Steppes of the Northern Kazakhstan — the syntaxonomical revision

Landscapes of the Northern Kazakhstan and southern part of the West Siberian Plain are deeply transformed and fragmented as a result of long-term agricultural exploitation. So, steppes became the most endangered ecosystems due to total ploughing of zonal soils. Presently, there are no large massifs of natural steppes. This determines the importance of data representing zonal steppe communities. One of the most important studies in this field is the publication by T. I. Isachenko and E. I. Rachkovskaya (1961), containing detailed characteristic of steppe vegetation from the Northern Kazakhstan and 199 relevés representing the unique dataset of zonal communities, which were destroyed later. Based on these data, Miloslav Toman (1969) has described the new order Helictotricho-Stipetalia, 2 alliances, 3 suballiances and 8 associations. He used only 40 of 199 original relevés, that led to some incorrect conclusions.

This study presents the analysis of 199 steppe relevés from the publication in question. We used the following methods: (1) the table sorting; (2) numerical analysis using plant indicator values, (3) Detrended Correspondence (DCA). All relevés were assigned into the order Helictotricho-Stipetalia Toman 1969 (Festuco-Brometea Br.-Bl. et Tx. ex Soó 1947) that represents the typical bunchgrass steppes and some variants of meadow steppes. They are distributed across the northern part of steppe zone and the southern part of forest-steppe zone from the Southern Urals to Altai Mountains.

We have identified 6 groups of relevés. Four ones represent the zonal vegetation: species rich bunchgrass steppes from relatively mesic habitats (ass. Helictotricho desertorum–Stipetum rubentis Toman 1969, syno­nyms Stipetum rubentis Toman 1969 and Peucedano morisonii–Stipetum rubentis Toman 1969); typical bunchgrass steppes (ass. Artemisio austriacae–Stipetum capillatae Schubert et. al. ex Korolyuk 2014); dry steppes dominated by Stipa korshinskyi (ass. Galatello subglabrae–Stipetum korshinskyi Toman 1969); dry steppes with Stipa lessingiana (ass. Linosyrido tataricae–Stipetum lessingianae Toman 1969). DCA-ordination of plant communities from the Northern Kazakhstan showed that some ecological factors, such as soil moisture, sand and rock debris content are important in differentiation of steppes. We also analyzed 21 associations of the order Helictotricho-Stipetalia from Southern Siberia, Kazakhstan and Southern Urals (Korolyuk, 2007, 2014; Yamalov et al., 2012). This analysis showed the higher value of regional differences in the species composition.

We proposed the system of alliances that reflects the influence of leading ecological factors in the differentiation of the order Helictotricho-Stipetalia. Three zonal alliances are distinguished according to moisture gradient. The alliance Helictotricho desertorum–Stipion rubentis Toman 1969 combines the species rich bunchgrass steppes and more xeric variants of meadow steppes (differential species (d. s.): Achillea asiatica, Artemisia glauca, A. pontica, Eryngium planum, Galatella biflora, Iris ruthenica, Peucedanum morisonii, Thalictrum minus, as well as some mesoxerophytes from the diagnostic combinations of the class Festuco-Brometea: Filipendula vulgaris, Fragaria viridis, Plantago urvillei, Poa angustifolia, Trommsdorffia maculata, Veronica spicata). The alliance Carici supinae–Stipion zalesskii all. nov. prov. unites more xeric typical bunchgrass steppes (d. s. of the alliance = d. s. of the order). The alliance Stipion korshinskyi Toman 1969 includes dry bunchgrass steppes (d. s.: Agropyron pectinatum, Allium flavescens, A. praescissum, Artemisia schrenkiana, Astragalus macropus, Dianthus leptopetalus, Eremogone koriniana, Ferula tatarica, Galatella divaricata, Iris glaucescens, Jurinea multiflora, Leymus ramosus, Nepeta ucranica, Palimbia salsa, Pedicularis physocalyx, Phlomoides agraria, Scorzonera stricta, Serratula cardunculus, Stipa korshinskyi, S. lessingiana, S. sareptana).

We also described 2 alliances representing typical edaphic variants of steppe vegetation. The alliance Helictotricho desertorum–Orostachyion spinosae all. nov. prov. (d. s.: Allium rubens, Alyssum obovatum, A. tortuosum, Aster alpinus, Carex pediformis, Centaurea sibirica, Clausia aprica, Euphorbia caesia, E. subcordata, Orostachys spinosa, Sedum hybridum) embraces all petrophytic steppes. There are significant differences in the species composition on dry rocky habitats between the Altai Mountains, the Northern Kazakhstan and Southern Urals. The alliance Sileno borysthenicae–Cleistogenion squarrosae all. nov. (d. s.: Artemisia marschalliana, Centaurea adpressa, Cleistogenes squarrosa, Gypsophila paniculata, Helichrysum arenarium, Herniaria polygama, Kochia laniflora, Koeleria glauca, Silene borysthenica, Stipa borysthenica) is characteristic of psammophyte steppes.

The analysis showed that classification systems of steppe vegetation proposed by T. I. Isachenko and E. I. Rachkovskaya and M. Toman are not conflicting due to the fact that in both surveys plant communities were identified based upon species composition. The actual syntaxonomy of the order Helictotricho-Stipetalia can be successfully applied to the vegetation studies of large areas.

Key words: steppe vegetation, syntaxonomy, Northern Kazakhstan, Festuco-Brometea

Section: Articles

How to cite

Korolyuk A. Yu. 2017. Steppes of the Northern Kazakhstan — the syntaxonomical revision // Vegetation of Russia. N 30. P. 61–77. https://doi.org/10.31111/vegrus/2017.30.61

Received April 5 2016

References