The spatial and temporal structure of spider communities was studied in the clay semi-desert of the
north-western Caspian Lowland, western Kazakhstan (49°23' N, 46°47' E). The soils and vegetation are complex,
being composed of a mosaic of desert and steppe plant communities. Besides the native associations, there are
plantations of different tree species. The ground-dwelling spider assemblages in the native habitats are the most
diverse. The number of species inhabiting forest plantations is three times as small. Gnaphosidae is the leading
family in the ground layer. They show high abundance and diversity levels during the whole season. Thomisidae,
Lycosidae, Philodromidae, and Salticidae are abundant as well. The species diversity of herbage-dwelling spiders
in different open native habitats is very similar. The spectrum of dominant families (Thomisidae, Oxyopidae,
Araneidae, and Salticidae) and the seasonal dynamics of their ratio in desert and steppe associations have much
in common. Spider assemblages of native and artificial habitats are characterised by change from multispecies
polydominant spring-summer communities to impoverished imbalanced autumn ones. Seasonal changes in the
species structure of mature spider groupings in native habitats are well pronounced, while the impact of seasonal
conditions is even stronger than between-habitat differences. Complexes of typical species with different levels
of habitat preference are revealed.