Archive

  • Select all
    |
    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Chen Hongjing, Feng Huilin
    Download PDF ( )   Knowledge map   Save
    Today the mineral energy resources are being reduced day by day in the world and people are widely interested in regenerated energy resources, particularly the land regenerated energy resources. This paper has estimated the regional and provincial land regenerated energy resources of China, the solar energy and wind energy being calculated, and the water energy and biological energy being statisted. On the basis of the comparative analysis of the quantity and distribution of the land regenerated energy resources, we propose some suggestions for the development of the land regenerated energy resources of China from a macroscopic standpoint.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Lou Huixin
    Download PDF ( )   Knowledge map   Save
    The object of this paper is to make a research on the use of red-yellow soil resources for the development of the dairy cattle industry. Using the Grey System methods, we have studied the main factors of the dairy cattle industry Cluster Method. We divide the whole region into seven districts and point put the development strategy of each district. And through the application of the Verhulst's Model, the development object is presented and the measures are mentioned.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Yu Xusheng
    Download PDF ( )   Knowledge map   Save
    For hundreds of years, many great geographers and thinkers have looked upon food as a mirror to reflect the man-nature relation which they were studying. The calculation of the population carrying capacity of the land resource, a reseach field appearing in the early 1980's, still follows the trail of such thought. It is essential to pay attention to lessons left by ancient pioneers when we are going to use methods and models of calculation of other countries in the study of our own country. (1) the potential productivity of the land is a synthetical reflection of the physical characteristics of the land and the management of mankind. So we should fully consider man's reactions to the land and the influence of the development of sciences and technology. (2) All the calculation models and experimental coefficients should be corrected according to the characteristics of the region concerned, the research purpose, and the level of study. (3) The potential capability of the land resource should be differentiatad from the potential productivity of the land, espulation carrying capacity of Binghai and Su-tion carrying capacity of some economic kernel regions. Proceeding from the above principles, the author engages in the calculation of the population carrying capacity of Binhai and Su-zhou, two different types of land use regions, by means of the method of computer-assisted multi-elements analysis.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Liu Yanhua, Yang Qinye
    Download PDF ( )   Knowledge map   Save
    In most of the developing mountainous areas, the agricultural production is the main activity on which people depend for their livelihood. The agricultural development is closely related to the environmental condition. The population is closely linked with the agricultural development. Rapid population growth in mountainous areas usually causes the competition for limited resources or, in other words, it increases the pressure on the physical, economic and social environment. Based on this idea, the land system, agricultural development, population growth and their interaction in the Tibet Autonomous Region are discussed in this paper.The land types in the region are very complex and varied. Because the physicogeograph-ical conditions, including elevation, temperature, moisture etc., are unfavourable, only a few of the lands can be used to grow crops and the crop production per unit is not high, too. After analysing the regional differentiation, land, food, population, growth and their interaction, it is pointed that the crop production can not meet the basic or minimum needs of the population. The food consumption of the region depends heavily on subsidy. The high expense for transporting a big amount of food is not economically worthwhile.To solve the unbalanced development of the land, food and population, feasible measures, including expending the area of cultivated land properly, improving the irrigation conditions, increasing the use of fertilizer as well as increasing the agricultural investment should be taken. It is also important that the population growth should be controlled. In the mean while the population quality of the minority nationalities should be enhanced.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    He Xiwu
    Download PDF ( )   Knowledge map   Save
    China is a country with insufficient land and a large population. Meanwhile its land productivity is seriously restricted by water resource and other natural conditions. Since ancient time, natural disasters such as drought, flood, salinization and alkalization occur contin-ualy, which hinders the agricultural development. Water conservancy has become a leading: factor in increasing the carrying capacity of the land, so that the rational developmend of water resource plays a more and more important role. Therefore, strenthening the management of water resource and developing a large scale fundamental farmland construction which focuses on the water conservancy are the significant methods to raise the land productivity from current situation to a new level. In doing so the demand for food by the increasing population and natural economy can be ensured.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Wu Cifang, Lu Jinggang, Zhu Xizheng
    Download PDF ( )   Knowledge map   Save
    The basaltic soils are an important soil resource that has been overlooked for a long time. It is revealed that these soils have excellent fertility and good quality and can make many crops grow well. There are three types of basaltic soils. They are in different geochemical evolution stages and have great differences in the conditions of exploitation and utilization. Among them the soil with weak weathering has great exploitable potentiality according to contents of many nutritive elements and other factors of fertility. The content of total Fe2O3 reaches 220.75% (n = 23) and the amorphous Fe2O3 amounts to 9.08% (n = 18) in the soils. Consequently, soil structure similar to sand in the surface layer develops obviously and leads to exceptional effects on soil exploitation and utilization. It warrants careful consideration that soils derived from different geological horizons, different rocks properties and different new tectonic movements have significant geochemical variations and influences on the exploitation and utilization. But up to now the extent of the influence is little known.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Yang Baozhen, Kong Dezhen
    Download PDF ( )   Knowledge map   Save
    The zonal vegetation of the Nanling Mountains in Hunan Province is evergreen broadleaf forest. Due to unrational utilization of the land, many forests are severely destroyed and large areas of grassland have occurred. The total area of grassland is about 1497.2×107mu (9.98× 105 ha), occupying more than one fourth of the whole region. The classification and ordination of the grassland vegetation are studied with the numerical methods of TWINSPAN (Two-way indicative species analysis) and DCA (Detrended correspondence analysis). The methods use the data of 48 plots and 150 species for calculating. The plots of the fourth division are divided into 10 main vegetation types. At the first division level, the plots are distingguished into two types, the mountain grassland type (occurring at elevations of more than 1000 m) and the hill grassland type (occurring at elevations of less than 600m). The other levels are based on difference of ecological facters. The results are very similar to those of the qualitative classification, which demonstrates that the methods of TWINSPAN and DCA are suitable for the classification of the subtropical grassland.Distinctive types have different utilization ways. The types on the higher mountains should be dominated by forestry. At some place medicinal trees can be planted. At the places of the gentle slopes it is possible to establish artificial grassland for pasturage under paying attention to soil erosion- The slopes of over 25 degrees should be closed. At the places having slopes of 15-20 degrees it is suitable to develop both forestry and pasturage. The hills about 300-600m in elevation may be used for cultivating economical forests and fuel forests. Below the elevation of 300 m the fruit gardens (citrus) can be established if there is irrigation. On the hills of gentle slopes the artificial pasture ground can be developed, but it should be combined with forestry. In agricultural areas the rotation of cereal crops and forage grass should be put into practice. It is most important to increase the ecological and economical benefits.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Chen Shouchang
    Download PDF ( )   Knowledge map   Save
    In Sichuan, the resources of forest pharmaceutical fungi are rich and distribute widely in forest regions in the subtropical, temperature and cold-temperature forest zones.All of them possess the pharmaceutical value and many species are recognized to have anti-cancer function and are called the "healthy food".In this paper 81 species of forest pharmaceutical fungi are recorded, which belong to 52 genera and 25 families. Among them, 73 species (90.12%) are Basidiomycetes and 7 species (9.88%) are Ascomycetes. They are macrofungi belonging to the families of Polyporaceae, Aga-ricaceae, Russulaceae, etc.According to their ecological habitats, these species may be divided into 5 ecological groups: lignicolous, 40 species; bamboophilous, 5; geophilous, 14; entomophilous, 5; and ecto-mycorrhizal, 17. They may be grouped into some ecological types. This may provide the basis for artifical cultivation.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Ni Zubin
    Download PDF ( )   Knowledge map   Save
    This paper concerns mainly some basic problems of the integrated assessment of the benefits of cutting and regeneration of the forests, particularly of the timber forests. It discusses the characteristics of forest cutting and regeneration. The main contents of three aspects, four basic principles, fundamental method, and the index system of the integrated assessment are put forward. Finally the concrete methods of assessing the productive, ecological and social benefits of forest cutting and regeneration are explored.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    Li Fei
    Download PDF ( )   Knowledge map   Save
    In this paper, a mathematical model of the hydrological cycle of the forest set up on the basis of a man-made forest which originated from a bog land in the suburbs of Edinburgh in southern Scotland is described. The whole process is abstractly recognized as a forest ecosystem with 5 compartments, namely, trees, grasses, ditches, ditch slopes and ditch bottoms. With the aid of some methematical formulas and computer techniques, the hydrological process of the system, which includes flow interception, surface flow, stared in soil, groundwater and the other hydrological phenomena, can be systematically simulated in a quantitative form. The amounts of rainfall and evaporation are put into the model and the runoff water is drained away from it- It is given here for an example to simulate the hydrological process of the system in 1986 and check the simulation efficiency. Through comparing the computed and observed flows of the forest ecosystem, it is found that the simulation efficiency is 93.5% on the daily basis and 85.1% on the two-hour basis.The model reveals the mechanism of the hydrological cycle of the forest. We can estimate the runoff by using the amounts of input pricipitation and evaporation only. It will be helpful to understanding the hydrological effect of the man-made forest which originates from a bog land.