Table of Content

10 August 1992, Volume 11 Issue 04

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Influence of Heavy Metals and Their Interactions on Heavv Metal Contents in Wheat Seedlings

He Jianqun, Yang Jurong, Xu Jialin, Chen Yanfeng

1992, (4):  5-10,17. 

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Orthogonal experiments are carried out with water cultivation to learn the effects of heavy metals and their interactions on the accumulation of Zn, Cd, Cu and Pb in wheat seedlings. It revealed that the content of certain element in wheat seedlings is firstly dependent on the dose of this element, and then on the concentrations of coexistent elements. The significance of coexistent elements or their interactions for Zn content in plant is in the order of Zn^** >Cd^*>Zn-Pb^**>Zn-Cu^*, whereas for Cd, Pb and Cu, is Cd^*>Zn-Pb^**>Zn-Cu^**>Zn^*> Zn-Cd^**, Pb^**>Cu^**>Zn-Pb^**>Zn-Cd^* and Cu^**>Pb^* respectively. The uptake rate of heavy metals in leaves is in the order of Cd>Zn>Cu>Pb.

Buffering of Forest Litter to Soil Acidification and Its Effect on Root Growth

Wang Silong, Chen Chuying

1992, (4):  11-17. 

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Litters of main tree species in subtropical zone (Cunninghamia lanceolata and schima superba) are examined for their buffering to soil acidification and effect on root growth. The litter of S. superba is more capable of buffering and weakening the acidity of simulated acid rain because of its more content of base cations. Covered with it, soil pH, base-saturation percentage and organic matter content are increased markedly, and soil hydrolytic acidity and Al/Ca decreased a lot. Litters of S. superba have a stronger capacity of buffering soil acidification than those of C. lanceoiata and are more efficient to alleviate soil acidification and improve root growth environment.

Faunal and Ecological Studies on Blood-Sucking Midges Along the Border Line of Northeast China

Liu Guoping, Xu Zhengfu, Tao Zhengguang, Quan Lihua, Yu Yixin, Zhou Minji

1992, (4):  18-21,40. 

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Faunal and ecological studies of wood-sucking midg s carried out during 1980-1988 in 10 border of Northeast China, 4 new species and 5 new records of species are identified. Ecological investigations show that Culicoides obsoletus (35.7%) and C, punctatus (34.9%) are predominant species. The composition of midges varies with different habitats, places and seasons. The active durations are 110 days for C. punctatus, and 100 days for C.sinanoensis and C. erairai. During active seasons, there is only one peak for C.pulicaris, C.pallidicornis, and C. erairai, and two peaks for C. obsoletus, C. sinanoensis and C. punctatus. Diurnal observations on₅ species show that within₂₄ hours, two peaks of C, pulicaris, C.obsoletus, C.sinanoensis and C. punctatus appear at 1-2 hours after sunrise and sunset, C. odibilis, the peak appears at 2 hours before sunrise, and its active duration is from midnight to day break.

Effect of Forage on Perinereis aibuhitensis Growth and Development

Zhao Qingliang, Zhao Qiang

1992, (4):  22-26. 

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The Quality and quantity of forage have significant effects on Perinereis aibuhitensis growth and development. High forage quality can increase its growth rate and individual weight, and improve the silk quality. The forming of heteronereis can be postponed or prevented by supplying appropriate amount of forage at appropriate time, which is very useful for actual production of nereis. The feeding behavior and forming of heteronereis of P.aibuhitensis are minutely observed and analyzed in the paper.

Ecological Observation on Golden Monkey in ShennongJia Natural Reserve

Hu Zhenlin, Zhu Zhaoquan, Liu Cuihua

1992, (4):  17-30. 

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The habitats of golden monkey (Rhinopithecus roxellana) in Shennongjia Natural Reserve can be classified into two types:coniferous forest and coniferous broadleaved mixed fortst. There are two feeding peaks and a rest time(12:00-14:00)in the daily activity of Golden Monkeys. They feed chiefly on plants and communicate with each other by different cries. They mate with all the year round and the copulation season is from September to October. The birth season is concentrated in April and May. There are two colonies of them in Shennongjia,with 342 and 159 individuals each and about 501 in total.Human activity exerts an strong influence on Golden Monkey.

Research on Environmental Effects of Farmland Shelterbelt

Wang Mou, Zhang Enguang, Shen Hailiang

1992, (4):  31-35. 

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Various effects of farmland shelterbelts on absorbing toxic gasses, filtering dusts and reducing noise are studied in a definite region. The results show that farmland shelterbelts have a remarkable and positive effect in improving environment.

Community Features of Vitex trifolia var. simplicifolia and Its Adaptation to Sandy Land in Houtian Area

He Xingdong

1992, (4):  36-40. 

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As preliminary investigation indicates, plants in the community belong to 12 families and 27 species. At present, the community is in an unstable state. Cultivated Vitex trifolia var. simplicifolia is still the constructive species of the community, which has many profitable properties such as developed root system, vigorous growth in covered drifting sand, strong resistance to drought and barrenness, resistance to wind erosion, etc. It is a good pionrer species for drifting sand stabilization.

Articles

Patchiness and Patch Dynamics: Ⅰ.Concepts and Mechanisms

Wu Jianguo, Li Bailian, Wu Yegang

1992, (4):  41-45. 

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With enormously increasing awareness and research emphasis on spatial heterogeneity, the study of patchiness and patch dynamics has become a major theme in both aquatic and terrestrial ecology.Patch dynamics represents not only a field of study,but a new emerging ecological paradigm as well. It represents a view that emphasizes spatial and temporal heterogeneity,non-equilibrium properties, hierarchical structure,and scale-dependence of ecological systems. A great challenge for ecologists is to relate spatial patterns to ecological processes and vice versa. Understanding the mechanisms of patchiness and patch dynamics provides a basis for achieving the above goal. This paper introduces basic concepts in patch dynamics,presents a conceptual framework for causes and mechanisms of patchiness, and develops some general aspects of patch dynamics based on hierarchy theory.

Overseas Researches on Tree Fine Root

Shan Jianping, Tao Dali

1992, (4):  46-49. 

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The growth and decomposition of tree fine roots play an important role in energy flow and nutrient cycling of forest ecosystem. This paper reviews the methods in studying the dynamics of fine roots,factors influencing fine root growth and death,relationship between fine root turnover and forest productivity,and role of fine root decomposition in nutrient cycling of forest ecosystem.Finally,some new fields are suggested for further research on tree fine roots.

Analysis on Ecological Factors in Competitive Nodulation of Rhizobia

Ding Wu

1992, (4):  50-54. 

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There is no significant effect when rhizobia are inoculated to soil where leguminous plants have been grown for many years. Inoculated rhizobia form fewer nodules than those formed by indigenous rhizobia. This is called "Competitive nodulation" which also exists among other rhizobia. There are two kinds of factors influencing "competitive nodulation".One is nonbiological, including placement of rhizobia in soil, soil type, soil physical and chemical properties and temperature etc.; and another is biological, such as density and characters of rhizobia and many other biological elements in soil. In this paper, some ecological factors affecting "competitive nodulation" are analyzed from an ecological point of view.

Integrated Estimation on Benefits of Different Utilization Ways of Paddy Field

Gou Xiaohong, Zhang Hongsong

1992, (4):  55-60. 

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Fourteen indexes are used to make an integrated estimation on benefits of 22 typical utilization ways of paddy field in Chongqing. Index weight is determined by hierarchical analysis. According to the values of integrated benefit indexes, 10 optimum utilization ways of paddy field are of the following sequence; rape+hybrid double-harvest rice+Azolla imbricalla+fish, rape+hybrid double-harvest rice, wheat or maize+hybrid late rice, barley+hybrid double-harvest rice, vegetable+hybrid medium rice, barley+hybrid medium rice+sweet potato, hybrid medium rice+ratoon rice+Azolla imbrica+Zizania caduciflora+fish, green manure+ hybrid double-harvest rice, barley+hybrid medium rice+ratoon rice+fish, hybrid medium rice+ratoon rice+Zizania caduciflora+fish.

Agroecological Divisioning of Shanxi Province

Fan Lanying, Gao Huiqing

1992, (4):  61-65. 

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Using principles and methods of mathematical statistics and considering characteristics of natural environment and structure of agrobiological community, agroecosystems in Shanxi province are classified into 3 major types and 10 subtypes. It provides scientific basis for optimizing agroecosystem structure in the province.

Multiobjective Group Decision-Making for Cooperative Management of Plant Protection in Orange Plantations

Zhang Wenjun, Li Zhengqi

1992, (4):  66-68. 

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Multiobjective group decision-making theory is effective for solving problems in cooperative management of plant protection system.Taking fungicide and pesticide as protection measures, foreign trade department and farm as decision-makers,yield and quality of orange as objectives, and using multiobjective group decision-making algorithm, the dosage and frequency of applying fungicide and pesticide are determined coordinating with different needs. Main subprograms for multiobjective group decision-making algorithm are given in this paper.

Preliminary Analysis on Essence of Ecology

Wang Dehua

1992, (4):  69-71. 

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Ecology is a rapidly developing subject. Its definition and essence are not unified so far. According to various definitions and research objects in different fields of ecology, and from viewpoints of survival and adaptation, the essence of ecology can be considered as the adaptive survival strategies of organisms to their environment. The breadth of ecology, combined with its youth and great relevance to human problems, makes it a fascinating and exciting field, with real potential for progress and development.