The author as a chief of Latin American Research Mission of the University of Tsukuba carried out a field survey on natural environment in the Brazilian Northeast funded by the Ministry of Education, Science and Culture of Japan from December 1980 through February 1981.
Attention to the problems of desertification by the world opinion and the scientific community in many countries has increasingly been paid in the last decade. The drought of the Sahel, which extended from 1968 to 1973, focused public attention to the problems of desertification. In response, the United Nations' Conference on Desertification (UNCOD) was held in Nairobi Kenya, from August 29 to September 9 in 1977.
According to the United Nations' definition (Biswas and Biswas, 1980), “desertification is the diminition or destruction of biological potential of land and can lead ultimately to desertlike conditions; grazing lands cease to produce pasture, dryland agriculture fails, and irrigated fields are abandoned owing to salinization, waterlogging or some other form of soil deterioration”.
The purpose of this report is to present some findings of desertification and its causes by human impacts taking place in both states of
sert_??_o of Paraiba and Rio Grande do Norte.
The Nordeste (the Brazilian Northeast) covers an area of 1, 600, 000km
2, most of which. is semi-arid and has suffered several severe drought for a long time. The Nordeste can be divided into three physiographic divisions such as
zona da mata (humid litoral zone),
agreste (semi-arid transition zone) and
sert_??_o characterized by the
caatinga vegetation (semi-arid interior) (Fig. 1).
The
caatinga trees have been used for firewoods for chacoal-making, pottery and iron manufactures, and fence posts in domestic affairs. The wood piled in the field in Photos. 4 and 7 are preparing for uses of firewoods and others, and we can see these phenomena in many places in
sert_??_o. The deforestation of caatinga trees is one of the most important causes of desertification in
sert_??_o.
The deforested
caatinga trees have been transported by means of human and horse backs bicycles and big trucks (Photos. 8 and 9).
Recently, SUDENE (Superintendency for the Development of Northeast) has planned “Pros jet Sertanejos” a kind of pilot farm to improve the farmers' standard of living brought about by infrastructural improvements such as construction of irrigation canals, reservoirs, wells, and livestock sheds by borrowing the funds from banks. Although the purposes of the “Projet Sertanejos” have been carried out in many places, the demands of firewoods have been increased and accordingly the deforestation of the
caatinga trees has been also increased to meet their demands. These facts seem to bring a significant ecological imbalance.
It is very important to recognize the fact that the desertification in Nordeste is very severe and is now expanding in the area.
The solution of the problem of combating desertification which is truly a global issue has now become one of the most urgent target in the field of area studies and environmental con-servation.
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