Table of Content

10 April 1995, Volume 14 Issue 02

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Induced Protective Resistance in Greanium sylvaticum Populations

Liu Dengyi, Cha Demin, Zhou Zhongze, Lars Ericson

1995, (2):  1-5,26. 

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eranium sylvaticum plants differ in susceptibility to a macrocyclic rust, Uromyces geranii,depending upon whether they were previously infected by microcyclic rusts,Puccinia spp.and which rust(Puccinia morthieri or P. leveillei)previously diseased them. Field surrey, field transplantation and inoculation experiments show that previous infection by Puccinia spp. can decrease the susceptibility of G. sylvaticum to U. geranii. Furthermore,plants infected by P. morthieri show a lower probability of becoming infected by U. geranii compared to those infected by P. leveillei. Thus,interspecific pathogenic interactions and induced protective resistances are existed in G. sylvaticum populations. Induced protective resistance may be one important factor in explaining disease patterns observed in natural plant populations.

Simulation Model of Carbon Storage Dynamics in Temperate Broadleaved-Coniferous Mixed Forest Ecosystem:Ⅰ. Dynamics of Carbon Storage in Tree Layer

Yan Xiaodong, Zhao Shidong

1995, (2):  6-12. 

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basic model is developed to simulate the dynamics of carbon storage in tree layer of temperate broadleaved-coniferous mixed forest stand. The model can get close to the observations on different stands. It consists of 10 compartments, which can integrate daily results to simulate monthly and annual carbon cycling in stands. There are 3 basic characteristics of the model:(a)the concept of light trophic area is introduced to make it easily be applied to mixed forest;(b)different strategies of allocation of assimilation are used for evergreen and deciduous trees;(c)respiration of woody parts of trees is computed by using the known relationship between relative rates of respiration and diameters of woods.Because the model utilizes climatic data as driving variables,it can be applied to study the response of forest to climatic changes.

Spectral Analysis of Pb and Zn Contents in Tree Rings of Black Pine and Masson Pine and Pricipitation in Xixia Mountain Area of Nanjing

Dong Yawen, Pan Liangbao, Qian Junlong, Huang Jingsu

1995, (2):  13-17. 

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pectral analysis of Pb and Zn contents in annual growth rings of 2 back pine(Pins thunbergii Parl.)and 3 masson pine(Pinus massoniana Lamb)trees grown on a polyrnetal mine and its surrounding area of the Xixia Mountain in Nanjing shows that the length of periodicy plays a primary role in the periodic variations of Pb and Zn in tree rings. The synchronous variation of Pb with precipitation is dominated by long periodicy,while that of Zn by short periodicy.The ratio of orthogonal positive to orthogonal negative correlations of Pb and Zn variation,which is1/4 behind that of precipitation, varies with trees,Significant correlations between element and precipitation account for 0.30-0.60.For both of the element and precipitation sequences,their maximum and minimum delay time,and their corresponding periodicy vary with trees and elements.

Characters of Needles and Their Variation in Pinus sylvstriformis Population

Zou Chunjing, Bu Jun, Xu Wenduo

1995, (2):  18-22. 

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Biomass of needle,leaf area and leaf area index(LAI)of Pinus sylvestriformis population are studied and their character variations are discussed.The biomass of needle is 10.435t穐a^-1, leaf area of individual needle is 1.97cm²,and its leaf area index of is 11.75.There exist obvious variation of needle character,which are resulted from different environmental conditions.According to this,Pinus sylvestriformis can be classified into five types and each type adapts to a specific environment, which provides a possibility for the extension of distributed area of Pinus sylvestriformis.

Nutrient Utilization Efficiency of Grassl, Fernland and Shrubl and in Hong Kong

Guan Dongsheng

1995, (2):  23-26. 

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Four different methods are used to estimate the nutrient utlization efficiency of grassland,fernland and shrubland in Hong Kong. The results show that nutrient utilization efficiency calculated by Hirose(1975)and Vitousek(1982)methods are in the same order for three communities,i.e.,grassland > fernland>shrubland.Compared with other studies on tropical forest,it is found that the nutrient utilization efficiency of grassland fernland and shrubland is greater than that of forest land.

Thermodynamic Foundation and Information Theory in Understanding Landscape Heterogeneity

Michel Godron, Jacques Baudry, Richard T. T. Forman

1995, (2):  27-36,51. 

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theoretical framework based on the dynamics and information theory is outlined. Thermodynamic principles explain the flows of energy that.in turn,produce heterogeneity in thedistribution of energy and material.We describe the(1)trend toward a logarithmic vertical distribution of biomass.(2)thermedynamic linkage across scales(3)importance of entropy in isolated,closed and open systems,as a landscape changes,and(4)three resistances opposing the law of zonality or horizontal homogenization. Together they provide insight into heterogeneity at the landscape scale. The broad theory of information is used to measure and understand structure,i.e. spatial configuration. Based on probability and conditional algebras,a simple method for measuring the amount of information in a landscape map is described.

An Approach to the Regionalization of Ecological Environment in China

Gao Milai

1995, (2):  37-43. 

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The meaning,theoretical basis and principles for regionalization of ecological environment in China are outlined.The country is divided into 9 eco-environmental regions,i.e.,Liaoning-Jilin-Heilongjiang,Hebei-Shandong-Henan,Shanxi-Shanxi-Gansu-Ningxia,Jiangsu-Anhui-Hubei,Zhejiang-Jiangxi-Hunan,Fujian-Guangdong-Guangxi-Hainan,Sichuan-Yunnan-Guizhou,Neimenggu-Xinjiang and Qinghai-Xizang,The basic characteristics of each eco-environmental region are also outlined.

Techniques of Soil Improvement and Yield Increment on Terrace Field in Hilly-Ravine Areas of Loess Plateau

Liu Donghai, Zhao Tingning

1995, (2):  44-51. 

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The Huangjiaercha small drainage is a typical hilly-ravine area of Loess Plateau. Since the implementation of comprehensive harnessment, especially the construction of terrace field on slopes in 1983,great changes have taken place, To further enhance the crop yield and soil productivity,some other measures are adopted,which include deepening cultivated horizon,mproving soil physical and chemical proporties,applying manure and base fertilizers,returning straw onto field,selecting drought-resistant breeds,intercropping potato and beans,adopting integrated stereoscopic cultivation techniques,etc.

Designing Of Home Garden Ecolomic System with Methane Generating as a Tie and Its Application

Liu Dongbiao, Deng Liping

1995, (2):  52-60. 

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Based on the viewponits of systemology and the principles of agro-ecological engineering,the designing of home garden ecolomic system with methane generating as a tie in Nanxian county,Hunan province is differentiated and analysed systematically. Five kinds of developing types and basic ways of designing are introduced,and their structures,functions and efficiencies are analysed and evaluated quantitatively. The results show that in developing home garden economic system,methane generating can play a role of tie and multiple functions,make various vital factors of production and life of household ecosystem interdependent and inter-promotive,and achieve more comprehensive efficiency. The establishment of home garden economic system with methane generating as a tie is also discussed.

Effect of Temperature on Honeybee's Activity During Its Hibernation

Wang Shuxing, Wang Qifa, Li Weisan

1995, (2):  61-63. 

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Temperature is an important factor affecting honeybee's activity during its hibernation, Italian honeybee has been raised in China for a long time. In winter, it stops its out-honeycomb activity where the mean temperature is below 6℃,and gathers up as a group at 4℃. At 0℃,the group structure turns into a tight close-knit ball to preserve heat,and to prolong the individuals life.When the mean temperature is above 6 ℃,the bee group comes loose,which means the hibernation coming to an end,and the queen bee will start laying eggs.

A Philosophic Though on Environmental Capacity for Human Development

Chen Yian

1995, (2):  64-69,60. 

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The environmental capacity for human development can be enlarged by human action,but with limited space. This limitation can urge mankind to change his developmental patterns and enhance his developmental level.Above the environmental capacity,problems hindering human development can only be solved by natural-and social-ecological ways. Successes in social regulation indicate the human civilization having entered in a still higher development stage. To have an effective social-ecological regulation on the ecological imbalance between modern society and nature,the reproduction of environment must be strengthened.