Collembolan Communities in an Extrazonal Refugium: Forest Catenas of the Karkaraly Massif in the Arid Steppe Zone of Central Kazakhstan

Karkaraly National Park’s pine forests are a important study area for the soil biota within Central Kazakhstan’s dry steppes. Soil zoological research on macrofauna reveals these extrazonal pine forests as refugia for pan-European and Western Palearctic fauna. Microarthropods, however, remain largely unexplored. A recent study of small soil arthropods, particularly springtails, uncovered a new species of the genus Folsomides and the rare Aggressopygus sibiricus, highlighting the faunistic distinctiveness of this area. Six springtail species were recorded for Kazakhstan for the first time, including Asian, Palearctic, and cosmopolitan species. Predominantly eurybiont and forest-dwelling species were found, though many forest-specific genera remain undiscovered. The presence of numerous steppe species like Anurophorus stepposus suggests an ecotone nature of the springtail communities. Surveys across different positions within two forest catenas revealed variations in community composition. Generalized linear mixed models showed a significant relationship between the total number and diversity of springtail species and their position within the catena. The low abundance and species diversity of springtails are likely due to the region’s arid climate and the insular nature of the forests. This supports the island biogeography model, which predicts migration, colonization, and extinction dynamics.