EVALUATION OF THE FODDER STOCKS FOR THE PRZEWALSKI HORSE EQUUS FERUS PRZEWALSKII ON THE « PRE-URAL STEPPE » PLOT OF THE ORENBURG STATE NATURE RESERVE

In 2015 the Federal Government Funded Institution «Orenburg Reserves» started the Programme of Establishing of a Semi-Free Population of the Przewalski Horse at the Orenburg Reserve on the territory of the steppe area «PreUral Steppe». In 2014–2015 a pilot research was carried out to select the location for construction of the Centre of the re-introduction of the Przewalski horse. To evaluate the fodder stocks in the selected area we developed criteria for evaluating the vegetation condition under the influence of grazing. The results have shown that within the boundaries of the «Pre-Ural Steppe» plot it is most rational to place the Centre of the re-introduction of the Przewalski horse at the natural landmark Kursay. In 2015, the fodder stocks here ranged from 14 dt/ha (decitonne per hectare) in April to 30 dt/ha in September. Moreover, the grass cover vegetation here mostly consisted of species, well-grazed by Przewalski horse, particularly grasses, a significant number of legumes and well-grazed forbs. In the future, this area requires constant monitoring of the vegetation condition under the influence of the Przewalski horse grazing, with the following evaluation criteria: 1) the overall productivity of the plant mass; 2) the combination of well-grazed and ungrazed plant species in dynamics.


Introduction
The Federal Government Funded Institution "The Joint Directorate of State Nature Reserves «Orenburg» and «Shaitan Tau»" includes two Nature Reserves in the Orenburg region of Russia: the State Nature Reserve «Shaytan-Tau» (within Kuvandyksky district) and the Orenburg Reserve (within Pervomaysky district, Belyaevsky district, Kuvandayksky district, Svetlinsky district, Akbulaksky district).In 2015 the «Orenburg Reserves» started the Programme of Establishing of a Semi-Free Population of the Przewalski Horse at the Orenburg Reserve on the territory of the steppe area «Pre-Ural Steppe» (Bakirova & Zharkikh, 2015, 2016).Within the UN Development Program, the Global Environment Facility 00072294 «Improving the coverage and management efficiency of protected areas in the steppe biome of Russia» a pilot research was carried out to select the location for construction of the Centre of the re-introduction of the Przewalski horse.It was necessary to evaluate the fodder stocks in the area, selected for acclimatisation of imported groups -founders of the new Przewalski horse (Equus ferus przewalskii Groves, 1986) population -and to develop criteria for the vegetation condition evaluation under the influence of grazing.

Material and Methods
The first reintroduction of the Przewalski horse on protected areas in Russia took place on the «Pre-Ural Steppe» plot, 165.38 km 2 in area.In July 2014 and in April 2015 an overall visual evaluation of this area was carried out to select the location for the Centre of the re-introduction of the Przewalski horse.
After the spot for the Centre infrastructure had been determined, in 2015 a fodder stocks studies was held for the selected area.There were 4 expeditions undertaken to study the vegetation: in April, May (before the construction of acclimatisation corrals), July and September (inside the corrals).The GPS co-ordinates of the extreme western and eastern boundaries of acclimatisation corrals are: N 51° 09ʹ51.0ʺE 56° 06ʹ09.2ʺ.Characteristics of vegetation are provided according to the classification by E.M. Lavrenko (1940Lavrenko ( , 1956)).
The forage phytomass was studied by cutting the vegetation at a height of 3-4 cm above the ground (grazing simulation) on an area of about 0.25 m 2 (in total 45 recorded spots).The cut vegetation was divided into economic and biological groups: grasses, legumes, well-grazed forbs, ungrazed and avoided by Przewalski horse plants, dead grass.Then they were first air-cured and then oven dried at a temperature of 85°C till constant mass and weighed.To determine the forage amount, consumed by the Przewalski horse, and palatability of plants we used the Biosphere Reserve «Askania Nova» research data (Zharkikh & Yasynetska, 2009;Pozdnyakov et al., 2011).Since the amount of consumed forage de-Nature Conservation Research.Заповедная наука 2016. 1 (3): 90-94 pends on its quality, season of the year, and on the sex, age, weight and condition of the animal -we took an average value of 10 kg / individual / day to determine the allowable pasture load for this study.

Results and Discussion
SELECTION OF THE PLOT FOR ACCLIMA-TISATION INFRASTRUCTURE CONSTRUC-TION.The basic criteria for the Centre of the re-introduction location choice were the relative homogeneity of the vegetation at a large enough area (no less than 10 km 2 ), absolute predominance of well-grazed plant species and families, mainly grasses, and a welldeveloped herbage: projective cover and its height.
The natural landmark Kursay was chosen for the acclimatisation corrals construction on the basis of visual comparison of different areas, and because local hayfields are considered to be the best in the «Pre-Ural Steppe».
The length of the plot (within the reserve) makes approximately 10 km, the difference in elevation ranges between 300 and 190 m from east to west.The width at the widest part makes about 4.5 km.At the bottom here runs a dried-up creek bed (ravine Kursay), filled in when snow melts and by rain.The approximate GPS co-ordinates of the plot within the reserve are: N 51°09ʹ02.89ʺE 56°05ʹ26.71ʺ;N 51°11ʹ30.97ʺE 56°05ʹ42.31ʺ;N 51°09ʹ24.35ʺE 56°13ʹ41.54ʺ.
The northern slope is more gentle; its total length is between 1.5 and 4.0 km.The form is convex-concave: the length at the top makes 500-800 m, the elevation difference is between 15-25 m, at the bottom -the gradient makes 5-20 m, the slope vegetation is typical for fescue-feather grass steppes with xeromesophilic grasses.At the top, in the less moisturized part, the herb cover is less developed and sparse.Dominant species for the family Poaceae are Stipa lessingiana, S. pennata L., S. dasyphylla (Lind.)Trautv., S. pulcherrima C. Koch., S. zalesskii, Festuca valesiaca Gaud.The projective cover hovers around the value of 50%, the average height of the vegetation in the areas of grass formations makes 15-25 cm.
The floristic composition is an important characteristic of phytocenoses; it is the result of a longterm selection of species, capable of growing in a given environment (Rabotnov, 1978).The flora of the studied region incorporates more than 300 species of vascular plants, belonging to 57 families.Angiosperms make the basic number of species here; more than 90% of them belong to the family Poaceae and Asteraceae.The investigated area is dominated by wormwood-grass associations.There were registered Agropyron pectinatum -Artemisia austrica and Poa tranbaicalica -Artemisia austrica associations.
The lower part and the bottom of the plot are covered with better developed herbage: it is 40-60 cm high and the projective covering here reaches 90-100%, species have greater diversity, although the proportion of well-grazed species is lower.
DETERMINATION OF FORAGE CAPACITY.The grassland of this plot is rather heterogeneous; with all the diversity of plant communities, they can be divided into two groups to evaluate the suitability of the Przewalski horses' habitat.The first group of communities (forb-grass association) is dominated by grasses and other well-grazed plants; the second group is made by plants, growing on saline soils.Table 1 shows the main characteristics of the first group of fodder stock plant communities.
The forb-grass associations areas are dominated by well-grazed species, the share of avoided and ungrazed species here makes less than a half (Table 2).
Cut hay in April, prior to the beginning of the active vegetation, consisted almost entirely of low-nutrient dead grass; species available for grazing referred to the family Poaceae: Stipa capillata, Festuca valesiaca, Agropyron pectinatum, Poa transbaicalica, Koeleria cristata (L.) Pers., Poa bulbosa L., Bromopsis inermis, species of the family Asteraceae: Artemisia dracunculus L., A. absinthium L., A. austriaca Jacq., A. pontica L., A. vulgaris L., and ungrazed by the Przewalski horse Achillea millefolium L. and A. nobilis L.
In May and July, the possibility to determine results of the hay cutting into factions appeared: grasses, legumes, well-grazed forbs and ungrazed species, dead grasses (Tables 3, 4) The productivity of the saline soils vegetation ranged from 3.0 to 13.5 dt/ha, although there were a sufficient share of avoided and ungrazed species ( Abundance determination according to N. Ashikhmina: 1 point -a single specimen of this species registered at the experimental plot; 2 points -specimens are very rare and unevenly distributed; 3 points -specimens occur sporadically throughout the examined plot; 4 points -species is abundant; 5 points -species predominates, specimens often coalesce aboveground parts, forming thickets (background of the association).Abundance determination according to N. Ashikhmina: 1 point -a single specimen of this species registered at the experimental plot; 2 points -specimens are very rare and unevenly distributed; 3 points -specimens occur sporadically throughout the experimental plot; 4 points -species is abundant; 5 points -species predominates, specimens often coalesce above-ground parts, forming thickets (background of the association).
Based on these results the maximum permissible pasture load for the acclimatisation corrals was calculated.
Each corral has an area of 0.45 km 2 , saline soils occupy about 15% of the east corral, and about 20% of the west one.The productivity of the remaining areas with high-quality fodder is virtually the same in both corrals: 28.7 ± 1.9 and 27.9 ± 5.7 dt/ha in July and 30.1 ± 3.8 and 30.1 ± 0.5 dt/ ha in September.
If we evaluate the fodder stock only in terms of grazed species (grasses, legumes, grazed forbs) excluding the vegetation of unproductive saline soils, the fodder stock in each corral makes approximately 100 tons in summer and about 52 tons in winter.According to B.D. Abaturov (1979), the steppe vegetation can withstand without prejudice to both current and subsequent productivity alienation of about 50-55% of the top.Since it is at the moment for the «Pre-Ural Steppe» plot impossible to say how much of the plant mass is alienated by other herbivores species (insects, rodents, lagomorphs), we can reduce the permissible alienation to 35%.Thus, if the Przewalski horse adult specimens' consumption makes about 3.6 tons of vegetation per year, each acclimatisation corral can host 5-6 individuals in winter and up to 10 individuals in summer without damaging the vegetation cover.

Conclusion
The study showed that the natural landmark Kursay makes a perfect spot for the Centre of the re-introduction of the Przewalski horse within the area of the «Pre-Ural Steppe».The middle part of the northern exposure slope is optimal for the construction of acclimatisation corrals for the Przewalski horses, both in fodder and weather conditions -in winter the slope will be a less snowy than the bottom and, the tip of the slope will protect the corrals from southeast winds prevailing in winter.
In the year of study, the fodder stock at the investigated plot ranged from 14 dt/ha at the beginning of the vegetation up to 30 dt/ha at the end of the season, moreover the herbage cover was completely dominated by well grazed plant species, mainly grasses.Considering that the plot includes areas without Przewalski horse's vegetation and that there are other herbivorous species in the reserve, the allowable number of Przewalski horses, living at the plot ranges from 200 to 250 individuals.However, we must take into account the social structure of this speciesthe relatively small herds of natural populations and their habit to maintain an intergroup distance (Boyd, Houpt, 1994) can make animals to disperse throughout the «Pre-Ural steppe» area, so the population density may turn much lower than the fodder stocks allow.

Nature Conservation Research. Заповедная наука 2016. 1 (3): 90-94
In future, it is necessary to maintain a constant monitoring of the vegetation condition under the influence of the Przewalski horse's grazing.Taking into account the above, the evaluation criteria should be 1) the overall productivity of the plant mass; 2) the dynamics of the ratio between well-grazed and ungrazed species.

Table 5 )
. Palatable species here include Bromopsis inermis, Stipa capillata, although the Przewalski horse avoids them if there are more nutritious plant species available.These species indicate a significant pasture load in a given territory before nature reserve creation.Note: ͞ x -arithmetic average, S ͞ x -standard error, min -minimum characteristic value, max -maximum characteristic value

Table 1 .
Fodder stock evaluation of grass vegetation in the valley Kursay

Table 2 .
Assessment of species on the plots with forb-grass plant associations according to Przewalski horse's preferences

Table 3 .
Productivity of different groups of vegetation on the plots with forb-grass plant associations in the valley Kursay in May, dt/ha Note: ͞ x -arithmetic average, S ͞ x -standard error, min -minimum characteristic value, max -maximum characteristic

value Nature Conservation Research. Заповедная наука 2016. 1 (3): 90-94Table 4 .
Productivity of different groups of vegetation on the plots with forb-grass plant associations in the valley Kursay in June, dt/ha

Table 5 .
Assessment of species in saline plots according to Przewalski horse preferences