Vol 6, No 4 (2016)

The long-term annual, semiannual, and seasonal dynamics of the main meteorological ecosystem characteristics (total atmospheric precipitation and average, maximum, and minimum air temperature) are analyzed for the Aral Sea region and central Asia by their trends for a long-term period of 70–125 years until 2014 with the use of the diurnal records from eight meteorological stations of the WMO (the Aral Sea, Chimbai, Tamdy, Torgai, Irgiz, Samarkand, Turkestan, Chardzhou). Based on an analysis of the combined humidity- temperature regime for the long-term period, the main trends of climate changes are established, the share of variations in each meteorological characteristic is estimated by the proposed relative coefficient of variations in meteorological characteristics (RCV), and the impact of the climate changes on the ecosystems is studied.

Based on a study of processes developed upon desertification (salinization, solonetzization, and sand accumulation) in the soils of the Caspian Sea Lowland, it is shown that soil’s water retention capacity may be used as an integral parameter of all desertification trends. It is characterized by the water retention curve (WRC). The physical sense of the use of the WRC to characterize desertification consists in the fact that it shows the capability of soil to retain moisture and soil moisture mobility and availability for plants and thus characterizes the main edaphic factors, which limit biological productivity in natural ecosystems and the agroecosystems of arid regions. The soil WRC is a constant value without seasonal fluctuations, and this makes it universal in comparison with other soil parameters that undergo seasonal variations, thus making determination of the desertification rate difficult.

We evaluated changes in the deficit of irrigation water in the Fergana Valley of Central Asia under different scenarios of climate change and water management. The Fergana Valley is located within the Syr Darya River basin and is shared by Uzbekistan, Kyrgyzstan, and Tajikistan. We estimated the climate-related changes in irrigational water demand in the Fergana Valley in the 2020s, the 2050s, and 2080s. Considerably higher temperatures and a moderate change in precipitation lead to increasing potential evapotranspiration (PET), which nearly doubles the irrigation water demand by the 2080s. This is driving the request for a scientifically substantiated scheme of irrigation that takes into account the quality of soils and the ground water table, correction of the water consumption norms for different crops, and changes in the crop composition in favor of winter horticulture plantations and cereals.

The possibility of the occurrence of seropositive reactions against four pathogens in two feline species (Pallas cat (Otocolobus manul) and domestic cat (Felis catus)) and six species of their potential prey was studied. Blood serum was analyzed for the presence of antibodies to the pathogens by enzyme immunoassay. The occurrence pattern of influenza A virus in manuls was the largest among tested pathogens (22%, n = 18). In this case, positive animals were not discovered among domestic cats. Antibodies against Coxiella burnetii were registered only in domestic cats (3.6%, n = 55). Antibodies against Toxoplasma gondii were found in wild and domestic animals: domestic cats (14.7%, n = 61), Pallas’ cats (9.1%, n = 18), and their prey (3.7%, n = 273). The occurrence of Trichinella sp. was comparatively low in domestic cats (1.6%, n = 61); among prey, antibodies to the parasite were found only in one species, the transbaikal hamster (Cricetulus pseudogriseus) (10.9%, n = 119).