Table of Content

10 June 1999, Volume 18 Issue 03

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Studies on Indication of Bryophytes to Air Pollution in Fushun District, Northeast China

Xie Wei, Cao Tong, Han Guichun, Lai Yongbin, Jin Fujie, Sun Xiaoyi

1999, (3):  1-5. 

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Based on field investigation of species and their distribution,frequency and coverage at selected 30 sampling sites in Fushun District, Northeast China,the IAP(Index of Atmospheric Purity)was calculated. 159 species belonging to 91 genera and 41 families of bryophytes were recorded in the district. According to the results,the area investigated could be divided into four regions: 1)seriously polluted region: species of bryophytes less than 4,IAP<4,no epiphytic bryophytes,with air-quality > class 3 of National standard; 2)polluted region: species less than 10,IAP<15,no epiphytic bryophytes,with air-quality equal to Class 3 of National standard; 3)relatively clean region: species less than 20, IAP < 25,occurrence of epiphytic bryophytes, with air-quality equal to Class 2 of National Standard,and 4)basically no-polluted region: species more than 20, IAP>26, rich in epiphytic species, with air-quality clean. Pylaisiella polyantha(Hedw.)Grout., Anomodon minor(Hedw.)Fuernr., Atrichum undulatum(Hedw.)P. Beauv. and Plagiomnium cuspidatum(Hedw.)T. Kop. could be selected as indicate species to air-pollution in the district.

Characteristics of N₂O Emission from Rice Fields in the Hilly Area of Southern Jiangsu Province

Cao Jinliu, Xu Hua, ZhangHongkang, Xing guangxi, Ren Litong, Yang Baoling

1999, (3):  6-9. 

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The closed chamber method was used to observe the characteristics of N₂O emission from rice fields in the hilly area of southern Jiangsu province. The results showed that the N₂O emission fluxes varied between 22-31μg N₂O-N·m^-2 ·h^-1 during rice-growing season. The N₂O emission was enhanced by application of urea. 0.038%-0.195% of urea nitrogen added was lost to the atmosphere as nitrous oxide. There was no obvious correlation between fertilizer application rates and mean N₂O fluxes. Under the condition of water management of drying and irrigation alternation, the precipitation significantly influenced N₂O fluxes.

Preliminary Studies on Interconnections among the Main Tree Populations of Taxus chinensis var. mairei Community

Li Xiankun, Huang Yuqing, Su Zongming

1999, (3):  10-14. 

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Based on the 2?2 contingency table and different indices,the relationships among the populations of Taxus chinensis var. mairei community on the Yuanbaoshan Mountain of China were investigated. The interconnections were described with the diagrams of semimatricy and constellations. The results showed that there was slightly positive correlation among the main tree populations from an overall point of view. The W-test indicated this correlation was not significant. The most pairs of the tree populations in the community showed either positive or negative correlations. The X²-test indicated there was almost no significance in the interspecific correlation. The interconnections were also theoreticaly analysed in the present paper.

Effect of Temperature on Metabolism of Parent Female of Macrobrachium rosenbergii

Lin Xiaotao, Liang Xufang, Wu Jie, Ou Yunxia, Chen Miaofen

1999, (3):  15-18,9. 

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In order to test the effect of temperature on its metabolism,the parent female of Macrobrachium rosenbergii(De Man)were reared under a series of temperature, 20, 24, 28 and 32 ℃. Both respiration rate(RO)and excretion rate of ammonia-N(RN)increased with increasing temperature(T). Relationship between those parameters can be expressed as: RO = 0.1690 e0.1138T and RN = 0.7×10 - 4 e0.1981T, respectively. The energy consumption and the ratio of metabolic substrate were significant differences in different temperature. Energy consumption increased with increasing temperature, reaching 4 times higher at 32℃ than at 20℃. The ratio of metabolic substrate showed that protein was the first, followed by carbohydrate and lipid at 24 and 28℃, and ratio of protein further increased at 32℃. However, if temperature went down to 20℃, lipid became the dominant substrate instead of protein.

Study on Height Growth Model of Pinus koraiensis

Deng Hongbing, Hao Zhanqing, Wang Qingli, Jiang Ping

1999, (3):  19-22,31. 

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Growth model is an efficient way to study growing process of some factors of plants quantitatively. Height growth of the Korean pine(Pinus koraiensis)was studied by means of hyperbola equation, Logistic equation, Richards equation with three parameters and four parameters in this paper. The results showed that Richards equation with four parameters was the most suitable and could become the other theoretical equations when some parameters were given different value. The maximum height of trees can be given in advance when Richards equation with four parameters is used, and it was even more corresponding to reality. In addition, a height growth model with real height of fixed age as a parameter was discussed in the paper. This kind of growth model can be used to calculate height growth of a given tree.

A Study of Germination and Emergence Characteristics of the Crabgrass(Digitaria ciliaris)

Shao Xiaoming, Wu Wenliang

1999, (3):  23-26. 

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The experiment show that the most suitable temperature for crabgrass(Digitaria ciliaris)germination is 25℃-35℃, with germination rate up to 81% - 86%. Lighting is an inevitable condition. The crabgrass seed has wide adaptability to the solution pH from 2 to 10 and the solution potential,from -0.2 to -0.8 MPa which have no obvious impact on the crabgrass seed. The increase of nitrogen concentration between 0.01% - 0.18% speeds up the crabgrass seed germination than in deionized water. The main soil depth for seed emergence is 0 - 2 cm due to the undisturbed soil crop system. Some strategies for controlling the crabgrass can be made according to its germination and emergence characteristics.

Research on the Ecological Engineering Exploiting of the Musca domestica and its Larvae by System Dynamics Methods

Bao Cunkuan, Liang Zhengming

1999, (3):  27-31. 

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The system dynamics methods have been used widely in researchs of the behavings of many types of systems. In present study, this method is expected to be used in resolving some problems of the ecological engineering exploiting of the Larvae of Musca domestica . The results showed that the rate of the areas for Musca domestica and the larvae is 1:4(FAA:FWA=1:4);the rate of the larvae to turn into pup(PPR)is the most important key portion of the system. The overgrowth theory of biological population is base of the exploiting engineering, and the nutrition value of the larvae and the ability of the population overgrowth may provide many economical benefits.

Characteristics and Ecological Effects of the Active Organic Carbon in Soil

Shen Hong, Cao Zhihong, Hu Zhengyi

1999, (3):  32-38. 

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The active organic carbon in soil involved dissolved organic carbon,available carbon, mineralizable carbon, oxidizable carbon,and microbial biomass carbon . The determining methods of the active organic carbon in soil and its relation to environmental factors were reviewed. Some recent research results on the active organic carbon in soil and its ecological effects were discussed. Based on this, some prospects on the active organic carbon in soil and its ecological effects were put forward.

Progress and Prospect of Aphid Chemical Ecology

Han Baoyu, Chen Zongmao

1999, (3):  39-45. 

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Since the late of 1980s, the bioassay, including the use of olfactometer, proved that aphids orientate to plants by the means of the volatiles of host plants, and natural enemies orientate to aphids by the searching kairomone. The activity of semiochemicals among plant, aphid and natural enemy was detected by Electroantennograph(EAG), Single cell recording techniques(SCR)and SCR coupled to Gas chromatography(GC-SCR). The composition and spatial structure of semiochemicals were identified by combined GC-Mass spectrometry and infrared spectrum(GC-MS-IS). The sex pheromones of the most of aphids were the synergistic mixture of 2 or 3 kinds of nepetalactols. The main components of alarm pheromones were(E)-(-farnesene(EBF). Electrical penetration graph(EPG)exhibited eight types of waveforms which represent different physiological activities, including aphid stylets(probing, sucking, secreting accompanied by the excreting of honeydew, and revealed the spectrum difference between resistant and susceptible tea varieties to aphids. Results also showed that the contents of nutritional components(such as amino acides)and resistance-determining components in plant were related to aphid population density.

Environmental Impacts of Tourism in the Changbaishan Biosphere Reserve, Northeast China

Wang Xianli, Piao Zhengji, Shun Yongping, Cha Yoon-Jung, Hwang Yeong-Hyeon

1999, (3):  46-53,45. 

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Abstract Since tourism is the main huan activity inside Changbaishan Biosphere Reserve(CBR), the environmental impacts of tourism are considered the key problems of conservation and development in the area. The environmental impacts of tourism were analyzed based on the data obtained by field survey to various scenery sites and ecosystems in this article. The results showed that the environmental impacts of tourism tended to be serious, and strengthened management and education were leading ways to solve those problems. Some recommendations about exploitation and conservation were presented.

Snail-epiphyton Interaction and Its Effects on Submerged Macrophytes

You Wenhui

1999, (3):  54-58,74. 

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Epiphyton-feeding snails are often a conspicuous feature of the invertebrate fauna associated with submerged freshwater macrophytes. This paper reviewed the different interactions among snail, epiphyton and macrophytes.Studies on grazing by freshwater snail show that snails have a great impact on the biomass, productivity and species composition of epiphytic communities. Direct effects of the grazing on living macrophytes are probably of minor importance, but snails have a significant indirect effect on macrophytes by reducing the detrimental impact of epiphyton(e.g. shading and competition for nutrients). Predaters of snails can have a mediating effect on snail-epiphyton-macrophyte interactions, both through a direct predator-prey relationship(reducing the density of snails)and by inducing a habitat displacement of the snail.

Research Progress of Genetic Diversity

Xia Ming

1999, (3):  59-65. 

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Abstract As an important component of biodiversity, genetic diversity is the basis of species diversity and ecosystem diversity. With the improvement of research methods and experimental techniques, the research of genetic diversity has developed from morophological, cytological, physiological and biochemical level to molecular level which mainly study on nucleic acid. Using morophological methods, researchers can find out the level of genetic variation of a special species in a short time. The study on chromosome may reveal the changes of genome and chromosomal structure. Because of the emerge of allozyme analysis, people can study genetic diversity on biochemical level and have much deeper understanding about genetic variation and evolution. Owing to its efficiency, rapidity and convenience, allozyme analysis is still popularly used nowadays. From the late 1980's, some new techniques of DNA polymorphism analysis provided researchers with more efficient tools to study genetic diversity on higher level. This paper reviewed the research progress of genetic diversity on several levels, and pointed out that research should be conducted on different levels and from various angles. genetic diversity, genetic variation, genetic structure, allozyme analysis, RAPD.

The Pollination Costs of Ficus pumila L.

Li Hongqing, Chen Yong, Lu Xin'an, Ma Weiliang

1999, (3):  66-69. 

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In the interspecific relationship, one organism may supply the other with some material and energy produced in metabolism. This is the“costs” that one species paid for the another. The “costs” may be rewarded or not, rewarded more or less. The insect-pollinated plants need to pay pollination costs for pollen transfer. The pollination costs of the general insect-pollinated plants are confined to providing nectar sources and some structures favored for nectar collecting. In general, the plants needn't to provide nutrition and shelters to the pollinators. But the fig trees need to; otherwise they should have no seeds. The present paper dealt with the trees of dioecious Ficus pumila L.. It is showed that each gall tree bears about 43,000 pollinators(Wiebesia pumilae(Hill)Wieb.), and when the gall trees paid economically, the female trees were rewarded efficiently by the reasonable arrangement of inflorescences and flowers.

Application of the Leonard Jars for Germination Test in Soil Seed Bank Research

Zhang Zhiquan

1999, (3):  70-74. 

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The leonard jars were modified to use for germination test in soil seed bank research. Compared with the soil under sprinkle condition, the soil samples in the leonard jars can be regularly watered from below through the siphonage, kept porous, and avoid washing out by sprinkle. The water content of soil in Leonard jars varied from the one in the flower pots at 24h and 48h after sprinkle, and comparatively stable for 3 months. The man-made soil seed bank samples by mixing the select and known number of seeds with sterile soil were used for germination test in the Leonard jars and flower pots under sprinkle condition respectively. No significant differences were found in germination percentage(GP)and the mean rate of germination(CRG). The Leonard jars can be conveniently and effectively applied to germination test in soil seed bank research.

Study of The Data Cold Resistance of Rice

Li Taigui, Xu Xing, Chen Yan, Wang Lei

1999, (3):  75-78. 

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The dynamic simulation method was used for the first time in the data analyzing on rice resistant ability under cold temperature. The simulation results showed that “the inherent frequency” or “period”, the period size of plant growing system, could be used as the quantitative index of measuring cold resistance when the measurements well matched cold resistant magnitude. There are three different types of the indices in the plant resistance. The Dynamic simulation models could show inertia resistance, impedient resistance and recovery resistance.Dynamic simulation models are to be set up in the different plant growing stages,so that the plant growing process can be predicted and controlled.