Table of Content

10 December 2000, Volume 19 Issue 06

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Studies on the Xylem Draught-Tolerant Characteristics of Three Draught-Tolerant Tree Species

Shen Weijun, Peng Shaolin, Zhang Shuoxin

2000, (6):  1-6. 

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The xylem embolism vulnerability and refilling ability were measured in one-year-old twigs of three draught-tolerant tree species, which were Ulmus pumila L., Hippophae rhamnoides L., and Corylus heterophylla Fisch., and three types of vulnerability curves for them were also established. The results showed that the water potential threshold for inducing embolism in three species was -0.1-0.3MPa, and the embolism reached its maximum value at the water potential of -2.5-3.5MPa. The xylem embolism vulnerability of three species was in the order of Hippophae> Ulmus> Corylus. The refilling of embolized xylem could occur while the water potential is below zero in all the species. In Hippophae, fully restoring occurred after thirty minutes under the water potential of -0.5MPa and -1.0MPa, but for Ulmus and Corylus, the restoration could reach about 90% in thirty minutes under the water potential of -0.60MPa and -0.34MPa, respectively. Ulmus could restore fully through one night (12 hours) under the water potential of -0.59MPa. The refilling capacity of three species was Hippophae> Ulmus> Corylus . The xylem of the three draught-tolerant species is not only very vulnerable to embolization or very sensible to water stress but also capable of refilling its embolized xylem in a short period of time. Vulnerable and drought-tolerant species had significant xylem embolism in higher water potential, which decreased the hydraulic conductivity so that limited water loss. Drought-tolerant species had more ability to refill its embolized xylem in a short period of time. These were the ways through which trees resist and tolerate drought or water stress.

Species Diversity and Seasonal Dynamics of Scarabaeoidea in Secondary Cunninghamia Lanceolata Forest

Wang Miao, Li Qiurong, Ji Lanzhu, Zhao Min, Chen xin

2000, (6):  7-11. 

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According to two times investigation on Scarabaeoidea of Huitong secondary Cunninghamia lanceolata forest in early spring,summer, the number of species Scarabaeoidea in early spring,and summer is 23 and 24,respectively; the Shannon diversity index is 2.067 and 2.417, respectivety; the Shannon evenness is 0.659 and 0.761.In early spring, the dominant species are Malatera horosericea,Melolontha frater and Granida albosparsa.In summer, The dominant species are Anomala vividana, Anomala alabopilosa and Anomala lucens.The species abundance distribution of Scarabaeoidea in two different seasons is fitted in to logarithmic series distribution. Asmall number of species often become dominant in different seasons.

Survey on the Water Fowl on the Yangtze River above Gezhouba

Hu Hongxing, Xiao Huazhong, Pan Mingqing, Dai Xiaoyang, Tang Zhaozi

2000, (6):  12-15,33. 

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Boat surveys were made in 1980, 1981, 1982, 1983, 1992 and 1996 on the species and number of water fowl on the Yangtze River from Gezhouba to Chongqing. ①84 species were recorded, belonging to 26 families of 12 orders. The Anatidae, Hirundinidae and Apodidae are dominant taxa. ②Spotbill Duck, Mallard, Common Teal, House Swallow, Sand Martin have large population,while Merganser, Ruddy Shelduck, Great Crested Grebe have small population. ③These species use the Yangtze as their migration routes, and distribute along the way. ④405 Large Egret roost on the signaling boats by night in the Section between Zhongxian and Fengjie. ⑤After the construction of the Gezhou Dam, the river has widened, and the number of birds increased. 28 Mandarin Duck were found playing in this area in November 1992 and 1996.

Investigation,Separation and Inoculation of Mycorrhizal for Robinia Pseudoacacia

Tian Chunjie, He Xinyuan, Han Guiyun, Wu Qingfeng

2000, (6):  16-20. 

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Mycorrhizal resource of Robinia pseudoacacia forests in different places were investigated, and the results showed that eighteen species of Ectomycorrhizal and two species of VAM were main species for the Robinia pseudoacacia. Two stains of ECM fungi and VAM fungi were cultured,and the most suitable medium and inoculated plant were selected.Through the inoculation, it is indicated that Ectomycorrhizal and VAM were able to be formed actually for Robinia pseudoacacia.

Nutrient Cycling in the Reed Field

Zhu Qinghai, Qu Xiangrong, Xiuzhen Li

2000, (6):  21-23. 

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The nutrient cycling in the reed field has been studied via field investigation and laboratory analysis. The results indicate that Nabsorption in higher reed productvity field is 0.6044% (high level); The Pabsorption is 0.1100% (intermediate); The Kabsorption is 0.0153% (low level).the cycling coefficiencies for N,P and K are 0.16、 0.15 and 0.12,respectively. They are all at low levels.

Sustainable Developmental Pattern and Countermeasure in the Three Gorges Reservoir Areas

Wu Gang, Li Jing, Kong Hongmei, Zhao Jingzhu

2000, (6):  24-27. 

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This paper deals with the development pattern, development situation, and existing problems of land of the Zigui County in the Three Gorges Reservoir Areas. This paper also presents the sustainable development pattern and its countermeasure in the Three Gorges Reservoir Areas. A case of Zigui County in Hubei province, from the regional sustainable development, building the sustainable development framework of low mountains region, middle mountains region and high mountains region, presents the controlling measures of structural optimization of complex ecosystem.

Progress and Problem of Vine Adaptive Ecology

Cai Yongli, Guo Jia

2000, (6):  28-33. 

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Vines-climbing plants are plants that cannot remain free-standing to any appreciable height.With thery are specially adaptive capacity, they become prominent components in tropical and subtropical forests, but often neglected as a group of plants. At present, some knowledge of vine ecology mainly comes from stusies on tropical vines. Subtropical vines are abundant and diverse, but vine ecology is nearly blank in China. The progresses and problems of vine adaptive ecology on plasticity, heteroblastic development, selective to host, breeding strategy and so on about vines were discussed in this paper. More attention must be paid to the adaptive ecology of vine weeds.

Influence of Defoliation and Grazing on Range Plant

Wang Shiping

2000, (6):  34-39. 

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Morphological, physiological and demographic responses to defoliation and grazing encompass the ecological scales of tillers, plants and populations within grassland communities. The ability of individual plants to regrow following defoliation is a multi-facetted process including the meristematic potential and compensatory physiological processes of individual plants, intra- and inter-specific competition of plants, and abiotic variables within the enviroment. The inherent morphological and physiological attributes of individual plants establish the potentialing for regrowth while the intensity of plant competition, resource availability and enviroment conditions constrain the extent to which this regrowth potentiality is realized.

The Process of Cometabolic Degradation of Polycyclic Aromatic Hydrocarbons in the Contaminated Soils

Gong Zongqiang, Li Peijun, Wang Xin, Zhang Hairong, Zhang Chungui, Li Bin

2000, (6):  40-45. 

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The biodegradation of most PAHs with high molecular weight is carried out by means of cometabolism. The development of the theory about cometabolic degradation is reviewed in this paper, and the achievements on the cometabolic degradations of PAHs are also summarized. It is demonstrated that glucose, biphenyl, organic acids and mineral oil could be used as cometabolic substrate to enhance the degradation rate of PAHs, and there are complex interactions in the microbiological degradation process among different PAHs. Some low molecular PAHs could serve as cometabolic substrate, which could also be used to enhance the transformation rate of high molecular weight recalcitrant PAHs. To achieve the cometabolic degradation of the PAHs in the soils, the following problems must be solved: the screening out of efficient degradative strains, the selection of the appropriate cometabolic substrate, the addition of surfactant if necessary and the optimization of operational parameters with the contaminated soils. These problems are the important parts of the project for the cometabolic degradation of PAHs in the soils.

The Swidden Cultivation Agro-Ecosystem Succession:From Community Point of View

Xu Jianchu

2000, (6):  46-50,45. 

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Xishuangbanna is one of the highest biological and cultural diversity areas in China, which manifests in the richness of forest management systems practiced by the different ethnic groups. Destruction and fragmentation of tropical rainforests in Xishuangbanna however have threatened the wildlife and other biological diversity in the region because of the fragile tropical forest ecosystems.This paper analyzes the swidden agroecosystems in Xishuangbanna based on social organization, customary institutions, resource tenure, indigenous technological knowledge and market economy from community forestry point of views. It concludes that the swidden cultivation is a prototype of community forestry. It still evolves the diversity of community forestry in a transition to market economy in multi-ethnic minority areas in Xishuangbanna.

A Survey and Prospects on the Research of the Quality of Traditional Chinese Medicinal Materials by Means of Plant Ecology

Tian Yu, Chen Jianhua, Zhou Xiujia, Bai Qiaoming

2000, (6):  51-53,57. 

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A brief survey and prospect on the research of the quality of traditional Chinese medicinal materials by means of plant ecology is given in this paper. It is concluded that the new methods and accomplish ment in plant ecology,combined with other related subjects,should be used fully in this research.Such combination might result in some new disciphines.

Protected Areas System of Canada

Xu Xuegong

2000, (6):  69-74. 

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Canada and its protected area system occupy a leading position in the international natural protected community. The perfect protected area system consists of four main levels: national, provincial, regional and local. In addition, there are some systems combining two or more levels. The whole large and order system also link with international systems. Protected area holds a unique position within the field of resource and environment. Protected areas management is a global caurse. This paper analyses and introduces the protected areas system of Canada. We can study and use Canadian advanced experiences for reference in establishing and developing Chinese protected area system.

European Landscape Convention and Landscape Ecology

Xiao Duning, Cao Yu

2000, (6):  75-77. 

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In view of the growing social demand, the Council of Europe's Congress of Local and Regional Authorities (CLRAE) drew up the European Landscape Convention to promote landscape protection, management and planning, and to organize European co-operation on landscape issues in Europe. This paper summarizes the properties, origins, structure and content of the convention, and discusses the definitions on landscape and landscape policy to which the convention refers. Moreover, this paper sums up and concludes the perspective of landscape ecology in Europe.

The Distribution and Harm of the Exotic Weed Mikania Micrantha

Zan Qijie, Wang Yongjun, Wang Bosun, Liao Wenbo, Li Mingguang

2000, (6):  58-61,77. 

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Mikania micrantha kunth is an exotic weed species for sout heastern Asia and the Pacific region, which is an extremely fast growing, sprawling, perennial vine and belongs to Asteraceae. It was from tropical central and south America and crowded into Hong Kong, Hainan province and the region along the coast line of Guangdong province in P. R. China, such as Huizhou, Shenzhen, Zhongshan, Zhuhai, Yangjiang etc. since 1980s. M. micrantha has seriously harmed the crops and the forest . In Neilingding Island National Nature Reserve, about 6-7 ha of forest has degenerated into ecological invasion. This paper briefly describes the characteristics of M. micrantha about its biology and ecology, reports on invading fields and its harms in P. R. China and southeastern Asia. The research development on the control strategies (including biological control, chemical control and manual project control) is also presented.

The Investigation of the Rhizobia of the Pea Plants in Liaoning Province

Liu Hongsheng, Wu Yunhe, Ding Yanhuai, Li Yu, Zhang Huiwen, Wang Chunhui

2000, (6):  62-64. 

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Liaoning province is located in the Northeast of China, with special topographic features.The pea plants in Liaoning Province distribute extensively.We have seperated and collected 260 samples of rihzobia,including 53 species of 26 genera of pea plants and found that the growth condition of rihzobium was associated with the climate and topographic features.This paper provides original information and important data about the pea plants and the rihzobia in Liaoning Province.

Revealing the Relationship between Plant and Insect by Modern Molecular Biology Techniques

Li Mingguang, Zhou Changqing, Gu Dexiang, Zhang Junli, Wang Bosun

2000, (6):  65-68,57. 

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This paper reviews the latest development in using molecular method to reveal the relationship between insects and plant species. These include: the specialized relation between insects and their host plants, the origin of cultivated plants pests the effect of development stages of plant on the genetic structure of herbivorous insects the genetic structure of plant affected by the distance of pollen dispersal by insects, and the future of forecasting the fate of insect resistant plant species based upon the genetic polymorphism of the insect.

Sludge Disposal of Wastewater Treatment Plant is an Important Subject in Environmental Science

Chen Tao, Xiong Xianzhe

2000, (6):  54-57. 

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Three problems of disposal and utilization of sludge are necessary to be solved by applying it in agriculture and forestry:①The possoblity of heavy metals in sludge causing second pollution to soil and crops.②The potential effect of pathogens on the environment.③Groundwater pollution caused by high Nand Pconcentration.The aiteratures on the above three problems home and abroad were summarized in this paper.