drought-resistant plant. Under serious (20%-25%) soil water stress, the water and chlorophyll contents in E. mollis seedlings leaves decreased markedly,water potential was the smallest,MDA content reached the highest,and the seedlings were short and colored yellow,suggesting that the seedlings were significantly harmed by the drought stress and couldn’t grow normally.
    Relationships between overwintering Agrotis segetum population and snow
    Lü Zhaozhi1;WANG Peiling2;ZHANG Qiuhong3;GONG Zhizhong3;DING Hong3
    2006, 25(12):  1532-1534 . 
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    Based on the 1992-2001 data of light trap, this paper analyzed the relationships of overwintering Agrotis segetum population with the maximum snow depth and the days of snow covering in North Xinjiang. The results showed that the emerge nce of overwintering generation was from April 30 to June 15, and the population size fluctuated obviously among years. The population number of overwintering A. segetum had a significant negative correlation with the days of snow covering from January to early April (R2=0.6022, P<0.0083), but no significant correlations with the maximum snow depth(R2=0.23,P=0.1577)and the days of snow covering(R2=0.099,P<0.3748) from November to next April.The duration of snow covering from January to early April could be used as an important parameter in predicting the dynamic of A. segetum population.
    Ecological policy and its evaluation methods
    CAO Shixiong1;CHEN Jun2;GAO Wangsheng1
    2006, 25(12):  1535-1539 . 
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    Ecological policy is a subject of researching the guidelines of ecological actions performed in a definite period by the government, party, or other political organizations to serve the society, economy, culture, and environment. It is a branch of crossing with two branches of science, policy and ecology, and includes a series of strategies, laws, approaches, methods, and regulations performed with ecological conservation as the main project. The evaluation of ecological policy is the product of crossing with the two branches of science, with the contents of actuality evaluation, and the estimation of the effects of policy changing and adjusting. Regardless how the global ecological policy changed,the purpose of environment conservation should be the scientificutilization of resources, decrease of environment conservation cost, and increase of environment improvement speed. The key methods of ecological policy evaluation should include ecologic al health evaluation, ecological ecosystem services evaluation, economic analysis of ecological programs, and humanities and sociological evaluation.
    Remediation of contaminated soil: Its present research situation and prospect
    LI Peijun1,2;LIU Wan1;SUN Tieheng1,2;GONG Zongqiang1; FU Shasha1,3
    2006, 25(12):  1544-1548 . 
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    This paper introduced the outstanding characteristics and the harmfulness of soil contamination,looked back the research course and summarized the theoretical and applied research results in contaminated soil remediation,and brought forward the essence and technologic system of this remediation in China. Aimed at the actual conditions and demands of contaminated soil remediation, the urgent research contents were suggested, and the promotion effect of related research on the development of environmental sciences was predicted.
    World ecotourism regionalization
    ZHONG Linsheng1;LIU Min1,2;ZHENG Qunming3
    2006, 25(12):  1549-1553 . 
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    Ecotourism regionalization is one of the important means in describing the spatial pattern of ecotourism resources and ecotourism industry at global level, which is helpful to the whole understanding of the world's ecotourism development.This paper discussed the definition and theoretical bases of ecotourism regional ization, suggested that ecotourism regionalization should be on the bases of reg ional differentiation pattern and ecological theory, and classified the world ec otourism regional system into 6 ecotourism continents, 29 ecotourism districts, 71 ecotourism zones, and a number of ecotourism destinations in the light of the principles of overall planning, synthetic analysis,principal factors, and assorting with both administrative district and natural zone.The characteristics of ecotourism for each ecotourism continent were also expatiated.
    Ecotoxicological effect of chlorpromazine and its influence on human health
    LI Ting1;ZHOU Qixing1,2
    2006, 25(12):  1554-1558 . 
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    As an important and widely used ataractic veterinary medicine, chlorpromazine is mainly metabolized in liver and gradually discharged with urine. Due to its slow discharge, this chemical can usually induce the problem of remaining. With the improvement of people's living quality and the requirement of creatural food safety,more and more attention is paid to the remaining of chlorpromazine. The discharged chlorpromazine can enter into ecosystems and human bodies through many routes,and has potential influences on them. This paper analyzed the reasons of chlorpromazine remaining, summarized the ecotoxicological effects of chlorpromazine in environment and its potential influences on human health, and illustrated the close relationships of chlorpromazine remaining with environment and human health. A further study of this topic is of practical significance.
    Research advances in slow/controlled release fertilizers
    YU Lizhi1,2;LI Dongpo1;YU Shouneng2;ZOU Jihua2;MA Tao2;WU Zhijie1
    2006, 25(12):  1559-1563 . 
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    This paper introduced the main kinds of slow/controlled release fertilizers, and summarized the research advances in their action mechanisms and application effects in agriculture. Slow/controlled release fertilizers have positive effects on crop growth and grain yield, can improve the fertilizer N use efficiency to some extent, and protect the environment by inhibiting NH4+ oxidizing to NO3- and reducing the accumulation of NO3- in soil, which in turn decreases the fertilizer N losses and environmental pollution. The N2O emission from soil can be also mitigated by slow/controlled release fertilizers. The issues and further directions in the applied research of slow/controlled release fertilizers were brought forward.
    Research progress on microbial degradation of polychlorinated biphenyls
    SUN Hongbin1; LIU Yayun1,2; CHEN Guizhu1
    2006, 25(12):  1564-1569 . 
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    As one of the persistent organic pollutants, polychlorinated biphenyls (PCBs) are rarely degraded in the environment, while biodegradation is an effective way to remove PCBs from contaminated soil and sediments.This paper reviewed the effects of aerobic oxidation,anaerobic dechlorination, and biosurfactants in the microbial degradation of PCBs, introduced the application and potentials of coupling several removal methods, and pointed out the applied issues and the directions of further studies.
    Research progress in urban dew and its ecological effect
    YE Youhua1;ZHOU Kai2;LI Huangdi1; JIN Jianhua1;PENG Shaoli n1,2
    2006, 25(12):  1570-1573 . 
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    Urban dew is a non-negligible condensed water resource and humidity origin. To research its ecological effect is of great significance. This paper summarized the recent research advances on urban dew and its ecological effect, with the focus on the collection of urban dew,its amount under effects of urban ecological environment,chemical ecology,and simulation and modeling.The formation of urban dew was obviously affected by urban ecological environment, e.g., the dew amount tended to decrease, and its chemical components were highly related to the urban atmospheric environment. Limited studies have been done for the simulation and modeling of urban dew.The issues about urban dew and its ecological effect r esearch were listed, and some further research trends were prospected.
    Sources and implementation of marine ecosystem services
    ZHANG Zhaohui1;SHI Honghua2;JIANG Zhenbo3;CHEN Shang1;DING Dewen1
    2006, 25(12):  1574-1579 . 
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    This paper analyzed the marine ecosystem services from the aspects of ecosystem component, ecological process, and biodiversity. Based on the similar effects and characteristics, marine ecosystem services were classified into 15 types. Although many of the organisms and ecological processes in marine ecosystem were still unknown, the connections between its services and their sources were built, aimed to better understand the services implementation process. Marine ecosystem services were originated from biological components, and implemented by certain ecological process. Therefore, any damage to the ecosystem’s components and processes would weaken, and even lose the ecosystem services, which would further a ffect human being’s benefits and welfare. To understand the sources and impleme ntation processes of marine ecosystem services was of significance to realize the importance of marine ecosystem and to provide scientific supports to marine ecosystem restoration, and helpful to the services management and the sustainable development of whole society.
    Research advances in plant and its low-phosphorus environment—inducement, adaptation and countermeasures
    DAI Kaijie1,2;HE Fang1;GUAN Huilin3;SHEN Youxin2,4; ZHANG Guangming5
    2006, 25(12):  1580-1585 . 
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    The research of plant and its low-phosphorus environment has been attached importance since the finding in the 1970s that there was a marked increase of P availability in the rhizosphere of crops having adapted to low phosphorus environment. How plant adapts to low-phosphorus environment and makes effective use of soil phosphorus has become a hotspot both at home and abroad. Many researches indicate d that under low-phosphorus environment,plant root could make an adaptive change in morphology, and the matter allocation was inclined to root, inducing an increase of root/shoot ratio.The change of pH in rhizosphere, the exudation of organic acids, and the release of phosphatase were all beneficial to the activation and utilization of soil phosphorus. Different plant species or variety had different P-nutritional efficiency genotype, P-transporter system, and P-activation mechanism.The research on how plant adapts to low-phosphorus environment will be further continued,and it is of realistic significance for economy and environment protection to unveil the countermeasures of plant response to low-phosphorus environment, and to explore the potentialities of plant in making effective use of soil phosphorus.
    Spatio-temporal variation of population and its influence on the resources and environment in Pearl River Delta
    WU Rongsheng;GUAN Dongsheng
    2006, 25(12):  1586-1590 . 
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    Since the practice of reform and open-door policy, the economy in the Pearl River Delta has been developed rapidly, with the population growing up significantly, which made a greater pressure on the resources and environment, and restricted the regional economic and social sustainable development. In this paper, the recent years’ temporal-spatial variation of population and its relationship with the economic development of this area were analyzed, and the results indicated that due to the increase of population, the possess of land and forest resources per person was further decreased, and the air and water pollution became more serious. It was of significance to solve the population problem for the sustainable development in Pearl River Delta. Strictly controlling population growth, rationally utilizing natural resources,optimizing economic structure,increasing investment for environment protection,and strengthening regional cooperation should be the essential countermeasures for realizing the sustainable development in this area.
    Ultramicroscopic observation of normal microflora in digestive tract of healthy and diseased chickens
    LIN Xueyan;NIU Zhongxiang
    2006, 25(12):  1591-1593 . 
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    A scanning electron-microscopic observation on the normal microflora in the digestive tract (craw, ileum and caecum) of healthy and diseased chickens showed that in the digestive tract of healthy chicken,mucosa was integral, its surface was evenly covered with a lot of normal microflora, and the lactobacillus adhered on the surface of craw had the greatest density. In the digestive tract of chicken suffered from coccidiosis, the mucosa was shed, and the individuals of normal microflora decreased markedly, which could be the main reason of diarrhoea.
    Calculation of Pinus elliotii biomass: A comparison of different methods
    LI Xuanran1,2,3;LIU Qijing2;HU Lile4;MA Zeqing2,3
    2006, 25(12):  1594-1598 . 
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    In this paper, three methods including allometry with observed data (AMOD), allometry with calculated data (AMCD), and average sample tree determination(ASTD)were used to estimate the foliage biomass, branch biomass, trunk biomass, and to tal biomass of Pinus elliotii in Qianyanzhou station. The results showed tha t branch diameter was highly correlated to branch biomass and branch leaf biomass, and the linear equation with single parameter (d3) was the best type of equation to describe the correlation. The total biomass calculated by these three methods was adjacent, being 7.9×104kg·hm-2by AMOD, 8.0×104kg·hm-2 by AMCD, and 7.41×104 kg·hm-2 by ASTD. The foliage biomass , branch biomass and trunk biomass, especially the foliage biomass,had a distinct difference when estimated by the three methods, being >20% higher or lower by ASTD than by the other two methods. In related literatures, allometric equation s were also used to estimate the total biomass and apparatus biomass of P. elliotii, but the calculated values were all higher than those by the three methods. AMOD was most reliable when estimating forest biomass, while AMCD could take the place of AMOD in some extent.