Desert sagebrush-bunchgrass steppes of Central Kazakhstan

The considerable vegetation researches of the Kazakhstan steppes were realized in 1957–1959, 1964–1968. The vast materials with relevés of desert steppes’ communities were collected in according to the generally accepted methods of geobotanical investigations either with assistance of detailed field routes or at the scientific stations (Kratkoe…, 1952; Polevaya… 1964). Some data about foremost northern types of Kazakhstan steppes (Isachenko, Rachkovskaya, 1961) and desert steppes of one region only (i. e. south-west part of the Central Kazakhstan Melkosopochnik) were published earlier (Biokompleksnye …, 1969). This article is an effort to complete the missing information about desert sagebrush–bunchgrass steppe of Central Kazakhstan through its full characteristics and classification.

The desert sagebrush-feather grass steppe is the foremost southern type of steppes confined to light chestnut soils; its southern border coincides to the border between steppes and deserts (it’s about 48° N for Kazakhstan). Melkosopochnik (hilly, ridgy, and rocky) with relative elevations from 20–50 to 100–150 m is a dominating type of relief in the Central Kazakhstan. The hills are composed of the different rocks: granites, acidic and basic effusive rocks, sandstones and shales.

The classification of desert sagebrush-bunchgrass steppes is created on the basis of dominant — determinant approach. There are 9 associations regarding to 3 formations: Stipeta lessingianae, Stipeta sareptanae and Stipeta kirghisorum. The following characteristics are given for each association: geographic distribution, confinedness to specific type of soils, floristic richness, composition of dominant and determinant species, set of life forms, stratification, projective and real coverage, the ratio of ecological groups of species and its type of area.

The comparison of the species lists of associations for desert steppe in Central Kazakhstan demonstrates that associations of Stipeta lessingianae formation have the most floristic richness (40–50 species) whereas associations of Stipeta sareptanae steppes — not more than 20–30 species.

The steppe species dominate over the desert-steppe ones in Stipeta lessingianae communities. And, on the contrary, desert-steppe species dominate over the steppe ones in Stipeta sareptanae communities. The balance of these groups is almost equal for Stipeta kirghisorum formation.

The ecologic analysis declares the fact that the majority of Stipa lessingiana, S. sareptana and S. kirghisorum steppe communities show almost equal balance between the groups of pelitophil species and hemipetrophil-petrophil species. The exception is Stipa lessingiana+Festuca valesiaca+Artemisia compacta association with domination of hemipetrophil and petrophil species over pelitophil ones.

The areas of slightly disturbed steppes, which are preserved in the south part of Kazakhstan steppe zone, need to an urgent protection because the vast squares are used as the pastures. Technogenic factor is also impacts locally (Rachkovskaya et al., 1999).

Now sagebrush-feather grass steppes are protected in Korgaldzhyn Nature Reserve and Ulutau conservation area only (Bragina et al., 2013). It is suggested to organize some perspective territories of preferential protection in the Central Kazakhstan, for example, to start up the Central Kazakhstan Reserve near railway station Agadyr including the low mountains Ortau, Kyzyltau, Aktau, and also National Park on the base of Kyzylrai low mountains.

Key words: desert steppes, classifi cation, hilly land, Central Kazakhstan

Section: Articles

How to cite

Rachkovskaya E. I. 2016. Desert sagebrush-bunchgrass steppes of Central Kazakhstan // Vegetation of Russia. N 28. P. 108–124. https://doi.org/10.31111/vegrus/2016.28.108

Received April 11 2016

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