アラル海危機と植生変動の景観生態学的考察

抄録

Anthropogenic dynamics of vegetation caused by large scale of irrigation project have been illustratedon the examples of Middle Asia, with special reference to Kazakhstan.
(1) The Aral Sea was regarded worthless as compared to the irrigation agriculture by the authorities 20years ago.
(2) Possible plant productivity with irrigation is very high in such dry area, however extensive andcareless irrigated agriculture has caused severe salinization.
(3) There are not only the ecosystems adopted to dry condition supported by little precipitation but alsowetland ecosystems supported by rivers from mountains with glaciers.
(4) Traditional land use of nomadism and the Silk-road have close relationship to the natural environmentwhich is the suitable area for agriculture.
(5) On the other hand, large scale of irrigation agriculture seems to be planned from the view point ofeffective construction and has less consideration to the sustainability.
(6) Active invasion by plants can be seen in the dried up region of Aral Sea, however saksawool, whichis the most important tree species of this region could not be found.
(7) Rice production is an ecological land use, however it is in a trade off relation with the naturalwetland.
(8) Land use with ecological consideration, control of water use to preserve natural wetland of the Ili andrevegetation of saksawool and wetland forest are the main subjects to be carried out from the viewpoint of landscape ecology.