Архив метки: pasture digression

PALATABILITY OF PLANT COMMUNITIES AS ONE OF THE CRITERIA FOR QUALITATIVE EVALUATION OF MONGOLIAN PASTURES

Arid Ecosystems

UDC 551.45+631.585

Danzhalova E.V.,  Ariunbold E.,  Dorofeyuk N.I., Myagmarsuren D.,  Bazha S.N. PALATABILITY OF PLANT COMMUNITIES AS ONE OF THE CRITERIA FOR QUALITATIVE EVALUATION OF MONGOLIAN PASTURES // Arid Ecosystems. 2023. Vol. 29. № 2 (95). P. 98-108. | PDF

The study of the ecological state and the socio-economic value of pasture ecosystems in Mongolia lying under the progressive degradation remains an important task. The existing methods of pastures forage assessment are either labor-intensive (zootechnical method), or do not reflect the real situation (assessment of overall productivity) under formation of low-species or monodominant degraded communities. To determine the fodder value and productivity of pasture ecosystems in Mongolia, a Palatability Coefficient (PC) has been proposed. It was determined on the basis of data on the forage attractiveness of plant species making up the community, as well as the diversity of species eaten. The PC was calculated as the ratio of the consumed phytomass to the total aboveground phytomass, multiplied by the number of eaten species consisted of the composition of dominants and co-dominants. The PC was determined for 158 plant communities of meadow and steppe pasture ecosystems. They were ranked in 4 categories. It has been established that a significant part of the studied communities has a high PC. Although these communities are characterized by varying degrees of anthropogenic disturbance, including severe, the high PC is due to the fact that some of the digressively active species have a satisfactory or good palatability. Probably, this fact supports the potential for an increase in the number of livestock in Mongolia, as it has a wide range of forage preferences. At the same time, there are a high proportion of pastures with low and very low PC. To a greater extent, such pastures are formed by true and dry steppe plant communities, which are under the highest pasture load in Mongolia.

Keywords: Mongolia, meadow ecosystems, steppe ecosystems, nomadic animal husbandry, pasture, pasture digression, fodder assessment, above-ground phytomass, feed attractiveness of plants, palatability coefficient.

Financing. The research was carried out for the scientific program of the Joint Russian-Mongolian integrated biological expedition of the Russian and Mongolian Academies of Sciences, topic 3.1.2. “Assessment of Degradation of Vegetation Cover of Steppe Ecosystems Taking into Account Regional and Economic Factors”, and for the state task of the A.N. Severtsov Institute for Ecology and Evolution of the Russian Academy of Sciences, No. 0109-2019-0007 “Historical Ecology and Biogeocenology”.

DOI: 10.24412/1993-3916-2023-2-98-108

EDN: RXJSPZ

ASSESSING THE IMPACT OF AVIARY HOUSING OF ANIMALS ON THE ECOLOGICAL CONDITION OF SOILS

Arid Ecosystems

UDC 631.4; 574.4

Gobarova A.A., Kazeev K.Sh., Zhadobin A.V.,  Fedorenko A.N., Kolesnikov S.I. ASSESSING THE IMPACT OF AVIARY HOUSING OF ANIMALS ON THE ECOLOGICAL CONDITION OF SOILS // Arid Ecosystems. 2023. Vol. 29. № 2 (95). P. 109-117. | PDF

The activities of animals have a significant impact on the area of their habitat. The objects under our study are located in the dry steppes zone, the climate of which limits the development of vegetation and contributes to changes in soil characteristics, which, combined with the impact of animals, increases its effect. The aim of our work was to assess the impact of animals on the ecological condition of the soils in the enclosures of the “Wildlife Steppe” Association (orig. “Zhivaya Priroda Stepi”).

During our study, the main indicators of the ecological state of soil in the enclosures with animals, located in the arid area of Rostov Region, were determined. We studied enclosures of different sizes, with common ostriches (Struthio camelus), emus (Dromaius novaehollandiae), goats (Capra sp.), Przewalski’s horses (Equus ferus przevalskii) and saiga antelopes (Saiga tatarica), and the grazing areas of horses (Equus caballus), Bactrian camels (Camelus bactrianus), wild water buffalos (Bubalus arnee), wild yaks (Bos mutus) and guanacos (Lama ganicoe). Level of soil degradation differed from area to area. Soil moisture, temperature, density and texture were determined to assess the physical condition, pH, gross soil chemistry, humus content and biological activity; then the plots were ranked according to the degree of pasture degradation.

The enclosure of common ostriches had the maximum degradation of 10 degrees, characterized by severe vegetation depression and soil battering. The soil density in their enclosure was also the highest and reached 1.49 g/cm3, while the structure was the lowest and reached only 37%. These parameters had a strong negative correlation with hoof and foot pressure on the soil (-0.9). Moisture levels never exceeded 11% in the study areas, although soil enzymatic activity was more influenced by animal excreta than by hydrothermal conditions. In the enclosures with ungulates, goats in particular, catalase and urease activity was always higher than in other plots. There was also a high humus content (10.3%), uncharacteristic for chestnut soils and confirmed by the influence of animals’ activity.

According to the results of our study, the lowest values of structure, humus and biological activity, as well as increased density of soil compaction, were in the enclosure with common ostriches. The findings explain the reduced growth and development of vegetation in the area where the animals were kept in crowded conditions.

Keywords: pasture digression, ecological condition, enzymatic activity, bioindication, content of organic matter, physical properties.

Financing. The research was supported financially by the leading scientific school of Russia “Assessment and Forecast of Soil Conditions under Various Anthropogenic Influences and Climate Change” (NSH-449.2022.5).

DOI: 10.24412/1993-3916-2023-2-109-117

EDN: WRCBNN

DYNAMICS OF MODERN PASTURE DIGRESSION ON THE QUATERNARY TERRACES OF THE NORTH-WESTERN CASPIAN REGION

Arid Ecosystems

Lazareva V.G.,  Bananova V.A., Nguyen van Zung DYNAMICS OF MODERN PASTURE DIGRESSION ON THE QUATERNARY TERRACES OF THE NORTH-WESTERN CASPIAN REGION // Arid ecosystems. 2020. V. 26. № 4 (85). P. 26-34. | PDF

In this article we discuss the results of long-term researches of desertification (degradation) in the dry lands of the Northwest Caspian Basin. We consider the modern vegetation to be the result of pastures overload caused by cattle, and determined desertification as a process of unification which leads to decrease in species diversity in the plant communities and, therefore, unification of vegetation cover. The complex structure of soil and vegetation cover, common for Caspian Region, vanishes, and the native plant communities are replaced with groups of their transit derivatives. The quantitative evaluation of desertification includes stages (classes) of poaching, criteria of pasture digression and their indicators (plant communities). They determine the ecological and dynamical series of plant communities representing the process of degradation. Our research showed that out of all quaternary terraces the vegetation of the youngest one (New Caspian) is more vulnerable to degradation.

Keywords: Caspian quaternary terraces, pasture digression, indicators of pasture poaching, ecological and dynamical series of plant communities under desertification, unified vegetation.

DOI: 10.24411/1993-3916-2020-10115