Ecological restoration of fodder productivity of degraded pastures in the foothill desert zone of Central Asia

Irrational, ecologically unregulated economic activity in the vast deserts of Central Asia has led to biodiversity depletion, decrease in the fodder productivity of natural pastures and, as a result, deterioration in the fodder base of grassland farming. Forage production of these degraded pastures requires ecological restoration. To enrich the species composition and to increase the fodder productivity of degraded pastures we conducted strip sowing of black saxaul. Restorative succession on degraded pastures led to the formation of a long-term halophytic shrub-ephemeral pasture community consisting of two layers: upper (I) layer represented by black saxaul and lower (II) layer composed of ephemeroids, ephemerals and annual saltwort. Ephemerals are short-growing fodder plants (March–April); Haloxylon aphyllum refers to long-growing (226–242 days) fodder plants, which sprout in the period from late March to early December. Annual salsolas Salsola carinata and Halocharis hispida develop well under the crown of Haloxylon aphyllum. Here they are much larger than between the crowns. The shrub-ephemeral pasture community is dominated by annual grasses and Poa bulbosa. They are mainly concentrated on the outer border of the undercrown ring and are characterized by lush development. In the halophytic semi-shrub-ephemeroid pasture community, the total yield of forage mass of ephemera was 0.90 t/ha; the total yield of forage mass of annual saltwort was 0.14 t/ha; the total yield of forage mass of Haloxylon aphyllum was 0.89 t/ha; the total yield of forage mass was 1.93 t/ha.

Formation of the vegetation cover in the desert pasture phytocenoses

Rising global temperatures in recent years have led to a sharp increase in the area of desert areas. Desert areas are widely used as pastures. The productivity of desert pastures in Uzbekistan is very low, ie 1-3 ts/ha. This limits the year-round use of desert pastures. One of the resource-saving and long-term effective ways to increase their productivity is to plant enclosures, as well as reclamation and forage rows in these desert pastures using plants such as Haloxylon aphyllum, Calligonum caput-medusae, Salsola paletzkiana. This is because protected areas have been scientifically proven to show their positive properties in other areas (around mountainous and irrigated fields). In these areas, enclosures not only perform a protective function, but also serve as a source of fodder for livestock in the autumn-winter seasons.

The environmental forming and productional functions of the haloxylon aphyllum in the Karnabchul desert

We have conducted investigation of the environmental function of the desert tree of black saxaul (Haloxylon aphyllum) in the Karnabchul desert. As a result, it was found that different age plants of black saxaul had different effects on the degree of illumination. The greatest influence on the intensity of solar radiation was exerted by the saxaul plant of the black middle-aged state, the least the old generative individuals. Saxaul black had a significant impact on the temperature of the air: in the daytime, especially in the period 13-16 h, reducing the temperature under the crown and on the edge of the crown, and at night increasing it in the same areas. It also had a noticeable effect on the temperature of the soil. The temperature of the soil surface under the crown at night is higher, and during the day the warming was slower than in the outer part of the saxaul crown. Under the influence of black saxaul and soil moisture changed. Under the saxaul crown soil moisture is significantly higher compared to the control (open natural pastures). The highest soil moisture was observed in the upper soil layers at the base of the saxaul trunk. As a result, under the environmental action of black saxaul more favorable hydrothermal conditions for the growth and development of natural wormwood-ephemeral vegetation under the protection of strips and adjacent areas of pastures are formed. The result of production activities chemotaxonomic postbestowal bands consists of two following components: production of fodder mass of the Haloxylon and fodder productivity of wormwood-ephemeral vegetation of natural pastures. By increasing the yield of natural pastures under the protection of pasture protection strips and the harvest of the black saxaul fodder productivity of desert pastures increases more than twice.

TRANSFORMATION OF CLAY MINERALS IN SOILS OF SANDY DESERTS UNDER DIFFERENT SAXAUL SPECIES

As a result of experimental studies carried out for the first time with the aim at determining the impact of black (Haloxylon aphyllum) and white Saxaul (Haloxylon persicum) on the mineralogical composition of fine-dispersed fractions in sandy desert soils, it seemed reasonable to conclude that the transformation of minerals is quite different in soils used under different Saxaul species. This is explained by differences in biogeochemical turnover of elements in soils under black Saxaul and as a consequence by a higher Na content in the litter and the soda for-mation in the soil profile. The latter serves as a cause of alkalinization of soil solutions and transformation of minerals affected by alkaline hydrolysis.