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    Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Ke lin
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    Dongting Lake drainage basin embraces Xiangjiang,Zishui,Yuanshui,Lishu i rivers and a part of the Yangtze River.Due to neglection of environmental mana gement,soil erosion in the upper and middle reaches of the Yangtze,lake sediment ation,large scale reclamation of marshes,irrational distribution of agriculture and improper cropping system in high water level zone,the flood regulation capa city of the lake was descending,and flood stage was risen and prolonged.Conseque ntly more and more river levees and lake dikes were reinforced almost every year to prevent the disasters,which made flood level go up and flood period last for more days.The frequency of flood and waterlogging disasters rose and their dama ge was enlarged. The countermeasures of watershed ecosystem management were presented as fo llows: (a)In order to publicize knowledge of territory safety, ecological disas ter relief strategy should be placed as an important part of state security system and on the agend a.(b)The reclamation without storing floodwater should be readjusted into new la nd use system with flood storage project.Cultivation and planning can be carried out in normal years.The relaimed land can be used for storing water while a cat astrophic flood takes place.Certain fields acting as a hindrance for flood flow should be merged properly with lakes for fish culture.(c)Environmental migration should be placed in towns so that the tremendous population pressure on land an d lakes can be relieved.(d) To readjust allocation,cropping system and build up high efficiency,multi ecosystem engineering projects which are suitable to the shallow waters,of shores lakes and rivers as well as paddy fields.(e)The adjust ment of hilly land use structure and reconstruction of mountain vegetation wil l serve as fundamental measures for disaster relief.Soil erosion in hilly areas is much more serious,so to set up ecological land use patterns in hilly areas of the upper and middle reaches of the Yangtze is the key project for water and so il conservation.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Qun ying, GONG Dao yi
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    Rainfall resource is very important to social economic system, especi ally to North China which is now facing serious challenge of water shortage. Bas ed on the observational records covering the period from 1951 to present, the ch aracteristics of precipitation changing over North China and its possible connec tion to El Nio were studied using tendency analysis, correlation analysis and wavelet analysis. Results showed that the rainfall in North China had a down te ndency in summer and autumn at a rate of-9.6mm/10a and -4.5mm/10a respectively. And annual precipitation was decreasin g at the rate of -12.9mm/10a. In decadal time scale, abrupt changes were observ ed in the mid 1960s for summer and annual precipitation.Precipitation was signi ficantly less for the decade after about 1985 in contrast to the decade before. The time series showed perio dicities at 2-4, 8, 20 years for summer rainfall and at 2-4, 8 years for autum n rainfall. El Nio had prominent impacts on precipitation of North China,under El Nio condition the rainfall will decrease significantly in summer and autum n, and increase in spring.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WANG Gen xu, CHENG Guo dong, XU Zhong min
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    The northwest arid area of China,having about 1/4 of the total area o f China,is located near the center of the Eurasian continent.There are many mounta ins with elevations of 4300-7000m,which scatter between plains feeding 676 inla nd rivers.In the late 50 years,the exploitation and utilization of water resourc es in those rivers have led to the formation of 390 07×104 ha of man made oas es that scattered all over the river basins,and built of about 622 reservoirs wi th a storage capacity of 65 5×108m3 The large scale utilization of water reso urces has not only facilitated the steady development of agricultural economy bu t also resulted in very serious impacts on eco environment in the arid area: (a) The runoff courses of most rivers were shorten ed and the terminal lakes were reduced or dried up.The water quality in the lower reach esbecame worsened.(b)Soil salinization and desertification became more and more s erious in these regions.The salinized area totalled about 210 18×104ha,and des ertified area about 674 93×104ha.(c)Vegetation has been seriously degraded or destroyed.The natural vegetated area was reduced by 49%-58%,grassland reduced by 16%-92% and degraded grassland area occupied about 52%.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHOU Hua feng, MA Ke ming, FU Bo jie
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    The disturbance,which is the major source of landscape heterogeneity,c an change the landscape pattern and also be affected by the landscape pattern.In this paper ILWIS GIS is used to analyze the forest landscape patterns in Dongli ng mountain area in Beijing.The study is based on the 1∶20 000 scale vegetation map while in combination with field research.The buffer analysis method is used to study the impacts of human activities on forest landscape patterns of th is area. The results indicate that: (a) In Dongling mountain area,the intensity of human activities is to some extent relat ive to the landscape fragmentation.In places with high intensity of human activi ties,the area of the patch is relatively smaller; while in places with low inten sity of human activities,the area of the patch is relatively larger.The human ac tivities obviously contribute to the landscape fragmentation.(b)With changes of the distance from the selected disturbed area,the indices of landscape diversit y show no regular change.In spite of the enhancement of human activities in this area,natural factors are still the decisive ones to the landscape patterns at p resent.Human activities only affect the landscape patterns but not decide it.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YU You sen, REN San xue, TAN Kai yan
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    Based on meteorological models related to oil content of oiltea camell ia,the spatial and vertical distribution of oil content of oiltea camellia in su btropical producing areas are calculated and analyzed,the climatic regionalizati on of oiltea camellia quality and the determination of the optimal climatic laye r and belt are made.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LI Xin rong, ZHANG Jing guang, LI Yu jun, SHI Qin ghui, LIU Xin min
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    About 300 species of plants have been introduced successfully to the s outheastern edge of the Tengger Desert since the establishment of Shapotou Deser t Research and Experimental Station in 1956.It is now a research base for large scale off site conservation of biodiversity.Based on successive observations m ade from 1987 to 1997,this paper studies the phenological characteristics and the relationship between the phenolo gical period of shrubby species and environmental factors.The results show that the mean temperature and accumulated sunshine duration are the dominant factors of the main shrub phenological period,but the precipitation is closely related t o the resurrection,and the wind speed also plays an important role in leaf expan sion.The classification of 30 shrubby species by clustering analysis according t o the environmental factors of resurrection and leaf expansion,4 phenological ty pes of shrubby blooming are identified.The research results of this paper are of an important significance to the establishment of artificial vegetation and off site conservation of biodiversity.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    CHEN Yi song, ZHAO Jian an, FENG Zhi ming
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    Based on the introduction of the basic legal system on agricultural na tural resources,this paper analyzes the main problems in the enforcement of the existing laws and regulations of China. Faced these problems,some suggestions co ncerning the strengthening the management of the agricultural natural resources are put forward: (a)to formulate the comprehensive laws of agricultural natural resources as soon as possible,and to perfect the structure of the legal system of the agricultural na tural resources;(b)to renew and substantiate the existing law of agricultural na turalresources to meet the need for socialist market economy; and (c)to reform the m anagement system through the two aspects of mechanism and means,and to strengthe n theunified and comprehensive management of agricultural natural resources.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    XUE Da yuan, BAO Hao sheng,
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    Based on field investigations and by using the expense payment method, travel cost method (TCM) and contingent valuation method (CVM),the tourism value of biodiversity in Changbaishan Mountain Biosphere Reserve (CMBR) is evaluated in this paper.The tourism value is considered as the sum of the tourists' trave l cost,consumer surplus,time value and other expenses.To calculate the consumer surplus,the TCM technique,popular in some western countries,is used.By dividing the country into small geographic sub regions and carrying out on site samplin g investigations of 3 131 visitors,the visiting rates of the tourists from the s tarting sub regions to CMBR are calculated,a regression model between the visit ing rates and the variables such as population,incomes,travel costs,and travel t ime of the sub regions,and a supply demand curve is established and the consum er's surplus of all the tourists is thus figured out.The results showed that in 1996,the total tourism value of biodiversity in CMBR reached 432 million yuan,o f which domestic tourism value was 137 83 million yuan and international touri sm value,294.2 million yuan.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WU Wen shan, FANG Yu lin
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    Ficus pumila L.,widely distributed in areas south of the Yangtze River in China,belongs to Moraceae plants.For generations,dried achenia of Ficus pumi la L. were made into jelly among the people.For the first time,we studied the nu tritive composition of the achenia.The main results show that the perianths of F icus pumila L. contain pectin 32.70%,protein 3.80%,total sugar 20.33%,total f lavonoids 15.14%,and the seeds of Ficus pumila L. contain pectin 15.15%,protei n 15.70%,crude fibre 26 20%,total flavonoids 2.08%.The seeds contain 30.13% of oil,in which the ratio of polyunsaturated fatty acid to saturated fatty acid (PUFA/SF) is 10.93 to 1. Contents of mineral elements and vitamins are rich in the achenia.The results provide scientific basis for the rational exploitation a nd development of Ficus pumila L. into a health food.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    GU Shu zhong
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    The benefit cost analysis is used to analyze the benefits and cost of terracing in dynamic terms. It is concluded from this analysis that terracing is one of the most effective and efficient ways for realizing sustainable agricultural development in Karst areas such as Guizhou Province. Terracing can effectively improve the u tilization capacity and utilization efficiency of cultivated land and water reso urces in agriculture.Meanwhile, it can also improve the anti disaster capabilit y of agricultural system.Terracing can simultaneously increase economic, resourc es, ecological, environmental and social efficiencies in agriculture, including increasing farmers income, alleviating rural grain deficit and poverty situat ion, protecting scarce natural resources, and managing soil and water erosion. T erracing has plaid,is playing and will play an important role in sustainable agr icultural development in Karst areas.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LIU Yan peng, LI Li xian, SHI Yu lin
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    This article describes the definition of rate of rural labor in and out migra tion,calculates the rates by provinces,analyses the distribution of characterist ics of rural labor in and out migration,and proves the three fundamental cond itions for rural floating labor force,which are the economic strength,cultural l evel and travel ability.Based on these discussions,corresponding policies and su ggestions are raised.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    YU Qiang, LU Pei ling, LIU Jian dong, FU Bao pu, YAO Ke min
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    A biologically based model of both practical and theoretical significa nce was developed to simulate rice growth.On conditions with suitable water and fertilizers,the crop growth processes were simulated by considering solar radiat ion and temperature.Its spatial scale is leaf level,and temporal scale is hourly .The model can simulate instantaneous canopy photosynthesis.The model was valida ted using data from geographically sowing experiment.It is showed that the model can interpret 92 5%-95 8% of the changes of dry matter accumulation with d evelopmental stage and sowing date in different climatic areas.Using regular met eorological data,including solar radiation,we studied ecological acclimation of hybrid rice numerically in the north,middle,and south subtropical zones and Yunn an Guizhou Plateau.The result shows that Yunnan Guizhou Plateau is a high dry matter production area for middle rice,because of higher radiation,lower tempera ture and longer growth period.In the south of China,the early and middle rice is low productive,because of higher temperature and shorter growth period,but it i s a high productive area in late rice.Also in Changjiang River Valley,the suitab le sowed late rice has higher productivity provided the high temperature in summ er and low temperature in autumn in its middle and late period of growth can be avoided.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LIU Jian dong, YU Qiang, FU Bao pu
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    A photo temperature numerical model related to winter wheat producti vity was established, which included development stage,photosynthesis,respirati on,partitio ning of carbohydrate and consenescence of winter wheat.The simulation result of the winter wheat photo temperature productivity in Huang Huai Hai Region by using the model indicated that:(a)The productivity changed from 9 000kg/ha to 1 0 950kg/ha in the region,and the highest value was found in Shijiazhuang Area of Hebei Province and Jiaodong Area of Shandong Province. (b)The winter wheat phot o temperature producti vity was interrelated well with the solar radiation accumulated from 10 days be fore heading to maturity. (c)Analysis of the photo temperature productivity by using the power spectrum found that the change of the productivity in Beijing Area has 4 year and 9-10 year cycles.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    LEI Xiao zhang, WANG Jin xi, PENG Pei hao, CHENG Guo xian, TANG Yun jing
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    By studying the evaluation and index of sustainable forest development throughout the world and connecting the development status of the ecological fo rest engineering of China, this paper uses the knowledge of soft system method(S SM),method of synthesis integration(SIM), general induce method of determined s tudy and enginee ring system to form the soft system method of induce integration(SSMII)and usi ng this as the soft supporting for constructing evaluation index system The paper combines the expertise with the experimental data to construct the ev aluation system of the ecological engineering of China
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    WU Xiao bing, CHEN Bi hui
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    This paper evaluates the alligator resource according to the values on economy,ecology and scientific research.From the analysis of the number of alli gators in the wild and breeding,the current situation and problems existed in th e exploition and utilization of alligators are examied.The developmental counter measures on the resource exploition and utilization of Alligator sinensis are al so put forward.
  • Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS
    ZHOU Sheng lu, WU Wen hong, PENG Bu zhuo
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    The methodology for the foundation of regional towns' land standard p rice system to identify was discussed in this paper by taking Liuhe county of J iangsu Province as a case study. The result shows that it is an effective way to identify regional towns' land standard price system by means of classifying the towns' land first, and then comparing and synthesizing the land price estimate d by land deferential profit and market exchange according to towns' land classi fication.