Earthworm fauna of Kazakh upland

Abstract

The species composition of earthworms of different ecosystems in Kazakh upland (Kazakhstan) representing different soil types was assessed for the first time. This eco-region encompasses a large dry steppe area. It is considerably higher than the surrounding Western Siberian plains and Turgay plains. It features elevated plains, melkosopochniki (the local name for highly eroded plateaus), and low mountains. Habitat types characteristic to this area include petrophitic steppes with shrubs and brushwoods, granite rock pinewoods in the low mountains, and micro-phyllous woods associated with lakes and wetlands. Well represented intrazonal communities include wetlands and associated forests. Pine, birch, and aspen woods are found. Earthworms from Kazakh upland belong to seven genera, nine species, and three subspecies. These earthworms are widespread, a majority of which have an antropochoric dispersion however there are several native Asian species and subspecies as well. Development of a hydrological network promotes preservation of some forest species from the past, e.g., Dendrobaena octaedra and Eisenia norden-skioldi pallida. Moreover the boreal species of soil fauna specify the connection of area of research with the West-Siberian plain, Altai and southern Urals Mountains in the past. The epigeic D. octaedra and Dendrodrilus rubidus tenuis play a key role in the structure and function of the earthworm assemblages in the biotopes studied. The earthworm fauna is more diverse in forests of the northern and the southern parts of Kazakh upland than elsewhere in this arid zone of the country.

Key words:

• Dry steppe region
• earthworms
• epigeic and endogeic species
• Kazakh Upland