Vegetation Landscape Around the Arkaim Eco-Preserve, Southeastern Ural, Russia Susumu Okitsua, Valentina E

HortResearch № 65 97－101（2011） 97

●Article Vegetation landscape around the Arkaim eco-preserve, southeastern Ural, Russia Susumu Okitsua, Valentina E. Prikhodkob, aGraduate School of Horticulture, Chiba University, Japan b Institute of physicochemical and biological problems in soil science of the Russian a a Miwa Matsushima , and Kazuyuki Inubushi Academy of Sciences, Pushchino, Moscow region, Russia

Abstract Cool temperate semi-arid vegetation landscape around the Arkaim eco-preserve was introduced and the phytogeographical differences between forest steppe in and around the Arkaim, south-eastern Ural, and semi-arid subtropical savanna in south-western Africa were discussed. We considered forests of Betula pendula and Pinus sylvestris, instead of some types of steppe, as potential natural vegetation in and around the Arkaim, because of relatively sufficient water supply to the vegetation. Both the Betula forest and Pinus forest will be climax vegetation in a cool temperate semi-arid zone characterized by the severe condition as arid and/or low temperature. Peo- ple who occupied around the Arkaim in the Bronze Age are assumed to have used forests and changed them into steppe. Forest area in south-eastern Ural is usually bounded clearly by the area of grass steppe. Contrarily semi-arid subtropical woody vegetation, savanna, is represented by open woodland with sparse distribution of trees. Forest vegetation accompanying with water deficiency in sub-tropical zone shows open and sparse forest type because root competition among individual roots from insufficiency of soil water should reduce density of stands.

Key Words: Betula pendula, Cool temperate semi-arid vegetation, Forest steppe, Steppe, Subtropical semi-arid savanna, water supply.

Corresponding author: Susumu Okitsu, Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsu- do city, Chiba prefecture, 271-8510 Japan, E-mail: [email protected]

fairly unfamiliar to the Japanese ecologists and geographers, and 2） to Introduction discuss the phytogeographical differences between forest steppe and savanna, both of them develop under similar semi-arid environment The Arkaim eco-preserve（ hereafter the Arkaim） is located on but occur different climatic regions, cool temperate and subtropics. southeastern area of the Ural range in the administrative region of Chelyabinsk in south Ural, Russia. In 1987, many important archaeo- Study area logical monuments were discoverd including fortress constructed about 4,000 years ago（ i.e., the Bronze age） on the proposed site for a new Arkaim eco-preserve is located near the Ural range in 400 km south dam around the Arkaim. For that reason the area around the Arkaim of a big town Chelyabinsk and 120 km south of a middle town Magni- was made an appointment of eco-preserve. togorsk（53ﾟ13′ N, 60ﾟ30′E: Fig. 1）. The area around the Arkaim belongs climatically to the cool Phytogeographically the Arkaim area, south-eastern Ural, belongs to temperate semi-arid region where steppes, pastures, and forests occur a transitional vegetation zone from forest-steppe to typical steppe in （Ermolaev, 1999）. The vegetation landscape in cool temperate semi- central Eurasia（ Lavrenko, 1956）. The Arkim area contains four major arid zone is different from that in the cool temperate humid zone such vegetation types by physiognomy: forest steppe, typical steppe, semi- as Japan, where closed forest vegetation occupies. Hence it is worth desert steppe and steppe like semi-desert（ Lavrenko and Sochava, introducing cool temperate semi-arid vegetation to geographers and 1954）. The forest of the area is represented by Betula pendula forest, ecologists in humid zone. followed by Pinus sylvestris and rarely Larix sibirica forests. From a phytogeographical point of view, it is interesting to compare Climate around the Arkaim belongs to cool temperate semi-arid structure of sem-arid woody vegetation in cool temperate zone in zone. Fig. 2 shows mean monthly temperature and precipitation at south-eastern Ural with that in subtropical zone. The different structure Chelyabinsk. Annual precipitation amounts to 443 mm at Chelyabinsk of woody vegetation will reﬂ ect on different effects of subtropical and and 250-350 mm at the Arkaim, indicating semi-arid condition for cool temperate climates. plants. Precipitation concentrates mainly in the summer season, and ac- The aims of this study are: 1） to introduce cool temperate semi-arid tually no severe water deﬁ cit season appears during a year. The total vegetation landscape around the Arkaim, which is very interesting but amounts of yearly precipitation, however, supports establishment of

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are frozen, and water is not absorbed into them. The annual evaporation ranges from 450 mm to 650 mm. The coeﬃ cient of moistening is made up 0.4-0.8. In some years dry winds and deﬁ lation have a severe damage to the soils and crops.

Method

We drove approximately 400 km by automobile from Chelyabinsk through Stepnoie to the Arkaim and recorded vegetation structure at random by visual observation along major trafﬁ c roads running with automobile approximately 10 km in distance（ Fig. 1）. Totally 50 study Fig. 1. Location of the Arkaim（ A） and observation route（ B） plots including 23 between Chelyabinsk and Stepnoie（ Area C-S） and the Arkaim（ Area S-A） were selected in vegetations along the major 50 100 Precipitation (443 mm yearly total) roads. The types of vegetation depended mainly on physiognomy with C) ﾟ 40 80 relatively smaller scale approximately some hundreds square meters: Precipitation (mm) Precipitation

30 60 Pinus forest, Betula forest, cultivated land and pasture. 50 study points were established. Plots along the major roads were randomly selected 20 40 to cover representative vegetation pattern. Further, around the Arkaim, 10 20 Mean Temperature major vegetation types ware described. 0 0 Field observations were carried out during early summer season, 1 2 3 4 5 6 7 8 9 10 11 12 -10 middle June in 2009. Month Mean Monthly Temperature ( Temperature Monthly Mean -20 Results and discussions Fig. 2. Monthly mean temperature（●） and precipitation（■） at Chelyabinsk（ MSN. Weather forecast, 2010） Changes in vegetation landscape from Celyabinsk to the Arkaim Major components of the vegetation by dominants in stands along forests at a very limit. Average annual temperature at Chelyabinsk the roads from Celyabinsk to the Arkaim are: Larix and Pinus shrubs, amounts to 3.1℃. Betula and Pinus forest, herb steppe, fog steppe and turf steppe The Arkaim reserve is located in the temperate climatic （Lavrenko and Sochava, 1954）. Larix and Pinus shrubs appear gener- belt, within the west Siberian region of continental climate; it ally in highlands and seldom appear along the major traffic roads. lies within the steppe zone with some participation of forest Therefore we mention these two types of vegetation no more hereafter. parches（1%） . The mixed structure of the vegetation around the Arkaim means that The continental climate, characterized by great variation of the relationships between the types of vegetation and the environments annual, seasonal and daily temperatures, has an infl uence on and human activity are fi ne scaled. Development of forest vegetations soil formation. The average annual air temperatures vary around the Arkaim indicate that steppes are not necessarily an obligato- from 1 to 3℃; the average January temperature is from -16 ry dominant vegetation even in the semi-arid area near the Arkaim to -18℃, the average July temperature is about 19-20℃. The Table 1 summarizes the results of vegetation observation from Cely- sum of the temperatures exceeding 10℃ equals 1950-2300, abinsk to the Arkaim. Points of Pinus and Betula forest found in the the time of no frosted period is 111-125 days. Frosts in the area south of Stepnoie（ steppe） are smaller than those in the area north hollows and deep valleys were 2-5℃ stronger as compared to of Stepnoie（ forest steppe）. Decrease of total amounts of annual pre- the open areas, on the hills’tops -2℃ weaker. The annual precipitation from Celyabinsk, 443 mm, to the Arkaim, ca. 350 mm esti- cipitation in the region is 250-350 mm, 45% of all precipitations mated from the precipitation data in Magnitogorsk, 100 km north to the as storm reins fall in summer and 10-12 % - in winter. The Arkaim（ MSN. Weather forecast, 2010）, reads to the reduction of for- thickness of snow cover is 0.25 m maximum. The soils freeze ests. Contrarily cultivated land（ mainly wheat and potato） and pasture in the depth of 0.8-2.0 m and are kept in frozen the state up increased from Chelyabinsk to the Arkaim. The vegetation changes to fi ve months. The snow melting takes place when the soils from relatively humid forest steppe to semi-arid semi-desert steppe

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Fig. 3. Glass steppe vegetation near Stepnoie（53゜15′ N, Fig. 5. Pinus sylvestris forest near Chelyabinsk（55ﾟ10′ N, 61ﾟ 61ﾟ54′E）. 40′E）.

Fig. 4. Pastures near the Arkaim（53ﾟ15′ N, 61ﾟ54′E）. Fig. 6. Inner view of a Betula pendula closed forest at the Arkaim（53ﾟ15′ N, 60ﾟ40′E）.

from Chelyabinsk to the Arkaim. tatin type is well represented by tuft grass occupying the south of the Forest dimensions such as a diameter of stems, tree height and stem forest-steppe zone in the southern Eurasia. The graminoids of Stipa density reduce near the Arkaim, ca. 15 cm in mean D.B.H. and ca. 10 species are dominant in pasture with Festuca. m in mean tree height, as compared with those of a Betula forest near Forest consists of two major types: Pinus sylvestris forest and Betula Chelyabinsk, ca. 30 cm in mean D.B.H. and ca. 15 m in mean tree pendula forest. Pinus sylvestris forest（ Fig. 5） occurs chiefly on the height. A drier climate prevents trees from growing thicker and taller. area between Chelyabinsk and Stepnoie; it seldom occurs on the area between Stepnoie and the Arkaim（ Table 1）. Forest ﬂ oor of this forest Major vegetation types around the Arkaim and their structure Vegetation landscape around the Arkim consists of three major Table 1. Results of vegetation observation from Chelyabinsk to types: steppe, pasture, and forest（ Fil’roze, 1999; Gaiduchenko and the Arkaim through Stepnoie. AreaC-S means the observations from Chelyabinsk to Stepnoie, Area S-A Musatov, 1999）. means the observations from Stepnoie to the Arkaim. Steppe（ Fig. 3） covers a wide area around the Arkim. This vegetation is similar with pasture at present but free from human use differing Vegetation type Area C-S Area S-A Total from pasture. This is represented by sagebrush steppe composed main- Pinus forest 606 ly of Stipa and Festuca. Drought-tolerant wormwood（ Artemisia spp.） Betula forest 8210 and leguminous plants such as Oxytropsis and Astragalus are common Cultivated land 3710 Pasture 61824 in this type of steppe. Total Pasture（ Fig. 4） occupies a huge area around the Arkim. This vege- 23 27 50

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northern boreal coniferous forest zone and southern semi-arid steppe and semi-desert zone including the area around the Arkaim, making a clear vegetation belt throughout Russian territory associated with aspen forest（ Labrenko and Sochava, 1954; Isachenko and Lykicheva, 1956）. Archbold（1995） presented a similar zonal position of the birch and aspen forest in Eurasia. Those fi ndings support that Betula pendula forest around the Arkaim is a climax one. In the plains of southeastern Ural steppe is frequently interspersed with groves of pine and birch（Fig. 7）. Sizes of pine or birch groves usually range from some hundred square meters to some hectors. It consists of a mixed mosaic of Betula pendula closed forests, grass Fig. 7. Forest steppe（ Betula pendula forests, grass steppe and steppe and pasture. Betula pendula forests within this area are usually pasture） at the Arkaim（53ﾟ13′ N, 60ﾟ30′E）. bordered clearly by to grass steppe. Both Betula pendula forest and Pinus sylvestris forest make climax ones in the cool temperate semi-arid condition. It indicates that shade intolerant but fast growing Betula and Pinus spp. make occasionally climax vegetation in the severe condition such as arid or low temperature（ Lavrenko and Sochava, 1954; Archibold, 1995）. Hence representative types of potential natural vegetation around the Arkaim are thought to be forest from Betula pendula and partly from Pinus sylvestris, as well as several types of steppes. Pollen analysis by Lavrushin and Spiridonova（1999） revealed that forest vegetation of spruce, pine and birch occurred around the Arkaim in the Bronze Age. People of Bronze Age was thought to have occupied southern Ural steppe zone, and changed forests into steppe, be- Fig. 8. A reconstruction of the fortress of Bronze Age using cause fortress of Bronze Age（ Fig. 8） is assumed to have been con- abundant timber at the Arkaim. structed by abundant timber. This means the area around the Arkaim at the Bronze Age supplied suffi cient timbers. This infers that people in consists mainly of such tree species as Tilia, Lonicera, Betula, Larix, the Bronze Age caused any vegetation change from forests to steppes. Sorbus, Corylus. The size distribution of the pine shows fairly continuous; in Fig. 5 larger size stems（ diameter at breast height of ca. 30 cm） Phytogeographical differences between forest steppe and prevail but also smaller stems also exists. This size distribution indi- savanna cates that this forest is self-maintained climax vegetation. Pine forest Forest area within the Arkaim is usually bounded clearly by the area spreads widely between northern boreal coniferous forest zone and of grass steppe（ Fig. 7）. Semi-arid subtropical woody vegetation, sa- southern semi-arid steppe and semi-desert zone including the area vanna in Namibia, southwestern Africa, shows open woodland with around the Arkaim, forming a clear vegetation belt throughout Russian sparse distribution of trees（ Fig. 9）. Vegetation structure of savanna in territory（ Labrenko and Sochava, 1954; Semenova-Tyan-Shanskaya, Namibia is usually a combination of open Acacia woodland and 1956）. This finding supports that Pinus sylvestris forest around the graminoid in the fl oor that is covered by woods at most 30 % in area Arkaim is a climax one. （Okitsu, 2005）. Betula pendula forest（ Fig. 6） appears in the area between Stepnoie Most of the land in Namibia suffers from serious water deficit and the Arkaim, although infrequently, as well as in the area between （Mendelsohn et al., 2002） even with similar precipitation, yearly Chelyabinsk and Stepnoie（ Table 1）. The size distribution of the birch amount ca. 400 mm, as that of the forest steppe because of higher shows fairly continuous, as well as that of the pine; in Fig. 6 larger size evapotranspiration. Average annual temperature of Numihia amounts stems（ diameter at breast height of ca. 20 cm） prevail but also smaller to around 20℃ being much higher than that of the Arkaim. Contrarily, stems also exists. This size distribution indicates that this forest is self- the Arikaim experiences actually no serious water deficit around the maintained climax vegetation. Birch forest occurs also widely between year（ Fig. 2）.

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Ermolaev, A. M.（1999） : Dynamics of anhtropogenic herbaceous ecosystems with different ages in Arkaim. In: Natural System of the Southern Urals. Proceedings of Chelyabinsk State University, pp.164-184. Chelyabinsk State University, Chelyabinsk.（ in Russian） Fil’roze, E. M.（1999） : Forests at Museum Preserve Arkaim and its surround- ings. in: Natural Systems of Southern Urals. In: Proceedings of Chely- abinsk State University, pp.146-163. Chelyabinsk State University, Chelyabinsk.（ in Russian） Gaiduchenko, L. L. and V. A. Musatov（1999） : Landscape structure of territory of the essential area of Museum Preserve Arkaim. In: Natural Systems of Southern Urals. Proceedings of Chelyabinsk State Univer- sity, pp.59-65. Chelyabinsk State University, Chelyabinsk.（ in Rus- Fig. 9. Savanna in Namibia: Evergreen nanophyll type（ near sian） Tsumeb, northeastern most part of Namibia, 19ﾟ06′S， Isachenko, T. N. and A. N. Lykicheva（1956） : Birch and aspen forest. In: 18ﾟ37′E）（ Okitsu, 2005） Lavrenko, E. M. and V. A. Sochava（ eds.） Description of the vegetation of the USSR. I. pp. 319-345. Soviet Academy of Science, Lenin- Woody vegetation with water defi cit condition such as savanna in grad.（ in Russian） Namibia becomes open sparse, probably because root competition Lavrenko, E. M.（1956） : Steppe and agricultural land in the steppe zone. In: about insufficient soil water makes trees obligatory separate. In this Lavrenko, E. M. and V. B. Sochava（ eds.） Description of the vegetation of the USSR. II. pp. 595-730. Soviet Academy of Science, Len- case water defi cit determines the vegetation structure. ingrad.（ in Russian） The causes of clear boundary of the forest in forest steppe in the Lavrenko, E. M. and V. B. Sochava（1954） : Geobotanical Map of the USSR. Arkaim are still uncertain yet. Possible explanations for them are 1） A scale of 1：4000000. Komarov Botanical Institute, Soviet Acade- Forming woodland mainly in negative relief elements: hollows, infl ec- my of Science, Leningrad.（ in Russian） tions of slopes, received extra moisture and have a limited size. Al- 2） Lavrushin, Yu. A. and E. A. Spiridonova（1999） : Fundamentals of geological though no serious water defi cit in summer appears, total yearly precipi- and paleoecological events in the end stage of late Pleistocene and tation still remain semi-arid climatic condition and it hardly permit early Holocene around east part of southern Ural. In: Natural Systems establishment of closed forest in and scape revel: number of trees in an of Southern Urals. Proceedings of Chelyabinsk State University, area becomes obligatory smaller, and 3） grasses of steppe develop a pp.66-103. Chelyabinsk State University, Chelyabinsk.（ in Russian） network of fi ne roots which penetrate to depth of 45-90 cm, and ap- Mendelsohn, J., A. Jarvis, C. Boberts, and T. Robertson（2002） : Atlas of Na- proximately 90 % of the root mass is found in the upper of the soil so mibia. A Portrait of the Land and its People. 200 p. David Philip, Cape moisture from sporadic precipitation events is absorbed by grasses effi - Town. ciently during the growing season（ Archibold, 1995）: this prevent es- MSN Weather forecast（2010） : Climate of Celyabinsk. http://weather.jp.msn. com/ accessed November in Japanese tablishment of tree seedlings. （ 22 2010）（） Okitsu, S.（2005） : Factors controlling geographical distribution in savanna vegetation in Namibia. African Study Monographs, Suppl. 30, 135- Acknowledgements 151. This study was supported by JSPS and RFBR Joint Research pro- Semenova-Tyan-Shanskaya, A. M.（1956） : Pine forest. In: Lavrenko, E. M. gram 2009-2010. and V. B. Sochava（ eds.） Description of the vegetation of the USSR. 1. pp. 217-248. Soviet Academy of Science, Leningrad.（ in Russian） References （Received 27 Dec. 2010 ; Accepted 21 Feb. 2011） Archibold, O. W.（1995） : Ecology of World Vegetation. 510 p. Chapman & Hall, London.

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