Although Eurasia’s Caspian basin once supported the world’s richest and most diverse complex of sturgeon species, recent human activities have decimated populations of these ecologically and economically important fish. All five anadromous Caspian sturgeon species are critically endangered, and the potamodromous sterlet is also threatened. The precipitous decline of these species is due to a combination of factors that includes illegal, unreported, and unregulated (IUU) fishing; destruction of feeding and spawning habitat; water pollution; and the environmental consequences of climate change. International efforts are currently underway to re-establish sustained naturally reproducing sturgeon populations in the basin. Here, we update and review the status of sturgeon in the Caspian Sea with emphasis on the northern basin and the inflowing Volga and Ural rivers. We then focus on efforts to restore sturgeon in the Ural, which originates in Russia and flows through Kazakhstan before entering the Caspian Sea. With nearly ideal hydrological conditions for sturgeon, the Ural is the basin’s sole remaining river that allows migrating sturgeon unimpeded access to potentially productive spawning grounds. The challenge of re-establishing sturgeon in the Ural River exhibits the classical characteristics of wicked problems: ambiguous definitions, changing assumptions and unanticipated consequences, tradeoffs and economic dependencies, an incomplete and contradictory knowledge base, and no straightforward pathway toward a final solution. This challenge is examined here for the first time from the perspective of its wicked dynamics, with consideration given to approaches that have proven effective elsewhere in resolving wicked environmental problems.

Forest ecosystems are one of the most important components of the Earth's biosphere due to their global ecological and socio-economic importance. In hydromorphic landscapes of arid regions of Central Asia with its sharply continental climate, these ecosystems are represented by unique in their biodiversity and environment-forming role coastal tugay forests in river floodplains, flooded lowlands and islands. Among desert, semi-desert and steppe ecosystems, tugay forests are ecosystems with the highest aboveground biomass and biodiversity. Due to the growing reduction of runoff of most rivers in Central Asia due to increased water consumption by agrarian and industrial production and negative climatic changes, the area of tugay forest ecosystems has catastrophically decreased. Ecological restoration of degraded tugay forests is a key factor in combating desertification in arid regions. Taking into account the fact that tugay forest ecosystems are currently represented only by scattered areas exclusively in West and Central Asia, their conservation is of global importance. The results of a comprehensive study using remote sensing and GIS-technologies, field work to assess the successional dynamics of tugay ecosystems in the middle reaches of the Ili River in connection with hydrological and climatic factors are presented in the article. Key words: tugay ecosystems, remote sensing methods, vegetation degradation, climate change, river flow regulation, ecosystem conservation.