Vegetation pattern within a thermokarst landscape in the central Altay Mountains (West Siberia)

Feddes Repertorium 115 (2004) 7–8 , 574–584 DOI: 10.1002/fedr.200411055 Weinheim, Dezember 2004

© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 0014-8962/04/7-812-0574

Ernst Moritz Arndt University Greifswald, Botanic Institute and Botanic Garden, Greifswald

P. KÖNIG & S. RILKE

Vegetation pattern within a thermokarst landscape in the central Altay Mountains (West Siberia)

Results from the 8th soil-ecological excursion across Western Siberia (July 29–August 19, 2002)

With one Map and 6 Figures

Summary

In a mountain basin landscape influenced by a semi-desert climate in the South Siberian Altay, a geobotanical study was conducted by placing a transect through a run-off runnel and creating a vegetation map for the wet mire and meadow regions of the study area. The close proximity of semi-desert and mire associations, formed by thermokarst phe-nomena, is noteworthy. The associations are pre-sented in terms of their locations, and a phyto-geographic classification of species is given. Com-parisons with the conditions in NW Mongolia dem-onstrate the close relationships of dry slopes in the Chuya Basin with the typical Central Asian semi-desert flora, which extends from the Great Lakes Basin into the southern desert zone of Mongolia.

Zusammenfassung

Vegetationsmuster in einer durch Thermokarst geprägten Landschaft im zentralen Altai-Gebirge (Westsibirien) In einer durch Halbwüstenklima geprägten montanen Beckenlandschaft des südlichen sibirischen Altay wurden geobotanische Untersuchungen durchge-führt, deren Ergebnisse in Form eines Transektes durch eine Abflussrinne und einer Vegetationskarte für die feuchten Moor- und Wiesenbereiche vorge-legt werden. Beeindruckend ist die enge räumliche Nähe von Halbwüsten- und Moorgesellschaften, die durch Thermokarst-Erscheinungen bedingt ist. Die Vergesellschaftungen werden in ihrer standörtlichen Bindung dargestellt und eine pflanzengeografische Einordnung der Arten gegeben. Vergleiche mit den Verhältnissen der NW-Mongolei zeigen die engen Beziehungen der trockenen Hänge im Čuja-Becken zu der typischen zentralasiatischen Halbwüstenflora, die sich vom Becken der Großen Seen bis in die südliche Wüstenzone der Mongolei erstreckt.

1 Introduction

Since 1995, international excursions have been conducted through Siberia with a special focus on soil and ecology. Currently, these excur-sions are organized by members of the Siberian Institute for Ecological Initiatives (a NGO, headquarters in Novosibirsk) and the Institute of Ecology and Biology (Technique University Berlin). The authors of this paper participated in the 2002 excursion, which started in Novosi-birsk, continued through Yurty, Barnaul, and Seminsky Pass, on up to Beltir SW of Kosh-

Agach, ended at the Karagem Pass near the Mongolian border. The route presented a tran-sect through the main vegetation types of west-ern Siberia and the Altay, e.g. black taiga, for-est steppe, steppe, mountain tundra, dry steppe, and semi-desert, with special reference to the respective soil types. Botanical results with a general species list have been compiled by KÖNIG (2002). The present article contributes to the knowledge of one of the mountain basins in the central Siberian Altay, in the Kosh-Agach district.

K. KÖNIG & S. RILKE: Vegetation pattern within a thermokarst landscape in central Altay Mountains 575

© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

2 Location

The study area is situated on one of the tributar-ies of the Chuya river in the northwestern part of the Chuya depression at an elevation of ca. 1800 m a.s.l. and geographic position 50°06′04″ N, 88°26′13″ E (Map 1). This moun-tain valley extends about 70 km from west to east and 40 km from north to south, and is enclosed on all sides by high mountains. Chagan-Uzun, the nearest small village is lo-cated 3 km to the west, and the Mongolian border only 80 km away to the east. Thus, the relationship to Mongolian vegetation types is obvious, and a comparison based upon the comprehensive studies of German-Mongolian field work in the 1970s/1980s is possible (HIL-BIG & SCHAMSRAN 1977; HILBIG 1995). An interesting feature of Chagan-Uzun area is the presence of permafrost together with semi-desert vegetation. A thick layer of perma-nent ice is found some meters below the ground surface as a remnant of the last ice age. It is an ice lens from pre-Pleistocene lakes covered by glacial sediments. The zone of discontinuous permafrost distribution in basins and valleys reaches south to central Mongolia because of the continental climate, and is favoured by temperature inversion during winter. The melting away of the subterranean ice during summer (active layer) produces erosion runnels with slopes up to 10 m high in the Cha-gan-Uzun area (chap. 6.1). In the runnels, ice may be found only a few dm under the soil surface in some places. The process of melting ice is appar-ently quite slow, the drain-off takes place subter-raneously, and, finally, the water finds its way to the runnel delta. Thus, there is little sign of ero-sion detectable at the surface. In some places (see chapter 6.2), this spring-like water provides the basis for meadow and mire vegetation. Geologically, the area is tectonically active as part of the Devon subduction zone, and is characterized by metamorphic rocks. Serpen-tinite is common. The high content of iron, manganese and especially nickel was used by a small scale mining industry in the past.

3 Climate

The Chuya and Kurai valleys are some of the highest valleys in the Siberian Altay (KUMI-

NOVA 1960), and most remote in terms of west-ern precipitation influence. The climate is ex-traordinarily continental, with long, cold, dry winters and short summers. Thus, the rainfall during the winter half-year is negligible, but summer rains, influenced by the monsoon, are heavier, yielding a moderate annual rainfall of around 100 mm. The average annual tempera-ture is –6.6 °C (Map 1). For comparison, cli-mate diagrams are given for Turochak ENE Gorno-Altaysk (foot-hills of North Siberian Altay), Kosh-Agach (South Siberian Altay) and Hovd (NW Mongolia). Kosh-Agach is very close to the study area, and the other two areas are 250 to 300 km to the NW and SE, respec-tively. The similarity in the amount of precipita-tion, timing of rainy season, and temperature course between the stations Kosh-Agach and Hovd is evident. The study area represents an exclave of Mongolian semi-desert climate in West Siberia. Climatically, Turochak is already situated in the west wind zone. The relatively small amount of precipitation from November through March is due to the fact that low-lying winter clouds do not reach the Altay.

4 General vegetation characteristics of the Chuya basin and its surroundings

A short overview may elucidate the plant eco-logical situation in the study area. In the basins and valleys of the central and southern Altay, some islands of steppe vegetation exist, as already mentioned by LEDEBOUR (1829) who travelled with Alexander von Bunge and Carl Anton Meyer in 1826 up to the “Tschuja” basin. The three driest basins near Ongudai, Kurai, and Kosh-Agach are covered by deserti-fied steppe vegetation; the largest and south-ernmost basin near Kosh-Agach is called “Chu-iskaya” or Chuya steppe. The floristic analysis of this vegetation type (KUMINOVA 1960) yields to 177 species within 87 genera and 28 families. The ecophysiological calculation show large proportions of specialized groups, i.e. 41.8% xerophytes, 25.5% xeropetrophytes, and 13.5% halophytes. A striking feature of the slopes is the higher percentage of members of the Chenopodiaceae family: Anabasis brevifolia, Halogeton glo-

576 Feddes Repert., Weinheim 115 (2004) 7–8


Map 1 Location of study area with representative climatic diagrams of Turochak (N Altay, WALTER 1974), Kosh-Agach (S Altay, KUMINOVA 1960) and Hovd (NW Mongolia, STRÄSSER 1999). Contour lines in the bottom map detail give an impression of the topography within the Chuya basin



meratus, Kochia prostrata, Krascheninnikovia ceratoides (= Ceratoides papposa), Salsola rosacea, Ceratocarpus arenarius and Cheno-podium frutescens are obvious. Among the grasses, Psathyrostachys juncea is common on clay or often salty soil in depressions, while Agropyron cristatum is found with inferior abundance on dry rocky slopes. Achnatherum (= Lasiagrostis) splendens, the up to 2 m tall “Siberian pampas grass”, occurs sporadically in the transition from deserts to groundwater-influenced vegetation, and becomes more common further east in so-called “chee-grass stands“. It is used for matting, fences, walls, or as fuel, and therefore is of outstanding eco-nomic importance for the inhabitants of the dry steppe. The undershrub Krascheninnikovia cera-toides shows a disjunct range in Lower Austria (FISCHER 1994) and elsewhere in South Europe (JALAS & SUOMINEN 1980). It is considered a glacial relict of the cold steppe. Other typical species include the xerophytic Atraphaxis pungens, Bupleurum bicaule and Euphorbia tshuiensis (endemic to the Altay), the halophytic Zygophyllum pterocarpum and Reaumuria soongorica. The gymnosperm ge-nus Ephedra, a typical element of the Mongo-lian deserts, is obvious. E. monosperma re-places the closely related E. dahurica (= E. dis-tachya) which colonizes the stony slopes only few kilometers further west. Further on, some Caragana shrubs, i.e. C. bungei and C. pygmaea (= C. splendens), are found in situations with additional water supply. Both are characteristic of the shrub desert steppe. C. pygmaea has conspicuously yellow-barked twigs, which are used ornamen-tally under the name “Chinese golden birch”, and covers wide areas in the steppes of Trans-baikalia and Mongolia. The riparian vegetation midway along the course of the river is dominated by Larix si-birica and Salix pyrolifolia on gravelly ground. Different types of meadows and mires are in-corporated, with numerous herbs such as Halerpestes salsuginosa (= H. ruthenica), Cir-sium esculentum, Nepeta sibirica, Ziziphora clinopodioides, the latter with an intensive menthol odor. Further downstream, the river terrace at the Chuya river includes a greater proportion of fine material, with Populus lauri-

folia and Salix ledebouriana as characteristic elements. Generally, the water flow has two origins: melting snow and glaciers in the higher mountains, and water from Pleistocene ice lenses. The mountain ridges from about 2,500 m elevation upwards are covered by alpine mead-ows with Kobresia myosuroides among the typical constituents. Detailed vegetation studies of rock communities are presented by PYAK (2003). In the following, special focus will be placed on two strongly interconnected vegeta-tion types: semi-desert covering the slopes of thermokarst runnels, and meadows, or mires characteristic of the outflow areas.

5 Methods

To document the vegetation sequence of the runnels, a semi-quantitative transect technique was used. The transect covers an area of 10 m × 42 m and was divided into sections of 1 m × 10 m with 5 grids. Based on plant size and extension of vegetation structure, a grid size of 1 to 2 m was chosen as ap-propriate. Every second section was analyzed and the presence in the five grids per section noted. Thus, the maximum frequency was 5 per section and species. Results are shown in Fig. 2. For the meadow and mire vegetation, a species list of dominant constituents was prepared and the main plant communities mapped (Fig. 4). Nomenclature follows CZEREPANOW (1995) for vascular plants, FRAHM & FREY (1992) for bryo-phytes, and KOPACZEVSKAJA et al. (1971) for li-chens. Transliteration is according to Times Atlas practice.

6 Results

6.1 Vegetation of a thermokarstic runnel

A transect across an erosion runnel gives in-formation about the vegetation cover (Fig. 2). Exposition and substrate composition are sup-posed to be the main factors influencing species composition. In the 220 m2 transect area, 33 species were found. They cover about 5% (slope) to 50% (runnel) of the ground surface. Accumulation of fine earth at the bottom of the runnel offered suitable conditions especially for annuals and herbs (Polygonum avicu-



Fig.1 General view of the study area near Chagan-Uzun

lare to Ceratocarpus arenarius) or semi-shrubs, such as Artemisia santolinifolia which require a greater water supply. Some of them find there way out of the bottom and extend more or less to the slope sites. The slopes themselves are mainly domi-nated by different woody plants, especially semishrubs, e.g. Anabasis brevifolia, Artemisia frigida, Kochia prostrata, Krascheninnikovia ceratoides, Potentilla bifurca, and the grasses Psathyrostachys juncea and Stipa glareosa. Caragana pygmaea and the deep-rooted Convolvulus ammanii prefer the eastern stony slope. Small surface runnels with some fine earth accumulation on western slopes provide shelter for mobile Aspicilia lichens. A. tominii, endemic to mountain steppe, is more dominant than its “sister species” A. vagans, which is distributed through Middle Asia up to the Ural mountains. The steppe species Artemisia santolinifolia and Heteropappus altaicus prefer the lower part of the western slope with higher moisture content. Only single specimens of Orostachys

thyrsiflora with purple anthers shining in white flowers, Artemisia macrocephala, an element of the Artemisia-Festuca-Stipa steppes, and A. compacta are found. Even Ancathia ignaria, a herb with cactus-like leaves spread in north-western Mongolia on stony debris slopes, and Goniolimon speciosum, a widely distributed steppe species of plains and mountains, are not common in the study area. Altogether, Psathyrostachys juncea, Ar-temisia frigida, Krascheninnikovia ceratoides and Kochia prostrata are found with the great-est frequency. Species with ruderal tendencies are more likely to establish themselves at the bottom of runnels (e.g. Polygonum aviculare, Chenopodium foliosum, Lepidium densiflo-rum). Besides exposition, the summer water sup-ply determines a mosaic of steppe and desert plants. HELMECKE & HILBIG (1986) studied the Anabasis brevifolia-Stipa glareosa community, which is reported from the southern deserts up to Central and NW Mongolia. Both species favorite rocky underground, which character-



Fig. 2 Distribution and frequency of plants across an erosion runnel created by thermokarst



Fig. 3 View of the western slope from the SE direction

izes the eastern part of the runnel. Anabasis brevifolia is one of the predominant species in Mongolian winter-cold semi-deserts and de-serts, being excellently adapted due to its cau-dex and C4 photosynthetic pathway. HILBIG (1995) distinguished two subassociations of the community. The Convolvulus ammanii subas-sociation, with which the community of the eastern slope is associated, covers 5 to 20% of the surface, is comparatively species rich, and inhabits less extreme semi-desert sites. Stands of the Reaumuria soongorica subassociation, however, are more sparse and found predomi-nantly in Southern Mongolia. Grazing also has a marked influence on species composition. GUNIN et al. (1999) pre-sented results of 20 years of observation in desertified steppe near Bulgan (S Mongolia). Due to grazing intensification, species coverage of Stipa glareosa changed from 6 to 2%, while Artemisia frigida increased from 1 to 2% and Convolvulus ammanii from 0.5 to 3%. An indicator of intensive total pasture degradation

is also Saussurea amara (GUNIN at al. 1999); Artemisia frigida, Carex duriuscula, Kochia prostrata and Potentilla bifurca may profit from overgrazing as well. 18% of the species found within the tran-sect belong to the Chenopodiaceae. According to studies of REIMANN (2003), Ceratocarpus arenarius, Kochia prostrata and Kraschenin-nikovia ceratoides are among the family mem-bers with a low sodium content. These species grow on sites less influenced by salt, accumu-late more potassium, and are probably better adapted to drought stress. The latter two are ecophysiological xeropyhtes. Halogeton glo- meratus and Anabasis brevifolia, however, accumulate sodium and are classified as xero-halophytes. Real halophytes, however, are missing, a fact which is related to dry soil con-ditions without distinct salt accumulation. Based on the classification of KUMINOVA (1960), 20 of 30 assignable transect species are xerophytes, eight are halophytes, and two are mesophytes.



6.2 Vegetation of spring mire and surroundings

As already mentioned in part 4, the sections between slopes and rivers are sometimes cov-ered by small patches of mires. They are fed by the water of melting Pleistocene ice lenses. Due to the spring water percolating through meadow and mire, the vegetation pattern shows a small-scale mosaic. Nevertheless, the general distribution of relevant communities is given in Fig. 4, and the vegetation structure can be summarized as follows. First of all, the sharp contrast of the green meadow and mire communities of the river banks against the dull slopes is obvious. The latter are covered by a semi-desert (desert-steppe) association, dominated by Kraschenin-nikovia ceratoides and Psathyrostachys juncea, and some Equisetum arvense, Gypsophila pa-trinii, Artemisia schrenkiana and Linaria al-taica at the bottom of slopes with a higher content of fine earth. Psathyrostachys juncea

occupies a marginal position around meadows too, and characterizes the flat depressions nearby (Psathyrostachys juncea community). At the base of the slopes, some springs feed into different watercourses colonized by Koenigia islandica and Ranunculus natans (Koenigia islandica community). Among the mosses, Bryum pseudotriquetrum, Cratoneuron filicinum and Drepanocladus sp. show higher coverage. At the end, the watercourses empty into the gravelly river bed. Chiefly close to the slope, meadow com-munities have developed which are character-ized by Cirsium esculentum, Halerpestes sal-suginosa, Euphrasia officinalis s.l., Gentiana decumbens, Potentilla anserina, Geranium sibiricum, Ranunculus longicaulis var. pulchel-lus (= R. pulchellus); the salt indicator Hor-deum brevisubulatum, and Arctopoa (= Poa) tibetica and Deschampsia cespitosa are locally dominant. Among these meadows Larix si-birica may find suitable conditions.

Fig. 4 Vegetation map of a small spring mire fed by Pleistocene water



Fig. 5 Meadow and mire at Chuja tributary, view from West

Fig. 6 Relationship of ferns and seed plants in geographical regions of the former USSR according to CZEREPANOV (1995) with additions for Central Asia according to GRUBOV (2001). Species are mostly spread over more than one region but with different extent (nsemi-desert = 60, nmire/river = 42)



Typical species among the mire communi-ties are Carex altaica (= C. bigelowii subsp. altaica), C. curaica, C. songorica, Parnassia palustris, Bistorta vivipara (= Polygonum vi-viparum), Juncus castaneus and Calamagrostis neglecta. Somewhat salty conditions are indi-cated by Blysmus rufus, Glaux maritima and Triglochin maritima. Meadow and mire communities give way to river gravel or semi-desert in transition zones. In general, mire vegetation is far from well-known in the study region and needs further research (KUMINOVA 1960; HILBIG 1995).

6.3 Phytogeography

In a wider territorial sense, the study area is quite close to the phytogeographic meeting place of Central Asian, Western Siberian and Middle Asian elements. According to TAKHTA-JAN (1986), the Altay mountains including part of Northwestern Mongolia belong to the Altay-Sayan Province within a broader-seized Cir-cumboreal Region characterized by coniferous forests and alpine meadows in the high moun-tains. On the contrary, the Mongolian Altay and the Basin of the Great Lakes are part of the Mongolian Province within the Central Asiatic Subregion of the Irano-Turanian Region, a vast territory of unique cold deserts, desert-steppes and high mountain steppes. A comparable classification but with more strictly grouped regions is given by MEUSEL & JÄGER (1992). Thus, the Altay is divided in a northern part neighbouring the Sayan Province, and a southern part situated at the eastern edge of the Pontic-South Siberian Region. The study area belongs to the South Altayan Province which is located at the borderline to the West Mongolian Province of the Central Asiatic Region. In view of kettlehole and mountain effects, northernmost outposts of extrazonal semi-desert vegetation are linked in the study area (KARAMYŠEVA et al. 1986). They find there southern continuation from Uvs Nuur (51° N) and Achit Nuur Basin through Great Lakes Basin (Mongolia), and pass at his southern end around 46° N into zonal vegetation. The lee-ward position behind the Altay mountain range in connection with the comparatively low alti-tude results in distinct continentality and arid-

ity. Thus, the Mongolian semi-desert belt ex-tends further north (HANELT 1970). The semi-desert vegetation of the study area is predominantly composed of Central Asian and endemic species. It contains numerous Mongolian or Central Asian species which have their northernmost distribution range in the study area (e.g. Anabasis brevifolia, Stipa glareosa, Caragana pygmaea, Chenopodium frutescens, Oxytropis aciphylla, O. pumila). The transect communities of the slopes form a transition to the deserts of Mongolia, they rep-resent the dominant vegetation of the inter-mountain basins of Khovd district, of the cen-tral basin of the Great Lakes depressions and are widespread on gravel sides in all parts of the Gobi (WALTER & BOX 1983). For the 177 species of desertified steppes in the central Altay, KUMINOVA (1960) calculated a proportion of 35.6% Central Asian elements and 19.2% species restricted to the Altay und NW Mongolia. Within the transect, 25% of the species are Central Asian, 9.3% are endemic, and 43.7% are widely distributed. Focusing on the eastern slope, about 50% show a main distribution area within the Central Asian re-gion (due to drier conditions), while on the western slope, only Anabasis brevifolia is a Central Asian element and most species are widely distributed. The species of the meadow and mire vege-tation show a more general distribution with higher amounts of extra-Siberian relationships (Fig. 6).

Acknowledgements

The outstanding preparation by the organizing com-mittee (Russian team plus Christian S iewer t ) is kindly appreciated. Special thanks to Kolja (Nicolai) Lashinsk i , our excellent botanist from Novosi-birsk Botanical Garden, M. Manthey (bryophytes) and B. Li t te rsk i (Aspicilia) from Greifswald, H. Fre i tag (Ephedra) from Kassel, A. Pyak and T. V. Ebel (Artemisia, Carex) from Tomsk for the revision of collections.

References

CZEREPANOV, S. K. 1995: Vascular plants of Russia and adjacent states (the former USSR). – Cam–bridge.

FISCHER, M. A. (ed.) 1994: Exkursionsflora von Österreich. – Stuttgart, Wien.



FRAHM, J.-P. & FREY, W. 1992: Moosflora, 3. Aufl. – Stuttgart.

GRUBOV, V. I. 2001: Key to the vascular plants of Mongolia (with an atlas), 2 vols. – Enfield/USA (English translation from the Russian version of 1982).

GUNIN, P. D.; VOSTOKOVA, E. A.; DOROFEYUK, N. I.; TARASOV, P. E. & BLACK, C. C. (eds.) 1999: Vegetation dynamics of Mongolia. – Geobotany 26: 238 pp

HANELT, P. 1970: Vorkommen und Vergesell–schaftung von Nanophytum erinaceum (Pall.) Bge. in der Mongolischen Volksrepublik. – Arch. Naturschutz Landschaftsforsch. 10: 19–40.

HELMECKE, K. & HILBIG, W. 1986: Standortunter–suchungen in der Halbwüstenvegetation des Gobi-Altai (MVR). – Erforsch. biol. Ress. MVR 5, Wiss. Beitr. Univ. Halle-Wittenberg 18 (1985): 149–159.

HILBIG, W. 1995: The vegetation of Mongolia. – Amsterdam.

HILBIG, W. & SCHAMSRAN, Z. 1977: Beitrag zur Kenntnis der Vegetation im Chovd Aimak (Mongolische Volksrepublik). – Arch. Natursch. Landschaftsforsch. 17: 35–82.

JALAS, J. & SUOMINEN, J. 1980: Atlas Florae Europaeae 5, Chenopodiaceae to Basellaceae. – Helsinki.

KARAMYŠEVA, Z. V.; SUMERINA, I. J.; BEKET, U. & BUJAN-ORŠICH, O. 1986: Pflanzengeographische Untersuchungen im Westen der Mongolischen Volksrepublik. – Erforsch. biol. Ress. MVR 5, Wiss. Beitr. Univ. Halle-Wittenberg 18 (1985): 109–113.

KÖNIG, P. 2002: Botanical results of the 8th Soil-ecological excursion across W Siberia, July 29–August 19, 2002. – http://sibirien.csiewert.de/ SonstigeInfo/sonstigeinfo.html: 5 pp. Text + 30 pp. Appendix Species list (pdf-files).

KOPACZEVSKAJA, E. G.; MAKAREVICZ, M. F.; OXNER, A. N. & RASSADINA, K. A. 1971: Hand-

book of the lichens of the U.S.S.R. 1. Pertu-sariaceae, Lecanoraceae and Parmeliaceae. – Leningrad.

KUMINOVA, A. V. 1960: The vegetation of the Altai. – Novosibirsk (in Russian).

LEDEBOUR, C. F. VON 1829: Carl Friedrich von Ledebour’s Reise durch das Altai-Gebirge und die soongorische Kirgisen-Steppe. Teil 1. –Berlin.

MEUSEL, H. & JÄGER, E. 1992: Vergleichende Cho-rologie der zentraleuropäischen Flora, Vol. 3. –Jena.

PYAK, A. J. 2003: Petrofity Russkogo Altaya. – Tomsk (in Russian).

REIMANN, C. 2003: Vergleichende Untersuchungen zum Salzhaushalt der Chenopodiaceae, unter besonderer Berücksichtigung der Kalium-Natrium-Verhältnisse. – Diss. Bot. 372, Stuttgart.

STRÄSSER, M. 1999: Klimadiagramm-Atlas der Erde. Teil 2: Asien, Lateinamerika, Afrika, Australien und Ozeanien, Polarländer. Monats- und Jahresmittelwerte von Temperatur und Nieder–schlag für den Zeitraum 1961 – 1990. – Duis–burger Geograph. Arb. 20, Dortmund.

TAKHTAJAN, A. 1986: Floristic regions of the world. – Berkeley et al.

WALTER, H. 1974: Die Vegetation Osteuropas, Nord- und Zentralasiens. – Stuttgart.

WALTER, H. & BOX, E. O. 1983: The deserts of central Asia: 193–236. – In: N. E. WEST (ed.), Ecosystems of the world 5. – Amsterdam.

Address of the authors:

Dr. Peter König , Dr. Sabrina Ri lke , Ernst Moritz Arndt University of Greifswald, Botanic Institute and Botanic Garden, Grimmer Straße 88, D-17487 Greifswald, Germany. e-mail: [email protected] Manuscript received: January 23rd, 2004/revised version, August 23rd, 2004.

Documents

Vegetation pattern within a thermokarst landscape in the central Altay Mountains (West Siberia)