Taking the Suijiawopu small watershed as an example, this paper briefly analyses the status, characteristics, and causes of the degraded ecosystem,and then, according to the principles of eco economics, puts forward the principles,orientation,ways and measures of the degraded ecosystem reconstruction and agricultural resources exploitation.Obvious ecological benefits and economic benefits have been achieved in eco economic valleys, protective forest system,artificial grassland, drought resistant farmland and culture demonstration area for high yield through 5 years' practice.

On the basis of the vegetational investigation in Maowusu sandland, the family and genera composition,geographic components, life form and ecological characteristics of the flora of the shrub resource in the area are analysed. The important position and significance of the shrub in this special ecotone of the geographic landscape are analysed too. According to these, we put forward the countermeasures for the protection and restoration of the diversification of the shrub resource.

This paper generally describes the present study state of Eucommia ulmoides in the aspects of resources, cultivation, chemical constituents, medicinal activity and clinical application. Furthermore, the prospects of its exploitation and utilization are forecastad.

n this paper, on the basis of analyzing the environmental background of the study area, the mechanism, time space law and expansion trend of land degradation are studied systematically by means of combining qualitative analysis with quantitative one and combining remote sensing with GIS technique. The conclusions are as follows: (a) In the study area, population is the basic contributing factor of land degradation and the land degradation is a result of uncoordinated development of ecologically vulnerable environment and social economy. In especial, the potential vulnerability of the natural environment is transformed into practical destruction because of unreasonable land use and management way. (b) The main type of land degradation in the study area is land desertification. On the whole, during the past 30 years the degree of land degradation has been intensifying, and the land degradation type has showed a diversified tendency. (c) Land degradation is a dynamic process, which possesses four characteristics, namely, long term, gradual change, continuity and locality. Therefore, higher precision and efficiency in monitoring, appraising and forecasting the land degradation can be obtained if remote sensing and GIS technique are used. (d) To manage the land degradation should take the landscape ecology theory and sustainable development ideas as the guide, consider both the ecological benefits and the economic benefits, and adopt varied technical ways . Besides, it is necessary to do the easy first and then the difficult and to take measures according to local conditions.

In Southeast Tibet the planting industry plays an important part in rural economic development. This article fully expounds and proves the important aspects of tobacco planting in Southeast Tibet, such as its feasibility, necessity, importance, development scale and strategic policies. This study is aiming at arousing the attention of policy making departments and academic circles, thus promoting the rural economic development in this region.

ith the area of Chinese fir plantation increasing constantly, the soil fertility degradation of the site of Chinese fir plantation is increasingly serious. Controlled burning is one of the major causes which cause the soil fertility degradation of the site of Chinese fir plantation. On the basis of the achievements of previous related studies, we, in this paper, fully expound the effects of controlled burning on the slashes, soil and water loss, soil fertility and Chinese fir growth at home and abroad, summarize the advantages and disadvantages of controlled burning,and raise some corresponding countermeasures. This is of great significance for changing the traditional culture system of Chinese fir and for the sustainable use of the resources of the mountainous area in South China.

This paper has studied the problems that are related to the standardization of the concepts and methods in the computation of the economic loss of ecological resources destruction. The problems are: (a) the muliti value character of ecological resources and the value concept system, (b) the two computation structures used to compute the economic loss of ecological resources, (c) the determination of 1. the amount of ecological resources destruction in the computation structure of the resource value type and 2. the unit function value of resources, (d) the determination of the effect weight of the ecological resources destruction to disasters, and (e) the battering effects of the disasters tempted by ecological destruction on the whole economic social system.

his paper studies the species composition and ecological distribution of the ant resourse in Jilin Province.We found that there are 18 species of ants belonging to 10 genera and 2 subfamilies and that the species composition and distribution of ants have close relation to environmental conditions.It also deals with the edible and medical values of ants.In the end,the paper offers some proposals concerning the development and protection of the ant resource.

his paper points out the main technical links of setting up, in China, a working system for yield estimations of the main crops (wheat, maize, rice, cotton, soybean ) by means of the remote sensing techniques according to the basic features of the farmland and the cropping system as well as the practice of yield estimations by means of remote sensing in the major crop growing regions from 1991 to 1996. The key links include the overall design of the engineering of the working system, the regionalization of estimating the yield by satellite remote sensing, the background database establishment, the assimilative techniques of remote sensing information, the extraction of the planting area of crops, the monitoring of crop growth and the model of the per unit area yield, and the establishment of a working system. This paper also describes the envi sagement of the technical programme and steps for realizing the system; that is, to unify organization and implementation and to avoid repeat. First of all, grasking the yield estimations by satellite remote sensing for the main production area of crops and choosing Henan, Anhei and Jiangsu provinces to develop the experiment of integrated yield estimations of the five crops. Then setting up a method system of the extraction of planting area of crops and of monitoring the crop growth and yield for different regions or crops. According to the practical conditions an authentic or fictitious working system for the yield estimations by satellite remote sensing may be set up.

The paper makes an investigation of the resource of the fruit trees of Ribes in the Northeast and Inner Mongolia area. We preliminarily as certain that there are 19 species, 2 varieties and 1 forma. We also make researches on their features, characteristics, ecological environment, distribution and utilization value. Finally, we summarize the research achievements of domestication cultivation and put forward some suggestions about their exploitation and utilization.

his paper gives a comprehensive description of the main models of land use and land cover change (LUCC) in global change studies with particular attention to vegetation models and the models which consider social driving forces. The main trends of LUCC modeling are:(a) Future LUCC models should be able to simulate the major social economic and physical driving forces of land use and land cover change,including the major feedback relations from LUCC to driving force sand global change.(b) The models are geographically explicit.With appropriate spatial resolution they can predict the long period (50-100 years) LUCC and associated biophysical parameters, such as vegetation attributes and resource accumulation and degradation.(c) The models can improve our understanding of the local, regional, and global dynamics and consequences of the relationships between LUCC and its main driving forces,and make us consider the sensitivity of land use and land cover change to exogenous variables ( e.g., policy,technological progress, population growth, economic development, market change, and some cultural factors, such as attitudes and values).(d) New methods of LUCC modeling will be developed, which can link LUCC models with other global change models, especially with climatic models.

he ARID CROP model is used to study the numerical simulation of the climatic productivity of winter wheat in the Huanghuaihai region .The distribution map of the climatic productivity (Yq) is given first. Then the distribution condition of the productivity of photo temperature (Yw) is studied at the time when the moisture condition is most suitable.On the basis of these studies, the distribution map of the increasing production force of moisture Q(Q=(Yw-Yq)/Yq) is given. The results show that the climatic productivity of winter wheat in the Huanghuaihai region changes from 3 750～9 750 kg/ha , the general tendency is that the value is lower in the north but higher in the south, and there is a low value of about 3 750 kg/ha in the Heilonggang Area. Mois ture is a main factor which limits the climatic productivity of winter wheat in the northern part of the Huanghuaihai region.When moisture is suitable for winter wheat growth, the climatic productivity can only increase about 5%～10% in the southern part of the Huaihe River basin, whereas in the northern part of the Huanghuaihai region it can increase about 75%～100%. The high production records of winter wheat in the Huanghuaihai region are used to compare with the simulate value of productivity . The results show that it is feasible to simulate the climatic productivity of winter wheat by using the ARID CROP model in the Huanghuaihai region. This study will provide a theoretical basis for conducting water from the Huanghe River for irrigation to a certain extent.

he regional territory resources evaluation is a very important basic work in the decision making of many important economic strategies. But in our country, now there are many quite serious problems in the resource evaluation method. The purpose of this paper is to study a better evaluational method for raising the level of the regional territory resources evaluation.The systemic analysis method expounded in this paper has mainly solved two problems: one is the evaluation of the superiority and inferiority of the resources as a whole and the other is evaluation of the compositional and coordinational situations of the resources. The concrete contents are as follows: (a) Setting up systemic thought and sense, understanding the territory resources system and its gradation and structure and understanding the regional system and its gradation and structure; (b) Choosing the representative quantitative basic indexes; (c) Establishing the mathematical mo dels, synthesizing the quantitative basic indexes grade by grade into the quantitative indexes which reflect the higher grade resources items and reflecting the whole superiority and inferiority of (1)the resources items of every grade of the regions and (2) the three big resource items (nature, economics and society) by means of the comparison of the synthetical quantitative indexes;(d) Calculating the compositional indexes of the resources items of every grade with the formula“standard disparity”, and reflecting the compositional and coordinational situations of the resources items of every grade of the regions of the same grade by means of the comparison of the campositional indexes.

According to the measured soil moisture,the agricultural meteologic data and the satellite monitoring data of the wheat season of the North China Plain in the years1993—1995,a regional soil moisture model is tested to simulate the process of the dynamic change of soil moisture and its related elements and to overcome the defect that former remote sensing model of soil moisture can only determine the soil moisture content but not the structure of water amount. This test has gained satisfactory effects. It successfully uses the remote sensing data as the input of the model and reaches the goals of monitoring the soil moisture conditions,analysing the hydrology and water conservancy and estimating the crop production based on remote sensing. At the time of exporting the structure of water amount,the model can also provide the information about the impacts of human activity on the water environment.

The sustainability of China's agricultural and forestry resources is being seriously challenged by changing physical and social economic conditons.Experiences in China suggest that agroforestry complex system can play an important role in the sustainable development of China. Though reviewing the methods of economic evaluation of the agroforestry complex system in China, this paper reveals that at present the economic evaluation of the agroforestry complex system is mainly limited to financial profits. This is necessary, but it shows insufficient when the sustainable development of the agroforestry complex system is considered. Lastly, an exploration is made for the development direction of the economic evaluation of the agroforestry complex system in China.

n the study of reestablishing the ecological system of the mining area, we selected the plant strains fit for growing, compared different growing methods, and cultivated the deteriorated land with manure. According to the experimental results and the na tural ecological environment conditions, we think that planting the green manure crop legume is an effective way for quickly restoring the soil fertility, protecting the land resource of the mining area, and reestablishing the ecological environment of the mining area.

In this paper, on the basis of the situation of the Lower Liaohe Plain, the knowledge base for the agroecological pattern of multiple cropping is built by using the expert system development tool. The procedures for building the knowledge base of expert system are put forward. They include knowledge acquisition, knowledge expression, making codes, and verification. The building of the knowledge base can transfer the expertise and the domain experts' experiences on multiple cropping to the agricultural policy makers in an acceptable fashion, thus improving the automation and scientism of agricultural policy making.

The analysis determination of the rational annual cut of forests is one the critical techniques used to work out the quota of the annual forest cut. It is also one of the important contents of forest management. In this paper, according to sustained utilization theory of forests, a synthetic evaluation model of the analysis determination is established and a precise method of the analysis determination of the rational annual cut of forests suggested, thus effectively assuring the results to be scientific and accurate.

aking the practicality of the farmland shortage in China as the background and using the economic principles this paper analyses the importance of farmland protection to raising the efficiency of agricultural investment and assuring the rapid growth of the national economy.Then a national economic appraisal method which adapts to the farmland shortage is worked out. Finally, a countermeasure system for the farmland protection in China is advanced.

Agricultural production efficiency,crop livestock integration, grain problem, layout of agricultural production and object of the study of sustainable agriculture have been highlighted by scientists and decision makers in China.These problelms play a crucial role not only in correct policy making, but aslo in the direction of agricultural research. There have been, however, some confusions and misunderstandings in the current viewpoints held by some of the scientists and decision makers in China. Pointing at this situation, this paper makes a significant discussion for the sake of finding a correct answer through a profound analysis and statement based on the researches conducted by the authors themselves and a large amount of study results collected at home and abroad.The conclusions are: (a)Sustainable agriculture is an academic term, not a new model for replacing the conventional agriculture, and the study of sustainable agriculture should give priority to developing input reducing technology and increasing farmers income in order to make Chinas agriculture environmentally sound and healthy; (b)The emphasis of researches on crop livestock integration should be shifted to focusing on how to adjust the composition of energy and protein in feed supplied by cropping and consumed by livestock; (c)The main ways for eliminating the increase of grain shortage in China are to put the strategy of grain substitution into practice as soon as possible and to properly restrain food consumption which has been highly speeded up; (d)According to the principle of less external input and higher efficiency, the priority of developing grain production should be placed on the high yield farmland rather than on medium yield farmland; and (e)The energy efficiency in Chians agricultural production has increased from time to time, which is very important for a correct policy making in China's sustainable agriculture.

In this study,we analyze several calculation methods of the production rate of methane in rubbish and make a detailed calculation of the production rate and the cumulate output of methane. On the basis of this study,we use a real rubbish dumping field to calculate the production rate and the cumulate output of methane. It helps to supply the useful reference deta for producing electricity from rubbish in the rubbish dumping fields. Finally we calculate the methane output from rubbish of every province and the potential methane resource in rubbish of the whole country.

甘肃东部旱作地区干旱区年降水量小于300mm,半干旱区为300～450mm,半湿润区为450～600mm,湿润区大于600 mm4种气候类型1989～1992年14个测站0～2m深的土壤湿度实测资料,从降水土壤水作物系统观点出发,分析研究旱作小麦的实际耗水指标和耗水特点,探讨麦田水分供需平衡,为发展旱作区小麦高产稳产的栽培管理措施提供科 学依据。

山东矿产资源以能源矿、非金属矿、金矿和铁矿等具优势,常用矿产与优势矿产吻合程度高,主要矿产资源地区匹配关系好,便于综合开发利用。矿产资源开发利用对山东工业发展具有重要导向作用,但也存在加工程度低、综合利用效益差、资源浪费重、对生态环境影响大等问题。在综合分析资源特点和利用现状的基础上,构想了山东主要矿产资源开发基地的布局和发展趋势。

Based on data obtained from field investigations and observations concer ning “development and utilization of grassland resources in southern China”organized by Biological Division of the Chinese Academy of Sciences (CAS),and referred to relevant data provided by local organizations,the paper puts forward a high efficiency animal husbandry development strategy related to “evergreen grassland belt”in China according to present conditions on ecological rehabilitation and environmental protection of grassland and grass covers in hilly areas of southern China as well as their development and utilization. The conclusion is that the development of 134 000km₂ grassland in next twenty years is feasible,the grassland animal husbandry in southern China will became one of the important bases of China's animal husbandry,and the construction of some development and experimental bases is very indispensable.

Qinghai Xizang Plateau is a high yield wheat area, and the highest yield of wheat can reach 15 2t/ha. Reasons accountable for high yield according to traditional concept are: (a)plentiful solar radiation; (b)great temperature range; (c)high intensity of photosynthesis of wheat; and (d)low consumption rate of respiration, which are thoughyt to be favorable for more accumulation of assimilation pro ducts in this area. However, experimental studies show that the mean rate of dry matters accumulation of wheat is a slightly lower than plain areas and traditional points can not explain this explicitly. Actually, because of low CO2 density in the plateau region, the efficiency of wheat leaf photosynthesis is just about 2/3 that of plain areas. Yet the high solar radiation and advantageous wheat community structure can make up deficiency of CO2 to some extent, so the mean rate of accumulation in the plateau region is just a slightly lower than plain areas. On the other hand, the annual average temperature is low in the plateau region which can elongate the duration of wheat growth greatly. So wheat has long time to take advantage of all the agro ecological conditions. The two factors, a slightly lower rate of dry matters accumulation and much longer duration of growing season, decide high product of dry matters in the plateau region. High harvest index wheat in the plateau region can get unusual high yield product.

At present, agriculture still belongs to high resources consumption low benefit type of agriculture in China. However, as agricultural natural resources are limited, high benefit utilization of agricultural resources must be achieved. Agricultural resources utilization models and mechanism transformation among deferent models are studied in this paper from mesoscopic regional point of view.Case analysis indicated that agricultural resources utilization models are in change process, and this process has distinct hierarchies ;material resources input level in the change process is added, agricultural resources utilization efficiency is increased;and agricultural resources utilization technology system adaptable to agricultural resources utilization model has diversity and hierarchies.

Based on measurement data of winter wheat field in the Tibet Plateau, the dynamic change curves of dry matter production of winter wheat under present climatic as well as suitable soil water and fertilizer conditions are obtained by means of simulation models. The results show that on the Tibet Plateau, the growing period of wheat is prolonged because the climate in summer is cool. And the high yield of wheat in Tibet Plateau is due to the long accumulating time of dry matter. The advantageous temperature in summer is the key reason of the high yield of the winter wheat in the Tibet Plateau. The potential yield of the dry matter of the winter wheat in the Tibet Plateau is 32t/ha.The potential yield of the grain is 14 4t/ha and 1 45 times as much as that on the plain.

The methodologies of environmental and development planning have been severely challenged when classic concepts and models such as economic optimum,ecological fitness,safe minimum standard,carrying capacity,and even sustainability have been questioned. It is observed that:(a) it is extremely difficult to have the planning aimed at being either ecological or economic optimum,i e. planning is not a process determined absolutely in terms of environmental and economic criteria,but rather a defensible one (b) there are some“ultimate ”or “absolute”constraints,which the planning has to come to terms with,but these constraints are hardly definable or acceptable. Therefore,they play a quite limited role in the practice of environmental and development planning. What is urgent is to find some new and effective make the planning process both defensible and operational. As to how to find and design such a defensible strategy serves as an essential field concerning methodologies for sustainable development planning The security pattern approach in planning is an attempt in this direction.

In this paper,the climate related corn yield in 55 stations in Gansu province is resolved by means of EOF and REOF. According to the analysis of loading vecter, southeast Gansu is of most representative in corn yield. Furthermore,the climate related corn yield areas can be divided into 5 natural climatic zones:Eastern Gansu, Southern Gansu,Middle and Humid Mountain Area,Arid Mountain Area and Western Irrigated Agricultural Areas of Gansu.The first main component of the climate related corn yield can represent the temporal tendency of the climate related corn yield of Gansu.It is well correlated to the OLR in May and September of the same year.

The three cropping patterns, i.e., winter wheat/spring corn/summer corn/autumn corn, winter wheat/spring corn/summer corn, and winter wheat summer corn, were analyzed from aspects of yield, resources utilization rate and economic benefit in the paper. The results showed that yield of all the three cropping patterns could surpass 15t/ha, indicating the reality of reaching 15t/ha in Huang Huai PLain under condition of intensive multiple cropping system. The yield differences among the three cropping patterns showed that intensive multiple cropping and reasonable adjustment techniques were effective ways to further increase field annual yield in this region. The highest yield of winter wheat/spring corn/summer corn/au tumn corn reached to 22.01t/ha, which was one of the effective cropping patterns to near or to top 22.50t/ha with present techniques. For cropping pattern of winter wheat/spring corn/summer corn/autumn corn, the key to yield increase was due tothe total ears added; the high assimilation rate could be maintained and light heat resources utilization rate could be increased by effective measures in combination with transplanting and other relevant practices. The economic benefit was reflected in high input/high output, but some indexes of output to input rate tended to be declining.Comprehensive judgment from the viewpoint of yield, net income, material expenses and labor employed indicated that winter wheat/spring corn/summer corn/autumncorn pattern had advantages in general.