Phytomelioration of Solonchaks in the Uzbekistan Pre-Aral Region Under Recent Climate Change

Abstract

The results of vegetation experiments performed to create artificial pastures using halophytic plant species on the former bottom of the Aral Sea under conditions of rapid regional climate change are considered. On the basis of the long-term monitoring of the climate, soils and vegetation as well as experiments on phytomelioration, new approaches have been developed to rehabilitate the strongly and moderately saline soils developed on the desiccated seafloor of the Aral Sea. It seems reasonable to reconstruct the tugai ecosystems, which perished because of man-made regulation of the river flows of the Amu Darya and the Syr Darya, into halophytic productive pastures on desiccated delta sites. Shrubs such as saxaul, cherkez and teresken are recommended for planting to improve the plant communities under degradation. This may also be reasonable if the forecasts of a decreased river flow of the Amu Darya and the Syr Darya in view of changing climatic conditions and mainly of the growing deficit of water resources in Central Asia come to reality. The mixed halophytic–tugai ecosystems formed in such a way (turanga–saxaul, tamarisk–black saxaul and others) will be conducive to maintaining the productivity of ecosystems and the main elements of tugai flora to be human-modified analogues of relict tugai halophytic ecotones. In the case of an increase of the natural moisture conditions or improvement of water management situation, they can be restored or rehabilitated into typical tugai ecosystems in the nearest future.