Special Column:Celebration of the 70th Anniversary of IGSNRR, CAS

A STUDY ON GLOBAL LAND USE CHANGE UNDER THE PRESSURE OF POPULATION GROWTH

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  • Commission for Integrated Survey of Natural Resources, CAS, Beijing 100101

Received date: 1998-06-25

  Revised date: 1998-12-08

  Online published: 1999-09-25

Abstract

Theoretically,the 4 factors of population,cultivated land,grassland and forest form the global man land interaction system centering around man.In this system changes of population undoubtedly cause the increase or decrease as well as mutual transformation of cultivated land,grassland and forest.A man land equilibrium model was built in the study.Based on the model,the authors have analyzed the global land use changes in 1970~1995 and in the future 50 years.Results indicated: (a)Du ring 1970~1995,population increased by 54 6%,but no sharp decrease in cultivated land and grassland have been found.Reasons for this relative stable equilibrium is that the improved agricultural technology,which is marked by irrigated area expansion and a large amount of chemical fertilizer application,leads to the rise of cultivated land productivity to 63 9%,and offsets the cultivated land increase,grassland and forest decrease under the pressure of population growth. (b)In the future 50 years,population will reach 100×108,an increase of 74%,and per capita available cultivated land,grassland and forest will decrease to below 0 13ha,0 34ha,and 0.37ha respectively.However,it is impossible to expand cultivated land by 74%,as the key to sustain current global stable land cover is to raise cultivated land productivity to over 74%,by relying on improved agricultural technology.(c)Amongst the former mechanisms to sustaining land use change relative stable,it will be difficult to improve land productivity through cultivated land expansion and a large amount of chemical ferti lizer application.Assuming both the current cultivated land area and productivity maintain the same level,the current cultivated land can still feed the projected global population in 2050 which is 55×108 more than the present level.Even if the natural disasters cause cultivated land productivity a drop of 0 99t/ha or cultivated land area 4 77×108ha, the cultivated land can still provide enough food to feed the global po pulation of 100×108.That means the man land system will not get collapsed in the next 50 years.The reduction of grassland and forest may be unavertible.

Key words: population; land use; globe

Cite this article

XIE Gao di, CHENG Sheng kui, DING Xian zhong . A STUDY ON GLOBAL LAND USE CHANGE UNDER THE PRESSURE OF POPULATION GROWTH[J]. JOURNAL OF NATURAL RESOURCES, 1999 , 14(3) : 193 -199 . DOI: 10.11849/zrzyxb.1999.03.001

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