Table of Content

10 April 1994, Volume 13 Issue 02

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Ecological Efficiency of High-Lift Irrigated Farmland along Yellow River Banks of Baiyin City

Lu Manji, Qin Yanan, Li daxiang, Wang Donghui

1994, (2):  1-6. 

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In the farmaland system along Yellow River banks of Baiyin city,which consists of wheat,wheat-soybean, maize,maize-broad bean,wheat-maize,pea-soybean or hyacinth bean-millet,high-lift irrigation gives a high ecological efficiency. The biological, equivalent,crude protein and grain yields are 1.78 ?10⁴,1529 and 7077 kg. ha^-1,respectively. 85.7% of dry matters are harvested,and only 14.2% of them are returned back to soil system. The total average input of energy is 1.17?10¹¹J. ha^-1, of which, 81.2% comes from in organic. The output-input ratio of energy is respectively 1.53 and 0.66 and average solar energy efficiency is 0.81% and 0.35% for biomass and grain. As for the economic benefits, the output-input ratio is 2.72 and 1.23 yuan. yuan^-1 for net output and net income, respectively.

Effect of VAM Fungus Glomus mosseae on Microbial Population and Biomass in Cotton Root Zone

Gu Xiangyang, Hu Zhengjia

1994, (2):  7-11. 

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In cotton rcot zone,the infection of VAM fungus Glomus mosseae induces a greater change of microbial population and biomass. After infection, the total number of bacteria,actinomycetes,N-fixers and fungi in root zone are decreased at seedling and bud stages,but increased at flowering and boll-forming stages(except that of fungi). In the whole growing period of cotton,the microbial biomass in root zone is remarkably higher after VAM infection.

Xylem Structure of Pinus massonions Stem at Different Altitudes

Zhang Dapeng

1994, (2):  12-18. 

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Comparative anatomic study shows that for the early wood of Pinus massonions,the thickness of secondary xylem and the number of tracheid layer are decreased gradually with the altitude from 700 to 1100m. At the altitude of 1300m,they are only respectively 71.21 and 57.70% of the late wood,which is considered to be related with the lower temperature at this altitude. The ratio of toacheid wall to luace and the percentage of pit density to ray area increased with altitude,being the maximum at 1300m of altitude,and the pit diameler and resin passage are decreased with it,being the minimun at that altitude. The decrease of annual formation of axial resin passage and the increase of its density w1th altitude are the results of the reduction of fracheid layer number and lumen diameter.

Habitat Investigation of Algae and Bacteria in a Typha Purification Pond With Pb-Zn sewage and Selection of Resistant Algae

Liu Yu, Mai zhiqin, Hu Wenfeng

1994, (2):  19-22,29. 

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After many years purification,the concentration of heavy metals in a Typha purification pond are decreased and water quality is improved. The species and biomass of algae,bacteria and aquatic animals are increased correspondingly. Only a species of algae,Nitzschia sp.,can survive in the area with higher concentration ofheavy metals(e.g. in a shallow influent area), and most algae are existed in the area with lower concentration of heavy metals and deeper water, among which. Nitzschia and Phormidium are the dominant groups and have greater resistance to Pb-Zn pollution. They can to selected out for purifying Pb-Zn sewage.

Effect of Environmental Factors on Vetiver Grass Growth

Xia Hanping, Ao Huixiu, He Daoquan

1994, (2):  23-26. 

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Observation and studies show that shading significantly reduces the tiller formation, plant height and shoot weight of vetiver. After shading removed,the plants perform better, but not so well in plant heigat and shoot weight as those not been shaded.Fertilization promotes the height growth and tiller formation,and stopping it will result in a decrease of plant growth.In order to increase tillers,the plant should be cut twice annually,but excessive cutting is unfavourable.

Causes of Early Leaf Fall of Prunus Mume and Method for Its Prevention

Liu Chao, Wu Fang zheng, Fu Liusong

1994, (2):  27-29. 

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The causes of early fall of prunus mume leaves in some zones are analysed,which shows that it is induced by fluoride pollution.The paper discusses the physiological mechanism of early leaf fall induced by airborne fluoride and method to prevent abscission.

Impact of Swamp Ecosystem Succession in Sanjiang Plain on Soil Fauna

Sun Fan, Zhao Hongin, Lu Xianguo, Yang Qing

1994, (2):  30-33,39. 

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Soil fauna inhabiting fourtypes of landscapes were investigated at different stages of swamp ecosystem succession. 35 kinds and 1972 individuals of soil animals were found.They belong to 3 phylums,7 classes,13orders and 21 families. The kind and individual numbers and the biomass of the soil animals are the highest in Calamagrostis angustifolis-Carex schmiotii swampy meadow,and are the lowest in Phragmites swamp and farmland. The similarity of soil fauna group is the lowest and the homeogeneity of soil fauna in vertival distribution is the highest in Phragmites swamp and farmland. According to different landscapes and stages,four groups of the animal fauna are divided.

Species Diversity and Population Distribution Pattern of Mangrove Community in Aotou of Guangdong

Chen Guizhu, Miao Shenyu

1994, (2):  34-35,43. 

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For mangrove community in Aotou of Guangdong,its Simpson index is 0.647,Shannon-Wiener index is 1.904,PIE is 0.552,and evenness is 73.66%,Compared with southern subtropical evergreen broadleaf forest community,the species diversity of the mangrove community is much lower,but its evenness makes no significant difference. Except for Avzicennia marina which shows a poisson distribution all the species of mangrove community are basically clumped distributed,which characterizes the features of the mangrove community.

Study on Water Flus in Soil on A Forested Hillslope

Sun Ge

1994, (2):  36-39. 

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The longterm water flux monitoring on forested hillslope at Dakeng valley in Xiushui county , south China,showed that the fluctuation of water flux was consistent to that of rainfall pattern and stream flow annual variation. In rainy season,the top 15cm soil was the source of stream water supply,and in nonrainy season watershed runoff was from deep soil layer. Water flux had close relationship with vegetation quality.

Life Table Analysis of Dendrolimus spectabilis Growth and Decline Patterns

Mu Zongzhao, Ni Yule, Sun Jiajiang

1994, (2):  40-43. 

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A six years life table analysis is made for a Dendrolimus spectabillis population in Wendeng city of Shandong province. The key period affecting its population change is larva peried before and after winter time. Wasps and birds predation,pathogen affection and low temperature during larva period after winter,as well as ants and mantis predation and precipitation during larva period before winter are the main reasons for the annual change of Dendrolimus spectabillis population.The population tendency index is defined as I=5.0440.

Relationship Between Ecological Environmental Change and Human Activity in Qinghai Lake Region:A Preliminary Study

Chen Guishen, Peng Min, Zhou Lihua, Zhao Jing

1994, (2):  44-49. 

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Studies on the main characteristics of ecological environmental change and human activity in Qinghai lake region show that the destruction of ecological environment is caused by the uplift of the plateau and the human activity. Climatic change is the dominant factor in the ecological environmental change,and human activity is the catalytic and inducing one. The effect of human activity on the ecological environment should not be ignored in the region.

Climatic Productive Potential of Pinus massoniana

Ou Yanghui

1994, (2):  50-56. 

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In this paper,the photosynthesis,light-temperature and climatic productive potential models of Pinus massoniana are established,and its climatic productive potentials in various mountainous systems and at various altitudes in the eastern part of subtropical China are estimated. Through comparing the differences of methods for estimating the climatic preductive potentials of crops and woods, and utilizing the growth formula of Pinus massoniana ,the dynamic model on the growth of this tree species is established,and a correction on its estimated climatic productive potential is made. The estimated results show that the actual climatic productive potential of Pinus massoniana is higher in in southern subtropics,medium in middle subtropics,and lower in northern subtropics.

Integration in Clonal Plant Populations:Current Situation of the Researck and Its Application Prospect

Wang Yusheng

1994, (2):  57-60. 

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Based on the evidences obtained by population ecologists in the world,progress in the research on integrationin clonal plant populations is reviewed and its meaning in plant production is pointed out.The auther suggests that this research should be linked closely to the raise of economic production of various crops.

Home Range Study of Primates

Li Baoguo, Liu Anhong

1994, (2):  61-65,75. 

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Home range is polularly defined as the area traversed by an individual in its normal activities of food gathering,mating and caring youngs;Its study plays an important role in primatology.After a surrey on the seasonal home range of Sichuan golden monkey(Rhinopithecus roxellanae)in Yuhangmiao region located at the north slope of Qinling mountain,and based on the summarizing of related references,the methodology of its home range study of primates is presented in this paper.

Effect of Silver Carp Stocking on Water Qualityg: Research Advances

Dong Shuanglin

1994, (2):  66-68. 

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Silver carp stocking can supress the growth of zooplankton and net-phytoplankton,therefore is favorable to the growth of nano-phytoplankton. Fish activities may disturb the vertical distribution of nutrients in shallow waters. Fishing reduces the overall nutrient content in water ,however,stocking of the fish may accelerate nutrient cyclings by increasing the amount of nutrients that go into higher trophic levels,and therefore can more effectively reduce nuttient content and improve water quality. These functions are affected by water depth,trophic status istructure of plankton community,stocking density iseasons etc.

Preliminary Study on Automatical Plant Classification by Use of Computer

Fu Xing, Lu Hanqing, Luo Manli, Cao Wei, Yu Xinghua

1994, (2):  69-71. 

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Image analysis and pattern recognition are used in dealing with plant classification in this paper. The characteristics of Acer truncatum and A. pseudo-sieboldianum are extracted automatically and classified in VAX 785mini computer. The results show that(1) automatic extractions of characteristics could be achieved ;(2)the similarity of characteristic pattern plate of the same species is higher than that of other species;(3)the correctitude of recognition of the two species is 100%.

Rhizospheric N-fixation Effect of Whole Stalk Mulching on a Non-Tillaged Corn Farmland

SiQingliang, Ma Yuzhen, ding Yuchuan

1994, (2):  72-73. 

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Under the condition of continental semi-arid climate in Shanxi province,whole stalk mulching on non-tillaged corn farmlands has a favourable effect on the rhizospheric N-fixation and yield increasing.with annual mulching,the N-fixation intensity of corn root system and its rhizosphere at the early vegetative growing stage is respectively 310 and 38.2% higher than that without mulching, and 85.8 and 25.3% higher than that with traditional tillage. Whole stalk mulching can increase the soil moisture content of cultivatedlayer by 2.1-3.0%,organic matter content by 0.1-0.28% and average yield by 57.7%。It also has astronger effect on the veriical distribution of N-fixation intensity in corn rhizosphere.

Ecological Investigation on Blood-Sucking Mosquitoes in Bord Regions of Jilin Province

Ding Zhaofu, Sun Quanzhong, Qiaomu

1994, (2):  74-75. 

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Ecological habit of blood-sucking mosquitoes in bord egions of Jilin province were investigated in 1981.During July-September of that year 968 individuals of 11 spoies and 3 genera were captured,of which,the dominant species is Ae. vexans (488 heads,50.4% of the total)and the second is Cx.pipiens pallens (228 heads,23.6% of the total).Their 24 hours activity peaks are respectively at one hour before and after sunset.

Overview on the Role of Theory and Model in Ecology

1994, (2):  76-79. 

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In ecology, theory should be considered not only as a conceptual framework for research, but an ultimate product of ecological studies as well. Model may serve as the basic unit for many theoretical and applied studies. Theory and model can be used to generate new hypotheses, to clarify and test existing hypotheses, to identify key components in complex systems, to suggest critical experiments, to synthesize knowledge across disciplines and scales, and to make assessment or optimization for decision-making processes. Models become indispensable when we deal with both spatial and temporal dynamics of systems simultaneously, and when the scales of the phenomenon become large. Ecologists should keep themselves up-to-date of the state of the art in their field,and try to equip themselves with advanced methods and approaches. Empirical and theoret- ical ecology are interdependent and interactive. Minimizing the gap between theoreticians and empiricists will certainly help promote the development of the science of ecology.